// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
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DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
pragma solidity ^0.8.0;
/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822Proxiable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/ERC1967/ERC1967Proxy.sol)
pragma solidity ^0.8.0;
import "../Proxy.sol";
import "./ERC1967Upgrade.sol";
/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 */
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _upgradeToAndCall(_logic, _data, false);
    }
    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        return ERC1967Upgrade._getImplementation();
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)
pragma solidity ^0.8.2;
import "../beacon/IBeacon.sol";
import "../../interfaces/draft-IERC1822.sol";
import "../../utils/Address.sol";
import "../../utils/StorageSlot.sol";
/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);
    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }
    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }
    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }
    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }
    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);
    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }
    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }
    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);
    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }
    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/Proxy.sol)
pragma solidity ^0.8.0;
/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())
            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())
            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }
    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);
    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }
    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
pragma solidity ^0.8.0;
/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/StorageSlot.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }
    struct BooleanSlot {
        bool value;
    }
    struct Bytes32Slot {
        bytes32 value;
    }
    struct Uint256Slot {
        uint256 value;
    }
    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1000000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { ERC1967Proxy } from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
import { AccessDenied, Utils } from "./Utils.sol";
/**
 * @dev this contract is a slightly optimized version of the original TransparentUpgradeableProxy solely designed to
 * work with the ProxyAdmin contract:
 *
 * - the address of the admin is stored as an immutable state variables and as the result:
 * - the address of the admin can't be change, so the changeAdmin() function was subsequently removed
 */
contract TransparentUpgradeableProxyImmutable is ERC1967Proxy, Utils {
    address internal immutable _admin;
    /**
     * @dev initializes an upgradeable proxy managed by `initAdmin`, backed by the implementation at `logic`, and
     * optionally initialized with `data` as explained in {ERC1967Proxy-constructor}
     */
    constructor(
        address logic,
        address initAdmin,
        bytes memory data
    ) payable ERC1967Proxy(logic, data) validAddress(initAdmin) {
        _admin = initAdmin;
        // still store it to work with EIP-1967
        _changeAdmin(initAdmin);
    }
    modifier ifAdmin() {
        if (msg.sender == _admin) {
            _;
        } else {
            _fallback();
        }
    }
    /**
     * @dev returns the current admin
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function admin() external ifAdmin returns (address) {
        return _admin;
    }
    /**
     * @dev returns the current implementation.
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function implementation() external ifAdmin returns (address) {
        return _implementation();
    }
    /**
     * @dev upgrades the implementation of the proxy
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeToAndCall(newImplementation, bytes(""), false);
    }
    /**
     * @dev upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by data, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
        _upgradeToAndCall(newImplementation, data, true);
    }
    /**
     * @dev makes sure the admin cannot access the fallback function
     */
    function _beforeFallback() internal virtual override {
        if (msg.sender == _admin) {
            revert AccessDenied();
        }
        super._beforeFallback();
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidType();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
/// @title Claimable contract interface
interface IClaimable {
    function owner() external view returns (address);
    function transferOwnership(address newOwner) external;
    function acceptOwnership() external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IClaimable.sol";
/// @title Mintable Token interface
interface IMintableToken is IERC20, IClaimable {
    function issue(address to, uint256 amount) external;
    function destroy(address from, uint256 amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "./IMintableToken.sol";
/// @title The interface for mintable/burnable token governance.
interface ITokenGovernance {
    // The address of the mintable ERC20 token.
    function token() external view returns (IMintableToken);
    /// @dev Mints new tokens.
    ///
    /// @param to Account to receive the new amount.
    /// @param amount Amount to increase the supply by.
    ///
    function mint(address to, uint256 amount) external;
    /// @dev Burns tokens from the caller.
    ///
    /// @param amount Amount to decrease the supply by.
    ///
    function burn(uint256 amount) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlEnumerableUpgradeable.sol";
import "./AccessControlUpgradeable.sol";
import "../utils/structs/EnumerableSetUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Extension of {AccessControl} that allows enumerating the members of each role.
 */
abstract contract AccessControlEnumerableUpgradeable is Initializable, IAccessControlEnumerableUpgradeable, AccessControlUpgradeable {
    function __AccessControlEnumerable_init() internal onlyInitializing {
    }
    function __AccessControlEnumerable_init_unchained() internal onlyInitializing {
    }
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    mapping(bytes32 => EnumerableSetUpgradeable.AddressSet) private _roleMembers;
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlEnumerableUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
        return _roleMembers[role].at(index);
    }
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
        return _roleMembers[role].length();
    }
    /**
     * @dev Overload {_grantRole} to track enumerable memberships
     */
    function _grantRole(bytes32 role, address account) internal virtual override {
        super._grantRole(role, account);
        _roleMembers[role].add(account);
    }
    /**
     * @dev Overload {_revokeRole} to track enumerable memberships
     */
    function _revokeRole(bytes32 role, address account) internal virtual override {
        super._revokeRole(role, account);
        _roleMembers[role].remove(account);
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "../utils/StringsUpgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
    function __AccessControl_init() internal onlyInitializing {
    }
    function __AccessControl_init_unchained() internal onlyInitializing {
    }
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }
    mapping(bytes32 => RoleData) private _roles;
    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }
    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(uint160(account), 20),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");
        _revokeRole(role, account);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }
    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
/**
 * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
 */
interface IAccessControlEnumerableUpgradeable is IAccessControlUpgradeable {
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) external view returns (address);
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.0;
import "../../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }
    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }
    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165Upgradeable.sol";
import "../../proxy/utils/Initializable.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    function __ERC165_init() internal onlyInitializing {
    }
    function __ERC165_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165Upgradeable).interfaceId;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;
        assembly {
            result := store
        }
        return result;
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;
        assembly {
            result := store
        }
        return result;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][spender] + addedValue);
        return true;
    }
    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }
        return true;
    }
    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        _beforeTokenTransfer(from, to, amount);
        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;
        emit Transfer(from, to, amount);
        _afterTokenTransfer(from, to, amount);
    }
    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address(0), account, amount);
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
        _afterTokenTransfer(address(0), account, amount);
    }
    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        _beforeTokenTransfer(account, address(0), amount);
        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;
        emit Transfer(account, address(0), amount);
        _afterTokenTransfer(account, address(0), amount);
    }
    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @dev Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }
    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }
    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import { EnumerableSetUpgradeable } from "@openzeppelin/contracts-upgradeable/utils/structs/EnumerableSetUpgradeable.sol";
import { PausableUpgradeable } from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import { ITokenGovernance } from "@bancor/token-governance/contracts/ITokenGovernance.sol";
import { IVersioned } from "../utility/interfaces/IVersioned.sol";
import { PPM_RESOLUTION } from "../utility/Constants.sol";
import { Upgradeable } from "../utility/Upgradeable.sol";
import { Time } from "../utility/Time.sol";
import { MathEx } from "../utility/MathEx.sol";
// prettier-ignore
import {
    Utils,
    AlreadyExists,
    DoesNotExist,
    InvalidToken,
    InvalidPool,
    InvalidPoolCollection,
    NotEmpty
} from "../utility/Utils.sol";
import { ROLE_ASSET_MANAGER } from "../vaults/interfaces/IVault.sol";
import { IMasterVault } from "../vaults/interfaces/IMasterVault.sol";
import { IExternalProtectionVault } from "../vaults/interfaces/IExternalProtectionVault.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { IPoolCollection, TradeAmountAndFee } from "../pools/interfaces/IPoolCollection.sol";
import { IPoolMigrator } from "../pools/interfaces/IPoolMigrator.sol";
// prettier-ignore
import {
    IBNTPool,
    ROLE_BNT_MANAGER,
    ROLE_VAULT_MANAGER,
    ROLE_FUNDING_MANAGER
} from "../pools/interfaces/IBNTPool.sol";
import { IPoolToken } from "../pools/interfaces/IPoolToken.sol";
import { INetworkSettings, NotWhitelisted } from "./interfaces/INetworkSettings.sol";
import { IPendingWithdrawals, CompletedWithdrawal } from "./interfaces/IPendingWithdrawals.sol";
import { IBancorNetwork, IFlashLoanRecipient } from "./interfaces/IBancorNetwork.sol";
/**
 * @dev Bancor Network contract
 */
contract BancorNetwork is IBancorNetwork, Upgradeable, ReentrancyGuardUpgradeable, PausableUpgradeable, Time, Utils {
    using Address for address payable;
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    using TokenLibrary for Token;
    using SafeERC20 for IPoolToken;
    error DeadlineExpired();
    error DepositingDisabled();
    error NativeTokenAmountMismatch();
    error InsufficientFlashLoanReturn();
    struct TradeParams {
        uint256 amount;
        uint256 limit;
        bool bySourceAmount;
    }
    struct TradeResult {
        uint256 sourceAmount;
        uint256 targetAmount;
        uint256 tradingFeeAmount;
        uint256 networkFeeAmount;
    }
    struct TradeTokens {
        Token sourceToken;
        Token targetToken;
    }
    struct TraderInfo {
        address trader;
        address beneficiary;
    }
    // the migration manager role is required for migrating liquidity
    bytes32 private constant ROLE_MIGRATION_MANAGER = keccak256("ROLE_MIGRATION_MANAGER");
    // the emergency manager role is required to pause/unpause the network
    bytes32 private constant ROLE_EMERGENCY_STOPPER = keccak256("ROLE_EMERGENCY_STOPPER");
    // the network fee manager role is required to pull the accumulated pending network fees
    bytes32 private constant ROLE_NETWORK_FEE_MANAGER = keccak256("ROLE_NETWORK_FEE_MANAGER");
    // the address of the BNT token
    IERC20 private immutable _bnt;
    // the address of the BNT token governance
    ITokenGovernance private immutable _bntGovernance;
    // the address of the vBNT token
    IERC20 private immutable _vbnt;
    // the address of the vBNT token governance
    ITokenGovernance private immutable _vbntGovernance;
    // the network settings contract
    INetworkSettings private immutable _networkSettings;
    // the master vault contract
    IMasterVault private immutable _masterVault;
    // the address of the external protection vault
    IExternalProtectionVault private immutable _externalProtectionVault;
    // the BNT pool token
    IPoolToken internal immutable _bntPoolToken;
    // the BNT pool contract
    IBNTPool internal _bntPool;
    // the pending withdrawals contract
    IPendingWithdrawals internal _pendingWithdrawals;
    // the pool migrator contract
    IPoolMigrator internal _poolMigrator;
    // the set of all valid pool collections
    EnumerableSetUpgradeable.AddressSet private _poolCollections;
    // DEPRECATED (mapping(uint16 => IPoolCollection) _latestPoolCollections)
    uint256 private _deprecated0;
    // the set of all pools
    EnumerableSetUpgradeable.AddressSet private _liquidityPools;
    // a mapping between pools and their respective pool collections
    mapping(Token => IPoolCollection) private _collectionByPool;
    // the pending network fee amount to be burned by the vortex
    uint256 internal _pendingNetworkFeeAmount;
    bool private _depositingEnabled = true;
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 11] private __gap;
    /**
     * @dev triggered when a new pool collection is added
     */
    event PoolCollectionAdded(uint16 indexed poolType, IPoolCollection indexed poolCollection);
    /**
     * @dev triggered when an existing pool collection is removed
     */
    event PoolCollectionRemoved(uint16 indexed poolType, IPoolCollection indexed poolCollection);
    /**
     * @dev triggered when a pool is created
     */
    event PoolCreated(Token indexed pool, IPoolCollection indexed poolCollection);
    /**
     * @dev triggered when a new pool is added to a pool collection
     */
    event PoolAdded(Token indexed pool, IPoolCollection indexed poolCollection);
    /**
     * @dev triggered when a new pool is removed from a pool collection
     */
    event PoolRemoved(Token indexed pool, IPoolCollection indexed poolCollection);
    /**
     * @dev triggered when funds are migrated
     */
    event FundsMigrated(
        bytes32 indexed contextId,
        Token indexed token,
        address indexed provider,
        uint256 amount,
        uint256 availableAmount,
        uint256 originalAmount
    );
    /**
     * @dev triggered on a successful trade
     */
    event TokensTraded(
        bytes32 indexed contextId,
        Token indexed sourceToken,
        Token indexed targetToken,
        uint256 sourceAmount,
        uint256 targetAmount,
        uint256 bntAmount,
        uint256 targetFeeAmount,
        uint256 bntFeeAmount,
        address trader
    );
    /**
     * @dev triggered when a flash-loan is completed
     */
    event FlashLoanCompleted(Token indexed token, address indexed borrower, uint256 amount, uint256 feeAmount);
    /**
     * @dev triggered when network fees are withdrawn
     */
    event NetworkFeesWithdrawn(address indexed caller, address indexed recipient, uint256 amount);
    /**
     * @dev a "virtual" constructor that is only used to set immutable state variables
     */
    constructor(
        ITokenGovernance initBNTGovernance,
        ITokenGovernance initVBNTGovernance,
        INetworkSettings initNetworkSettings,
        IMasterVault initMasterVault,
        IExternalProtectionVault initExternalProtectionVault,
        IPoolToken initBNTPoolToken
    )
        validAddress(address(initBNTGovernance))
        validAddress(address(initVBNTGovernance))
        validAddress(address(initNetworkSettings))
        validAddress(address(initMasterVault))
        validAddress(address(initExternalProtectionVault))
        validAddress(address(initBNTPoolToken))
    {
        _bntGovernance = initBNTGovernance;
        _bnt = initBNTGovernance.token();
        _vbntGovernance = initVBNTGovernance;
        _vbnt = initVBNTGovernance.token();
        _networkSettings = initNetworkSettings;
        _masterVault = initMasterVault;
        _externalProtectionVault = initExternalProtectionVault;
        _bntPoolToken = initBNTPoolToken;
    }
    /**
     * @dev fully initializes the contract and its parents
     */
    function initialize(
        IBNTPool initBNTPool,
        IPendingWithdrawals initPendingWithdrawals,
        IPoolMigrator initPoolMigrator
    )
        external
        validAddress(address(initBNTPool))
        validAddress(address(initPendingWithdrawals))
        validAddress(address(initPoolMigrator))
        initializer
    {
        __BancorNetwork_init(initBNTPool, initPendingWithdrawals, initPoolMigrator);
    }
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __BancorNetwork_init(
        IBNTPool initBNTPool,
        IPendingWithdrawals initPendingWithdrawals,
        IPoolMigrator initPoolMigrator
    ) internal onlyInitializing {
        __Upgradeable_init();
        __ReentrancyGuard_init();
        __Pausable_init();
        __BancorNetwork_init_unchained(initBNTPool, initPendingWithdrawals, initPoolMigrator);
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __BancorNetwork_init_unchained(
        IBNTPool initBNTPool,
        IPendingWithdrawals initPendingWithdrawals,
        IPoolMigrator initPoolMigrator
    ) internal onlyInitializing {
        _bntPool = initBNTPool;
        _pendingWithdrawals = initPendingWithdrawals;
        _poolMigrator = initPoolMigrator;
        // set up administrative roles
        _setRoleAdmin(ROLE_MIGRATION_MANAGER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_EMERGENCY_STOPPER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_NETWORK_FEE_MANAGER, ROLE_ADMIN);
        _depositingEnabled = true;
    }
    // solhint-enable func-name-mixedcase
    modifier depositsEnabled() {
        _depositsEnabled();
        _;
    }
    function _depositsEnabled() internal view {
        if (!_depositingEnabled) {
            revert DepositingDisabled();
        }
    }
    receive() external payable {}
    /**
     * @inheritdoc Upgradeable
     */
    function version() public pure override(IVersioned, Upgradeable) returns (uint16) {
        return 7;
    }
    /**
     * @dev returns the migration manager role
     */
    function roleMigrationManager() external pure returns (bytes32) {
        return ROLE_MIGRATION_MANAGER;
    }
    /**
     * @dev returns the emergency stopper role
     */
    function roleEmergencyStopper() external pure returns (bytes32) {
        return ROLE_EMERGENCY_STOPPER;
    }
    /**
     * @dev returns the network fee manager role
     */
    function roleNetworkFeeManager() external pure returns (bytes32) {
        return ROLE_NETWORK_FEE_MANAGER;
    }
    /**
     * @dev returns the pending network fee amount to be burned by the vortex
     */
    function pendingNetworkFeeAmount() external view returns (uint256) {
        return _pendingNetworkFeeAmount;
    }
    /**
     * @dev registers new pool collection with the network
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function registerPoolCollection(IPoolCollection newPoolCollection)
        external
        validAddress(address(newPoolCollection))
        onlyAdmin
        nonReentrant
    {
        // verify that there is no pool collection of the same type and version
        uint16 newPoolType = newPoolCollection.poolType();
        uint16 newPoolVersion = newPoolCollection.version();
        IPoolCollection poolCollection = _findPoolCollection(newPoolType, newPoolVersion);
        if (poolCollection != IPoolCollection(address(0)) || !_poolCollections.add(address(newPoolCollection))) {
            revert AlreadyExists();
        }
        _setAccessRoles(newPoolCollection, true);
        emit PoolCollectionAdded({ poolType: newPoolCollection.poolType(), poolCollection: newPoolCollection });
    }
    /**
     * @dev unregisters an existing pool collection from the network
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function unregisterPoolCollection(IPoolCollection poolCollection)
        external
        validAddress(address(poolCollection))
        onlyAdmin
        nonReentrant
    {
        // verify that no pools are associated with the specified pool collection
        if (poolCollection.poolCount() != 0) {
            revert NotEmpty();
        }
        if (!_poolCollections.remove(address(poolCollection))) {
            revert DoesNotExist();
        }
        _setAccessRoles(poolCollection, false);
        emit PoolCollectionRemoved({ poolType: poolCollection.poolType(), poolCollection: poolCollection });
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function poolCollections() external view returns (IPoolCollection[] memory) {
        uint256 length = _poolCollections.length();
        IPoolCollection[] memory list = new IPoolCollection[](length);
        for (uint256 i = 0; i < length; i++) {
            list[i] = IPoolCollection(_poolCollections.at(i));
        }
        return list;
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function liquidityPools() external view returns (Token[] memory) {
        uint256 length = _liquidityPools.length();
        Token[] memory list = new Token[](length);
        for (uint256 i = 0; i < length; i++) {
            list[i] = Token(_liquidityPools.at(i));
        }
        return list;
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function collectionByPool(Token pool) external view returns (IPoolCollection) {
        return _collectionByPool[pool];
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function createPools(Token[] calldata tokens, IPoolCollection poolCollection)
        external
        validAddress(address(poolCollection))
        onlyAdmin
        nonReentrant
    {
        if (!_poolCollections.contains(address(poolCollection))) {
            revert DoesNotExist();
        }
        uint256 length = tokens.length;
        for (uint256 i = 0; i < length; i++) {
            _createPool(tokens[i], poolCollection);
        }
    }
    /**
     * @dev creates a new pool
     */
    function _createPool(Token token, IPoolCollection poolCollection) private {
        _validAddress(address(token));
        if (token.isEqual(_bnt)) {
            revert InvalidToken();
        }
        if (!_liquidityPools.add(address(token))) {
            revert AlreadyExists();
        }
        // this is where the magic happens...
        poolCollection.createPool(token);
        // add the pool collection to the reverse pool collection lookup
        _collectionByPool[token] = poolCollection;
        emit PoolCreated({ pool: token, poolCollection: poolCollection });
        emit PoolAdded({ pool: token, poolCollection: poolCollection });
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function migratePools(Token[] calldata pools, IPoolCollection newPoolCollection) external nonReentrant {
        if (!_poolCollections.contains(address(newPoolCollection))) {
            revert DoesNotExist();
        }
        uint256 length = pools.length;
        for (uint256 i = 0; i < length; i++) {
            Token pool = pools[i];
            // request the pool migrator to migrate the pool to the new pool collection
            _poolMigrator.migratePool(pool, newPoolCollection);
            IPoolCollection prevPoolCollection = _collectionByPool[pool];
            // update the mapping between pools and their respective pool collections
            _collectionByPool[pool] = newPoolCollection;
            emit PoolRemoved(pool, prevPoolCollection);
            emit PoolAdded(pool, newPoolCollection);
        }
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function depositFor(
        address provider,
        Token pool,
        uint256 tokenAmount
    )
        external
        payable
        depositsEnabled
        validAddress(provider)
        validAddress(address(pool))
        greaterThanZero(tokenAmount)
        whenNotPaused
        nonReentrant
        returns (uint256)
    {
        return _depositFor(provider, pool, tokenAmount, msg.sender);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function deposit(Token pool, uint256 tokenAmount)
        external
        payable
        depositsEnabled
        validAddress(address(pool))
        greaterThanZero(tokenAmount)
        whenNotPaused
        nonReentrant
        returns (uint256)
    {
        return _depositFor(msg.sender, pool, tokenAmount, msg.sender);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function initWithdrawal(IPoolToken poolToken, uint256 poolTokenAmount)
        external
        validAddress(address(poolToken))
        greaterThanZero(poolTokenAmount)
        whenNotPaused
        nonReentrant
        returns (uint256)
    {
        return _initWithdrawal(msg.sender, poolToken, poolTokenAmount);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function cancelWithdrawal(uint256 id) external whenNotPaused nonReentrant returns (uint256) {
        return _pendingWithdrawals.cancelWithdrawal(msg.sender, id);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function withdraw(uint256 id) external whenNotPaused nonReentrant returns (uint256) {
        address provider = msg.sender;
        bytes32 contextId = _withdrawContextId(id, provider);
        // complete the withdrawal and claim the locked pool tokens
        CompletedWithdrawal memory completedRequest = _pendingWithdrawals.completeWithdrawal(contextId, provider, id);
        if (completedRequest.poolToken == _bntPoolToken) {
            return _withdrawBNT(contextId, provider, completedRequest);
        }
        return _withdrawBaseToken(contextId, provider, completedRequest);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function tradeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount,
        uint256 deadline,
        address beneficiary
    ) external payable whenNotPaused nonReentrant returns (uint256) {
        _verifyTradeParams(sourceToken, targetToken, sourceAmount, minReturnAmount, deadline);
        return
            _trade(
                TradeTokens({ sourceToken: sourceToken, targetToken: targetToken }),
                TradeParams({ bySourceAmount: true, amount: sourceAmount, limit: minReturnAmount }),
                TraderInfo({ trader: msg.sender, beneficiary: beneficiary }),
                deadline
            );
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function tradeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount,
        uint256 deadline,
        address beneficiary
    ) external payable whenNotPaused nonReentrant returns (uint256) {
        _verifyTradeParams(sourceToken, targetToken, targetAmount, maxSourceAmount, deadline);
        return
            _trade(
                TradeTokens({ sourceToken: sourceToken, targetToken: targetToken }),
                TradeParams({ bySourceAmount: false, amount: targetAmount, limit: maxSourceAmount }),
                TraderInfo({ trader: msg.sender, beneficiary: beneficiary }),
                deadline
            );
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function flashLoan(
        Token token,
        uint256 amount,
        IFlashLoanRecipient recipient,
        bytes calldata data
    )
        external
        validAddress(address(token))
        greaterThanZero(amount)
        validAddress(address(recipient))
        whenNotPaused
        nonReentrant
    {
        if (!token.isEqual(_bnt) && !_networkSettings.isTokenWhitelisted(token)) {
            revert NotWhitelisted();
        }
        uint256 feeAmount = MathEx.mulDivF(amount, _networkSettings.flashLoanFeePPM(token), PPM_RESOLUTION);
        // save the current balance
        uint256 prevBalance = token.balanceOf(address(this));
        // transfer the amount from the master vault to the recipient
        _masterVault.withdrawFunds(token, payable(address(recipient)), amount);
        // invoke the recipient's callback
        recipient.onFlashLoan(msg.sender, token.toIERC20(), amount, feeAmount, data);
        // ensure that the tokens + fee have been deposited back to the network
        uint256 returnedAmount = token.balanceOf(address(this)) - prevBalance;
        if (returnedAmount < amount + feeAmount) {
            revert InsufficientFlashLoanReturn();
        }
        // transfer the amount and the fee back to the vault
        if (token.isNative()) {
            payable(address(_masterVault)).sendValue(returnedAmount);
        } else {
            token.safeTransfer(payable(address(_masterVault)), returnedAmount);
        }
        // notify the pool of accrued fees
        if (token.isEqual(_bnt)) {
            IBNTPool cachedBNTPool = _bntPool;
            cachedBNTPool.onFeesCollected(token, feeAmount, false);
        } else {
            // get the pool and verify that it exists
            IPoolCollection poolCollection = _poolCollection(token);
            poolCollection.onFeesCollected(token, feeAmount);
        }
        emit FlashLoanCompleted({ token: token, borrower: msg.sender, amount: amount, feeAmount: feeAmount });
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function migrateLiquidity(
        Token token,
        address provider,
        uint256 amount,
        uint256 availableAmount,
        uint256 originalAmount
    ) external payable whenNotPaused onlyRoleMember(ROLE_MIGRATION_MANAGER) nonReentrant {
        bytes32 contextId = keccak256(
            abi.encodePacked(msg.sender, _time(), token, provider, amount, availableAmount, originalAmount)
        );
        if (token.isEqual(_bnt)) {
            _depositBNTFor(contextId, provider, amount, msg.sender, true, originalAmount);
        } else {
            _depositBaseTokenFor(contextId, provider, token, amount, msg.sender, availableAmount);
        }
        emit FundsMigrated(contextId, token, provider, amount, availableAmount, originalAmount);
    }
    /**
     * @inheritdoc IBancorNetwork
     */
    function withdrawNetworkFees(address recipient)
        external
        whenNotPaused
        onlyRoleMember(ROLE_NETWORK_FEE_MANAGER)
        validAddress(recipient)
        nonReentrant
        returns (uint256)
    {
        uint256 currentPendingNetworkFeeAmount = _pendingNetworkFeeAmount;
        if (currentPendingNetworkFeeAmount == 0) {
            return 0;
        }
        _pendingNetworkFeeAmount = 0;
        _masterVault.withdrawFunds(Token(address(_bnt)), payable(recipient), currentPendingNetworkFeeAmount);
        emit NetworkFeesWithdrawn(msg.sender, recipient, currentPendingNetworkFeeAmount);
        return currentPendingNetworkFeeAmount;
    }
    /**
     * @dev pauses the network
     *
     * requirements:
     *
     * - the caller must have the ROLE_EMERGENCY_STOPPER privilege
     */
    function pause() external onlyRoleMember(ROLE_EMERGENCY_STOPPER) {
        _pause();
    }
    /**
     * @dev resumes the network
     *
     * requirements:
     *
     * - the caller must have the ROLE_EMERGENCY_STOPPER privilege
     */
    function resume() external onlyRoleMember(ROLE_EMERGENCY_STOPPER) {
        _unpause();
    }
    /**
     * @dev returns whether deposits are enabled
     */
    function depositingEnabled() external view returns (bool) {
        return _depositingEnabled;
    }
    /**
     * @dev enables/disables depositing into a given pool
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function enableDepositing(bool status) external onlyAdmin {
        if (_depositingEnabled == status) {
            return;
        }
        _depositingEnabled = status;
    }
    /**
     * @dev generates context ID for a deposit request
     */
    function _depositContextId(
        address provider,
        Token pool,
        uint256 tokenAmount,
        address caller
    ) private view returns (bytes32) {
        return keccak256(abi.encodePacked(caller, _time(), provider, pool, tokenAmount));
    }
    /**
     * @dev generates context ID for a withdraw request
     */
    function _withdrawContextId(uint256 id, address caller) private view returns (bytes32) {
        return keccak256(abi.encodePacked(caller, _time(), id));
    }
    /**
     * @dev deposits liquidity for the specified provider from caller
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the liquidity tokens on its behalf
     */
    function _depositFor(
        address provider,
        Token pool,
        uint256 tokenAmount,
        address caller
    ) private returns (uint256) {
        bytes32 contextId = _depositContextId(provider, pool, tokenAmount, caller);
        if (pool.isEqual(_bnt)) {
            return _depositBNTFor(contextId, provider, tokenAmount, caller, false, 0);
        }
        return _depositBaseTokenFor(contextId, provider, pool, tokenAmount, caller, tokenAmount);
    }
    /**
     * @dev deposits BNT liquidity for the specified provider from caller
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer BNT on its behalf
     */
    function _depositBNTFor(
        bytes32 contextId,
        address provider,
        uint256 bntAmount,
        address caller,
        bool isMigrating,
        uint256 originalAmount
    ) private returns (uint256) {
        if (msg.value > 0) {
            revert NativeTokenAmountMismatch();
        }
        IBNTPool cachedBNTPool = _bntPool;
        // transfer the tokens from the caller to the BNT pool
        _bnt.transferFrom(caller, address(cachedBNTPool), bntAmount);
        // process BNT pool deposit
        return cachedBNTPool.depositFor(contextId, provider, bntAmount, isMigrating, originalAmount);
    }
    /**
     * @dev deposits base token liquidity for the specified provider from sender
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer base tokens to on its behalf
     */
    function _depositBaseTokenFor(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 tokenAmount,
        address caller,
        uint256 availableAmount
    ) private returns (uint256) {
        // transfer the tokens from the sender to the vault
        _depositToMasterVault(pool, caller, availableAmount);
        // get the pool collection that managed this pool
        IPoolCollection poolCollection = _poolCollection(pool);
        // process deposit to the base token pool (includes the native token pool)
        return poolCollection.depositFor(contextId, provider, pool, tokenAmount);
    }
    /**
     * @dev handles BNT withdrawal
     */
    function _withdrawBNT(
        bytes32 contextId,
        address provider,
        CompletedWithdrawal memory completedRequest
    ) private returns (uint256) {
        IBNTPool cachedBNTPool = _bntPool;
        // transfer the pool tokens to from the pending withdrawals contract to the BNT pool
        completedRequest.poolToken.transferFrom(
            address(_pendingWithdrawals),
            address(cachedBNTPool),
            completedRequest.poolTokenAmount
        );
        // transfer vBNT from the caller to the BNT pool
        _vbnt.transferFrom(provider, address(cachedBNTPool), completedRequest.poolTokenAmount);
        // call withdraw on the BNT pool
        return
            cachedBNTPool.withdraw(
                contextId,
                provider,
                completedRequest.poolTokenAmount,
                completedRequest.reserveTokenAmount
            );
    }
    /**
     * @dev handles base token withdrawal
     */
    function _withdrawBaseToken(
        bytes32 contextId,
        address provider,
        CompletedWithdrawal memory completedRequest
    ) private returns (uint256) {
        Token pool = completedRequest.poolToken.reserveToken();
        // get the pool collection that manages this pool
        IPoolCollection poolCollection = _poolCollection(pool);
        // transfer the pool tokens to from the pending withdrawals contract to the pool collection
        completedRequest.poolToken.transferFrom(
            address(_pendingWithdrawals),
            address(poolCollection),
            completedRequest.poolTokenAmount
        );
        // call withdraw on the base token pool - returns the amounts/breakdown
        return
            poolCollection.withdraw(
                contextId,
                provider,
                pool,
                completedRequest.poolTokenAmount,
                completedRequest.reserveTokenAmount
            );
    }
    /**
     * @dev verifies that the provided trade params are valid
     */
    function _verifyTradeParams(
        Token sourceToken,
        Token targetToken,
        uint256 amount,
        uint256 limit,
        uint256 deadline
    ) internal view {
        _validAddress(address(sourceToken));
        _validAddress(address(targetToken));
        if (sourceToken == targetToken) {
            revert InvalidToken();
        }
        _greaterThanZero(amount);
        _greaterThanZero(limit);
        if (deadline < _time()) {
            revert DeadlineExpired();
        }
    }
    /**
     * @dev performs a trade by providing either the source or target amount:
     *
     * - when trading by the source amount, the amount represents the source amount and the limit is the minimum return
     *   amount
     * - when trading by the target amount, the amount represents the target amount and the limit is the maximum source
     *   amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function _trade(
        TradeTokens memory tokens,
        TradeParams memory params,
        TraderInfo memory traderInfo,
        uint256 deadline
    ) private returns (uint256) {
        // ensure the beneficiary is set
        if (traderInfo.beneficiary == address(0)) {
            traderInfo.beneficiary = traderInfo.trader;
        }
        bytes32 contextId = keccak256(
            abi.encodePacked(
                traderInfo.trader,
                _time(),
                tokens.sourceToken,
                tokens.targetToken,
                params.amount,
                params.limit,
                params.bySourceAmount,
                deadline,
                traderInfo.beneficiary
            )
        );
        // perform either a single or double hop trade, based on the source and the target pool
        TradeResult memory firstHopTradeResult;
        TradeResult memory lastHopTradeResult;
        uint256 networkFeeAmount;
        if (tokens.sourceToken.isEqual(_bnt)) {
            lastHopTradeResult = _tradeBNT(contextId, tokens.targetToken, true, params);
            firstHopTradeResult = lastHopTradeResult;
            networkFeeAmount = lastHopTradeResult.networkFeeAmount;
            emit TokensTraded({
                contextId: contextId,
                sourceToken: tokens.sourceToken,
                targetToken: tokens.targetToken,
                sourceAmount: lastHopTradeResult.sourceAmount,
                targetAmount: lastHopTradeResult.targetAmount,
                bntAmount: lastHopTradeResult.sourceAmount,
                targetFeeAmount: lastHopTradeResult.tradingFeeAmount,
                bntFeeAmount: 0,
                trader: traderInfo.trader
            });
        } else if (tokens.targetToken.isEqual(_bnt)) {
            lastHopTradeResult = _tradeBNT(contextId, tokens.sourceToken, false, params);
            firstHopTradeResult = lastHopTradeResult;
            networkFeeAmount = lastHopTradeResult.networkFeeAmount;
            emit TokensTraded({
                contextId: contextId,
                sourceToken: tokens.sourceToken,
                targetToken: tokens.targetToken,
                sourceAmount: lastHopTradeResult.sourceAmount,
                targetAmount: lastHopTradeResult.targetAmount,
                bntAmount: lastHopTradeResult.targetAmount,
                targetFeeAmount: lastHopTradeResult.tradingFeeAmount,
                bntFeeAmount: lastHopTradeResult.tradingFeeAmount,
                trader: traderInfo.trader
            });
        } else {
            (firstHopTradeResult, lastHopTradeResult) = _tradeBaseTokens(contextId, tokens, params);
            networkFeeAmount = firstHopTradeResult.networkFeeAmount + lastHopTradeResult.networkFeeAmount;
            emit TokensTraded({
                contextId: contextId,
                sourceToken: tokens.sourceToken,
                targetToken: tokens.targetToken,
                sourceAmount: firstHopTradeResult.sourceAmount,
                targetAmount: lastHopTradeResult.targetAmount,
                bntAmount: firstHopTradeResult.targetAmount,
                targetFeeAmount: lastHopTradeResult.tradingFeeAmount,
                bntFeeAmount: firstHopTradeResult.tradingFeeAmount,
                trader: traderInfo.trader
            });
        }
        // transfer the tokens from the trader to the vault
        _depositToMasterVault(tokens.sourceToken, traderInfo.trader, firstHopTradeResult.sourceAmount);
        // transfer the target tokens/native token to the beneficiary
        _masterVault.withdrawFunds(
            tokens.targetToken,
            payable(traderInfo.beneficiary),
            lastHopTradeResult.targetAmount
        );
        // update the pending network fee amount to be burned by the vortex
        _pendingNetworkFeeAmount += networkFeeAmount;
        return params.bySourceAmount ? lastHopTradeResult.targetAmount : lastHopTradeResult.sourceAmount;
    }
    /**
     * @dev performs a single hop between BNT and a base token trade by providing either the source or the target amount
     *
     * - when trading by the source amount, the amount represents the source amount and the limit is the minimum return
     *   amount
     * - when trading by the target amount, the amount represents the target amount and the limit is the maximum source
     *   amount
     */
    function _tradeBNT(
        bytes32 contextId,
        Token pool,
        bool fromBNT,
        TradeParams memory params
    ) private returns (TradeResult memory) {
        TradeTokens memory tokens = fromBNT
            ? TradeTokens({ sourceToken: Token(address(_bnt)), targetToken: pool })
            : TradeTokens({ sourceToken: pool, targetToken: Token(address(_bnt)) });
        TradeAmountAndFee memory tradeAmountsAndFee = params.bySourceAmount
            ? _poolCollection(pool).tradeBySourceAmount(
                contextId,
                tokens.sourceToken,
                tokens.targetToken,
                params.amount,
                params.limit
            )
            : _poolCollection(pool).tradeByTargetAmount(
                contextId,
                tokens.sourceToken,
                tokens.targetToken,
                params.amount,
                params.limit
            );
        // if the target token is BNT, notify the BNT pool on collected fees (which shouldn't include the network fee
        // amount, so we have to deduct it explicitly from the full trading fee amount)
        if (!fromBNT) {
            _bntPool.onFeesCollected(
                pool,
                tradeAmountsAndFee.tradingFeeAmount - tradeAmountsAndFee.networkFeeAmount,
                true
            );
        }
        return
            TradeResult({
                sourceAmount: params.bySourceAmount ? params.amount : tradeAmountsAndFee.amount,
                targetAmount: params.bySourceAmount ? tradeAmountsAndFee.amount : params.amount,
                tradingFeeAmount: tradeAmountsAndFee.tradingFeeAmount,
                networkFeeAmount: tradeAmountsAndFee.networkFeeAmount
            });
    }
    /**
     * @dev performs a double hop trade between two base tokens by providing either the source or the target amount
     *
     * - when trading by the source amount, the amount represents the source amount and the limit is the minimum return
     *   amount
     * - when trading by the target amount, the amount represents the target amount and the limit is the maximum source
     *   amount
     */
    function _tradeBaseTokens(
        bytes32 contextId,
        TradeTokens memory tokens,
        TradeParams memory params
    ) private returns (TradeResult memory, TradeResult memory) {
        if (params.bySourceAmount) {
            uint256 sourceAmount = params.amount;
            uint256 minReturnAmount = params.limit;
            // trade source tokens to BNT (while accepting any return amount)
            TradeResult memory targetHop1 = _tradeBNT(
                contextId,
                tokens.sourceToken,
                false,
                TradeParams({ bySourceAmount: true, amount: sourceAmount, limit: 1 })
            );
            // trade the received BNT target amount to target tokens (while respecting the minimum return amount)
            TradeResult memory targetHop2 = _tradeBNT(
                contextId,
                tokens.targetToken,
                true,
                TradeParams({ bySourceAmount: true, amount: targetHop1.targetAmount, limit: minReturnAmount })
            );
            return (targetHop1, targetHop2);
        }
        uint256 targetAmount = params.amount;
        uint256 maxSourceAmount = params.limit;
        // trade any amount of BNT to get the requested target amount (we will use the actual traded amount to restrict
        // the trade from the source)
        TradeResult memory sourceHop2 = _tradeBNT(
            contextId,
            tokens.targetToken,
            true,
            TradeParams({ bySourceAmount: false, amount: targetAmount, limit: type(uint256).max })
        );
        // trade source tokens to the required amount of BNT (while respecting the maximum source amount)
        TradeResult memory sourceHop1 = _tradeBNT(
            contextId,
            tokens.sourceToken,
            false,
            TradeParams({ bySourceAmount: false, amount: sourceHop2.sourceAmount, limit: maxSourceAmount })
        );
        return (sourceHop1, sourceHop2);
    }
    /**
     * @dev deposits tokens to the master vault and verifies that msg.value corresponds to its type
     */
    function _depositToMasterVault(
        Token token,
        address caller,
        uint256 amount
    ) private {
        if (token.isNative()) {
            if (msg.value < amount) {
                revert NativeTokenAmountMismatch();
            }
            // using a regular transfer here would revert due to exceeding the 2300 gas limit which is why we're using
            // call instead (via sendValue), which the 2300 gas limit does not apply for
            payable(address(_masterVault)).sendValue(amount);
            // refund the caller for the remaining native token amount
            if (msg.value > amount) {
                payable(address(caller)).sendValue(msg.value - amount);
            }
        } else {
            if (msg.value > 0) {
                revert NativeTokenAmountMismatch();
            }
            token.safeTransferFrom(caller, address(_masterVault), amount);
        }
    }
    /**
     * @dev verifies that the specified pool is managed by a valid pool collection and returns it
     */
    function _poolCollection(Token token) private view returns (IPoolCollection) {
        // verify that the pool is managed by a valid pool collection
        IPoolCollection poolCollection = _collectionByPool[token];
        if (address(poolCollection) == address(0)) {
            revert InvalidToken();
        }
        return poolCollection;
    }
    /**
     * @dev initiates liquidity withdrawal
     */
    function _initWithdrawal(
        address provider,
        IPoolToken poolToken,
        uint256 poolTokenAmount
    ) private returns (uint256) {
        if (poolToken != _bntPoolToken) {
            Token reserveToken = poolToken.reserveToken();
            if (_poolCollection(reserveToken).poolToken(reserveToken) != poolToken) {
                revert InvalidPool();
            }
        }
        // transfer the pool tokens from the provider (we aren't using safeTransferFrom, since the PoolToken is a fully
        // compliant ERC20 token contract)
        poolToken.transferFrom(provider, address(_pendingWithdrawals), poolTokenAmount);
        return _pendingWithdrawals.initWithdrawal(provider, poolToken, poolTokenAmount);
    }
    /**
     * @dev grants/revokes required roles to/from a pool collection
     */
    function _setAccessRoles(IPoolCollection poolCollection, bool set) private {
        address poolCollectionAddress = address(poolCollection);
        if (set) {
            _bntPool.grantRole(ROLE_BNT_MANAGER, poolCollectionAddress);
            _bntPool.grantRole(ROLE_VAULT_MANAGER, poolCollectionAddress);
            _bntPool.grantRole(ROLE_FUNDING_MANAGER, poolCollectionAddress);
            _masterVault.grantRole(ROLE_ASSET_MANAGER, poolCollectionAddress);
            _externalProtectionVault.grantRole(ROLE_ASSET_MANAGER, poolCollectionAddress);
        } else {
            _bntPool.revokeRole(ROLE_BNT_MANAGER, poolCollectionAddress);
            _bntPool.revokeRole(ROLE_VAULT_MANAGER, poolCollectionAddress);
            _bntPool.revokeRole(ROLE_FUNDING_MANAGER, poolCollectionAddress);
            _masterVault.revokeRole(ROLE_ASSET_MANAGER, poolCollectionAddress);
            _externalProtectionVault.revokeRole(ROLE_ASSET_MANAGER, poolCollectionAddress);
        }
    }
    /*
     * @dev finds a pool collection with the given type and version
     */
    function _findPoolCollection(uint16 poolType, uint16 poolVersion) private view returns (IPoolCollection) {
        // note that there's no risk of using an unbounded loop here since the list of all the active pool collections
        // is always going to remain sufficiently small
        uint256 length = _poolCollections.length();
        for (uint256 i = 0; i < length; i++) {
            IPoolCollection poolCollection = IPoolCollection(_poolCollections.at(i));
            if ((poolCollection.poolType() == poolType && poolCollection.version() == poolVersion)) {
                return poolCollection;
            }
        }
        return IPoolCollection(address(0));
    }
    /**
     * @dev an optional post-upgrade callback that can be implemented by child contracts
     */
    function _postUpgrade(
        bytes calldata /* data */
    ) internal override {
        _depositingEnabled = true;
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
import { IPoolCollection } from "../../pools/interfaces/IPoolCollection.sol";
import { IPoolToken } from "../../pools/interfaces/IPoolToken.sol";
/**
 * @dev Flash-loan recipient interface
 */
interface IFlashLoanRecipient {
    /**
     * @dev a flash-loan recipient callback after each the caller must return the borrowed amount and an additional fee
     */
    function onFlashLoan(
        address caller,
        IERC20 erc20Token,
        uint256 amount,
        uint256 feeAmount,
        bytes memory data
    ) external;
}
/**
 * @dev Bancor Network interface
 */
interface IBancorNetwork is IUpgradeable {
    /**
     * @dev returns the set of all valid pool collections
     */
    function poolCollections() external view returns (IPoolCollection[] memory);
    /**
     * @dev returns the set of all liquidity pools
     */
    function liquidityPools() external view returns (Token[] memory);
    /**
     * @dev returns the respective pool collection for the provided pool
     */
    function collectionByPool(Token pool) external view returns (IPoolCollection);
    /**
     * @dev creates new pools
     *
     * requirements:
     *
     * - none of the pools already exists
     */
    function createPools(Token[] calldata tokens, IPoolCollection poolCollection) external;
    /**
     * @dev migrates a list of pools between pool collections
     *
     * notes:
     *
     * - invalid or incompatible pools will be skipped gracefully
     */
    function migratePools(Token[] calldata pools, IPoolCollection newPoolCollection) external;
    /**
     * @dev deposits liquidity for the specified provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function depositFor(
        address provider,
        Token pool,
        uint256 tokenAmount
    ) external payable returns (uint256);
    /**
     * @dev deposits liquidity for the current provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function deposit(Token pool, uint256 tokenAmount) external payable returns (uint256);
    /**
     * @dev initiates liquidity withdrawal
     *
     * requirements:
     *
     * - the caller must have approved the contract to transfer the pool token amount on its behalf
     */
    function initWithdrawal(IPoolToken poolToken, uint256 poolTokenAmount) external returns (uint256);
    /**
     * @dev cancels a withdrawal request, and returns the number of pool token amount associated with the withdrawal
     * request
     *
     * requirements:
     *
     * - the caller must have already initiated a withdrawal and received the specified id
     */
    function cancelWithdrawal(uint256 id) external returns (uint256);
    /**
     * @dev withdraws liquidity and returns the withdrawn amount
     *
     * requirements:
     *
     * - the provider must have already initiated a withdrawal and received the specified id
     * - the specified withdrawal request is eligible for completion
     * - the provider must have approved the network to transfer vBNT amount on its behalf, when withdrawing BNT
     * liquidity
     */
    function withdraw(uint256 id) external returns (uint256);
    /**
     * @dev performs a trade by providing the input source amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade target amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev performs a trade by providing the output target amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade source amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev provides a flash-loan
     *
     * requirements:
     *
     * - the recipient's callback must return *at least* the borrowed amount and fee back to the specified return address
     */
    function flashLoan(
        Token token,
        uint256 amount,
        IFlashLoanRecipient recipient,
        bytes calldata data
    ) external;
    /**
     * @dev deposits liquidity during a migration
     */
    function migrateLiquidity(
        Token token,
        address provider,
        uint256 amount,
        uint256 availableAmount,
        uint256 originalAmount
    ) external payable;
    /**
     * @dev withdraws pending network fees, and returns the amount of fees withdrawn
     *
     * requirements:
     *
     * - the caller must have the ROLE_NETWORK_FEE_MANAGER privilege
     */
    function withdrawNetworkFees(address recipient) external returns (uint256);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
error NotWhitelisted();
struct VortexRewards {
    // the percentage of converted BNT to be sent to the initiator of the burning event (in units of PPM)
    uint32 burnRewardPPM;
    // the maximum burn reward to be sent to the initiator of the burning event
    uint256 burnRewardMaxAmount;
}
/**
 * @dev Network Settings interface
 */
interface INetworkSettings is IUpgradeable {
    /**
     * @dev returns the protected tokens whitelist
     */
    function protectedTokenWhitelist() external view returns (Token[] memory);
    /**
     * @dev checks whether a given token is whitelisted
     */
    function isTokenWhitelisted(Token pool) external view returns (bool);
    /**
     * @dev returns the BNT funding limit for a given pool
     */
    function poolFundingLimit(Token pool) external view returns (uint256);
    /**
     * @dev returns the minimum BNT trading liquidity required before the system enables trading in the relevant pool
     */
    function minLiquidityForTrading() external view returns (uint256);
    /**
     * @dev returns the withdrawal fee (in units of PPM)
     */
    function withdrawalFeePPM() external view returns (uint32);
    /**
     * @dev returns the default flash-loan fee (in units of PPM)
     */
    function defaultFlashLoanFeePPM() external view returns (uint32);
    /**
     * @dev returns the flash-loan fee (in units of PPM) of a pool
     */
    function flashLoanFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns the vortex settings
     */
    function vortexRewards() external view returns (VortexRewards memory);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IPoolToken } from "../../pools/interfaces/IPoolToken.sol";
import { Token } from "../../token/Token.sol";
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
/**
 * @dev the data struct representing a pending withdrawal request
 */
struct WithdrawalRequest {
    address provider; // the liquidity provider
    IPoolToken poolToken; // the locked pool token
    Token reserveToken; // the reserve token to withdraw
    uint32 createdAt; // the time when the request was created (Unix timestamp)
    uint256 poolTokenAmount; // the locked pool token amount
    uint256 reserveTokenAmount; // the expected reserve token amount to withdraw
}
/**
 * @dev the data struct representing a completed withdrawal request
 */
struct CompletedWithdrawal {
    IPoolToken poolToken; // the withdraw pool token
    uint256 poolTokenAmount; // the original pool token amount in the withdrawal request
    uint256 reserveTokenAmount; // the original reserve token amount at the time of the withdrawal init request
}
/**
 * @dev Pending Withdrawals interface
 */
interface IPendingWithdrawals is IUpgradeable {
    /**
     * @dev returns the lock duration
     */
    function lockDuration() external view returns (uint32);
    /**
     * @dev returns the pending withdrawal requests count for a specific provider
     */
    function withdrawalRequestCount(address provider) external view returns (uint256);
    /**
     * @dev returns the pending withdrawal requests IDs for a specific provider
     */
    function withdrawalRequestIds(address provider) external view returns (uint256[] memory);
    /**
     * @dev returns the pending withdrawal request with the specified ID
     */
    function withdrawalRequest(uint256 id) external view returns (WithdrawalRequest memory);
    /**
     * @dev initiates liquidity withdrawal
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function initWithdrawal(
        address provider,
        IPoolToken poolToken,
        uint256 poolTokenAmount
    ) external returns (uint256);
    /**
     * @dev cancels a withdrawal request, and returns the number of pool tokens which were sent back to the provider
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the provider must have already initiated a withdrawal and received the specified id
     */
    function cancelWithdrawal(address provider, uint256 id) external returns (uint256);
    /**
     * @dev completes a withdrawal request, and returns the pool token and its transferred amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the provider must have already initiated a withdrawal and received the specified id
     * - the lock duration has ended
     */
    function completeWithdrawal(
        bytes32 contextId,
        address provider,
        uint256 id
    ) external returns (CompletedWithdrawal memory);
    /**
     * @dev returns whether the given request is ready for withdrawal
     */
    function isReadyForWithdrawal(uint256 id) external view returns (bool);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IPoolToken } from "./IPoolToken.sol";
import { Token } from "../../token/Token.sol";
import { IVault } from "../../vaults/interfaces/IVault.sol";
// the BNT pool token manager role is required to access the BNT pool tokens
bytes32 constant ROLE_BNT_POOL_TOKEN_MANAGER = keccak256("ROLE_BNT_POOL_TOKEN_MANAGER");
// the BNT manager role is required to request the BNT pool to mint BNT
bytes32 constant ROLE_BNT_MANAGER = keccak256("ROLE_BNT_MANAGER");
// the vault manager role is required to request the BNT pool to burn BNT from the master vault
bytes32 constant ROLE_VAULT_MANAGER = keccak256("ROLE_VAULT_MANAGER");
// the funding manager role is required to request or renounce funding from the BNT pool
bytes32 constant ROLE_FUNDING_MANAGER = keccak256("ROLE_FUNDING_MANAGER");
/**
 * @dev BNT Pool interface
 */
interface IBNTPool is IVault {
    /**
     * @dev returns the BNT pool token contract
     */
    function poolToken() external view returns (IPoolToken);
    /**
     * @dev returns the total staked BNT balance in the network
     */
    function stakedBalance() external view returns (uint256);
    /**
     * @dev returns the current funding of given pool
     */
    function currentPoolFunding(Token pool) external view returns (uint256);
    /**
     * @dev returns the available BNT funding for a given pool
     */
    function availableFunding(Token pool) external view returns (uint256);
    /**
     * @dev converts the specified pool token amount to the underlying BNT amount
     */
    function poolTokenToUnderlying(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying BNT amount to pool token amount
     */
    function underlyingToPoolToken(uint256 bntAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(uint256 bntAmountToDistribute) external view returns (uint256);
    /**
     * @dev mints BNT to the recipient
     *
     * requirements:
     *
     * - the caller must have the ROLE_BNT_MANAGER role
     */
    function mint(address recipient, uint256 bntAmount) external;
    /**
     * @dev burns BNT from the vault
     *
     * requirements:
     *
     * - the caller must have the ROLE_VAULT_MANAGER role
     */
    function burnFromVault(uint256 bntAmount) external;
    /**
     * @dev deposits BNT liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - BNT tokens must have been already deposited into the contract
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        uint256 bntAmount,
        bool isMigrating,
        uint256 originalVBNTAmount
    ) external returns (uint256);
    /**
     * @dev withdraws BNT liquidity on behalf of a specific provider and returns the withdrawn BNT amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - bnBNT token must have been already deposited into the contract
     * - vBNT token must have been already deposited into the contract
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        uint256 poolTokenAmount,
        uint256 bntAmount
    ) external returns (uint256);
    /**
     * @dev returns the withdrawn BNT amount
     */
    function withdrawalAmount(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev requests BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the request amount should be below the funding limit for a given pool
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function requestFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev renounces BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function renounceFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(
        Token pool,
        uint256 feeAmount,
        bool isTradeFee
    ) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { Fraction112 } from "../../utility/FractionLibrary.sol";
import { Token } from "../../token/Token.sol";
import { IPoolToken } from "./IPoolToken.sol";
struct PoolLiquidity {
    uint128 bntTradingLiquidity; // the BNT trading liquidity
    uint128 baseTokenTradingLiquidity; // the base token trading liquidity
    uint256 stakedBalance; // the staked balance
}
struct AverageRates {
    uint32 blockNumber;
    Fraction112 rate;
    Fraction112 invRate;
}
struct Pool {
    IPoolToken poolToken; // the pool token of the pool
    uint32 tradingFeePPM; // the trading fee (in units of PPM)
    bool tradingEnabled; // whether trading is enabled
    bool depositingEnabled; // whether depositing is enabled
    AverageRates averageRates; // the recent average rates
    PoolLiquidity liquidity; // the overall liquidity in the pool
}
struct WithdrawalAmounts {
    uint256 totalAmount;
    uint256 baseTokenAmount;
    uint256 bntAmount;
}
// trading enabling/disabling reasons
uint8 constant TRADING_STATUS_UPDATE_DEFAULT = 0;
uint8 constant TRADING_STATUS_UPDATE_ADMIN = 1;
uint8 constant TRADING_STATUS_UPDATE_MIN_LIQUIDITY = 2;
uint8 constant TRADING_STATUS_UPDATE_INVALID_STATE = 3;
struct TradeAmountAndFee {
    uint256 amount; // the source/target amount (depending on the context) resulting from the trade
    uint256 tradingFeeAmount; // the trading fee amount
    uint256 networkFeeAmount; // the network fee amount (always in units of BNT)
}
/**
 * @dev Pool Collection interface
 */
interface IPoolCollection is IVersioned {
    /**
     * @dev returns the type of the pool
     */
    function poolType() external view returns (uint16);
    /**
     * @dev returns the default trading fee (in units of PPM)
     */
    function defaultTradingFeePPM() external view returns (uint32);
    /**
     * @dev returns the network fee (in units of PPM)
     */
    function networkFeePPM() external view returns (uint32);
    /**
     * @dev returns all the pools which are managed by this pool collection
     */
    function pools() external view returns (Token[] memory);
    /**
     * @dev returns the number of all the pools which are managed by this pool collection
     */
    function poolCount() external view returns (uint256);
    /**
     * @dev returns whether a pool is valid
     */
    function isPoolValid(Token pool) external view returns (bool);
    /**
     * @dev returns the overall liquidity in the pool
     */
    function poolLiquidity(Token pool) external view returns (PoolLiquidity memory);
    /**
     * @dev returns the pool token of the pool
     */
    function poolToken(Token pool) external view returns (IPoolToken);
    /**
     * @dev returns the trading fee (in units of PPM)
     */
    function tradingFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns whether trading is enabled
     */
    function tradingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether depositing is enabled
     */
    function depositingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether the pool is stable
     */
    function isPoolStable(Token pool) external view returns (bool);
    /**
     * @dev converts the specified pool token amount to the underlying base token amount
     */
    function poolTokenToUnderlying(Token pool, uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying base token amount to pool token amount
     */
    function underlyingToPoolToken(Token pool, uint256 baseTokenAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(
        Token pool,
        uint256 baseTokenAmountToDistribute,
        uint256 protocolPoolTokenAmount
    ) external view returns (uint256);
    /**
     * @dev creates a new pool
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the pool should have been whitelisted
     * - the pool isn't already defined in the collection
     */
    function createPool(Token token) external;
    /**
     * @dev deposits base token liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - assumes that the base token has been already deposited in the vault
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev handles some of the withdrawal-related actions and returns the withdrawn base token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the caller must have approved the collection to transfer/burn the pool token amount on its behalf
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 poolTokenAmount,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev returns the amounts that would be returned if the position is currently withdrawn,
     * along with the breakdown of the base token and the BNT compensation
     */
    function withdrawalAmounts(Token pool, uint256 poolTokenAmount) external view returns (WithdrawalAmounts memory);
    /**
     * @dev performs a trade by providing the source amount and returns the target amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeBySourceAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev performs a trade by providing the target amount and returns the required source amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeByTargetAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev returns the output amount and fee when trading by providing the source amount
     */
    function tradeOutputAndFeeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev returns the input amount and fee when trading by providing the target amount
     */
    function tradeInputAndFeeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(Token pool, uint256 feeAmount) external;
    /**
     * @dev migrates a pool to this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolIn(Token pool, Pool calldata data) external;
    /**
     * @dev migrates a pool from this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolOut(Token pool, IPoolCollection targetPoolCollection) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Token } from "../../token/Token.sol";
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { IPoolCollection } from "./IPoolCollection.sol";
/**
 * @dev Pool Migrator interface
 */
interface IPoolMigrator is IVersioned {
    /**
     * @dev migrates a pool and returns the new pool collection it exists in
     *
     * notes:
     *
     * - invalid or incompatible pools will be skipped gracefully
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function migratePool(Token pool, IPoolCollection newPoolCollection) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { IERC20Burnable } from "../../token/interfaces/IERC20Burnable.sol";
import { Token } from "../../token/Token.sol";
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { IOwned } from "../../utility/interfaces/IOwned.sol";
/**
 * @dev Pool Token interface
 */
interface IPoolToken is IVersioned, IOwned, IERC20, IERC20Permit, IERC20Burnable {
    /**
     * @dev returns the address of the reserve token
     */
    function reserveToken() external view returns (Token);
    /**
     * @dev increases the token supply and sends the new tokens to the given account
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function mint(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
 * @dev extends the SafeERC20 library with additional operations
 */
library SafeERC20Ex {
    using SafeERC20 for IERC20;
    /**
     * @dev ensures that the spender has sufficient allowance
     */
    function ensureApprove(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance >= amount) {
            return;
        }
        if (allowance > 0) {
            token.safeApprove(spender, 0);
        }
        token.safeApprove(spender, amount);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev the main purpose of the Token interfaces is to ensure artificially that we won't use ERC20's standard functions,
 * but only their safe versions, which are provided by SafeERC20 and SafeERC20Ex via the TokenLibrary contract
 */
interface Token {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { SafeERC20Ex } from "./SafeERC20Ex.sol";
import { Token } from "./Token.sol";
/**
 * @dev This library implements ERC20 and SafeERC20 utilities for both the native token and for ERC20 tokens
 */
library TokenLibrary {
    using SafeERC20 for IERC20;
    using SafeERC20Ex for IERC20;
    error PermitUnsupported();
    // the address that represents the native token reserve
    address private constant NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    // the symbol that represents the native token
    string private constant NATIVE_TOKEN_SYMBOL = "ETH";
    // the decimals for the native token
    uint8 private constant NATIVE_TOKEN_DECIMALS = 18;
    // the token representing the native token
    Token public constant NATIVE_TOKEN = Token(NATIVE_TOKEN_ADDRESS);
    /**
     * @dev returns whether the provided token represents an ERC20 or the native token reserve
     */
    function isNative(Token token) internal pure returns (bool) {
        return address(token) == NATIVE_TOKEN_ADDRESS;
    }
    /**
     * @dev returns the symbol of the native token/ERC20 token
     */
    function symbol(Token token) internal view returns (string memory) {
        if (isNative(token)) {
            return NATIVE_TOKEN_SYMBOL;
        }
        return toERC20(token).symbol();
    }
    /**
     * @dev returns the decimals of the native token/ERC20 token
     */
    function decimals(Token token) internal view returns (uint8) {
        if (isNative(token)) {
            return NATIVE_TOKEN_DECIMALS;
        }
        return toERC20(token).decimals();
    }
    /**
     * @dev returns the balance of the native token/ERC20 token
     */
    function balanceOf(Token token, address account) internal view returns (uint256) {
        if (isNative(token)) {
            return account.balance;
        }
        return toIERC20(token).balanceOf(account);
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token
     */
    function safeTransfer(
        Token token,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        if (isNative(token)) {
            payable(to).transfer(amount);
        } else {
            toIERC20(token).safeTransfer(to, amount);
        }
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token from a specific holder using the allowance mechanism
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeTransferFrom(
        Token token,
        address from,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0 || isNative(token)) {
            return;
        }
        toIERC20(token).safeTransferFrom(from, to, amount);
    }
    /**
     * @dev approves a specific amount of the native token/ERC20 token from a specific holder
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).safeApprove(spender, amount);
    }
    /**
     * @dev ensures that the spender has sufficient allowance
     *
     * note that the function does not perform any action if the native token is provided
     */
    function ensureApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).ensureApprove(spender, amount);
    }
    /**
     * @dev compares between a token and another raw ERC20 token
     */
    function isEqual(Token token, IERC20 erc20Token) internal pure returns (bool) {
        return toIERC20(token) == erc20Token;
    }
    /**
     * @dev utility function that converts a token to an IERC20
     */
    function toIERC20(Token token) internal pure returns (IERC20) {
        return IERC20(address(token));
    }
    /**
     * @dev utility function that converts a token to an ERC20
     */
    function toERC20(Token token) internal pure returns (ERC20) {
        return ERC20(address(token));
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev burnable ERC20 interface
 */
interface IERC20Burnable {
    /**
     * @dev Destroys tokens from the caller.
     */
    function burn(uint256 amount) external;
    /**
     * @dev Destroys tokens from a recipient, deducting from the caller's allowance
     *
     * requirements:
     *
     * - the caller must have allowance for recipient's tokens of at least the specified amount
     */
    function burnFrom(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1_000_000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
struct Fraction {
    uint256 n;
    uint256 d;
}
struct Fraction112 {
    uint112 n;
    uint112 d;
}
error InvalidFraction();
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Fraction, Fraction112, InvalidFraction } from "./Fraction.sol";
import { MathEx } from "./MathEx.sol";
// solhint-disable-next-line func-visibility
function zeroFraction() pure returns (Fraction memory) {
    return Fraction({ n: 0, d: 1 });
}
// solhint-disable-next-line func-visibility
function zeroFraction112() pure returns (Fraction112 memory) {
    return Fraction112({ n: 0, d: 1 });
}
/**
 * @dev this library provides a set of fraction operations
 */
library FractionLibrary {
    /**
     * @dev returns whether a standard fraction is valid
     */
    function isValid(Fraction memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is valid
     */
    function isValid(Fraction112 memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a standard fraction is positive
     */
    function isPositive(Fraction memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is positive
     */
    function isPositive(Fraction112 memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction memory fraction) internal pure returns (Fraction memory) {
        Fraction memory invFraction = Fraction({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction112 memory fraction) internal pure returns (Fraction112 memory) {
        Fraction112 memory invFraction = Fraction112({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev reduces a standard fraction to a 112-bit fraction
     */
    function toFraction112(Fraction memory fraction) internal pure returns (Fraction112 memory) {
        Fraction memory reducedFraction = MathEx.reducedFraction(fraction, type(uint112).max);
        return Fraction112({ n: uint112(reducedFraction.n), d: uint112(reducedFraction.d) });
    }
    /**
     * @dev expands a 112-bit fraction to a standard fraction
     */
    function fromFraction112(Fraction112 memory fraction) internal pure returns (Fraction memory) {
        return Fraction({ n: fraction.n, d: fraction.d });
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Fraction, InvalidFraction } from "./Fraction.sol";
import { PPM_RESOLUTION } from "./Constants.sol";
uint256 constant ONE = 0x80000000000000000000000000000000;
uint256 constant LN2 = 0x58b90bfbe8e7bcd5e4f1d9cc01f97b57;
struct Uint512 {
    uint256 hi; // 256 most significant bits
    uint256 lo; // 256 least significant bits
}
struct Sint256 {
    uint256 value;
    bool isNeg;
}
/**
 * @dev this library provides a set of complex math operations
 */
library MathEx {
    error Overflow();
    /**
     * @dev returns `2 ^ f` by calculating `e ^ (f * ln(2))`, where `e` is Euler's number:
     * - Rewrite the input as a sum of binary exponents and a single residual r, as small as possible
     * - The exponentiation of each binary exponent is given (pre-calculated)
     * - The exponentiation of r is calculated via Taylor series for e^x, where x = r
     * - The exponentiation of the input is calculated by multiplying the intermediate results above
     * - For example: e^5.521692859 = e^(4 + 1 + 0.5 + 0.021692859) = e^4 * e^1 * e^0.5 * e^0.021692859
     */
    function exp2(Fraction memory f) internal pure returns (Fraction memory) {
        uint256 x = MathEx.mulDivF(LN2, f.n, f.d);
        uint256 y;
        uint256 z;
        uint256 n;
        if (x >= (ONE << 4)) {
            revert Overflow();
        }
        unchecked {
            z = y = x % (ONE >> 3); // get the input modulo 2^(-3)
            z = (z * y) / ONE;
            n += z * 0x10e1b3be415a0000; // add y^02 * (20! / 02!)
            z = (z * y) / ONE;
            n += z * 0x05a0913f6b1e0000; // add y^03 * (20! / 03!)
            z = (z * y) / ONE;
            n += z * 0x0168244fdac78000; // add y^04 * (20! / 04!)
            z = (z * y) / ONE;
            n += z * 0x004807432bc18000; // add y^05 * (20! / 05!)
            z = (z * y) / ONE;
            n += z * 0x000c0135dca04000; // add y^06 * (20! / 06!)
            z = (z * y) / ONE;
            n += z * 0x0001b707b1cdc000; // add y^07 * (20! / 07!)
            z = (z * y) / ONE;
            n += z * 0x000036e0f639b800; // add y^08 * (20! / 08!)
            z = (z * y) / ONE;
            n += z * 0x00000618fee9f800; // add y^09 * (20! / 09!)
            z = (z * y) / ONE;
            n += z * 0x0000009c197dcc00; // add y^10 * (20! / 10!)
            z = (z * y) / ONE;
            n += z * 0x0000000e30dce400; // add y^11 * (20! / 11!)
            z = (z * y) / ONE;
            n += z * 0x000000012ebd1300; // add y^12 * (20! / 12!)
            z = (z * y) / ONE;
            n += z * 0x0000000017499f00; // add y^13 * (20! / 13!)
            z = (z * y) / ONE;
            n += z * 0x0000000001a9d480; // add y^14 * (20! / 14!)
            z = (z * y) / ONE;
            n += z * 0x00000000001c6380; // add y^15 * (20! / 15!)
            z = (z * y) / ONE;
            n += z * 0x000000000001c638; // add y^16 * (20! / 16!)
            z = (z * y) / ONE;
            n += z * 0x0000000000001ab8; // add y^17 * (20! / 17!)
            z = (z * y) / ONE;
            n += z * 0x000000000000017c; // add y^18 * (20! / 18!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000014; // add y^19 * (20! / 19!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000001; // add y^20 * (20! / 20!)
            n = n / 0x21c3677c82b40000 + y + ONE; // divide by 20! and then add y^1 / 1! + y^0 / 0!
            if ((x & (ONE >> 3)) != 0)
                n = (n * 0x1c3d6a24ed82218787d624d3e5eba95f9) / 0x18ebef9eac820ae8682b9793ac6d1e776; // multiply by e^(2^-3)
            if ((x & (ONE >> 2)) != 0)
                n = (n * 0x18ebef9eac820ae8682b9793ac6d1e778) / 0x1368b2fc6f9609fe7aceb46aa619baed4; // multiply by e^(2^-2)
            if ((x & (ONE >> 1)) != 0)
                n = (n * 0x1368b2fc6f9609fe7aceb46aa619baed5) / 0x0bc5ab1b16779be3575bd8f0520a9f21f; // multiply by e^(2^-1)
            if ((x & (ONE << 0)) != 0)
                n = (n * 0x0bc5ab1b16779be3575bd8f0520a9f21e) / 0x0454aaa8efe072e7f6ddbab84b40a55c9; // multiply by e^(2^+0)
            if ((x & (ONE << 1)) != 0)
                n = (n * 0x0454aaa8efe072e7f6ddbab84b40a55c5) / 0x00960aadc109e7a3bf4578099615711ea; // multiply by e^(2^+1)
            if ((x & (ONE << 2)) != 0)
                n = (n * 0x00960aadc109e7a3bf4578099615711d7) / 0x0002bf84208204f5977f9a8cf01fdce3d; // multiply by e^(2^+2)
            if ((x & (ONE << 3)) != 0)
                n = (n * 0x0002bf84208204f5977f9a8cf01fdc307) / 0x0000003c6ab775dd0b95b4cbee7e65d11; // multiply by e^(2^+3)
        }
        return Fraction({ n: n, d: ONE });
    }
    /**
     * @dev returns a fraction with reduced components
     */
    function reducedFraction(Fraction memory fraction, uint256 max) internal pure returns (Fraction memory) {
        uint256 scale = Math.ceilDiv(Math.max(fraction.n, fraction.d), max);
        Fraction memory reduced = Fraction({ n: fraction.n / scale, d: fraction.d / scale });
        if (reduced.d == 0) {
            revert InvalidFraction();
        }
        return reduced;
    }
    /**
     * @dev returns the weighted average of two fractions
     */
    function weightedAverage(
        Fraction memory fraction1,
        Fraction memory fraction2,
        uint256 weight1,
        uint256 weight2
    ) internal pure returns (Fraction memory) {
        return
            Fraction({
                n: fraction1.n * fraction2.d * weight1 + fraction1.d * fraction2.n * weight2,
                d: fraction1.d * fraction2.d * (weight1 + weight2)
            });
    }
    /**
     * @dev returns whether or not the deviation of an offset sample from a base sample is within a permitted range
     * for example, if the maximum permitted deviation is 5%, then evaluate `95% * base <= offset <= 105% * base`
     */
    function isInRange(
        Fraction memory baseSample,
        Fraction memory offsetSample,
        uint32 maxDeviationPPM
    ) internal pure returns (bool) {
        Uint512 memory min = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION - maxDeviationPPM));
        Uint512 memory mid = mul512(baseSample.d, offsetSample.n * PPM_RESOLUTION);
        Uint512 memory max = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION + maxDeviationPPM));
        return lte512(min, mid) && lte512(mid, max);
    }
    /**
     * @dev returns an `Sint256` positive representation of an unsigned integer
     */
    function toPos256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: false });
    }
    /**
     * @dev returns an `Sint256` negative representation of an unsigned integer
     */
    function toNeg256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: true });
    }
    /**
     * @dev returns the largest integer smaller than or equal to `x * y / z`
     */
    function mulDivF(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        Uint512 memory xy = mul512(x, y);
        // if `x * y < 2 ^ 256`
        if (xy.hi == 0) {
            return xy.lo / z;
        }
        // assert `x * y / z < 2 ^ 256`
        if (xy.hi >= z) {
            revert Overflow();
        }
        uint256 m = _mulMod(x, y, z); // `m = x * y % z`
        Uint512 memory n = _sub512(xy, m); // `n = x * y - m` hence `n / z = floor(x * y / z)`
        // if `n < 2 ^ 256`
        if (n.hi == 0) {
            return n.lo / z;
        }
        uint256 p = _unsafeSub(0, z) & z; // `p` is the largest power of 2 which `z` is divisible by
        uint256 q = _div512(n, p); // `n` is divisible by `p` because `n` is divisible by `z` and `z` is divisible by `p`
        uint256 r = _inv256(z / p); // `z / p = 1 mod 2` hence `inverse(z / p) = 1 mod 2 ^ 256`
        return _unsafeMul(q, r); // `q * r = (n / p) * inverse(z / p) = n / z`
    }
    /**
     * @dev returns the smallest integer larger than or equal to `x * y / z`
     */
    function mulDivC(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        uint256 w = mulDivF(x, y, z);
        if (_mulMod(x, y, z) > 0) {
            if (w >= type(uint256).max) {
                revert Overflow();
            }
            return w + 1;
        }
        return w;
    }
    /**
     * @dev returns the maximum of `n1 - n2` and 0
     */
    function subMax0(uint256 n1, uint256 n2) internal pure returns (uint256) {
        return n1 > n2 ? n1 - n2 : 0;
    }
    /**
     * @dev returns the value of `x > y`
     */
    function gt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi > y.hi || (x.hi == y.hi && x.lo > y.lo);
    }
    /**
     * @dev returns the value of `x < y`
     */
    function lt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
    }
    /**
     * @dev returns the value of `x >= y`
     */
    function gte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !lt512(x, y);
    }
    /**
     * @dev returns the value of `x <= y`
     */
    function lte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !gt512(x, y);
    }
    /**
     * @dev returns the value of `x * y`
     */
    function mul512(uint256 x, uint256 y) internal pure returns (Uint512 memory) {
        uint256 p = _mulModMax(x, y);
        uint256 q = _unsafeMul(x, y);
        if (p >= q) {
            return Uint512({ hi: p - q, lo: q });
        }
        return Uint512({ hi: _unsafeSub(p, q) - 1, lo: q });
    }
    /**
     * @dev returns the value of `x - y`, given that `x >= y`
     */
    function _sub512(Uint512 memory x, uint256 y) private pure returns (Uint512 memory) {
        if (x.lo >= y) {
            return Uint512({ hi: x.hi, lo: x.lo - y });
        }
        return Uint512({ hi: x.hi - 1, lo: _unsafeSub(x.lo, y) });
    }
    /**
     * @dev returns the value of `x / pow2n`, given that `x` is divisible by `pow2n`
     */
    function _div512(Uint512 memory x, uint256 pow2n) private pure returns (uint256) {
        uint256 pow2nInv = _unsafeAdd(_unsafeSub(0, pow2n) / pow2n, 1); // `1 << (256 - n)`
        return _unsafeMul(x.hi, pow2nInv) | (x.lo / pow2n); // `(x.hi << (256 - n)) | (x.lo >> n)`
    }
    /**
     * @dev returns the inverse of `d` modulo `2 ^ 256`, given that `d` is congruent to `1` modulo `2`
     */
    function _inv256(uint256 d) private pure returns (uint256) {
        // approximate the root of `f(x) = 1 / x - d` using the newton–raphson convergence method
        uint256 x = 1;
        for (uint256 i = 0; i < 8; i++) {
            x = _unsafeMul(x, _unsafeSub(2, _unsafeMul(x, d))); // `x = x * (2 - x * d) mod 2 ^ 256`
        }
        return x;
    }
    /**
     * @dev returns `(x + y) % 2 ^ 256`
     */
    function _unsafeAdd(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x + y;
        }
    }
    /**
     * @dev returns `(x - y) % 2 ^ 256`
     */
    function _unsafeSub(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x - y;
        }
    }
    /**
     * @dev returns `(x * y) % 2 ^ 256`
     */
    function _unsafeMul(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x * y;
        }
    }
    /**
     * @dev returns `x * y % (2 ^ 256 - 1)`
     */
    function _mulModMax(uint256 x, uint256 y) private pure returns (uint256) {
        return mulmod(x, y, type(uint256).max);
    }
    /**
     * @dev returns `x * y % z`
     */
    function _mulMod(
        uint256 x,
        uint256 y,
        uint256 z
    ) private pure returns (uint256) {
        return mulmod(x, y, z);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev this contract abstracts the block timestamp in order to allow for more flexible control in tests
 */
abstract contract Time {
    /**
     * @dev returns the current time
     */
    function _time() internal view virtual returns (uint32) {
        return uint32(block.timestamp);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { AccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/AccessControlEnumerableUpgradeable.sol";
import { IUpgradeable } from "./interfaces/IUpgradeable.sol";
import { AccessDenied } from "./Utils.sol";
/**
 * @dev this contract provides common utilities for upgradeable contracts
 *
 * note that we're using the Transparent Upgradeable Proxy pattern and *not* the Universal Upgradeable Proxy Standard
 * (UUPS) pattern, therefore initializing the implementation contracts is not necessary or required
 */
abstract contract Upgradeable is IUpgradeable, AccessControlEnumerableUpgradeable {
    error AlreadyInitialized();
    // the admin role is used to allow a non-proxy admin to perform additional initialization/setup during contract
    // upgrades
    bytes32 internal constant ROLE_ADMIN = keccak256("ROLE_ADMIN");
    uint32 internal constant MAX_GAP = 50;
    uint16 internal _initializations;
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 1] private __gap;
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __Upgradeable_init() internal onlyInitializing {
        __AccessControl_init();
        __Upgradeable_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __Upgradeable_init_unchained() internal onlyInitializing {
        _initializations = 1;
        // set up administrative roles
        _setRoleAdmin(ROLE_ADMIN, ROLE_ADMIN);
        // allow the deployer to initially be the admin of the contract
        _setupRole(ROLE_ADMIN, msg.sender);
    }
    // solhint-enable func-name-mixedcase
    modifier onlyAdmin() {
        _hasRole(ROLE_ADMIN, msg.sender);
        _;
    }
    modifier onlyRoleMember(bytes32 role) {
        _hasRole(role, msg.sender);
        _;
    }
    function version() public view virtual override returns (uint16);
    /**
     * @dev returns the admin role
     */
    function roleAdmin() external pure returns (bytes32) {
        return ROLE_ADMIN;
    }
    /**
     * @dev performs post-upgrade initialization
     *
     * requirements:
     *
     * - this must can be called only once per-upgrade
     */
    function postUpgrade(bytes calldata data) external {
        uint16 initializations = _initializations + 1;
        if (initializations != version()) {
            revert AlreadyInitialized();
        }
        _initializations = initializations;
        _postUpgrade(data);
    }
    /**
     * @dev an optional post-upgrade callback that can be implemented by child contracts
     */
    function _postUpgrade(
        bytes calldata /* data */
    ) internal virtual {}
    function _hasRole(bytes32 role, address account) internal view {
        if (!hasRole(role, account)) {
            revert AccessDenied();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
abstract contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev Owned interface
 */
interface IOwned {
    /**
     * @dev returns the address of the current owner
     */
    function owner() external view returns (address);
    /**
     * @dev allows transferring the contract ownership
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     * - the new owner still needs to accept the transfer
     */
    function transferOwnership(address ownerCandidate) external;
    /**
     * @dev used by a new owner to accept an ownership transfer
     */
    function acceptOwnership() external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "./IVersioned.sol";
import { IAccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/IAccessControlEnumerableUpgradeable.sol";
/**
 * @dev this is the common interface for upgradeable contracts
 */
interface IUpgradeable is IAccessControlEnumerableUpgradeable, IVersioned {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev an interface for a versioned contract
 */
interface IVersioned {
    function version() external view returns (uint16);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IExternalProtectionVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IMasterVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
// the asset manager role is required to access all the funds
bytes32 constant ROLE_ASSET_MANAGER = keccak256("ROLE_ASSET_MANAGER");
interface IVault is IUpgradeable {
    /**
     * @dev triggered when tokens have been withdrawn from the vault
     */
    event FundsWithdrawn(Token indexed token, address indexed caller, address indexed target, uint256 amount);
    /**
     * @dev triggered when tokens have been burned from the vault
     */
    event FundsBurned(Token indexed token, address indexed caller, uint256 amount);
    /**
     * @dev tells whether the vault accepts native token deposits
     */
    function isPayable() external view returns (bool);
    /**
     * @dev withdraws funds held by the contract and sends them to an account
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    ) external;
    /**
     * @dev burns funds held by the contract
     */
    function burn(Token token, uint256 amount) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
/**
 * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
 */
interface IAccessControlEnumerableUpgradeable is IAccessControlUpgradeable {
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) external view returns (address);
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][spender] + addedValue);
        return true;
    }
    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }
        return true;
    }
    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        _beforeTokenTransfer(from, to, amount);
        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;
        emit Transfer(from, to, amount);
        _afterTokenTransfer(from, to, amount);
    }
    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address(0), account, amount);
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
        _afterTokenTransfer(address(0), account, amount);
    }
    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        _beforeTokenTransfer(account, address(0), amount);
        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;
        emit Transfer(account, address(0), amount);
        _afterTokenTransfer(account, address(0), amount);
    }
    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @dev Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }
    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }
    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/math/SafeCast.sol)
pragma solidity ^0.8.0;
/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
        return uint224(value);
    }
    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
        return uint128(value);
    }
    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
        return uint96(value);
    }
    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
        return uint64(value);
    }
    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
        return uint32(value);
    }
    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
        return uint16(value);
    }
    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
        return uint8(value);
    }
    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }
    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128) {
        require(value >= type(int128).min && value <= type(int128).max, "SafeCast: value doesn't fit in 128 bits");
        return int128(value);
    }
    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64) {
        require(value >= type(int64).min && value <= type(int64).max, "SafeCast: value doesn't fit in 64 bits");
        return int64(value);
    }
    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32) {
        require(value >= type(int32).min && value <= type(int32).max, "SafeCast: value doesn't fit in 32 bits");
        return int32(value);
    }
    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16) {
        require(value >= type(int16).min && value <= type(int16).max, "SafeCast: value doesn't fit in 16 bits");
        return int16(value);
    }
    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8) {
        require(value >= type(int8).min && value <= type(int8).max, "SafeCast: value doesn't fit in 8 bits");
        return int8(value);
    }
    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;
        assembly {
            result := store
        }
        return result;
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;
        assembly {
            result := store
        }
        return result;
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
import { IPoolCollection } from "../../pools/interfaces/IPoolCollection.sol";
import { IPoolToken } from "../../pools/interfaces/IPoolToken.sol";
/**
 * @dev Flash-loan recipient interface
 */
interface IFlashLoanRecipient {
    /**
     * @dev a flash-loan recipient callback after each the caller must return the borrowed amount and an additional fee
     */
    function onFlashLoan(
        address caller,
        IERC20 erc20Token,
        uint256 amount,
        uint256 feeAmount,
        bytes memory data
    ) external;
}
/**
 * @dev Bancor Network interface
 */
interface IBancorNetwork is IUpgradeable {
    /**
     * @dev returns the set of all valid pool collections
     */
    function poolCollections() external view returns (IPoolCollection[] memory);
    /**
     * @dev returns the set of all liquidity pools
     */
    function liquidityPools() external view returns (Token[] memory);
    /**
     * @dev returns the respective pool collection for the provided pool
     */
    function collectionByPool(Token pool) external view returns (IPoolCollection);
    /**
     * @dev creates new pools
     *
     * requirements:
     *
     * - none of the pools already exists
     */
    function createPools(Token[] calldata tokens, IPoolCollection poolCollection) external;
    /**
     * @dev migrates a list of pools between pool collections
     *
     * notes:
     *
     * - invalid or incompatible pools will be skipped gracefully
     */
    function migratePools(Token[] calldata pools, IPoolCollection newPoolCollection) external;
    /**
     * @dev deposits liquidity for the specified provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function depositFor(
        address provider,
        Token pool,
        uint256 tokenAmount
    ) external payable returns (uint256);
    /**
     * @dev deposits liquidity for the current provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function deposit(Token pool, uint256 tokenAmount) external payable returns (uint256);
    /**
     * @dev initiates liquidity withdrawal
     *
     * requirements:
     *
     * - the caller must have approved the contract to transfer the pool token amount on its behalf
     */
    function initWithdrawal(IPoolToken poolToken, uint256 poolTokenAmount) external returns (uint256);
    /**
     * @dev cancels a withdrawal request, and returns the number of pool token amount associated with the withdrawal
     * request
     *
     * requirements:
     *
     * - the caller must have already initiated a withdrawal and received the specified id
     */
    function cancelWithdrawal(uint256 id) external returns (uint256);
    /**
     * @dev withdraws liquidity and returns the withdrawn amount
     *
     * requirements:
     *
     * - the provider must have already initiated a withdrawal and received the specified id
     * - the specified withdrawal request is eligible for completion
     * - the provider must have approved the network to transfer vBNT amount on its behalf, when withdrawing BNT
     * liquidity
     */
    function withdraw(uint256 id) external returns (uint256);
    /**
     * @dev performs a trade by providing the input source amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade target amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev performs a trade by providing the output target amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade source amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev provides a flash-loan
     *
     * requirements:
     *
     * - the recipient's callback must return *at least* the borrowed amount and fee back to the specified return address
     */
    function flashLoan(
        Token token,
        uint256 amount,
        IFlashLoanRecipient recipient,
        bytes calldata data
    ) external;
    /**
     * @dev deposits liquidity during a migration
     */
    function migrateLiquidity(
        Token token,
        address provider,
        uint256 amount,
        uint256 availableAmount,
        uint256 originalAmount
    ) external payable;
    /**
     * @dev withdraws pending network fees, and returns the amount of fees withdrawn
     *
     * requirements:
     *
     * - the caller must have the ROLE_NETWORK_FEE_MANAGER privilege
     */
    function withdrawNetworkFees(address recipient) external returns (uint256);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
error NotWhitelisted();
struct VortexRewards {
    // the percentage of converted BNT to be sent to the initiator of the burning event (in units of PPM)
    uint32 burnRewardPPM;
    // the maximum burn reward to be sent to the initiator of the burning event
    uint256 burnRewardMaxAmount;
}
/**
 * @dev Network Settings interface
 */
interface INetworkSettings is IUpgradeable {
    /**
     * @dev returns the protected tokens whitelist
     */
    function protectedTokenWhitelist() external view returns (Token[] memory);
    /**
     * @dev checks whether a given token is whitelisted
     */
    function isTokenWhitelisted(Token pool) external view returns (bool);
    /**
     * @dev returns the BNT funding limit for a given pool
     */
    function poolFundingLimit(Token pool) external view returns (uint256);
    /**
     * @dev returns the minimum BNT trading liquidity required before the system enables trading in the relevant pool
     */
    function minLiquidityForTrading() external view returns (uint256);
    /**
     * @dev returns the withdrawal fee (in units of PPM)
     */
    function withdrawalFeePPM() external view returns (uint32);
    /**
     * @dev returns the default flash-loan fee (in units of PPM)
     */
    function defaultFlashLoanFeePPM() external view returns (uint32);
    /**
     * @dev returns the flash-loan fee (in units of PPM) of a pool
     */
    function flashLoanFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns the vortex settings
     */
    function vortexRewards() external view returns (VortexRewards memory);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { EnumerableSet } from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { SafeCast } from "@openzeppelin/contracts/utils/math/SafeCast.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { IMasterVault } from "../vaults/interfaces/IMasterVault.sol";
import { IExternalProtectionVault } from "../vaults/interfaces/IExternalProtectionVault.sol";
import { IVersioned } from "../utility/interfaces/IVersioned.sol";
import { PPM_RESOLUTION } from "../utility/Constants.sol";
import { Owned } from "../utility/Owned.sol";
import { BlockNumber } from "../utility/BlockNumber.sol";
import { Fraction, Fraction112, FractionLibrary, zeroFraction, zeroFraction112 } from "../utility/FractionLibrary.sol";
import { Sint256, MathEx } from "../utility/MathEx.sol";
// prettier-ignore
import {
    Utils,
    AlreadyExists,
    DoesNotExist,
    InvalidParam,
    InvalidPoolCollection,
    InvalidStakedBalance
} from "../utility/Utils.sol";
import { INetworkSettings, NotWhitelisted } from "../network/interfaces/INetworkSettings.sol";
import { IBancorNetwork } from "../network/interfaces/IBancorNetwork.sol";
import { IPoolToken } from "./interfaces/IPoolToken.sol";
import { IPoolTokenFactory } from "./interfaces/IPoolTokenFactory.sol";
import { IPoolMigrator } from "./interfaces/IPoolMigrator.sol";
// prettier-ignore
import {
    AverageRates,
    IPoolCollection,
    PoolLiquidity,
    Pool,
    TRADING_STATUS_UPDATE_DEFAULT,
    TRADING_STATUS_UPDATE_ADMIN,
    TRADING_STATUS_UPDATE_MIN_LIQUIDITY,
    TRADING_STATUS_UPDATE_INVALID_STATE,
    TradeAmountAndFee,
    WithdrawalAmounts
} from "./interfaces/IPoolCollection.sol";
import { IBNTPool } from "./interfaces/IBNTPool.sol";
import { PoolCollectionWithdrawal } from "./PoolCollectionWithdrawal.sol";
// base token withdrawal output amounts
struct InternalWithdrawalAmounts {
    uint256 baseTokensToTransferFromMasterVault; // base token amount to transfer from the master vault to the provider
    uint256 bntToMintForProvider; // BNT amount to mint directly for the provider
    uint256 baseTokensToTransferFromEPV; // base token amount to transfer from the external protection vault to the provider
    Sint256 baseTokensTradingLiquidityDelta; // base token amount to add to the trading liquidity
    Sint256 bntTradingLiquidityDelta; // BNT amount to add to the trading liquidity and to the master vault
    Sint256 bntProtocolHoldingsDelta; // BNT amount add to the protocol equity
    uint256 baseTokensWithdrawalFee; // base token amount to keep in the pool as a withdrawal fee
    uint256 baseTokensWithdrawalAmount; // base token amount equivalent to the base pool token's withdrawal amount
    uint256 poolTokenAmount; // base pool token
    uint256 poolTokenTotalSupply; // base pool token's total supply
    uint256 newBaseTokenTradingLiquidity; // new base token trading liquidity
    uint256 newBNTTradingLiquidity; // new BNT trading liquidity
}
struct TargetTradingLiquidity {
    bool update;
    uint256 bnt;
    uint256 baseToken;
}
enum PoolRateState {
    Uninitialized,
    Unstable,
    Stable
}
/**
 * @dev Pool Collection contract
 *
 * notes:
 *
 * - the address of reserve token serves as the pool unique ID in both contract functions and events
 */
contract PoolCollection is IPoolCollection, Owned, BlockNumber, Utils {
    using TokenLibrary for Token;
    using FractionLibrary for Fraction;
    using FractionLibrary for Fraction112;
    using EnumerableSet for EnumerableSet.AddressSet;
    using SafeCast for uint256;
    error AlreadyEnabled();
    error DepositingDisabled();
    error InsufficientLiquidity();
    error InsufficientSourceAmount();
    error InsufficientTargetAmount();
    error InvalidRate();
    error RateUnstable();
    error TradingDisabled();
    error FundingLimitTooHigh();
    uint16 private constant POOL_TYPE = 1;
    uint256 private constant LIQUIDITY_GROWTH_FACTOR = 2;
    uint256 private constant BOOTSTRAPPING_LIQUIDITY_BUFFER_FACTOR = 2;
    uint32 private constant DEFAULT_TRADING_FEE_PPM = 2_000; // 0.2%
    uint32 private constant DEFAULT_NETWORK_FEE_PPM = 200_000; // 20%
    uint32 private constant RATE_MAX_DEVIATION_PPM = 10_000; // %1
    uint32 private constant RATE_RESET_BLOCK_THRESHOLD = 100;
    // the average rate is recalculated based on the ratio between the weights of the rates the smaller the weights are,
    // the larger the supported range of each one of the rates is
    uint256 private constant EMA_AVERAGE_RATE_WEIGHT = 4;
    uint256 private constant EMA_SPOT_RATE_WEIGHT = 1;
    struct TradeIntermediateResult {
        uint256 sourceAmount;
        uint256 targetAmount;
        uint256 limit;
        uint256 tradingFeeAmount;
        uint256 networkFeeAmount;
        uint256 sourceBalance;
        uint256 targetBalance;
        uint256 stakedBalance;
        Token pool;
        bool isSourceBNT;
        bool bySourceAmount;
        uint32 tradingFeePPM;
        bytes32 contextId;
    }
    struct TradeAmountAndTradingFee {
        uint256 amount;
        uint256 tradingFeeAmount;
    }
    // the network contract
    IBancorNetwork private immutable _network;
    // the address of the BNT token
    IERC20 private immutable _bnt;
    // the network settings contract
    INetworkSettings private immutable _networkSettings;
    // the master vault contract
    IMasterVault private immutable _masterVault;
    // the BNT pool contract
    IBNTPool internal immutable _bntPool;
    // the address of the external protection vault
    IExternalProtectionVault private immutable _externalProtectionVault;
    // the pool token factory contract
    IPoolTokenFactory private immutable _poolTokenFactory;
    // the pool migrator contract
    IPoolMigrator private immutable _poolMigrator;
    // a mapping between tokens and their pools
    mapping(Token => Pool) internal _poolData;
    // the set of all pools which are managed by this pool collection
    EnumerableSet.AddressSet private _pools;
    // the default trading fee (in units of PPM)
    uint32 private _defaultTradingFeePPM;
    // the global network fee (in units of PPM)
    uint32 private _networkFeePPM;
    // true if protection is enabled, false otherwise
    bool private _protectionEnabled = true;
    /**
     * @dev triggered when the default trading fee is updated
     */
    event DefaultTradingFeePPMUpdated(uint32 prevFeePPM, uint32 newFeePPM);
    /**
     * @dev triggered when the network fee is updated
     */
    event NetworkFeePPMUpdated(uint32 prevFeePPM, uint32 newFeePPM);
    /**
     * @dev triggered when a specific pool's trading fee is updated
     */
    event TradingFeePPMUpdated(Token indexed pool, uint32 prevFeePPM, uint32 newFeePPM);
    /**
     * @dev triggered when trading in a specific pool is enabled/disabled
     */
    event TradingEnabled(Token indexed pool, bool indexed newStatus, uint8 indexed reason);
    /**
     * @dev triggered when depositing into a specific pool is enabled/disabled
     */
    event DepositingEnabled(Token indexed pool, bool indexed newStatus);
    /**
     * @dev triggered when new liquidity is deposited into a pool
     */
    event TokensDeposited(
        bytes32 indexed contextId,
        address indexed provider,
        Token indexed token,
        uint256 baseTokenAmount,
        uint256 poolTokenAmount
    );
    /**
     * @dev triggered when existing liquidity is withdrawn from a pool
     */
    event TokensWithdrawn(
        bytes32 indexed contextId,
        address indexed provider,
        Token indexed token,
        uint256 baseTokenAmount,
        uint256 poolTokenAmount,
        uint256 externalProtectionBaseTokenAmount,
        uint256 bntAmount,
        uint256 withdrawalFeeAmount
    );
    /**
     * @dev triggered when the trading liquidity in a pool is updated
     */
    event TradingLiquidityUpdated(
        bytes32 indexed contextId,
        Token indexed pool,
        Token indexed token,
        uint256 prevLiquidity,
        uint256 newLiquidity
    );
    /**
     * @dev triggered when the total liquidity in a pool is updated
     */
    event TotalLiquidityUpdated(
        bytes32 indexed contextId,
        Token indexed pool,
        uint256 liquidity,
        uint256 stakedBalance,
        uint256 poolTokenSupply
    );
    /**
     * @dev initializes a new PoolCollection contract
     */
    constructor(
        IBancorNetwork initNetwork,
        IERC20 initBNT,
        INetworkSettings initNetworkSettings,
        IMasterVault initMasterVault,
        IBNTPool initBNTPool,
        IExternalProtectionVault initExternalProtectionVault,
        IPoolTokenFactory initPoolTokenFactory,
        IPoolMigrator initPoolMigrator
    ) {
        _validAddress(address(initNetwork));
        _validAddress(address(initBNT));
        _validAddress(address(initNetworkSettings));
        _validAddress(address(initMasterVault));
        _validAddress(address(initBNTPool));
        _validAddress(address(initExternalProtectionVault));
        _validAddress(address(initPoolTokenFactory));
        _validAddress(address(initPoolMigrator));
        _network = initNetwork;
        _bnt = initBNT;
        _networkSettings = initNetworkSettings;
        _masterVault = initMasterVault;
        _bntPool = initBNTPool;
        _externalProtectionVault = initExternalProtectionVault;
        _poolTokenFactory = initPoolTokenFactory;
        _poolMigrator = initPoolMigrator;
        _setDefaultTradingFeePPM(DEFAULT_TRADING_FEE_PPM);
        _setNetworkFeePPM(DEFAULT_NETWORK_FEE_PPM);
    }
    /**
     * @inheritdoc IVersioned
     */
    function version() external view virtual returns (uint16) {
        return 10;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolType() external view virtual returns (uint16) {
        return POOL_TYPE;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function defaultTradingFeePPM() external view returns (uint32) {
        return _defaultTradingFeePPM;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function networkFeePPM() external view returns (uint32) {
        return _networkFeePPM;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function pools() external view returns (Token[] memory) {
        uint256 length = _pools.length();
        Token[] memory list = new Token[](length);
        for (uint256 i = 0; i < length; i++) {
            list[i] = Token(_pools.at(i));
        }
        return list;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolCount() external view returns (uint256) {
        return _pools.length();
    }
    /**
     * @dev sets the default trading fee (in units of PPM)
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function setDefaultTradingFeePPM(uint32 newDefaultTradingFeePPM)
        external
        onlyOwner
        validFee(newDefaultTradingFeePPM)
    {
        _setDefaultTradingFeePPM(newDefaultTradingFeePPM);
    }
    /**
     * @dev sets the network fee (in units of PPM)
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function setNetworkFeePPM(uint32 newNetworkFeePPM) external onlyOwner validFee(newNetworkFeePPM) {
        _setNetworkFeePPM(newNetworkFeePPM);
    }
    /**
     * @dev enables/disables protection
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function enableProtection(bool status) external onlyOwner {
        if (_protectionEnabled == status) {
            return;
        }
        _protectionEnabled = status;
    }
    /**
     * @dev returns the status of the protection
     */
    function protectionEnabled() external view returns (bool) {
        return _protectionEnabled;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function createPool(Token token) external only(address(_network)) {
        if (!_networkSettings.isTokenWhitelisted(token)) {
            revert NotWhitelisted();
        }
        IPoolToken newPoolToken = IPoolToken(_poolTokenFactory.createPoolToken(token));
        newPoolToken.acceptOwnership();
        Pool memory newPool = Pool({
            poolToken: newPoolToken,
            tradingFeePPM: _defaultTradingFeePPM,
            tradingEnabled: false,
            depositingEnabled: true,
            averageRates: AverageRates({ blockNumber: 0, rate: zeroFraction112(), invRate: zeroFraction112() }),
            liquidity: PoolLiquidity({ bntTradingLiquidity: 0, baseTokenTradingLiquidity: 0, stakedBalance: 0 })
        });
        _addPool(token, newPool);
        emit TradingEnabled({ pool: token, newStatus: newPool.tradingEnabled, reason: TRADING_STATUS_UPDATE_DEFAULT });
        emit TradingFeePPMUpdated({ pool: token, prevFeePPM: 0, newFeePPM: newPool.tradingFeePPM });
        emit DepositingEnabled({ pool: token, newStatus: newPool.depositingEnabled });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function isPoolValid(Token pool) external view returns (bool) {
        return address(_poolData[pool].poolToken) != address(0);
    }
    /**
     * @dev returns specific pool's data
     *
     * notes:
     *
     * - there is no guarantee that this function will remain forward compatible,
     *   so relying on it should be avoided and instead, rely on specific getters
     *   from the IPoolCollection interface
     */
    function poolData(Token pool) external view returns (Pool memory) {
        return _poolData[pool];
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolLiquidity(Token pool) external view returns (PoolLiquidity memory) {
        return _poolData[pool].liquidity;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolToken(Token pool) external view returns (IPoolToken) {
        return _poolData[pool].poolToken;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradingFeePPM(Token pool) external view returns (uint32) {
        return _poolData[pool].tradingFeePPM;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradingEnabled(Token pool) external view returns (bool) {
        return _poolData[pool].tradingEnabled;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function depositingEnabled(Token pool) external view returns (bool) {
        return _poolData[pool].depositingEnabled;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolTokenToUnderlying(Token pool, uint256 poolTokenAmount) external view returns (uint256) {
        Pool storage data = _poolData[pool];
        return _poolTokenToUnderlying(poolTokenAmount, data.poolToken.totalSupply(), data.liquidity.stakedBalance);
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function underlyingToPoolToken(Token pool, uint256 baseTokenAmount) external view returns (uint256) {
        Pool storage data = _poolData[pool];
        return _underlyingToPoolToken(baseTokenAmount, data.poolToken.totalSupply(), data.liquidity.stakedBalance);
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function poolTokenAmountToBurn(
        Token pool,
        uint256 baseTokenAmountToDistribute,
        uint256 protocolPoolTokenAmount
    ) external view returns (uint256) {
        if (baseTokenAmountToDistribute == 0) {
            return 0;
        }
        Pool storage data = _poolData[pool];
        uint256 poolTokenSupply = data.poolToken.totalSupply();
        uint256 val = baseTokenAmountToDistribute * poolTokenSupply;
        return
            MathEx.mulDivF(
                val,
                poolTokenSupply,
                val + data.liquidity.stakedBalance * (poolTokenSupply - protocolPoolTokenAmount)
            );
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function isPoolStable(Token pool) external view returns (bool) {
        Pool storage data = _poolData[pool];
        return _poolRateState(data) == PoolRateState.Stable;
    }
    /**
     * @dev sets the trading fee of a given pool
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function setTradingFeePPM(Token pool, uint32 newTradingFeePPM) external onlyOwner validFee(newTradingFeePPM) {
        Pool storage data = _poolStorage(pool);
        uint32 prevTradingFeePPM = data.tradingFeePPM;
        if (prevTradingFeePPM == newTradingFeePPM) {
            return;
        }
        data.tradingFeePPM = newTradingFeePPM;
        emit TradingFeePPMUpdated({ pool: pool, prevFeePPM: prevTradingFeePPM, newFeePPM: newTradingFeePPM });
    }
    /**
     * @dev enables trading in a given pool, by providing the funding rate as two virtual balances, and updates its
     * trading liquidity
     *
     * note that the virtual balances should be derived from token prices, normalized to the smallest unit of
     * tokens. In other words, the ratio between BNT and TKN virtual balances should be the ratio between the $ value
     * of 1 wei of TKN and 1 wei of BNT, taking both of their decimals into account. For example:
     *
     * - if the price of one (10**18 wei) BNT is $X and the price of one (10**18 wei) TKN is $Y, then the virtual balances
     *   should represent a ratio of X to Y
     * - if the price of one (10**18 wei) BNT is $X and the price of one (10**6 wei) USDC is $Y, then the virtual balances
     *   should represent a ratio of X to Y*10**12
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function enableTrading(
        Token pool,
        uint256 bntVirtualBalance,
        uint256 baseTokenVirtualBalance
    ) external onlyOwner {
        Fraction memory fundingRate = Fraction({ n: bntVirtualBalance, d: baseTokenVirtualBalance });
        _validRate(fundingRate);
        Pool storage data = _poolStorage(pool);
        if (data.tradingEnabled) {
            revert AlreadyEnabled();
        }
        // adjust the trading liquidity based on the base token vault balance and funding limits
        bytes32 contextId = keccak256(abi.encodePacked(msg.sender, pool, bntVirtualBalance, baseTokenVirtualBalance));
        uint256 minLiquidityForTrading = _networkSettings.minLiquidityForTrading();
        _updateTradingLiquidity(contextId, pool, data, fundingRate, minLiquidityForTrading);
        // verify that the BNT trading liquidity is equal or greater than the minimum liquidity for trading
        if (data.liquidity.bntTradingLiquidity < minLiquidityForTrading) {
            revert InsufficientLiquidity();
        }
        Fraction112 memory fundingRate112 = fundingRate.toFraction112();
        data.averageRates = AverageRates({
            blockNumber: _blockNumber(),
            rate: fundingRate112,
            invRate: fundingRate112.inverse()
        });
        data.tradingEnabled = true;
        emit TradingEnabled({ pool: pool, newStatus: true, reason: TRADING_STATUS_UPDATE_ADMIN });
    }
    /**
     * @dev disables trading in a given pool
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function disableTrading(Token pool) external onlyOwner {
        Pool storage data = _poolStorage(pool);
        _resetTradingLiquidity(bytes32(0), pool, data, data.liquidity, TRADING_STATUS_UPDATE_ADMIN);
    }
    /**
     * @dev adjusts the trading liquidity in the given pool based on the base token
     * vault balance/funding limit
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function updateTradingLiquidity(Token pool) external onlyOwner {
        Pool storage data = _poolStorage(pool);
        PoolLiquidity memory liquidity = data.liquidity;
        bytes32 contextId = keccak256(
            abi.encodePacked(msg.sender, pool, liquidity.bntTradingLiquidity, liquidity.baseTokenTradingLiquidity)
        );
        AverageRates memory effectiveAverageRates = _effectiveAverageRates(
            data.averageRates,
            Fraction({ n: liquidity.bntTradingLiquidity, d: liquidity.baseTokenTradingLiquidity })
        );
        uint256 minLiquidityForTrading = _networkSettings.minLiquidityForTrading();
        _updateTradingLiquidity(
            contextId,
            pool,
            data,
            effectiveAverageRates.rate.fromFraction112(),
            minLiquidityForTrading
        );
    }
    /**
     * @dev enables/disables depositing into a given pool
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function enableDepositing(Token pool, bool status) external onlyOwner {
        Pool storage data = _poolStorage(pool);
        if (data.depositingEnabled == status) {
            return;
        }
        data.depositingEnabled = status;
        emit DepositingEnabled({ pool: pool, newStatus: status });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 baseTokenAmount
    ) external only(address(_network)) validAddress(provider) greaterThanZero(baseTokenAmount) returns (uint256) {
        Pool storage data = _poolStorage(pool);
        if (!data.depositingEnabled) {
            revert DepositingDisabled();
        }
        // if there are no pool tokens available to support the staked balance - reset the
        // trading liquidity and the staked balance
        // in addition, get the effective average rates
        uint256 prevPoolTokenTotalSupply = data.poolToken.totalSupply();
        uint256 currentStakedBalance = data.liquidity.stakedBalance;
        AverageRates memory effectiveAverageRates;
        if (prevPoolTokenTotalSupply == 0 && currentStakedBalance != 0) {
            currentStakedBalance = 0;
            PoolLiquidity memory prevLiquidity = data.liquidity;
            _resetTradingLiquidity(contextId, pool, data, prevLiquidity, TRADING_STATUS_UPDATE_INVALID_STATE);
            effectiveAverageRates = AverageRates({
                blockNumber: 0,
                rate: zeroFraction112(),
                invRate: zeroFraction112()
            });
        } else {
            PoolLiquidity memory prevLiquidity = data.liquidity;
            effectiveAverageRates = _effectiveAverageRates(
                data.averageRates,
                Fraction({ n: prevLiquidity.bntTradingLiquidity, d: prevLiquidity.baseTokenTradingLiquidity })
            );
        }
        // calculate the pool token amount to mint
        uint256 poolTokenAmount = _underlyingToPoolToken(
            baseTokenAmount,
            prevPoolTokenTotalSupply,
            currentStakedBalance
        );
        // update the staked balance with the full base token amount
        data.liquidity.stakedBalance = currentStakedBalance + baseTokenAmount;
        // mint pool tokens to the provider
        data.poolToken.mint(provider, poolTokenAmount);
        // should be triggered before the trading liquidity is updated
        emit TokensDeposited({
            contextId: contextId,
            provider: provider,
            token: pool,
            baseTokenAmount: baseTokenAmount,
            poolTokenAmount: poolTokenAmount
        });
        emit TotalLiquidityUpdated({
            contextId: contextId,
            pool: pool,
            liquidity: pool.balanceOf(address(_masterVault)),
            stakedBalance: data.liquidity.stakedBalance,
            poolTokenSupply: prevPoolTokenTotalSupply + poolTokenAmount
        });
        // adjust the trading liquidity based on the base token vault balance and funding limits
        _updateTradingLiquidity(
            contextId,
            pool,
            data,
            effectiveAverageRates.rate.fromFraction112(),
            _networkSettings.minLiquidityForTrading()
        );
        // if trading is enabled, then update the recent average rates
        if (data.tradingEnabled) {
            PoolLiquidity memory liquidity = data.liquidity;
            _updateAverageRates(
                data,
                Fraction({ n: liquidity.bntTradingLiquidity, d: liquidity.baseTokenTradingLiquidity })
            );
        }
        return poolTokenAmount;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 poolTokenAmount,
        uint256 baseTokenAmount
    )
        external
        only(address(_network))
        validAddress(provider)
        greaterThanZero(poolTokenAmount)
        greaterThanZero(baseTokenAmount)
        returns (uint256)
    {
        Pool storage data = _poolStorage(pool);
        PoolLiquidity memory liquidity = data.liquidity;
        uint256 poolTokenTotalSupply = data.poolToken.totalSupply();
        uint256 underlyingAmount = _poolTokenToUnderlying(
            poolTokenAmount,
            poolTokenTotalSupply,
            liquidity.stakedBalance
        );
        if (baseTokenAmount > underlyingAmount) {
            revert InvalidParam();
        }
        if (_poolRateState(data) == PoolRateState.Unstable) {
            revert RateUnstable();
        }
        // obtain the withdrawal amounts
        InternalWithdrawalAmounts memory amounts = _poolWithdrawalAmounts(
            pool,
            poolTokenAmount,
            baseTokenAmount,
            liquidity,
            data.tradingFeePPM,
            poolTokenTotalSupply
        );
        // execute the actual withdrawal
        _executeWithdrawal(contextId, provider, pool, data, amounts);
        // if trading is enabled, then update the recent average rates
        if (data.tradingEnabled) {
            _updateAverageRates(
                data,
                Fraction({ n: data.liquidity.bntTradingLiquidity, d: data.liquidity.baseTokenTradingLiquidity })
            );
        }
        return amounts.baseTokensToTransferFromMasterVault;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function withdrawalAmounts(Token pool, uint256 poolTokenAmount)
        external
        view
        validAddress(address(pool))
        greaterThanZero(poolTokenAmount)
        returns (WithdrawalAmounts memory)
    {
        Pool storage data = _poolData[pool];
        PoolLiquidity memory liquidity = data.liquidity;
        uint256 poolTokenTotalSupply = data.poolToken.totalSupply();
        uint256 underlyingAmount = _poolTokenToUnderlying(
            poolTokenAmount,
            poolTokenTotalSupply,
            liquidity.stakedBalance
        );
        InternalWithdrawalAmounts memory amounts = _poolWithdrawalAmounts(
            pool,
            poolTokenAmount,
            underlyingAmount,
            liquidity,
            data.tradingFeePPM,
            poolTokenTotalSupply
        );
        return
            WithdrawalAmounts({
                totalAmount: amounts.baseTokensWithdrawalAmount - amounts.baseTokensWithdrawalFee,
                baseTokenAmount: amounts.baseTokensToTransferFromMasterVault + amounts.baseTokensToTransferFromEPV,
                bntAmount: _protectionEnabled ? amounts.bntToMintForProvider : 0
            });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradeBySourceAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount
    )
        external
        only(address(_network))
        greaterThanZero(sourceAmount)
        greaterThanZero(minReturnAmount)
        returns (TradeAmountAndFee memory)
    {
        TradeIntermediateResult memory result = _initTrade(
            contextId,
            sourceToken,
            targetToken,
            sourceAmount,
            minReturnAmount,
            true
        );
        _performTrade(result);
        return
            TradeAmountAndFee({
                amount: result.targetAmount,
                tradingFeeAmount: result.tradingFeeAmount,
                networkFeeAmount: result.networkFeeAmount
            });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradeByTargetAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount
    )
        external
        only(address(_network))
        greaterThanZero(targetAmount)
        greaterThanZero(maxSourceAmount)
        returns (TradeAmountAndFee memory)
    {
        TradeIntermediateResult memory result = _initTrade(
            contextId,
            sourceToken,
            targetToken,
            targetAmount,
            maxSourceAmount,
            false
        );
        _performTrade(result);
        return
            TradeAmountAndFee({
                amount: result.sourceAmount,
                tradingFeeAmount: result.tradingFeeAmount,
                networkFeeAmount: result.networkFeeAmount
            });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradeOutputAndFeeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount
    ) external view greaterThanZero(sourceAmount) returns (TradeAmountAndFee memory) {
        TradeIntermediateResult memory result = _initTrade(bytes32(0), sourceToken, targetToken, sourceAmount, 1, true);
        _processTrade(result);
        return
            TradeAmountAndFee({
                amount: result.targetAmount,
                tradingFeeAmount: result.tradingFeeAmount,
                networkFeeAmount: result.networkFeeAmount
            });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function tradeInputAndFeeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount
    ) external view greaterThanZero(targetAmount) returns (TradeAmountAndFee memory) {
        TradeIntermediateResult memory result = _initTrade(
            bytes32(0),
            sourceToken,
            targetToken,
            targetAmount,
            type(uint256).max,
            false
        );
        _processTrade(result);
        return
            TradeAmountAndFee({
                amount: result.sourceAmount,
                tradingFeeAmount: result.tradingFeeAmount,
                networkFeeAmount: result.networkFeeAmount
            });
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function onFeesCollected(Token pool, uint256 feeAmount) external only(address(_network)) {
        if (feeAmount == 0) {
            return;
        }
        Pool storage data = _poolStorage(pool);
        // increase the staked balance by the given amount
        data.liquidity.stakedBalance += feeAmount;
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function migratePoolIn(Token pool, Pool calldata data)
        external
        validAddress(address(pool))
        only(address(_poolMigrator))
    {
        _addPool(pool, data);
        data.poolToken.acceptOwnership();
    }
    /**
     * @inheritdoc IPoolCollection
     */
    function migratePoolOut(Token pool, IPoolCollection targetPoolCollection)
        external
        validAddress(address(targetPoolCollection))
        only(address(_poolMigrator))
    {
        IPoolToken cachedPoolToken = _poolData[pool].poolToken;
        _removePool(pool);
        cachedPoolToken.transferOwnership(address(targetPoolCollection));
    }
    /**
     * @dev adds a pool
     */
    function _addPool(Token pool, Pool memory data) private {
        if (!_pools.add(address(pool))) {
            revert AlreadyExists();
        }
        _poolData[pool] = data;
    }
    /**
     * @dev removes a pool
     */
    function _removePool(Token pool) private {
        if (!_pools.remove(address(pool))) {
            revert DoesNotExist();
        }
        delete _poolData[pool];
    }
    /**
     * @dev returns withdrawal amounts
     */
    function _poolWithdrawalAmounts(
        Token pool,
        uint256 poolTokenAmount,
        uint256 baseTokensWithdrawalAmount,
        PoolLiquidity memory liquidity,
        uint32 poolTradingFeePPM,
        uint256 poolTokenTotalSupply
    ) internal view returns (InternalWithdrawalAmounts memory) {
        // the base token trading liquidity of a given pool can never be higher than the base token balance of the vault
        // whenever the base token trading liquidity is updated, it is set to at most the base token balance of the vault
        uint256 baseTokenExcessAmount = pool.balanceOf(address(_masterVault)) - liquidity.baseTokenTradingLiquidity;
        PoolCollectionWithdrawal.Output memory output = PoolCollectionWithdrawal.calculateWithdrawalAmounts(
            liquidity.bntTradingLiquidity,
            liquidity.baseTokenTradingLiquidity,
            baseTokenExcessAmount,
            liquidity.stakedBalance,
            pool.balanceOf(address(_externalProtectionVault)),
            poolTradingFeePPM,
            _networkSettings.withdrawalFeePPM(),
            baseTokensWithdrawalAmount
        );
        return
            InternalWithdrawalAmounts({
                baseTokensToTransferFromMasterVault: output.s,
                bntToMintForProvider: output.t,
                baseTokensToTransferFromEPV: output.u,
                baseTokensTradingLiquidityDelta: output.r,
                bntTradingLiquidityDelta: output.p,
                bntProtocolHoldingsDelta: output.q,
                baseTokensWithdrawalFee: output.v,
                baseTokensWithdrawalAmount: baseTokensWithdrawalAmount,
                poolTokenAmount: poolTokenAmount,
                poolTokenTotalSupply: poolTokenTotalSupply,
                newBaseTokenTradingLiquidity: output.r.isNeg
                    ? liquidity.baseTokenTradingLiquidity - output.r.value
                    : liquidity.baseTokenTradingLiquidity + output.r.value,
                newBNTTradingLiquidity: output.p.isNeg
                    ? liquidity.bntTradingLiquidity - output.p.value
                    : liquidity.bntTradingLiquidity + output.p.value
            });
    }
    /**
     * @dev executes the following actions:
     *
     * - burn the network's base pool tokens
     * - update the pool's base token staked balance
     * - update the pool's base token trading liquidity
     * - update the pool's BNT trading liquidity
     * - update the pool's trading liquidity product
     * - emit an event if the pool's BNT trading liquidity has crossed the minimum threshold
     *   (either above the threshold or below the threshold)
     */
    function _executeWithdrawal(
        bytes32 contextId,
        address provider,
        Token pool,
        Pool storage data,
        InternalWithdrawalAmounts memory amounts
    ) private {
        PoolLiquidity storage liquidity = data.liquidity;
        PoolLiquidity memory prevLiquidity = liquidity;
        data.poolToken.burn(amounts.poolTokenAmount);
        uint256 newPoolTokenTotalSupply = amounts.poolTokenTotalSupply - amounts.poolTokenAmount;
        uint256 newStakedBalance = MathEx.mulDivF(
            liquidity.stakedBalance,
            newPoolTokenTotalSupply,
            amounts.poolTokenTotalSupply
        );
        liquidity.stakedBalance = newStakedBalance;
        // trading liquidity is assumed to never exceed 128 bits (the cast below will revert otherwise)
        liquidity.baseTokenTradingLiquidity = amounts.newBaseTokenTradingLiquidity.toUint128();
        liquidity.bntTradingLiquidity = amounts.newBNTTradingLiquidity.toUint128();
        if (amounts.bntProtocolHoldingsDelta.value > 0) {
            assert(amounts.bntProtocolHoldingsDelta.isNeg); // currently no support for requesting funding here
            _bntPool.renounceFunding(contextId, pool, amounts.bntProtocolHoldingsDelta.value);
        } else if (amounts.bntTradingLiquidityDelta.value > 0) {
            if (amounts.bntTradingLiquidityDelta.isNeg) {
                _bntPool.burnFromVault(amounts.bntTradingLiquidityDelta.value);
            } else {
                _bntPool.mint(address(_masterVault), amounts.bntTradingLiquidityDelta.value);
            }
        }
        // if the provider should receive some BNT - ask the BNT pool to mint BNT to the provider
        bool isProtectionEnabled = _protectionEnabled;
        if (amounts.bntToMintForProvider > 0 && isProtectionEnabled) {
            _bntPool.mint(address(provider), amounts.bntToMintForProvider);
        }
        // if the provider should receive some base tokens from the external protection vault - remove the tokens from
        // the external protection vault and send them to the master vault
        if (amounts.baseTokensToTransferFromEPV > 0) {
            _externalProtectionVault.withdrawFunds(
                pool,
                payable(address(_masterVault)),
                amounts.baseTokensToTransferFromEPV
            );
            amounts.baseTokensToTransferFromMasterVault += amounts.baseTokensToTransferFromEPV;
        }
        // if the provider should receive some base tokens from the master vault - remove the tokens from the master
        // vault and send them to the provider
        if (amounts.baseTokensToTransferFromMasterVault > 0) {
            _masterVault.withdrawFunds(pool, payable(provider), amounts.baseTokensToTransferFromMasterVault);
        }
        // ensure that the average rate is reset when the pool is being emptied
        if (amounts.newBaseTokenTradingLiquidity == 0) {
            data.averageRates.rate = zeroFraction112();
            data.averageRates.invRate = zeroFraction112();
        }
        // if the new BNT trading liquidity is below the minimum liquidity for trading - reset the liquidity
        if (amounts.newBNTTradingLiquidity < _networkSettings.minLiquidityForTrading()) {
            _resetTradingLiquidity(
                contextId,
                pool,
                data,
                prevLiquidity,
                amounts.newBNTTradingLiquidity,
                TRADING_STATUS_UPDATE_MIN_LIQUIDITY
            );
        } else {
            _dispatchTradingLiquidityEvents(contextId, pool, prevLiquidity, liquidity);
        }
        emit TokensWithdrawn({
            contextId: contextId,
            provider: provider,
            token: pool,
            baseTokenAmount: amounts.baseTokensToTransferFromMasterVault,
            poolTokenAmount: amounts.poolTokenAmount,
            externalProtectionBaseTokenAmount: amounts.baseTokensToTransferFromEPV,
            bntAmount: isProtectionEnabled ? amounts.bntToMintForProvider : 0,
            withdrawalFeeAmount: amounts.baseTokensWithdrawalFee
        });
        emit TotalLiquidityUpdated({
            contextId: contextId,
            pool: pool,
            liquidity: pool.balanceOf(address(_masterVault)),
            stakedBalance: newStakedBalance,
            poolTokenSupply: newPoolTokenTotalSupply
        });
    }
    /**
     * @dev sets the default trading fee (in units of PPM)
     */
    function _setDefaultTradingFeePPM(uint32 newDefaultTradingFeePPM) private {
        uint32 prevDefaultTradingFeePPM = _defaultTradingFeePPM;
        if (prevDefaultTradingFeePPM == newDefaultTradingFeePPM) {
            return;
        }
        _defaultTradingFeePPM = newDefaultTradingFeePPM;
        emit DefaultTradingFeePPMUpdated({ prevFeePPM: prevDefaultTradingFeePPM, newFeePPM: newDefaultTradingFeePPM });
    }
    /**
     * @dev sets the network fee (in units of PPM)
     */
    function _setNetworkFeePPM(uint32 newNetworkFeePPM) private {
        uint32 prevNetworkFeePPM = _networkFeePPM;
        if (prevNetworkFeePPM == newNetworkFeePPM) {
            return;
        }
        _networkFeePPM = newNetworkFeePPM;
        emit NetworkFeePPMUpdated({ prevFeePPM: prevNetworkFeePPM, newFeePPM: newNetworkFeePPM });
    }
    /**
     * @dev returns a storage reference to pool data
     */
    function _poolStorage(Token pool) private view returns (Pool storage) {
        Pool storage data = _poolData[pool];
        if (address(data.poolToken) == address(0)) {
            revert DoesNotExist();
        }
        return data;
    }
    /**
     * @dev calculates base tokens amount
     */
    function _poolTokenToUnderlying(
        uint256 poolTokenAmount,
        uint256 poolTokenSupply,
        uint256 stakedBalance
    ) private pure returns (uint256) {
        if (poolTokenSupply == 0) {
            // if this is the initial liquidity provision - use a one-to-one pool token to base token rate
            if (stakedBalance > 0) {
                revert InvalidStakedBalance();
            }
            return poolTokenAmount;
        }
        return MathEx.mulDivF(poolTokenAmount, stakedBalance, poolTokenSupply);
    }
    /**
     * @dev calculates pool tokens amount
     */
    function _underlyingToPoolToken(
        uint256 baseTokenAmount,
        uint256 poolTokenSupply,
        uint256 stakedBalance
    ) private pure returns (uint256) {
        if (poolTokenSupply == 0) {
            // if this is the initial liquidity provision - use a one-to-one pool token to base token rate
            if (stakedBalance > 0) {
                revert InvalidStakedBalance();
            }
            return baseTokenAmount;
        }
        return MathEx.mulDivC(baseTokenAmount, poolTokenSupply, stakedBalance);
    }
    /**
     * @dev calculates the target trading liquidities, taking into account the total out-of-curve base token liquidity,
     * and the deltas between the new and the previous states
     */
    function _calcTargetTradingLiquidity(
        uint256 baseTokenTotalLiquidity,
        uint256 fundingLimit,
        uint256 currentFunding,
        PoolLiquidity memory liquidity,
        Fraction memory fundingRate,
        uint256 minLiquidityForTrading
    ) private pure returns (TargetTradingLiquidity memory) {
        // calculate the target BNT trading liquidity based on the following:
        // - BNT liquidity required to match the based token unused (off-curve) liquidity
        // - BNT funding limit
        // - current BNT funding
        uint256 targetBNTTradingLiquidity = liquidity.bntTradingLiquidity;
        if (fundingLimit > currentFunding) {
            // increase the trading liquidity
            uint256 availableFunding = fundingLimit - currentFunding;
            uint256 baseTokenUnusedLiquidity = baseTokenTotalLiquidity - liquidity.baseTokenTradingLiquidity;
            uint256 targetBNTTradingLiquidityDelta = Math.min(
                MathEx.mulDivF(baseTokenUnusedLiquidity, fundingRate.n, fundingRate.d),
                availableFunding
            );
            targetBNTTradingLiquidity = liquidity.bntTradingLiquidity + targetBNTTradingLiquidityDelta;
        } else if (fundingLimit < currentFunding) {
            // decrease the trading liquidity
            uint256 excessFunding = currentFunding - fundingLimit;
            targetBNTTradingLiquidity = MathEx.subMax0(liquidity.bntTradingLiquidity, excessFunding);
        }
        // if the target is equal to the current trading liquidity, no update is needed
        if (targetBNTTradingLiquidity == liquidity.bntTradingLiquidity) {
            return TargetTradingLiquidity({ update: false, bnt: 0, baseToken: 0 });
        }
        // ensure that the target is above the minimum liquidity for trading
        if (targetBNTTradingLiquidity < minLiquidityForTrading) {
            return TargetTradingLiquidity({ update: true, bnt: 0, baseToken: 0 });
        }
        // calculate the target base token trading liquidity using the following:
        // - calculate the delta between the current/target BNT trading liquidity
        // - calculate the base token trading liquidity delta based on the BNT trading liquidity delta and the funding rate
        // - apply the base token trading liquidity delta to the current base token trading liquidity
        //
        // note that the effective funding rate is always the rate between BNT and the base token)
        uint256 bntTradingLiquidityDelta;
        uint256 baseTokenTradingLiquidityDelta;
        // liquidity increase
        // note that liquidity increase is capped
        if (targetBNTTradingLiquidity > liquidity.bntTradingLiquidity) {
            uint256 tradingLiquidityCap;
            if (liquidity.bntTradingLiquidity == 0) {
                // the current BNT trading liquidity is 0 - cap the target trading liquidity
                // by the default bootstrap amount, which includes a buffer to reduce the chance
                // for trading to be disabled as a result of trades in the pool
                tradingLiquidityCap = minLiquidityForTrading * BOOTSTRAPPING_LIQUIDITY_BUFFER_FACTOR;
            } else {
                // the current BNT trading liquidity is not 0 - cap the target using the growth factor
                tradingLiquidityCap = liquidity.bntTradingLiquidity * LIQUIDITY_GROWTH_FACTOR;
            }
            // apply the trading liquidity cap
            targetBNTTradingLiquidity = Math.min(targetBNTTradingLiquidity, tradingLiquidityCap);
            // calculate the trading liquidity deltas and return them
            bntTradingLiquidityDelta = targetBNTTradingLiquidity - liquidity.bntTradingLiquidity;
            baseTokenTradingLiquidityDelta = MathEx.mulDivF(bntTradingLiquidityDelta, fundingRate.d, fundingRate.n);
            return
                TargetTradingLiquidity({
                    update: true,
                    bnt: targetBNTTradingLiquidity,
                    baseToken: liquidity.baseTokenTradingLiquidity + baseTokenTradingLiquidityDelta
                });
        }
        // liquidity decrease
        // note that liquidity decrease isn't capped
        // calculate the trading liquidity deltas and return them
        bntTradingLiquidityDelta = liquidity.bntTradingLiquidity - targetBNTTradingLiquidity;
        baseTokenTradingLiquidityDelta = MathEx.mulDivF(bntTradingLiquidityDelta, fundingRate.d, fundingRate.n);
        return
            TargetTradingLiquidity({
                update: true,
                bnt: targetBNTTradingLiquidity,
                baseToken: MathEx.subMax0(liquidity.baseTokenTradingLiquidity, baseTokenTradingLiquidityDelta)
            });
    }
    /**
     * @dev adjusts the trading liquidity based on the newly added tokens delta amount, and funding limits
     */
    function _updateTradingLiquidity(
        bytes32 contextId,
        Token pool,
        Pool storage data,
        Fraction memory fundingRate,
        uint256 minLiquidityForTrading
    ) private {
        // ensure that the base token reserve isn't empty
        uint256 baseTokenTotalLiquidity = pool.balanceOf(address(_masterVault));
        if (baseTokenTotalLiquidity == 0) {
            revert InsufficientLiquidity();
        }
        if (_poolRateState(data) == PoolRateState.Unstable) {
            return;
        }
        PoolLiquidity memory prevLiquidity = data.liquidity;
        if (!fundingRate.isPositive()) {
            _resetTradingLiquidity(contextId, pool, data, prevLiquidity, TRADING_STATUS_UPDATE_MIN_LIQUIDITY);
            return;
        }
        TargetTradingLiquidity memory targetTradingLiquidity = _calcTargetTradingLiquidity(
            baseTokenTotalLiquidity,
            _networkSettings.poolFundingLimit(pool),
            _bntPool.currentPoolFunding(pool),
            prevLiquidity,
            fundingRate,
            minLiquidityForTrading
        );
        if (!targetTradingLiquidity.update) {
            return;
        }
        if (targetTradingLiquidity.bnt == 0 || targetTradingLiquidity.baseToken == 0) {
            _resetTradingLiquidity(contextId, pool, data, prevLiquidity, TRADING_STATUS_UPDATE_MIN_LIQUIDITY);
            return;
        }
        // update funding from the BNT pool
        if (targetTradingLiquidity.bnt > prevLiquidity.bntTradingLiquidity) {
            _bntPool.requestFunding(contextId, pool, targetTradingLiquidity.bnt - prevLiquidity.bntTradingLiquidity);
        } else if (targetTradingLiquidity.bnt < prevLiquidity.bntTradingLiquidity) {
            _bntPool.renounceFunding(contextId, pool, prevLiquidity.bntTradingLiquidity - targetTradingLiquidity.bnt);
        }
        // trading liquidity is assumed to never exceed 128 bits (the cast below will revert otherwise)
        PoolLiquidity memory newLiquidity = PoolLiquidity({
            bntTradingLiquidity: targetTradingLiquidity.bnt.toUint128(),
            baseTokenTradingLiquidity: targetTradingLiquidity.baseToken.toUint128(),
            stakedBalance: prevLiquidity.stakedBalance
        });
        // update the liquidity data of the pool
        data.liquidity = newLiquidity;
        _dispatchTradingLiquidityEvents(contextId, pool, prevLiquidity, newLiquidity);
    }
    function _dispatchTradingLiquidityEvents(
        bytes32 contextId,
        Token pool,
        PoolLiquidity memory prevLiquidity,
        PoolLiquidity memory newLiquidity
    ) private {
        if (newLiquidity.bntTradingLiquidity != prevLiquidity.bntTradingLiquidity) {
            emit TradingLiquidityUpdated({
                contextId: contextId,
                pool: pool,
                token: Token(address(_bnt)),
                prevLiquidity: prevLiquidity.bntTradingLiquidity,
                newLiquidity: newLiquidity.bntTradingLiquidity
            });
        }
        if (newLiquidity.baseTokenTradingLiquidity != prevLiquidity.baseTokenTradingLiquidity) {
            emit TradingLiquidityUpdated({
                contextId: contextId,
                pool: pool,
                token: pool,
                prevLiquidity: prevLiquidity.baseTokenTradingLiquidity,
                newLiquidity: newLiquidity.baseTokenTradingLiquidity
            });
        }
    }
    /**
     * @dev resets trading liquidity and renounces any remaining BNT funding
     */
    function _resetTradingLiquidity(
        bytes32 contextId,
        Token pool,
        Pool storage data,
        PoolLiquidity memory prevLiquidity,
        uint8 reason
    ) private {
        _resetTradingLiquidity(contextId, pool, data, prevLiquidity, data.liquidity.bntTradingLiquidity, reason);
    }
    /**
     * @dev resets trading liquidity and renounces any remaining BNT funding
     */
    function _resetTradingLiquidity(
        bytes32 contextId,
        Token pool,
        Pool storage data,
        PoolLiquidity memory prevLiquidity,
        uint256 currentBNTTradingLiquidity,
        uint8 reason
    ) private {
        // reset the network and base token trading liquidities
        data.liquidity.bntTradingLiquidity = 0;
        data.liquidity.baseTokenTradingLiquidity = 0;
        // reset the recent average rage
        data.averageRates = AverageRates({ blockNumber: 0, rate: zeroFraction112(), invRate: zeroFraction112() });
        // ensure that trading is disabled
        if (data.tradingEnabled) {
            data.tradingEnabled = false;
            emit TradingEnabled({ pool: pool, newStatus: false, reason: reason });
        }
        // renounce all network liquidity
        if (currentBNTTradingLiquidity > 0) {
            _bntPool.renounceFunding(contextId, pool, currentBNTTradingLiquidity);
        }
        _dispatchTradingLiquidityEvents(contextId, pool, prevLiquidity, data.liquidity);
    }
    /**
     * @dev returns initial trading params
     */
    function _initTrade(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 amount,
        uint256 limit,
        bool bySourceAmount
    ) private view returns (TradeIntermediateResult memory result) {
        // ensure that BNT is either the source or the target token
        bool isSourceBNT = sourceToken.isEqual(_bnt);
        bool isTargetBNT = targetToken.isEqual(_bnt);
        if (isSourceBNT && !isTargetBNT) {
            result.isSourceBNT = true;
            result.pool = targetToken;
        } else if (!isSourceBNT && isTargetBNT) {
            result.isSourceBNT = false;
            result.pool = sourceToken;
        } else {
            // BNT isn't one of the tokens or is both of them
            revert DoesNotExist();
        }
        Pool storage data = _poolStorage(result.pool);
        // verify that trading is enabled
        if (!data.tradingEnabled) {
            revert TradingDisabled();
        }
        result.contextId = contextId;
        result.bySourceAmount = bySourceAmount;
        if (result.bySourceAmount) {
            result.sourceAmount = amount;
        } else {
            result.targetAmount = amount;
        }
        result.limit = limit;
        result.tradingFeePPM = data.tradingFeePPM;
        PoolLiquidity memory liquidity = data.liquidity;
        if (result.isSourceBNT) {
            result.sourceBalance = liquidity.bntTradingLiquidity;
            result.targetBalance = liquidity.baseTokenTradingLiquidity;
        } else {
            result.sourceBalance = liquidity.baseTokenTradingLiquidity;
            result.targetBalance = liquidity.bntTradingLiquidity;
        }
        result.stakedBalance = liquidity.stakedBalance;
    }
    /**
     * @dev returns trade amount and fee by providing the source amount
     */
    function _tradeAmountAndFeeBySourceAmount(
        uint256 sourceBalance,
        uint256 targetBalance,
        uint32 feePPM,
        uint256 sourceAmount
    ) private pure returns (TradeAmountAndTradingFee memory) {
        if (sourceBalance == 0 || targetBalance == 0) {
            revert InsufficientLiquidity();
        }
        uint256 targetAmount = MathEx.mulDivF(targetBalance, sourceAmount, sourceBalance + sourceAmount);
        uint256 tradingFeeAmount = MathEx.mulDivF(targetAmount, feePPM, PPM_RESOLUTION);
        return
            TradeAmountAndTradingFee({ amount: targetAmount - tradingFeeAmount, tradingFeeAmount: tradingFeeAmount });
    }
    /**
     * @dev returns trade amount and fee by providing either the target amount
     */
    function _tradeAmountAndFeeByTargetAmount(
        uint256 sourceBalance,
        uint256 targetBalance,
        uint32 feePPM,
        uint256 targetAmount
    ) private pure returns (TradeAmountAndTradingFee memory) {
        if (sourceBalance == 0) {
            revert InsufficientLiquidity();
        }
        uint256 tradingFeeAmount = MathEx.mulDivF(targetAmount, feePPM, PPM_RESOLUTION - feePPM);
        uint256 fullTargetAmount = targetAmount + tradingFeeAmount;
        uint256 sourceAmount = MathEx.mulDivF(sourceBalance, fullTargetAmount, targetBalance - fullTargetAmount);
        return TradeAmountAndTradingFee({ amount: sourceAmount, tradingFeeAmount: tradingFeeAmount });
    }
    /**
     * @dev processes a trade by providing either the source or the target amount and updates the in-memory intermediate
     * result
     */
    function _processTrade(TradeIntermediateResult memory result) private view {
        TradeAmountAndTradingFee memory tradeAmountAndFee;
        if (result.bySourceAmount) {
            tradeAmountAndFee = _tradeAmountAndFeeBySourceAmount(
                result.sourceBalance,
                result.targetBalance,
                result.tradingFeePPM,
                result.sourceAmount
            );
            result.targetAmount = tradeAmountAndFee.amount;
            // ensure that the target amount is above the requested minimum return amount
            if (result.targetAmount < result.limit) {
                revert InsufficientTargetAmount();
            }
        } else {
            tradeAmountAndFee = _tradeAmountAndFeeByTargetAmount(
                result.sourceBalance,
                result.targetBalance,
                result.tradingFeePPM,
                result.targetAmount
            );
            result.sourceAmount = tradeAmountAndFee.amount;
            // ensure that the user has provided enough tokens to make the trade
            if (result.sourceAmount == 0 || result.sourceAmount > result.limit) {
                revert InsufficientSourceAmount();
            }
        }
        result.tradingFeeAmount = tradeAmountAndFee.tradingFeeAmount;
        // sync the trading and staked balance
        result.sourceBalance += result.sourceAmount;
        result.targetBalance -= result.targetAmount;
        if (result.isSourceBNT) {
            result.stakedBalance += result.tradingFeeAmount;
        }
        _processNetworkFee(result);
    }
    /**
     * @dev processes the network fee and updates the in-memory intermediate result
     */
    function _processNetworkFee(TradeIntermediateResult memory result) private view {
        if (_networkFeePPM == 0) {
            return;
        }
        // calculate the target network fee amount
        uint256 targetNetworkFeeAmount = MathEx.mulDivF(result.tradingFeeAmount, _networkFeePPM, PPM_RESOLUTION);
        // update the target balance (but don't deduct it from the full trading fee amount)
        result.targetBalance -= targetNetworkFeeAmount;
        if (!result.isSourceBNT) {
            result.networkFeeAmount = targetNetworkFeeAmount;
            return;
        }
        // trade the network fee (taken from the base token) to BNT
        result.networkFeeAmount = _tradeAmountAndFeeBySourceAmount(
            result.targetBalance,
            result.sourceBalance,
            0,
            targetNetworkFeeAmount
        ).amount;
        // since we have received the network fee in base tokens and have traded them for BNT (so that the network fee
        // is always kept in BNT), we'd need to adapt the trading liquidity and the staked balance accordingly
        result.targetBalance += targetNetworkFeeAmount;
        result.sourceBalance -= result.networkFeeAmount;
        result.stakedBalance -= targetNetworkFeeAmount;
    }
    /**
     * @dev performs a trade
     */
    function _performTrade(TradeIntermediateResult memory result) private {
        Pool storage data = _poolData[result.pool];
        PoolLiquidity memory prevLiquidity = data.liquidity;
        // update the recent average rate
        _updateAverageRates(
            data,
            Fraction({ n: prevLiquidity.bntTradingLiquidity, d: prevLiquidity.baseTokenTradingLiquidity })
        );
        _processTrade(result);
        // trading liquidity is assumed to never exceed 128 bits (the cast below will revert otherwise)
        PoolLiquidity memory newLiquidity = PoolLiquidity({
            bntTradingLiquidity: (result.isSourceBNT ? result.sourceBalance : result.targetBalance).toUint128(),
            baseTokenTradingLiquidity: (result.isSourceBNT ? result.targetBalance : result.sourceBalance).toUint128(),
            stakedBalance: result.stakedBalance
        });
        _dispatchTradingLiquidityEvents(result.contextId, result.pool, prevLiquidity, newLiquidity);
        // update the liquidity data of the pool
        data.liquidity = newLiquidity;
    }
    /**
     * @dev returns the state of a pool's rate
     */
    function _poolRateState(Pool storage data) internal view returns (PoolRateState) {
        Fraction memory spotRate = Fraction({
            n: data.liquidity.bntTradingLiquidity,
            d: data.liquidity.baseTokenTradingLiquidity
        });
        AverageRates memory averageRates = data.averageRates;
        Fraction112 memory rate = averageRates.rate;
        if (!spotRate.isPositive() || !rate.isPositive()) {
            return PoolRateState.Uninitialized;
        }
        Fraction memory invSpotRate = spotRate.inverse();
        Fraction112 memory invRate = averageRates.invRate;
        if (!invSpotRate.isPositive() || !invRate.isPositive()) {
            return PoolRateState.Uninitialized;
        }
        AverageRates memory effectiveAverageRates = _effectiveAverageRates(averageRates, spotRate);
        if (
            MathEx.isInRange(effectiveAverageRates.rate.fromFraction112(), spotRate, RATE_MAX_DEVIATION_PPM) &&
            MathEx.isInRange(effectiveAverageRates.invRate.fromFraction112(), invSpotRate, RATE_MAX_DEVIATION_PPM)
        ) {
            return PoolRateState.Stable;
        }
        return PoolRateState.Unstable;
    }
    /**
     * @dev updates the average rates
     */
    function _updateAverageRates(Pool storage data, Fraction memory spotRate) private {
        data.averageRates = _effectiveAverageRates(data.averageRates, spotRate);
    }
    /**
     * @dev returns the effective average rates
     */
    function _effectiveAverageRates(AverageRates memory averageRates, Fraction memory spotRate)
        private
        view
        returns (AverageRates memory)
    {
        // if the spot rate is 0, reset the average rates
        if (!spotRate.isPositive()) {
            return AverageRates({ blockNumber: 0, rate: zeroFraction112(), invRate: zeroFraction112() });
        }
        uint32 blockNumber = _blockNumber();
        // can only be updated once in a single block
        uint32 prevUpdateBlock = averageRates.blockNumber;
        if (prevUpdateBlock == blockNumber) {
            return averageRates;
        }
        // if sufficient blocks have passed, or if one of the rates isn't positive,
        // reset the average rates
        if (
            blockNumber - prevUpdateBlock >= RATE_RESET_BLOCK_THRESHOLD ||
            !averageRates.rate.isPositive() ||
            !averageRates.invRate.isPositive()
        ) {
            if (spotRate.isPositive()) {
                return
                    AverageRates({
                        blockNumber: blockNumber,
                        rate: spotRate.toFraction112(),
                        invRate: spotRate.inverse().toFraction112()
                    });
            }
            return AverageRates({ blockNumber: 0, rate: zeroFraction112(), invRate: zeroFraction112() });
        }
        return
            AverageRates({
                blockNumber: blockNumber,
                rate: _calcAverageRate(averageRates.rate, spotRate),
                invRate: _calcAverageRate(averageRates.invRate, spotRate.inverse())
            });
    }
    /**
     * @dev calculates the average rate
     */
    function _calcAverageRate(Fraction112 memory averageRate, Fraction memory rate)
        private
        pure
        returns (Fraction112 memory)
    {
        if (rate.n * averageRate.d == rate.d * averageRate.n) {
            return averageRate;
        }
        return
            MathEx
                .weightedAverage(averageRate.fromFraction112(), rate, EMA_AVERAGE_RATE_WEIGHT, EMA_SPOT_RATE_WEIGHT)
                .toFraction112();
    }
    /**
     * @dev verifies if the provided rate is valid
     */
    function _validRate(Fraction memory rate) internal pure {
        if (!rate.isPositive()) {
            revert InvalidRate();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION as M } from "../utility/Constants.sol";
import { Sint256, Uint512, MathEx } from "../utility/MathEx.sol";
error PoolCollectionWithdrawalInputInvalid();
/**
 * @dev This library implements the mathematics behind base-token withdrawal.
 * It exposes a single function which takes the following input values:
 * `a` - BNT trading liquidity
 * `b` - base token trading liquidity
 * `c` - base token excess amount
 * `e` - base token staked amount
 * `w` - base token external protection vault balance
 * `m` - trading fee in PPM units
 * `n` - withdrawal fee in PPM units
 * `x` - base token withdrawal amount
 * And returns the following output values:
 * `p` - BNT amount to add to the trading liquidity and to the master vault
 * `q` - BNT amount to add to the protocol equity
 * `r` - base token amount to add to the trading liquidity
 * `s` - base token amount to transfer from the master vault to the provider
 * `t` - BNT amount to mint directly for the provider
 * `u` - base token amount to transfer from the external protection vault to the provider
 * `v` - base token amount to keep in the pool as a withdrawal fee
 * The following table depicts the actual formulae based on the current state of the system:
 * +-----------+---------------------------------------------------------+----------------------------------------------------------+
 * |           |                         Deficit                         |                       Surplus                            |
 * +-----------+---------------------------------------------------------+----------------------------------------------------------+
 * |           | p = a*x*(e*(1-n)-b-c)*(1-m)/(b*e-x*(e*(1-n)-b-c)*(1-m)) | p = -a*x*(b+c-e*(1-n))/(b*e*(1-m)+x*(b+c-e*(1-n))*(1-m)) |
 * |           | q = 0                                                   | q = 0                                                    |
 * |           | r = -x*(e*(1-n)-b-c)/e                                  | r = x*(b+c-e*(1-n))/e                                    |
 * | Arbitrage | s = x*(1-n)                                             | s = x*(1-n)                                              |
 * |           | t = 0                                                   | t = 0                                                    |
 * |           | u = 0                                                   | u = 0                                                    |
 * |           | v = x*n                                                 | v = x*n                                                  |
 * +-----------+---------------------------------------------------------+----------------------------------------------------------+
 * |           | p = -a*z/(b*e) where z = max(x*(1-n)*b-c*(e-x*(1-n)),0) | p = -a*z/b where z = max(x*(1-n)-c,0)                    |
 * |           | q = -a*z/(b*e) where z = max(x*(1-n)*b-c*(e-x*(1-n)),0) | q = -a*z/b where z = max(x*(1-n)-c,0)                    |
 * |           | r = -z/e       where z = max(x*(1-n)*b-c*(e-x*(1-n)),0) | r = -z     where z = max(x*(1-n)-c,0)                    |
 * | Default   | s = x*(1-n)*(b+c)/e                                     | s = x*(1-n)                                              |
 * |           | t = see function `externalProtection`                   | t = 0                                                    |
 * |           | u = see function `externalProtection`                   | u = 0                                                    |
 * |           | v = x*n                                                 | v = x*n                                                  |
 * +-----------+---------------------------------------------------------+----------------------------------------------------------+
 * |           | p = 0                                                   | p = 0                                                    |
 * |           | q = 0                                                   | q = 0                                                    |
 * |           | r = 0                                                   | r = 0                                                    |
 * | Bootstrap | s = x*(1-n)*c/e                                         | s = x*(1-n)                                              |
 * |           | t = see function `externalProtection`                   | t = 0                                                    |
 * |           | u = see function `externalProtection`                   | u = 0                                                    |
 * |           | v = x*n                                                 | v = x*n                                                  |
 * +-----------+---------------------------------------------------------+----------------------------------------------------------+
 * Note that for the sake of illustration, both `m` and `n` are assumed normalized (between 0 and 1).
 * During runtime, it is taken into account that they are given in PPM units (between 0 and 1000000).
 */
library PoolCollectionWithdrawal {
    using MathEx for uint256;
    struct Output {
        Sint256 p;
        Sint256 q;
        Sint256 r;
        uint256 s;
        uint256 t;
        uint256 u;
        uint256 v;
    }
    /**
     * @dev returns `p`, `q`, `r`, `s`, `t`, `u` and `v` according to the current state:
     * +-------------------+-----------------------------------------------------------+
     * | `e > (b+c)/(1-n)` | bootstrap deficit or default deficit or arbitrage deficit |
     * +-------------------+-----------------------------------------------------------+
     * | `e < (b+c)`       | bootstrap surplus or default surplus or arbitrage surplus |
     * +-------------------+-----------------------------------------------------------+
     * | otherwise         | bootstrap surplus or default surplus                      |
     * +-------------------+-----------------------------------------------------------+
     */
    function calculateWithdrawalAmounts(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 c, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 w, // <= 2**128-1
        uint256 m, // <= M == 1000000
        uint256 n, // <= M == 1000000
        uint256 x /// <= e <= 2**128-1
    ) internal pure returns (Output memory output) {
        if (
            a > type(uint128).max ||
            b > type(uint128).max ||
            c > type(uint128).max ||
            e > type(uint128).max ||
            w > type(uint128).max ||
            m > M ||
            n > M ||
            x > e
        ) {
            revert PoolCollectionWithdrawalInputInvalid();
        }
        uint256 y = (x * (M - n)) / M;
        if ((e * (M - n)) / M > b + c) {
            uint256 f = (e * (M - n)) / M - (b + c);
            uint256 g = e - (b + c);
            if (isStable(b, c, e, x) && affordableDeficit(b, e, f, g, m, n, x)) {
                output = arbitrageDeficit(a, b, e, f, m, x, y);
            } else if (a > 0) {
                output = defaultDeficit(a, b, c, e, y);
                (output.t, output.u) = externalProtection(a, b, e, g, y, w);
            } else {
                output.s = (y * c) / e;
                (output.t, output.u) = externalProtection(a, b, e, g, y, w);
            }
        } else {
            uint256 f = MathEx.subMax0(b + c, e);
            if (f > 0 && isStable(b, c, e, x) && affordableSurplus(b, e, f, m, n, x)) {
                output = arbitrageSurplus(a, b, e, f, m, n, x, y);
            } else if (a > 0) {
                output = defaultSurplus(a, b, c, y);
            } else {
                output.s = y;
            }
        }
        output.v = x - y;
    }
    /**
     * @dev returns `x < e*c/(b+c)`
     */
    function isStable(
        uint256 b, // <= 2**128-1
        uint256 c, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 x /// <= e <= 2**128-1
    ) private pure returns (bool) {
        return b * x < c * (e - x);
    }
    /**
     * @dev returns `b*e*((e*(1-n)-b-c)*m+e*n) > (e*(1-n)-b-c)*x*(e-b-c)*(1-m)`
     */
    function affordableDeficit(
        uint256, /*b*/ // <= 2**128-1
        uint256, /*e*/ // <= 2**128-1
        uint256, /*f*/ // == e*(1-n)-b-c <= e <= 2**128-1
        uint256, /*g*/ // == e-b-c <= e <= 2**128-1
        uint256, /*m*/ // <= M == 1000000
        uint256, /*n*/ // <= M == 1000000
        uint256 /*x*/ /// <  e*c/(b+c) <= e <= 2**128-1
    ) private pure returns (bool) {
        // temporarily disabled
        //Uint512 memory lhs = MathEx.mul512(b * e, f * m + e * n);
        //Uint512 memory rhs = MathEx.mul512(f * x, g * (M - m));
        //return MathEx.gt512(lhs, rhs);
        return false;
    }
    /**
     * @dev returns `b*e*((b+c-e)*m+e*n) > (b+c-e)*x*(b+c-e*(1-n))*(1-m)`
     */
    function affordableSurplus(
        uint256 b, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 f, // == b+c-e <= 2**129-2
        uint256 m, // <= M == 1000000
        uint256 n, // <= M == 1000000
        uint256 x /// <  e*c/(b+c) <= e <= 2**128-1
    ) private pure returns (bool) {
        Uint512 memory lhs = MathEx.mul512(b * e, (f * m + e * n) * M);
        Uint512 memory rhs = MathEx.mul512(f * x, (f * M + e * n) * (M - m));
        return MathEx.gt512(lhs, rhs); // `x < e*c/(b+c)` --> `f*x < e*c*(b+c-e)/(b+c) <= e*c <= 2**256-1`
    }
    /**
     * @dev returns:
     * `p = a*x*(e*(1-n)-b-c)*(1-m)/(b*e-x*(e*(1-n)-b-c)*(1-m))`
     * `q = 0`
     * `r = -x*(e*(1-n)-b-c)/e`
     * `s = x*(1-n)`
     */
    function arbitrageDeficit(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 f, // == e*(1-n)-b-c <= e <= 2**128-1
        uint256 m, // <= M == 1000000
        uint256 x, // <= e <= 2**128-1
        uint256 y /// == x*(1-n) <= x <= e <= 2**128-1
    ) private pure returns (Output memory output) {
        uint256 i = f * (M - m);
        uint256 j = mulSubMulDivF(b, e * M, x, i, 1);
        output.p = MathEx.mulDivF(a * x, i, j).toPos256();
        output.r = MathEx.mulDivF(x, f, e).toNeg256();
        output.s = y;
    }
    /**
     * @dev returns:
     * `p = -a*x*(b+c-e*(1-n))/(b*e*(1-m)+x*(b+c-e*(1-n))*(1-m))`
     * `q = 0`
     * `r = x*(b+c-e*(1-n))/e`
     * `s = x*(1-n)`
     */
    function arbitrageSurplus(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 f, // == b+c-e <= 2**129-2
        uint256 m, // <= M == 1000000
        uint256 n, // <= M == 1000000
        uint256 x, // <= e <= 2**128-1
        uint256 y /// == x*(1-n) <= x <= e <= 2**128-1
    ) private pure returns (Output memory output) {
        uint256 i = f * M + e * n;
        uint256 j = mulAddMulDivF(b, e * (M - m), x, i * (M - m), M);
        output.p = MathEx.mulDivF(a * x, i, j).toNeg256();
        output.r = MathEx.mulDivF(x, i, e * M).toPos256();
        output.s = y;
    }
    /**
     * @dev returns:
     * `p = -a*z/(b*e)` where `z = max(x*(1-n)*b-c*(e-x*(1-n)),0)`
     * `q = -a*z/(b*e)` where `z = max(x*(1-n)*b-c*(e-x*(1-n)),0)`
     * `r = -z/e` where `z = max(x*(1-n)*b-c*(e-x*(1-n)),0)`
     * `s = x*(1-n)*(b+c)/e`
     */
    function defaultDeficit(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 c, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 y /// == x*(1-n) <= x <= e <= 2**128-1
    ) private pure returns (Output memory output) {
        uint256 z = MathEx.subMax0(y * b, c * (e - y));
        output.p = MathEx.mulDivF(a, z, b * e).toNeg256();
        output.q = output.p;
        output.r = (z / e).toNeg256();
        output.s = MathEx.mulDivF(y, b + c, e);
    }
    /**
     * @dev returns:
     * `p = -a*z/b` where `z = max(x*(1-n)-c,0)`
     * `q = -a*z/b` where `z = max(x*(1-n)-c,0)`
     * `r = -z` where `z = max(x*(1-n)-c,0)`
     * `s = x*(1-n)`
     */
    function defaultSurplus(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 c, // <= 2**128-1
        uint256 y /// == x*(1-n) <= x <= e <= 2**128-1
    ) private pure returns (Output memory output) {
        uint256 z = MathEx.subMax0(y, c);
        output.p = MathEx.mulDivF(a, z, b).toNeg256();
        output.q = output.p;
        output.r = z.toNeg256();
        output.s = y;
    }
    /**
     * @dev returns `t` and `u` according to the current state:
     * +-----------------------+-------+---------------------------+-------------------+
     * | x*(1-n)*(e-b-c)/e > w | a > 0 | t                         | u                 |
     * +-----------------------+-------+---------------------------+-------------------+
     * | true                  | true  | a*(x*(1-n)*(e-b-c)/e-w)/b | w                 |
     * +-----------------------+-------+---------------------------+-------------------+
     * | true                  | false | 0                         | w                 |
     * +-----------------------+-------+---------------------------+-------------------+
     * | false                 | true  | 0                         | x*(1-n)*(e-b-c)/e |
     * +-----------------------+-------+---------------------------+-------------------+
     * | false                 | false | 0                         | x*(1-n)*(e-b-c)/e |
     * +-----------------------+-------+---------------------------+-------------------+
     */
    function externalProtection(
        uint256 a, // <= 2**128-1
        uint256 b, // <= 2**128-1
        uint256 e, // <= 2**128-1
        uint256 g, // == e-b-c <= e <= 2**128-1
        uint256 y, // == x*(1-n) <= x <= e <= 2**128-1
        uint256 w /// <= 2**128-1
    ) private pure returns (uint256 t, uint256 u) {
        uint256 yg = y * g;
        uint256 we = w * e;
        if (yg > we) {
            t = a > 0 ? MathEx.mulDivF(a, yg - we, b * e) : 0;
            u = w;
        } else {
            t = 0;
            u = yg / e;
        }
    }
    /**
     * @dev returns `a*b+x*y/z`
     */
    function mulAddMulDivF(
        uint256 a,
        uint256 b,
        uint256 x,
        uint256 y,
        uint256 z
    ) private pure returns (uint256) {
        return a * b + MathEx.mulDivF(x, y, z);
    }
    /**
     * @dev returns `a*b-x*y/z`
     */
    function mulSubMulDivF(
        uint256 a,
        uint256 b,
        uint256 x,
        uint256 y,
        uint256 z
    ) private pure returns (uint256) {
        return a * b - MathEx.mulDivF(x, y, z);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IPoolToken } from "./IPoolToken.sol";
import { Token } from "../../token/Token.sol";
import { IVault } from "../../vaults/interfaces/IVault.sol";
// the BNT pool token manager role is required to access the BNT pool tokens
bytes32 constant ROLE_BNT_POOL_TOKEN_MANAGER = keccak256("ROLE_BNT_POOL_TOKEN_MANAGER");
// the BNT manager role is required to request the BNT pool to mint BNT
bytes32 constant ROLE_BNT_MANAGER = keccak256("ROLE_BNT_MANAGER");
// the vault manager role is required to request the BNT pool to burn BNT from the master vault
bytes32 constant ROLE_VAULT_MANAGER = keccak256("ROLE_VAULT_MANAGER");
// the funding manager role is required to request or renounce funding from the BNT pool
bytes32 constant ROLE_FUNDING_MANAGER = keccak256("ROLE_FUNDING_MANAGER");
/**
 * @dev BNT Pool interface
 */
interface IBNTPool is IVault {
    /**
     * @dev returns the BNT pool token contract
     */
    function poolToken() external view returns (IPoolToken);
    /**
     * @dev returns the total staked BNT balance in the network
     */
    function stakedBalance() external view returns (uint256);
    /**
     * @dev returns the current funding of given pool
     */
    function currentPoolFunding(Token pool) external view returns (uint256);
    /**
     * @dev returns the available BNT funding for a given pool
     */
    function availableFunding(Token pool) external view returns (uint256);
    /**
     * @dev converts the specified pool token amount to the underlying BNT amount
     */
    function poolTokenToUnderlying(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying BNT amount to pool token amount
     */
    function underlyingToPoolToken(uint256 bntAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(uint256 bntAmountToDistribute) external view returns (uint256);
    /**
     * @dev mints BNT to the recipient
     *
     * requirements:
     *
     * - the caller must have the ROLE_BNT_MANAGER role
     */
    function mint(address recipient, uint256 bntAmount) external;
    /**
     * @dev burns BNT from the vault
     *
     * requirements:
     *
     * - the caller must have the ROLE_VAULT_MANAGER role
     */
    function burnFromVault(uint256 bntAmount) external;
    /**
     * @dev deposits BNT liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - BNT tokens must have been already deposited into the contract
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        uint256 bntAmount,
        bool isMigrating,
        uint256 originalVBNTAmount
    ) external returns (uint256);
    /**
     * @dev withdraws BNT liquidity on behalf of a specific provider and returns the withdrawn BNT amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - bnBNT token must have been already deposited into the contract
     * - vBNT token must have been already deposited into the contract
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        uint256 poolTokenAmount,
        uint256 bntAmount
    ) external returns (uint256);
    /**
     * @dev returns the withdrawn BNT amount
     */
    function withdrawalAmount(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev requests BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the request amount should be below the funding limit for a given pool
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function requestFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev renounces BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function renounceFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(
        Token pool,
        uint256 feeAmount,
        bool isTradeFee
    ) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { Fraction112 } from "../../utility/FractionLibrary.sol";
import { Token } from "../../token/Token.sol";
import { IPoolToken } from "./IPoolToken.sol";
struct PoolLiquidity {
    uint128 bntTradingLiquidity; // the BNT trading liquidity
    uint128 baseTokenTradingLiquidity; // the base token trading liquidity
    uint256 stakedBalance; // the staked balance
}
struct AverageRates {
    uint32 blockNumber;
    Fraction112 rate;
    Fraction112 invRate;
}
struct Pool {
    IPoolToken poolToken; // the pool token of the pool
    uint32 tradingFeePPM; // the trading fee (in units of PPM)
    bool tradingEnabled; // whether trading is enabled
    bool depositingEnabled; // whether depositing is enabled
    AverageRates averageRates; // the recent average rates
    PoolLiquidity liquidity; // the overall liquidity in the pool
}
struct WithdrawalAmounts {
    uint256 totalAmount;
    uint256 baseTokenAmount;
    uint256 bntAmount;
}
// trading enabling/disabling reasons
uint8 constant TRADING_STATUS_UPDATE_DEFAULT = 0;
uint8 constant TRADING_STATUS_UPDATE_ADMIN = 1;
uint8 constant TRADING_STATUS_UPDATE_MIN_LIQUIDITY = 2;
uint8 constant TRADING_STATUS_UPDATE_INVALID_STATE = 3;
struct TradeAmountAndFee {
    uint256 amount; // the source/target amount (depending on the context) resulting from the trade
    uint256 tradingFeeAmount; // the trading fee amount
    uint256 networkFeeAmount; // the network fee amount (always in units of BNT)
}
/**
 * @dev Pool Collection interface
 */
interface IPoolCollection is IVersioned {
    /**
     * @dev returns the type of the pool
     */
    function poolType() external view returns (uint16);
    /**
     * @dev returns the default trading fee (in units of PPM)
     */
    function defaultTradingFeePPM() external view returns (uint32);
    /**
     * @dev returns the network fee (in units of PPM)
     */
    function networkFeePPM() external view returns (uint32);
    /**
     * @dev returns all the pools which are managed by this pool collection
     */
    function pools() external view returns (Token[] memory);
    /**
     * @dev returns the number of all the pools which are managed by this pool collection
     */
    function poolCount() external view returns (uint256);
    /**
     * @dev returns whether a pool is valid
     */
    function isPoolValid(Token pool) external view returns (bool);
    /**
     * @dev returns the overall liquidity in the pool
     */
    function poolLiquidity(Token pool) external view returns (PoolLiquidity memory);
    /**
     * @dev returns the pool token of the pool
     */
    function poolToken(Token pool) external view returns (IPoolToken);
    /**
     * @dev returns the trading fee (in units of PPM)
     */
    function tradingFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns whether trading is enabled
     */
    function tradingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether depositing is enabled
     */
    function depositingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether the pool is stable
     */
    function isPoolStable(Token pool) external view returns (bool);
    /**
     * @dev converts the specified pool token amount to the underlying base token amount
     */
    function poolTokenToUnderlying(Token pool, uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying base token amount to pool token amount
     */
    function underlyingToPoolToken(Token pool, uint256 baseTokenAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(
        Token pool,
        uint256 baseTokenAmountToDistribute,
        uint256 protocolPoolTokenAmount
    ) external view returns (uint256);
    /**
     * @dev creates a new pool
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the pool should have been whitelisted
     * - the pool isn't already defined in the collection
     */
    function createPool(Token token) external;
    /**
     * @dev deposits base token liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - assumes that the base token has been already deposited in the vault
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev handles some of the withdrawal-related actions and returns the withdrawn base token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the caller must have approved the collection to transfer/burn the pool token amount on its behalf
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 poolTokenAmount,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev returns the amounts that would be returned if the position is currently withdrawn,
     * along with the breakdown of the base token and the BNT compensation
     */
    function withdrawalAmounts(Token pool, uint256 poolTokenAmount) external view returns (WithdrawalAmounts memory);
    /**
     * @dev performs a trade by providing the source amount and returns the target amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeBySourceAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev performs a trade by providing the target amount and returns the required source amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeByTargetAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev returns the output amount and fee when trading by providing the source amount
     */
    function tradeOutputAndFeeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev returns the input amount and fee when trading by providing the target amount
     */
    function tradeInputAndFeeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(Token pool, uint256 feeAmount) external;
    /**
     * @dev migrates a pool to this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolIn(Token pool, Pool calldata data) external;
    /**
     * @dev migrates a pool from this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolOut(Token pool, IPoolCollection targetPoolCollection) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Token } from "../../token/Token.sol";
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { IPoolCollection } from "./IPoolCollection.sol";
/**
 * @dev Pool Migrator interface
 */
interface IPoolMigrator is IVersioned {
    /**
     * @dev migrates a pool and returns the new pool collection it exists in
     *
     * notes:
     *
     * - invalid or incompatible pools will be skipped gracefully
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function migratePool(Token pool, IPoolCollection newPoolCollection) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { IERC20Burnable } from "../../token/interfaces/IERC20Burnable.sol";
import { Token } from "../../token/Token.sol";
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { IOwned } from "../../utility/interfaces/IOwned.sol";
/**
 * @dev Pool Token interface
 */
interface IPoolToken is IVersioned, IOwned, IERC20, IERC20Permit, IERC20Burnable {
    /**
     * @dev returns the address of the reserve token
     */
    function reserveToken() external view returns (Token);
    /**
     * @dev increases the token supply and sends the new tokens to the given account
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function mint(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Token } from "../../token/Token.sol";
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { IPoolToken } from "./IPoolToken.sol";
/**
 * @dev Pool Token Factory interface
 */
interface IPoolTokenFactory is IUpgradeable {
    /**
     * @dev returns the custom symbol override for a given reserve token
     */
    function tokenSymbolOverride(Token token) external view returns (string memory);
    /**
     * @dev returns the custom decimals override for a given reserve token
     */
    function tokenDecimalsOverride(Token token) external view returns (uint8);
    /**
     * @dev creates a pool token for the specified token
     */
    function createPoolToken(Token token) external returns (IPoolToken);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
 * @dev extends the SafeERC20 library with additional operations
 */
library SafeERC20Ex {
    using SafeERC20 for IERC20;
    /**
     * @dev ensures that the spender has sufficient allowance
     */
    function ensureApprove(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance >= amount) {
            return;
        }
        if (allowance > 0) {
            token.safeApprove(spender, 0);
        }
        token.safeApprove(spender, amount);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev the main purpose of the Token interfaces is to ensure artificially that we won't use ERC20's standard functions,
 * but only their safe versions, which are provided by SafeERC20 and SafeERC20Ex via the TokenLibrary contract
 */
interface Token {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { SafeERC20Ex } from "./SafeERC20Ex.sol";
import { Token } from "./Token.sol";
/**
 * @dev This library implements ERC20 and SafeERC20 utilities for both the native token and for ERC20 tokens
 */
library TokenLibrary {
    using SafeERC20 for IERC20;
    using SafeERC20Ex for IERC20;
    error PermitUnsupported();
    // the address that represents the native token reserve
    address private constant NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    // the symbol that represents the native token
    string private constant NATIVE_TOKEN_SYMBOL = "ETH";
    // the decimals for the native token
    uint8 private constant NATIVE_TOKEN_DECIMALS = 18;
    // the token representing the native token
    Token public constant NATIVE_TOKEN = Token(NATIVE_TOKEN_ADDRESS);
    /**
     * @dev returns whether the provided token represents an ERC20 or the native token reserve
     */
    function isNative(Token token) internal pure returns (bool) {
        return address(token) == NATIVE_TOKEN_ADDRESS;
    }
    /**
     * @dev returns the symbol of the native token/ERC20 token
     */
    function symbol(Token token) internal view returns (string memory) {
        if (isNative(token)) {
            return NATIVE_TOKEN_SYMBOL;
        }
        return toERC20(token).symbol();
    }
    /**
     * @dev returns the decimals of the native token/ERC20 token
     */
    function decimals(Token token) internal view returns (uint8) {
        if (isNative(token)) {
            return NATIVE_TOKEN_DECIMALS;
        }
        return toERC20(token).decimals();
    }
    /**
     * @dev returns the balance of the native token/ERC20 token
     */
    function balanceOf(Token token, address account) internal view returns (uint256) {
        if (isNative(token)) {
            return account.balance;
        }
        return toIERC20(token).balanceOf(account);
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token
     */
    function safeTransfer(
        Token token,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        if (isNative(token)) {
            payable(to).transfer(amount);
        } else {
            toIERC20(token).safeTransfer(to, amount);
        }
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token from a specific holder using the allowance mechanism
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeTransferFrom(
        Token token,
        address from,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0 || isNative(token)) {
            return;
        }
        toIERC20(token).safeTransferFrom(from, to, amount);
    }
    /**
     * @dev approves a specific amount of the native token/ERC20 token from a specific holder
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).safeApprove(spender, amount);
    }
    /**
     * @dev ensures that the spender has sufficient allowance
     *
     * note that the function does not perform any action if the native token is provided
     */
    function ensureApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).ensureApprove(spender, amount);
    }
    /**
     * @dev compares between a token and another raw ERC20 token
     */
    function isEqual(Token token, IERC20 erc20Token) internal pure returns (bool) {
        return toIERC20(token) == erc20Token;
    }
    /**
     * @dev utility function that converts a token to an IERC20
     */
    function toIERC20(Token token) internal pure returns (IERC20) {
        return IERC20(address(token));
    }
    /**
     * @dev utility function that converts a token to an ERC20
     */
    function toERC20(Token token) internal pure returns (ERC20) {
        return ERC20(address(token));
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev burnable ERC20 interface
 */
interface IERC20Burnable {
    /**
     * @dev Destroys tokens from the caller.
     */
    function burn(uint256 amount) external;
    /**
     * @dev Destroys tokens from a recipient, deducting from the caller's allowance
     *
     * requirements:
     *
     * - the caller must have allowance for recipient's tokens of at least the specified amount
     */
    function burnFrom(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev this contract abstracts the block number in order to allow for more flexible control in tests
 */
abstract contract BlockNumber {
    /**
     * @dev returns the current block-number
     */
    function _blockNumber() internal view virtual returns (uint32) {
        return uint32(block.number);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1_000_000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
struct Fraction {
    uint256 n;
    uint256 d;
}
struct Fraction112 {
    uint112 n;
    uint112 d;
}
error InvalidFraction();
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Fraction, Fraction112, InvalidFraction } from "./Fraction.sol";
import { MathEx } from "./MathEx.sol";
// solhint-disable-next-line func-visibility
function zeroFraction() pure returns (Fraction memory) {
    return Fraction({ n: 0, d: 1 });
}
// solhint-disable-next-line func-visibility
function zeroFraction112() pure returns (Fraction112 memory) {
    return Fraction112({ n: 0, d: 1 });
}
/**
 * @dev this library provides a set of fraction operations
 */
library FractionLibrary {
    /**
     * @dev returns whether a standard fraction is valid
     */
    function isValid(Fraction memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is valid
     */
    function isValid(Fraction112 memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a standard fraction is positive
     */
    function isPositive(Fraction memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is positive
     */
    function isPositive(Fraction112 memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction memory fraction) internal pure returns (Fraction memory) {
        Fraction memory invFraction = Fraction({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction112 memory fraction) internal pure returns (Fraction112 memory) {
        Fraction112 memory invFraction = Fraction112({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev reduces a standard fraction to a 112-bit fraction
     */
    function toFraction112(Fraction memory fraction) internal pure returns (Fraction112 memory) {
        Fraction memory truncatedFraction = MathEx.truncatedFraction(fraction, type(uint112).max);
        return Fraction112({ n: uint112(truncatedFraction.n), d: uint112(truncatedFraction.d) });
    }
    /**
     * @dev expands a 112-bit fraction to a standard fraction
     */
    function fromFraction112(Fraction112 memory fraction) internal pure returns (Fraction memory) {
        return Fraction({ n: fraction.n, d: fraction.d });
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Fraction, InvalidFraction } from "./Fraction.sol";
import { PPM_RESOLUTION } from "./Constants.sol";
uint256 constant ONE = 0x80000000000000000000000000000000;
uint256 constant LN2 = 0x58b90bfbe8e7bcd5e4f1d9cc01f97b57;
struct Uint512 {
    uint256 hi; // 256 most significant bits
    uint256 lo; // 256 least significant bits
}
struct Sint256 {
    uint256 value;
    bool isNeg;
}
/**
 * @dev this library provides a set of complex math operations
 */
library MathEx {
    error Overflow();
    /**
     * @dev returns `2 ^ f` by calculating `e ^ (f * ln(2))`, where `e` is Euler's number:
     * - Rewrite the input as a sum of binary exponents and a single residual r, as small as possible
     * - The exponentiation of each binary exponent is given (pre-calculated)
     * - The exponentiation of r is calculated via Taylor series for e^x, where x = r
     * - The exponentiation of the input is calculated by multiplying the intermediate results above
     * - For example: e^5.521692859 = e^(4 + 1 + 0.5 + 0.021692859) = e^4 * e^1 * e^0.5 * e^0.021692859
     */
    function exp2(Fraction memory f) internal pure returns (Fraction memory) {
        uint256 x = MathEx.mulDivF(LN2, f.n, f.d);
        uint256 y;
        uint256 z;
        uint256 n;
        if (x >= (ONE << 4)) {
            revert Overflow();
        }
        unchecked {
            z = y = x % (ONE >> 3); // get the input modulo 2^(-3)
            z = (z * y) / ONE;
            n += z * 0x10e1b3be415a0000; // add y^02 * (20! / 02!)
            z = (z * y) / ONE;
            n += z * 0x05a0913f6b1e0000; // add y^03 * (20! / 03!)
            z = (z * y) / ONE;
            n += z * 0x0168244fdac78000; // add y^04 * (20! / 04!)
            z = (z * y) / ONE;
            n += z * 0x004807432bc18000; // add y^05 * (20! / 05!)
            z = (z * y) / ONE;
            n += z * 0x000c0135dca04000; // add y^06 * (20! / 06!)
            z = (z * y) / ONE;
            n += z * 0x0001b707b1cdc000; // add y^07 * (20! / 07!)
            z = (z * y) / ONE;
            n += z * 0x000036e0f639b800; // add y^08 * (20! / 08!)
            z = (z * y) / ONE;
            n += z * 0x00000618fee9f800; // add y^09 * (20! / 09!)
            z = (z * y) / ONE;
            n += z * 0x0000009c197dcc00; // add y^10 * (20! / 10!)
            z = (z * y) / ONE;
            n += z * 0x0000000e30dce400; // add y^11 * (20! / 11!)
            z = (z * y) / ONE;
            n += z * 0x000000012ebd1300; // add y^12 * (20! / 12!)
            z = (z * y) / ONE;
            n += z * 0x0000000017499f00; // add y^13 * (20! / 13!)
            z = (z * y) / ONE;
            n += z * 0x0000000001a9d480; // add y^14 * (20! / 14!)
            z = (z * y) / ONE;
            n += z * 0x00000000001c6380; // add y^15 * (20! / 15!)
            z = (z * y) / ONE;
            n += z * 0x000000000001c638; // add y^16 * (20! / 16!)
            z = (z * y) / ONE;
            n += z * 0x0000000000001ab8; // add y^17 * (20! / 17!)
            z = (z * y) / ONE;
            n += z * 0x000000000000017c; // add y^18 * (20! / 18!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000014; // add y^19 * (20! / 19!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000001; // add y^20 * (20! / 20!)
            n = n / 0x21c3677c82b40000 + y + ONE; // divide by 20! and then add y^1 / 1! + y^0 / 0!
            if ((x & (ONE >> 3)) != 0)
                n = (n * 0x1c3d6a24ed82218787d624d3e5eba95f9) / 0x18ebef9eac820ae8682b9793ac6d1e776; // multiply by e^(2^-3)
            if ((x & (ONE >> 2)) != 0)
                n = (n * 0x18ebef9eac820ae8682b9793ac6d1e778) / 0x1368b2fc6f9609fe7aceb46aa619baed4; // multiply by e^(2^-2)
            if ((x & (ONE >> 1)) != 0)
                n = (n * 0x1368b2fc6f9609fe7aceb46aa619baed5) / 0x0bc5ab1b16779be3575bd8f0520a9f21f; // multiply by e^(2^-1)
            if ((x & (ONE << 0)) != 0)
                n = (n * 0x0bc5ab1b16779be3575bd8f0520a9f21e) / 0x0454aaa8efe072e7f6ddbab84b40a55c9; // multiply by e^(2^+0)
            if ((x & (ONE << 1)) != 0)
                n = (n * 0x0454aaa8efe072e7f6ddbab84b40a55c5) / 0x00960aadc109e7a3bf4578099615711ea; // multiply by e^(2^+1)
            if ((x & (ONE << 2)) != 0)
                n = (n * 0x00960aadc109e7a3bf4578099615711d7) / 0x0002bf84208204f5977f9a8cf01fdce3d; // multiply by e^(2^+2)
            if ((x & (ONE << 3)) != 0)
                n = (n * 0x0002bf84208204f5977f9a8cf01fdc307) / 0x0000003c6ab775dd0b95b4cbee7e65d11; // multiply by e^(2^+3)
        }
        return Fraction({ n: n, d: ONE });
    }
    /**
     * @dev returns a fraction with truncated components
     */
    function truncatedFraction(Fraction memory fraction, uint256 max) internal pure returns (Fraction memory) {
        uint256 scale = Math.ceilDiv(Math.max(fraction.n, fraction.d), max);
        Fraction memory truncated = Fraction({ n: fraction.n / scale, d: fraction.d / scale });
        if (truncated.d == 0) {
            revert InvalidFraction();
        }
        return truncated;
    }
    /**
     * @dev returns the weighted average of two fractions
     */
    function weightedAverage(
        Fraction memory fraction1,
        Fraction memory fraction2,
        uint256 weight1,
        uint256 weight2
    ) internal pure returns (Fraction memory) {
        return
            Fraction({
                n: fraction1.n * fraction2.d * weight1 + fraction1.d * fraction2.n * weight2,
                d: fraction1.d * fraction2.d * (weight1 + weight2)
            });
    }
    /**
     * @dev returns whether or not the deviation of an offset sample from a base sample is within a permitted range
     * for example, if the maximum permitted deviation is 5%, then evaluate `95% * base <= offset <= 105% * base`
     */
    function isInRange(
        Fraction memory baseSample,
        Fraction memory offsetSample,
        uint32 maxDeviationPPM
    ) internal pure returns (bool) {
        Uint512 memory min = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION - maxDeviationPPM));
        Uint512 memory mid = mul512(baseSample.d, offsetSample.n * PPM_RESOLUTION);
        Uint512 memory max = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION + maxDeviationPPM));
        return lte512(min, mid) && lte512(mid, max);
    }
    /**
     * @dev returns an `Sint256` positive representation of an unsigned integer
     */
    function toPos256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: false });
    }
    /**
     * @dev returns an `Sint256` negative representation of an unsigned integer
     */
    function toNeg256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: true });
    }
    /**
     * @dev returns the largest integer smaller than or equal to `x * y / z`
     */
    function mulDivF(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        Uint512 memory xy = mul512(x, y);
        // if `x * y < 2 ^ 256`
        if (xy.hi == 0) {
            return xy.lo / z;
        }
        // assert `x * y / z < 2 ^ 256`
        if (xy.hi >= z) {
            revert Overflow();
        }
        uint256 m = _mulMod(x, y, z); // `m = x * y % z`
        Uint512 memory n = _sub512(xy, m); // `n = x * y - m` hence `n / z = floor(x * y / z)`
        // if `n < 2 ^ 256`
        if (n.hi == 0) {
            return n.lo / z;
        }
        uint256 p = _unsafeSub(0, z) & z; // `p` is the largest power of 2 which `z` is divisible by
        uint256 q = _div512(n, p); // `n` is divisible by `p` because `n` is divisible by `z` and `z` is divisible by `p`
        uint256 r = _inv256(z / p); // `z / p = 1 mod 2` hence `inverse(z / p) = 1 mod 2 ^ 256`
        return _unsafeMul(q, r); // `q * r = (n / p) * inverse(z / p) = n / z`
    }
    /**
     * @dev returns the smallest integer larger than or equal to `x * y / z`
     */
    function mulDivC(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        uint256 w = mulDivF(x, y, z);
        if (_mulMod(x, y, z) > 0) {
            if (w >= type(uint256).max) {
                revert Overflow();
            }
            return w + 1;
        }
        return w;
    }
    /**
     * @dev returns the maximum of `n1 - n2` and 0
     */
    function subMax0(uint256 n1, uint256 n2) internal pure returns (uint256) {
        return n1 > n2 ? n1 - n2 : 0;
    }
    /**
     * @dev returns the value of `x > y`
     */
    function gt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi > y.hi || (x.hi == y.hi && x.lo > y.lo);
    }
    /**
     * @dev returns the value of `x < y`
     */
    function lt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
    }
    /**
     * @dev returns the value of `x >= y`
     */
    function gte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !lt512(x, y);
    }
    /**
     * @dev returns the value of `x <= y`
     */
    function lte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !gt512(x, y);
    }
    /**
     * @dev returns the value of `x * y`
     */
    function mul512(uint256 x, uint256 y) internal pure returns (Uint512 memory) {
        uint256 p = _mulModMax(x, y);
        uint256 q = _unsafeMul(x, y);
        if (p >= q) {
            return Uint512({ hi: p - q, lo: q });
        }
        return Uint512({ hi: _unsafeSub(p, q) - 1, lo: q });
    }
    /**
     * @dev returns the value of `x - y`, given that `x >= y`
     */
    function _sub512(Uint512 memory x, uint256 y) private pure returns (Uint512 memory) {
        if (x.lo >= y) {
            return Uint512({ hi: x.hi, lo: x.lo - y });
        }
        return Uint512({ hi: x.hi - 1, lo: _unsafeSub(x.lo, y) });
    }
    /**
     * @dev returns the value of `x / pow2n`, given that `x` is divisible by `pow2n`
     */
    function _div512(Uint512 memory x, uint256 pow2n) private pure returns (uint256) {
        uint256 pow2nInv = _unsafeAdd(_unsafeSub(0, pow2n) / pow2n, 1); // `1 << (256 - n)`
        return _unsafeMul(x.hi, pow2nInv) | (x.lo / pow2n); // `(x.hi << (256 - n)) | (x.lo >> n)`
    }
    /**
     * @dev returns the inverse of `d` modulo `2 ^ 256`, given that `d` is congruent to `1` modulo `2`
     */
    function _inv256(uint256 d) private pure returns (uint256) {
        // approximate the root of `f(x) = 1 / x - d` using the newton–raphson convergence method
        uint256 x = 1;
        for (uint256 i = 0; i < 8; i++) {
            x = _unsafeMul(x, _unsafeSub(2, _unsafeMul(x, d))); // `x = x * (2 - x * d) mod 2 ^ 256`
        }
        return x;
    }
    /**
     * @dev returns `(x + y) % 2 ^ 256`
     */
    function _unsafeAdd(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x + y;
        }
    }
    /**
     * @dev returns `(x - y) % 2 ^ 256`
     */
    function _unsafeSub(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x - y;
        }
    }
    /**
     * @dev returns `(x * y) % 2 ^ 256`
     */
    function _unsafeMul(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x * y;
        }
    }
    /**
     * @dev returns `x * y % (2 ^ 256 - 1)`
     */
    function _mulModMax(uint256 x, uint256 y) private pure returns (uint256) {
        return mulmod(x, y, type(uint256).max);
    }
    /**
     * @dev returns `x * y % z`
     */
    function _mulMod(
        uint256 x,
        uint256 y,
        uint256 z
    ) private pure returns (uint256) {
        return mulmod(x, y, z);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IOwned } from "./interfaces/IOwned.sol";
import { AccessDenied } from "./Utils.sol";
/**
 * @dev this contract provides support and utilities for contract ownership
 */
abstract contract Owned is IOwned {
    error SameOwner();
    address private _owner;
    address private _newOwner;
    /**
     * @dev triggered when the owner is updated
     */
    event OwnerUpdate(address indexed prevOwner, address indexed newOwner);
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract
     */
    constructor() {
        _setOwnership(msg.sender);
    }
    // solhint-enable func-name-mixedcase
    // allows execution by the owner only
    modifier onlyOwner() {
        _onlyOwner();
        _;
    }
    // error message binary size optimization
    function _onlyOwner() private view {
        if (msg.sender != _owner) {
            revert AccessDenied();
        }
    }
    /**
     * @inheritdoc IOwned
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @inheritdoc IOwned
     */
    function transferOwnership(address ownerCandidate) public virtual onlyOwner {
        if (ownerCandidate == _owner) {
            revert SameOwner();
        }
        _newOwner = ownerCandidate;
    }
    /**
     * @inheritdoc IOwned
     */
    function acceptOwnership() public virtual {
        if (msg.sender != _newOwner) {
            revert AccessDenied();
        }
        _setOwnership(_newOwner);
    }
    /**
     * @dev returns the address of the new owner candidate
     */
    function newOwner() external view returns (address) {
        return _newOwner;
    }
    /**
     * @dev sets the new owner internally
     */
    function _setOwnership(address ownerCandidate) private {
        address prevOwner = _owner;
        _owner = ownerCandidate;
        _newOwner = address(0);
        emit OwnerUpdate({ prevOwner: prevOwner, newOwner: ownerCandidate });
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
abstract contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev Owned interface
 */
interface IOwned {
    /**
     * @dev returns the address of the current owner
     */
    function owner() external view returns (address);
    /**
     * @dev allows transferring the contract ownership
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     * - the new owner still needs to accept the transfer
     */
    function transferOwnership(address ownerCandidate) external;
    /**
     * @dev used by a new owner to accept an ownership transfer
     */
    function acceptOwnership() external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "./IVersioned.sol";
import { IAccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/IAccessControlEnumerableUpgradeable.sol";
/**
 * @dev this is the common interface for upgradeable contracts
 */
interface IUpgradeable is IAccessControlEnumerableUpgradeable, IVersioned {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev an interface for a versioned contract
 */
interface IVersioned {
    function version() external view returns (uint16);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IExternalProtectionVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IMasterVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
// the asset manager role is required to access all the funds
bytes32 constant ROLE_ASSET_MANAGER = keccak256("ROLE_ASSET_MANAGER");
interface IVault is IUpgradeable {
    /**
     * @dev triggered when tokens have been withdrawn from the vault
     */
    event FundsWithdrawn(Token indexed token, address indexed caller, address indexed target, uint256 amount);
    /**
     * @dev triggered when tokens have been burned from the vault
     */
    event FundsBurned(Token indexed token, address indexed caller, uint256 amount);
    /**
     * @dev tells whether the vault accepts native token deposits
     */
    function isPayable() external view returns (bool);
    /**
     * @dev withdraws funds held by the contract and sends them to an account
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    ) external;
    /**
     * @dev burns funds held by the contract
     */
    function burn(Token token, uint256 amount) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
pragma solidity ^0.8.0;
/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822Proxiable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/ERC1967/ERC1967Proxy.sol)
pragma solidity ^0.8.0;
import "../Proxy.sol";
import "./ERC1967Upgrade.sol";
/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 */
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _upgradeToAndCall(_logic, _data, false);
    }
    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        return ERC1967Upgrade._getImplementation();
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)
pragma solidity ^0.8.2;
import "../beacon/IBeacon.sol";
import "../../interfaces/draft-IERC1822.sol";
import "../../utils/Address.sol";
import "../../utils/StorageSlot.sol";
/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);
    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }
    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }
    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }
    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }
    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);
    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }
    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }
    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);
    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }
    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/Proxy.sol)
pragma solidity ^0.8.0;
/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())
            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())
            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }
    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);
    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }
    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
pragma solidity ^0.8.0;
/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/StorageSlot.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }
    struct BooleanSlot {
        bool value;
    }
    struct Bytes32Slot {
        bytes32 value;
    }
    struct Uint256Slot {
        uint256 value;
    }
    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1000000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { ERC1967Proxy } from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
import { AccessDenied, Utils } from "./Utils.sol";
/**
 * @dev this contract is a slightly optimized version of the original TransparentUpgradeableProxy solely designed to
 * work with the ProxyAdmin contract:
 *
 * - the address of the admin is stored as an immutable state variables and as the result:
 * - the address of the admin can't be change, so the changeAdmin() function was subsequently removed
 */
contract TransparentUpgradeableProxyImmutable is ERC1967Proxy, Utils {
    address internal immutable _admin;
    /**
     * @dev initializes an upgradeable proxy managed by `initAdmin`, backed by the implementation at `logic`, and
     * optionally initialized with `data` as explained in {ERC1967Proxy-constructor}
     */
    constructor(
        address logic,
        address initAdmin,
        bytes memory data
    ) payable ERC1967Proxy(logic, data) validAddress(initAdmin) {
        _admin = initAdmin;
        // still store it to work with EIP-1967
        _changeAdmin(initAdmin);
    }
    modifier ifAdmin() {
        if (msg.sender == _admin) {
            _;
        } else {
            _fallback();
        }
    }
    /**
     * @dev returns the current admin
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function admin() external ifAdmin returns (address) {
        return _admin;
    }
    /**
     * @dev returns the current implementation.
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function implementation() external ifAdmin returns (address) {
        return _implementation();
    }
    /**
     * @dev upgrades the implementation of the proxy
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeToAndCall(newImplementation, bytes(""), false);
    }
    /**
     * @dev upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by data, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
        _upgradeToAndCall(newImplementation, data, true);
    }
    /**
     * @dev makes sure the admin cannot access the fallback function
     */
    function _beforeFallback() internal virtual override {
        if (msg.sender == _admin) {
            revert AccessDenied();
        }
        super._beforeFallback();
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidType();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
/// @title Claimable contract interface
interface IClaimable {
    function owner() external view returns (address);
    function transferOwnership(address newOwner) external;
    function acceptOwnership() external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IClaimable.sol";
/// @title Mintable Token interface
interface IMintableToken is IERC20, IClaimable {
    function issue(address to, uint256 amount) external;
    function destroy(address from, uint256 amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "./IMintableToken.sol";
/// @title The interface for mintable/burnable token governance.
interface ITokenGovernance {
    // The address of the mintable ERC20 token.
    function token() external view returns (IMintableToken);
    /// @dev Mints new tokens.
    ///
    /// @param to Account to receive the new amount.
    /// @param amount Amount to increase the supply by.
    ///
    function mint(address to, uint256 amount) external;
    /// @dev Burns tokens from the caller.
    ///
    /// @param amount Amount to decrease the supply by.
    ///
    function burn(uint256 amount) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlEnumerableUpgradeable.sol";
import "./AccessControlUpgradeable.sol";
import "../utils/structs/EnumerableSetUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Extension of {AccessControl} that allows enumerating the members of each role.
 */
abstract contract AccessControlEnumerableUpgradeable is Initializable, IAccessControlEnumerableUpgradeable, AccessControlUpgradeable {
    function __AccessControlEnumerable_init() internal onlyInitializing {
    }
    function __AccessControlEnumerable_init_unchained() internal onlyInitializing {
    }
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    mapping(bytes32 => EnumerableSetUpgradeable.AddressSet) private _roleMembers;
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlEnumerableUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
        return _roleMembers[role].at(index);
    }
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
        return _roleMembers[role].length();
    }
    /**
     * @dev Overload {_grantRole} to track enumerable memberships
     */
    function _grantRole(bytes32 role, address account) internal virtual override {
        super._grantRole(role, account);
        _roleMembers[role].add(account);
    }
    /**
     * @dev Overload {_revokeRole} to track enumerable memberships
     */
    function _revokeRole(bytes32 role, address account) internal virtual override {
        super._revokeRole(role, account);
        _roleMembers[role].remove(account);
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "../utils/StringsUpgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
    function __AccessControl_init() internal onlyInitializing {
    }
    function __AccessControl_init_unchained() internal onlyInitializing {
    }
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }
    mapping(bytes32 => RoleData) private _roles;
    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }
    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(uint160(account), 20),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");
        _revokeRole(role, account);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }
    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
/**
 * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
 */
interface IAccessControlEnumerableUpgradeable is IAccessControlUpgradeable {
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) external view returns (address);
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.0;
import "../../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }
    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }
    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165Upgradeable.sol";
import "../../proxy/utils/Initializable.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    function __ERC165_init() internal onlyInitializing {
    }
    function __ERC165_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165Upgradeable).interfaceId;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;
        assembly {
            result := store
        }
        return result;
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;
        assembly {
            result := store
        }
        return result;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][spender] + addedValue);
        return true;
    }
    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }
        return true;
    }
    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        _beforeTokenTransfer(from, to, amount);
        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;
        emit Transfer(from, to, amount);
        _afterTokenTransfer(from, to, amount);
    }
    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address(0), account, amount);
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
        _afterTokenTransfer(address(0), account, amount);
    }
    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        _beforeTokenTransfer(account, address(0), amount);
        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;
        emit Transfer(account, address(0), amount);
        _afterTokenTransfer(account, address(0), amount);
    }
    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @dev Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }
    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }
    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
import { IPoolCollection } from "../../pools/interfaces/IPoolCollection.sol";
import { IPoolToken } from "../../pools/interfaces/IPoolToken.sol";
/**
 * @dev Flash-loan recipient interface
 */
interface IFlashLoanRecipient {
    /**
     * @dev a flash-loan recipient callback after each the caller must return the borrowed amount and an additional fee
     */
    function onFlashLoan(
        address caller,
        IERC20 erc20Token,
        uint256 amount,
        uint256 feeAmount,
        bytes memory data
    ) external;
}
/**
 * @dev Bancor Network interface
 */
interface IBancorNetwork is IUpgradeable {
    /**
     * @dev returns the set of all valid pool collections
     */
    function poolCollections() external view returns (IPoolCollection[] memory);
    /**
     * @dev returns the set of all liquidity pools
     */
    function liquidityPools() external view returns (Token[] memory);
    /**
     * @dev returns the respective pool collection for the provided pool
     */
    function collectionByPool(Token pool) external view returns (IPoolCollection);
    /**
     * @dev creates new pools
     *
     * requirements:
     *
     * - none of the pools already exists
     */
    function createPools(Token[] calldata tokens, IPoolCollection poolCollection) external;
    /**
     * @dev migrates a list of pools between pool collections
     *
     * notes:
     *
     * - invalid or incompatible pools will be skipped gracefully
     */
    function migratePools(Token[] calldata pools, IPoolCollection newPoolCollection) external;
    /**
     * @dev deposits liquidity for the specified provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function depositFor(
        address provider,
        Token pool,
        uint256 tokenAmount
    ) external payable returns (uint256);
    /**
     * @dev deposits liquidity for the current provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the tokens on its behalf (except for in the
     *   native token case)
     */
    function deposit(Token pool, uint256 tokenAmount) external payable returns (uint256);
    /**
     * @dev initiates liquidity withdrawal
     *
     * requirements:
     *
     * - the caller must have approved the contract to transfer the pool token amount on its behalf
     */
    function initWithdrawal(IPoolToken poolToken, uint256 poolTokenAmount) external returns (uint256);
    /**
     * @dev cancels a withdrawal request, and returns the number of pool token amount associated with the withdrawal
     * request
     *
     * requirements:
     *
     * - the caller must have already initiated a withdrawal and received the specified id
     */
    function cancelWithdrawal(uint256 id) external returns (uint256);
    /**
     * @dev withdraws liquidity and returns the withdrawn amount
     *
     * requirements:
     *
     * - the provider must have already initiated a withdrawal and received the specified id
     * - the specified withdrawal request is eligible for completion
     * - the provider must have approved the network to transfer vBNT amount on its behalf, when withdrawing BNT
     * liquidity
     */
    function withdraw(uint256 id) external returns (uint256);
    /**
     * @dev performs a trade by providing the input source amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade target amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev performs a trade by providing the output target amount, sends the proceeds to the optional beneficiary (or
     * to the address of the caller, in case it's not supplied), and returns the trade source amount
     *
     * requirements:
     *
     * - the caller must have approved the network to transfer the source tokens on its behalf (except for in the
     *   native token case)
     */
    function tradeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount,
        uint256 deadline,
        address beneficiary
    ) external payable returns (uint256);
    /**
     * @dev provides a flash-loan
     *
     * requirements:
     *
     * - the recipient's callback must return *at least* the borrowed amount and fee back to the specified return address
     */
    function flashLoan(
        Token token,
        uint256 amount,
        IFlashLoanRecipient recipient,
        bytes calldata data
    ) external;
    /**
     * @dev deposits liquidity during a migration
     */
    function migrateLiquidity(
        Token token,
        address provider,
        uint256 amount,
        uint256 availableAmount,
        uint256 originalAmount
    ) external payable;
    /**
     * @dev withdraws pending network fees, and returns the amount of fees withdrawn
     *
     * requirements:
     *
     * - the caller must have the ROLE_NETWORK_FEE_MANAGER privilege
     */
    function withdrawNetworkFees(address recipient) external returns (uint256);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
error NotWhitelisted();
struct VortexRewards {
    // the percentage of converted BNT to be sent to the initiator of the burning event (in units of PPM)
    uint32 burnRewardPPM;
    // the maximum burn reward to be sent to the initiator of the burning event
    uint256 burnRewardMaxAmount;
}
/**
 * @dev Network Settings interface
 */
interface INetworkSettings is IUpgradeable {
    /**
     * @dev returns the protected tokens whitelist
     */
    function protectedTokenWhitelist() external view returns (Token[] memory);
    /**
     * @dev checks whether a given token is whitelisted
     */
    function isTokenWhitelisted(Token pool) external view returns (bool);
    /**
     * @dev returns the BNT funding limit for a given pool
     */
    function poolFundingLimit(Token pool) external view returns (uint256);
    /**
     * @dev returns the minimum BNT trading liquidity required before the system enables trading in the relevant pool
     */
    function minLiquidityForTrading() external view returns (uint256);
    /**
     * @dev returns the withdrawal fee (in units of PPM)
     */
    function withdrawalFeePPM() external view returns (uint32);
    /**
     * @dev returns the default flash-loan fee (in units of PPM)
     */
    function defaultFlashLoanFeePPM() external view returns (uint32);
    /**
     * @dev returns the flash-loan fee (in units of PPM) of a pool
     */
    function flashLoanFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns the vortex settings
     */
    function vortexRewards() external view returns (VortexRewards memory);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { ITokenGovernance } from "@bancor/token-governance/contracts/ITokenGovernance.sol";
import { IVersioned } from "../utility/interfaces/IVersioned.sol";
import { Upgradeable } from "../utility/Upgradeable.sol";
import { InvalidParam, InvalidStakedBalance } from "../utility/Utils.sol";
import { PPM_RESOLUTION } from "../utility/Constants.sol";
import { MathEx } from "../utility/MathEx.sol";
import { IBancorNetwork } from "../network/interfaces/IBancorNetwork.sol";
import { INetworkSettings, NotWhitelisted } from "../network/interfaces/INetworkSettings.sol";
import { IMasterVault } from "../vaults/interfaces/IMasterVault.sol";
// prettier-ignore
import {
    IBNTPool,
    ROLE_BNT_POOL_TOKEN_MANAGER,
    ROLE_BNT_MANAGER,
    ROLE_VAULT_MANAGER,
    ROLE_FUNDING_MANAGER
} from "./interfaces/IBNTPool.sol";
import { IPoolToken } from "./interfaces/IPoolToken.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { Vault } from "../vaults/Vault.sol";
import { IVault } from "../vaults/interfaces/IVault.sol";
/**
 * @dev BNT Pool contract
 */
contract BNTPool is IBNTPool, Vault {
    using TokenLibrary for Token;
    error FundingLimitExceeded();
    struct InternalWithdrawalAmounts {
        uint256 bntAmount;
        uint256 withdrawalFeeAmount;
    }
    // the network contract
    IBancorNetwork private immutable _network;
    // the network settings contract
    INetworkSettings private immutable _networkSettings;
    // the master vault contract
    IMasterVault private immutable _masterVault;
    // the BNT pool token
    IPoolToken internal immutable _poolToken;
    // the total staked BNT balance in the network
    uint256 private _stakedBalance;
    // a mapping between pools and their current funding
    mapping(Token => uint256) private _currentPoolFunding;
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 2] private __gap;
    /**
     * @dev triggered when liquidity is deposited
     */
    event TokensDeposited(
        bytes32 indexed contextId,
        address indexed provider,
        uint256 bntAmount,
        uint256 poolTokenAmount,
        uint256 vbntAmount
    );
    /**
     * @dev triggered when liquidity is withdrawn
     */
    event TokensWithdrawn(
        bytes32 indexed contextId,
        address indexed provider,
        uint256 bntAmount,
        uint256 poolTokenAmount,
        uint256 vbntAmount,
        uint256 withdrawalFeeAmount
    );
    /**
     * @dev triggered when funding is requested
     */
    event FundingRequested(bytes32 indexed contextId, Token indexed pool, uint256 bntAmount, uint256 poolTokenAmount);
    /**
     * @dev triggered when funding is renounced
     */
    event FundingRenounced(bytes32 indexed contextId, Token indexed pool, uint256 bntAmount, uint256 poolTokenAmount);
    /**
     * @dev triggered when the total liquidity in the BNT pool is updated
     */
    event TotalLiquidityUpdated(
        bytes32 indexed contextId,
        uint256 liquidity,
        uint256 stakedBalance,
        uint256 poolTokenSupply
    );
    /**
     * @dev a "virtual" constructor that is only used to set immutable state variables
     */
    constructor(
        IBancorNetwork initNetwork,
        ITokenGovernance initBNTGovernance,
        ITokenGovernance initVBNTGovernance,
        INetworkSettings initNetworkSettings,
        IMasterVault initMasterVault,
        IPoolToken initBNTPoolToken
    )
        Vault(initBNTGovernance, initVBNTGovernance)
        validAddress(address(initNetwork))
        validAddress(address(initNetworkSettings))
        validAddress(address(initMasterVault))
        validAddress(address(initBNTPoolToken))
    {
        _network = initNetwork;
        _networkSettings = initNetworkSettings;
        _masterVault = initMasterVault;
        _poolToken = initBNTPoolToken;
    }
    /**
     * @dev fully initializes the contract and its parents
     */
    function initialize() external initializer {
        __BNTPool_init();
    }
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __BNTPool_init() internal onlyInitializing {
        __Vault_init();
        __BNTPool_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __BNTPool_init_unchained() internal onlyInitializing {
        _poolToken.acceptOwnership();
        // set up administrative roles
        _setRoleAdmin(ROLE_BNT_POOL_TOKEN_MANAGER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_BNT_MANAGER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_VAULT_MANAGER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_FUNDING_MANAGER, ROLE_ADMIN);
    }
    // solhint-enable func-name-mixedcase
    modifier poolWhitelisted(Token pool) {
        _poolWhitelisted(pool);
        _;
    }
    /**
     * @dev validates that the provided pool is whitelisted
     */
    function _poolWhitelisted(Token pool) internal view {
        if (!_networkSettings.isTokenWhitelisted(pool)) {
            revert NotWhitelisted();
        }
    }
    /**
     * @inheritdoc Upgradeable
     */
    function version() public pure override(IVersioned, Upgradeable) returns (uint16) {
        return 3;
    }
    /**
     * @inheritdoc Vault
     */
    function isPayable() public pure override(IVault, Vault) returns (bool) {
        return false;
    }
    /**
     * @dev returns the BNT pool token manager role
     */
    function roleBNTPoolTokenManager() external pure returns (bytes32) {
        return ROLE_BNT_POOL_TOKEN_MANAGER;
    }
    /**
     * @dev returns the BNT manager role
     */
    function roleBNTManager() external pure returns (bytes32) {
        return ROLE_BNT_MANAGER;
    }
    /**
     * @dev returns the vault manager role
     */
    function roleVaultManager() external pure returns (bytes32) {
        return ROLE_VAULT_MANAGER;
    }
    /**
     * @dev returns the funding manager role
     */
    function roleFundingManager() external pure returns (bytes32) {
        return ROLE_FUNDING_MANAGER;
    }
    /**
     * @dev returns whether the given caller is allowed access to the given token
     *
     * requirements:
     *
     * - the token must be the BNT pool token
     * - the caller must have the ROLE_BNT_POOL_TOKEN_MANAGER role
     */
    function isAuthorizedWithdrawal(
        address caller,
        Token token,
        address, /* target */
        uint256 /* amount */
    ) internal view override returns (bool) {
        return token.isEqual(_poolToken) && hasRole(ROLE_BNT_POOL_TOKEN_MANAGER, caller);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function poolToken() external view returns (IPoolToken) {
        return _poolToken;
    }
    /**
     * @inheritdoc IBNTPool
     */
    function stakedBalance() external view returns (uint256) {
        return _stakedBalance;
    }
    /**
     * @inheritdoc IBNTPool
     */
    function currentPoolFunding(Token pool) external view returns (uint256) {
        return _currentPoolFunding[pool];
    }
    /**
     * @inheritdoc IBNTPool
     */
    function availableFunding(Token pool) external view returns (uint256) {
        return MathEx.subMax0(_networkSettings.poolFundingLimit(pool), _currentPoolFunding[pool]);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function poolTokenToUnderlying(uint256 poolTokenAmount) external view returns (uint256) {
        return _poolTokenToUnderlying(poolTokenAmount);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function underlyingToPoolToken(uint256 bntAmount) external view returns (uint256) {
        return _underlyingToPoolToken(bntAmount);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function poolTokenAmountToBurn(uint256 bntAmountToDistribute) external view returns (uint256) {
        if (bntAmountToDistribute == 0) {
            return 0;
        }
        uint256 poolTokenSupply = _poolToken.totalSupply();
        uint256 val = bntAmountToDistribute * poolTokenSupply;
        return
            MathEx.mulDivF(
                val,
                poolTokenSupply,
                val + _stakedBalance * (poolTokenSupply - _poolToken.balanceOf(address(this)))
            );
    }
    /**
     * @inheritdoc IBNTPool
     */
    function mint(address recipient, uint256 bntAmount)
        external
        onlyRoleMember(ROLE_BNT_MANAGER)
        validAddress(recipient)
        greaterThanZero(bntAmount)
    {
        _bntGovernance.mint(recipient, bntAmount);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function burnFromVault(uint256 bntAmount) external onlyRoleMember(ROLE_VAULT_MANAGER) greaterThanZero(bntAmount) {
        _masterVault.burn(Token(address(_bnt)), bntAmount);
    }
    /**
     * @inheritdoc IBNTPool
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        uint256 bntAmount,
        bool isMigrating,
        uint256 originalVBNTAmount
    ) external only(address(_network)) validAddress(provider) greaterThanZero(bntAmount) returns (uint256) {
        // calculate the required pool token amount
        uint256 currentStakedBalance = _stakedBalance;
        uint256 poolTokenTotalSupply = _poolToken.totalSupply();
        if (poolTokenTotalSupply == 0 && currentStakedBalance > 0) {
            revert InvalidStakedBalance();
        }
        uint256 poolTokenAmount = _underlyingToPoolToken(bntAmount, poolTokenTotalSupply, currentStakedBalance);
        // if the protocol doesn't have enough pool tokens, mint new ones
        uint256 poolTokenBalance = _poolToken.balanceOf(address(this));
        if (poolTokenAmount > poolTokenBalance) {
            uint256 newPoolTokenAmount = poolTokenAmount - poolTokenBalance;
            uint256 increaseStakedBalanceAmount = _poolTokenToUnderlying(
                newPoolTokenAmount,
                currentStakedBalance,
                poolTokenTotalSupply
            );
            // update the staked balance
            _stakedBalance = currentStakedBalance + increaseStakedBalanceAmount;
            // mint pool tokens to the protocol
            _poolToken.mint(address(this), newPoolTokenAmount);
        }
        // transfer pool tokens from the protocol to the provider
        _poolToken.transfer(provider, poolTokenAmount);
        // burn the previously received BNT
        _bntGovernance.burn(bntAmount);
        uint256 vbntAmount = poolTokenAmount;
        // the provider should receive pool tokens and vBNT in equal amounts. since the provider might already have
        // some vBNT during migration, the contract only mints the delta between the full amount and the amount the
        // provider already has
        if (isMigrating) {
            vbntAmount = MathEx.subMax0(vbntAmount, originalVBNTAmount);
        }
        // mint vBNT to the provider
        if (vbntAmount > 0) {
            _vbntGovernance.mint(provider, vbntAmount);
        }
        emit TokensDeposited({
            contextId: contextId,
            provider: provider,
            bntAmount: bntAmount,
            poolTokenAmount: poolTokenAmount,
            vbntAmount: vbntAmount
        });
        return poolTokenAmount;
    }
    /**
     * @inheritdoc IBNTPool
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        uint256 poolTokenAmount,
        uint256 bntAmount
    )
        external
        only(address(_network))
        validAddress(provider)
        greaterThanZero(poolTokenAmount)
        greaterThanZero(bntAmount)
        returns (uint256)
    {
        // ensure that the provided amounts correspond to the state of the pool. Note the pool tokens should
        // have been already deposited back from the network
        uint256 underlyingAmount = _poolTokenToUnderlying(poolTokenAmount);
        if (bntAmount > underlyingAmount) {
            revert InvalidParam();
        }
        InternalWithdrawalAmounts memory amounts = _withdrawalAmounts(bntAmount);
        // burn the respective vBNT amount
        _vbntGovernance.burn(poolTokenAmount);
        // mint BNT to the provider
        _bntGovernance.mint(provider, amounts.bntAmount);
        emit TokensWithdrawn({
            contextId: contextId,
            provider: provider,
            bntAmount: amounts.bntAmount,
            poolTokenAmount: poolTokenAmount,
            vbntAmount: poolTokenAmount,
            withdrawalFeeAmount: amounts.withdrawalFeeAmount
        });
        return amounts.bntAmount;
    }
    /**
     * @inheritdoc IBNTPool
     */
    function withdrawalAmount(uint256 poolTokenAmount)
        external
        view
        greaterThanZero(poolTokenAmount)
        returns (uint256)
    {
        return _withdrawalAmounts(_poolTokenToUnderlying(poolTokenAmount)).bntAmount;
    }
    /**
     * @inheritdoc IBNTPool
     */
    function requestFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external onlyRoleMember(ROLE_FUNDING_MANAGER) poolWhitelisted(pool) greaterThanZero(bntAmount) {
        uint256 currentFunding = _currentPoolFunding[pool];
        uint256 fundingLimit = _networkSettings.poolFundingLimit(pool);
        uint256 newFunding = currentFunding + bntAmount;
        // verify that the new funding amount doesn't exceed the limit
        if (newFunding > fundingLimit) {
            revert FundingLimitExceeded();
        }
        // calculate the pool token amount to mint
        uint256 currentStakedBalance = _stakedBalance;
        uint256 poolTokenAmount;
        uint256 poolTokenTotalSupply = _poolToken.totalSupply();
        if (poolTokenTotalSupply == 0 && currentStakedBalance > 0) {
            revert InvalidStakedBalance();
        }
        poolTokenAmount = _underlyingToPoolToken(bntAmount, poolTokenTotalSupply, currentStakedBalance);
        // update the staked balance
        uint256 newStakedBalance = currentStakedBalance + bntAmount;
        _stakedBalance = newStakedBalance;
        // update the current funding amount
        _currentPoolFunding[pool] = newFunding;
        // mint pool tokens to the protocol
        _poolToken.mint(address(this), poolTokenAmount);
        // mint BNT to the vault
        _bntGovernance.mint(address(_masterVault), bntAmount);
        emit FundingRequested({
            contextId: contextId,
            pool: pool,
            bntAmount: bntAmount,
            poolTokenAmount: poolTokenAmount
        });
        emit TotalLiquidityUpdated({
            contextId: contextId,
            liquidity: _bnt.balanceOf(address(_masterVault)),
            stakedBalance: newStakedBalance,
            poolTokenSupply: poolTokenTotalSupply + poolTokenAmount
        });
    }
    /**
     * @inheritdoc IBNTPool
     */
    function renounceFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external onlyRoleMember(ROLE_FUNDING_MANAGER) poolWhitelisted(pool) greaterThanZero(bntAmount) {
        uint256 currentStakedBalance = _stakedBalance;
        // calculate the final amount to deduct from the current pool funding
        uint256 currentFunding = _currentPoolFunding[pool];
        uint256 reduceFundingAmount = Math.min(currentFunding, bntAmount);
        // calculate the amount of pool tokens to burn
        // note that the given amount can exceed the total available but the request shouldn't fail
        uint256 poolTokenTotalSupply = _poolToken.totalSupply();
        uint256 poolTokenAmount = _underlyingToPoolToken(
            reduceFundingAmount,
            poolTokenTotalSupply,
            currentStakedBalance
        );
        // ensure the amount of pool tokens doesn't exceed the total available
        poolTokenAmount = Math.min(poolTokenAmount, _poolToken.balanceOf(address(this)));
        // calculate the final amount to deduct from the staked balance
        uint256 reduceStakedBalanceAmount = _poolTokenToUnderlying(
            poolTokenAmount,
            currentStakedBalance,
            poolTokenTotalSupply
        );
        // update the current pool funding. Note that the given amount can exceed the funding amount but the
        // request shouldn't fail (and the funding amount cannot get negative)
        _currentPoolFunding[pool] = currentFunding - reduceFundingAmount;
        // update the staked balance
        uint256 newStakedBalance = currentStakedBalance - reduceStakedBalanceAmount;
        _stakedBalance = newStakedBalance;
        // burn pool tokens from the protocol
        _poolToken.burn(poolTokenAmount);
        // burn all BNT from the master vault
        _masterVault.burn(Token(address(_bnt)), bntAmount);
        emit FundingRenounced({
            contextId: contextId,
            pool: pool,
            bntAmount: bntAmount,
            poolTokenAmount: poolTokenAmount
        });
        emit TotalLiquidityUpdated({
            contextId: contextId,
            liquidity: _bnt.balanceOf(address(_masterVault)),
            stakedBalance: newStakedBalance,
            poolTokenSupply: poolTokenTotalSupply - poolTokenAmount
        });
    }
    /**
     * @inheritdoc IBNTPool
     */
    function onFeesCollected(
        Token pool,
        uint256 feeAmount,
        bool isTradeFee
    ) external only(address(_network)) validAddress(address(pool)) {
        if (feeAmount == 0) {
            return;
        }
        // increase the staked balance by the given amount
        _stakedBalance += feeAmount;
        if (isTradeFee) {
            // increase the current funding for the specified pool by the given amount
            _currentPoolFunding[pool] += feeAmount;
        }
    }
    /**
     * @dev converts the specified pool token amount to the underlying BNT amount
     */
    function _poolTokenToUnderlying(uint256 poolTokenAmount) private view returns (uint256) {
        return _poolTokenToUnderlying(poolTokenAmount, _stakedBalance, _poolToken.totalSupply());
    }
    /**
     * @dev converts the specified pool token amount to the underlying BNT amount
     */
    function _poolTokenToUnderlying(
        uint256 poolTokenAmount,
        uint256 currentStakedBalance,
        uint256 poolTokenTotalSupply
    ) private pure returns (uint256) {
        // if no pool token supply exists yet, use a one-to-one pool token to BNT rate
        if (poolTokenTotalSupply == 0) {
            return poolTokenAmount;
        }
        return MathEx.mulDivF(poolTokenAmount, currentStakedBalance, poolTokenTotalSupply);
    }
    /**
     * @dev converts the specified underlying BNT amount to pool token amount
     */
    function _underlyingToPoolToken(uint256 bntAmount) private view returns (uint256) {
        return _underlyingToPoolToken(bntAmount, _poolToken.totalSupply(), _stakedBalance);
    }
    /**
     * @dev converts the specified underlying BNT amount to pool token amount
     */
    function _underlyingToPoolToken(
        uint256 bntAmount,
        uint256 poolTokenTotalSupply,
        uint256 currentStakedBalance
    ) private pure returns (uint256) {
        // if no pool token supply exists yet, use a one-to-one pool token to BNT rate
        if (poolTokenTotalSupply == 0) {
            return bntAmount;
        }
        return MathEx.mulDivC(bntAmount, poolTokenTotalSupply, currentStakedBalance);
    }
    /**
     * @dev returns withdrawal amounts
     */
    function _withdrawalAmounts(uint256 bntAmount) internal view returns (InternalWithdrawalAmounts memory) {
        // deduct the exit fee from BNT amount
        uint256 withdrawalFeeAmount = MathEx.mulDivF(bntAmount, _networkSettings.withdrawalFeePPM(), PPM_RESOLUTION);
        bntAmount -= withdrawalFeeAmount;
        return InternalWithdrawalAmounts({ bntAmount: bntAmount, withdrawalFeeAmount: withdrawalFeeAmount });
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IPoolToken } from "./IPoolToken.sol";
import { Token } from "../../token/Token.sol";
import { IVault } from "../../vaults/interfaces/IVault.sol";
// the BNT pool token manager role is required to access the BNT pool tokens
bytes32 constant ROLE_BNT_POOL_TOKEN_MANAGER = keccak256("ROLE_BNT_POOL_TOKEN_MANAGER");
// the BNT manager role is required to request the BNT pool to mint BNT
bytes32 constant ROLE_BNT_MANAGER = keccak256("ROLE_BNT_MANAGER");
// the vault manager role is required to request the BNT pool to burn BNT from the master vault
bytes32 constant ROLE_VAULT_MANAGER = keccak256("ROLE_VAULT_MANAGER");
// the funding manager role is required to request or renounce funding from the BNT pool
bytes32 constant ROLE_FUNDING_MANAGER = keccak256("ROLE_FUNDING_MANAGER");
/**
 * @dev BNT Pool interface
 */
interface IBNTPool is IVault {
    /**
     * @dev returns the BNT pool token contract
     */
    function poolToken() external view returns (IPoolToken);
    /**
     * @dev returns the total staked BNT balance in the network
     */
    function stakedBalance() external view returns (uint256);
    /**
     * @dev returns the current funding of given pool
     */
    function currentPoolFunding(Token pool) external view returns (uint256);
    /**
     * @dev returns the available BNT funding for a given pool
     */
    function availableFunding(Token pool) external view returns (uint256);
    /**
     * @dev converts the specified pool token amount to the underlying BNT amount
     */
    function poolTokenToUnderlying(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying BNT amount to pool token amount
     */
    function underlyingToPoolToken(uint256 bntAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(uint256 bntAmountToDistribute) external view returns (uint256);
    /**
     * @dev mints BNT to the recipient
     *
     * requirements:
     *
     * - the caller must have the ROLE_BNT_MANAGER role
     */
    function mint(address recipient, uint256 bntAmount) external;
    /**
     * @dev burns BNT from the vault
     *
     * requirements:
     *
     * - the caller must have the ROLE_VAULT_MANAGER role
     */
    function burnFromVault(uint256 bntAmount) external;
    /**
     * @dev deposits BNT liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - BNT tokens must have been already deposited into the contract
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        uint256 bntAmount,
        bool isMigrating,
        uint256 originalVBNTAmount
    ) external returns (uint256);
    /**
     * @dev withdraws BNT liquidity on behalf of a specific provider and returns the withdrawn BNT amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - bnBNT token must have been already deposited into the contract
     * - vBNT token must have been already deposited into the contract
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        uint256 poolTokenAmount,
        uint256 bntAmount
    ) external returns (uint256);
    /**
     * @dev returns the withdrawn BNT amount
     */
    function withdrawalAmount(uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev requests BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the request amount should be below the funding limit for a given pool
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function requestFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev renounces BNT funding
     *
     * requirements:
     *
     * - the caller must have the ROLE_FUNDING_MANAGER role
     * - the token must have been whitelisted
     * - the average rate of the pool must not deviate too much from its spot rate
     */
    function renounceFunding(
        bytes32 contextId,
        Token pool,
        uint256 bntAmount
    ) external;
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(
        Token pool,
        uint256 feeAmount,
        bool isTradeFee
    ) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { Fraction112 } from "../../utility/FractionLibrary.sol";
import { Token } from "../../token/Token.sol";
import { IPoolToken } from "./IPoolToken.sol";
struct PoolLiquidity {
    uint128 bntTradingLiquidity; // the BNT trading liquidity
    uint128 baseTokenTradingLiquidity; // the base token trading liquidity
    uint256 stakedBalance; // the staked balance
}
struct AverageRates {
    uint32 blockNumber;
    Fraction112 rate;
    Fraction112 invRate;
}
struct Pool {
    IPoolToken poolToken; // the pool token of the pool
    uint32 tradingFeePPM; // the trading fee (in units of PPM)
    bool tradingEnabled; // whether trading is enabled
    bool depositingEnabled; // whether depositing is enabled
    AverageRates averageRates; // the recent average rates
    PoolLiquidity liquidity; // the overall liquidity in the pool
}
struct WithdrawalAmounts {
    uint256 totalAmount;
    uint256 baseTokenAmount;
    uint256 bntAmount;
}
// trading enabling/disabling reasons
uint8 constant TRADING_STATUS_UPDATE_DEFAULT = 0;
uint8 constant TRADING_STATUS_UPDATE_ADMIN = 1;
uint8 constant TRADING_STATUS_UPDATE_MIN_LIQUIDITY = 2;
uint8 constant TRADING_STATUS_UPDATE_INVALID_STATE = 3;
struct TradeAmountAndFee {
    uint256 amount; // the source/target amount (depending on the context) resulting from the trade
    uint256 tradingFeeAmount; // the trading fee amount
    uint256 networkFeeAmount; // the network fee amount (always in units of BNT)
}
/**
 * @dev Pool Collection interface
 */
interface IPoolCollection is IVersioned {
    /**
     * @dev returns the type of the pool
     */
    function poolType() external view returns (uint16);
    /**
     * @dev returns the default trading fee (in units of PPM)
     */
    function defaultTradingFeePPM() external view returns (uint32);
    /**
     * @dev returns the network fee (in units of PPM)
     */
    function networkFeePPM() external view returns (uint32);
    /**
     * @dev returns all the pools which are managed by this pool collection
     */
    function pools() external view returns (Token[] memory);
    /**
     * @dev returns the number of all the pools which are managed by this pool collection
     */
    function poolCount() external view returns (uint256);
    /**
     * @dev returns whether a pool is valid
     */
    function isPoolValid(Token pool) external view returns (bool);
    /**
     * @dev returns the overall liquidity in the pool
     */
    function poolLiquidity(Token pool) external view returns (PoolLiquidity memory);
    /**
     * @dev returns the pool token of the pool
     */
    function poolToken(Token pool) external view returns (IPoolToken);
    /**
     * @dev returns the trading fee (in units of PPM)
     */
    function tradingFeePPM(Token pool) external view returns (uint32);
    /**
     * @dev returns whether trading is enabled
     */
    function tradingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether depositing is enabled
     */
    function depositingEnabled(Token pool) external view returns (bool);
    /**
     * @dev returns whether the pool is stable
     */
    function isPoolStable(Token pool) external view returns (bool);
    /**
     * @dev converts the specified pool token amount to the underlying base token amount
     */
    function poolTokenToUnderlying(Token pool, uint256 poolTokenAmount) external view returns (uint256);
    /**
     * @dev converts the specified underlying base token amount to pool token amount
     */
    function underlyingToPoolToken(Token pool, uint256 baseTokenAmount) external view returns (uint256);
    /**
     * @dev returns the number of pool token to burn in order to increase everyone's underlying value by the specified
     * amount
     */
    function poolTokenAmountToBurn(
        Token pool,
        uint256 baseTokenAmountToDistribute,
        uint256 protocolPoolTokenAmount
    ) external view returns (uint256);
    /**
     * @dev creates a new pool
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the pool should have been whitelisted
     * - the pool isn't already defined in the collection
     */
    function createPool(Token token) external;
    /**
     * @dev deposits base token liquidity on behalf of a specific provider and returns the respective pool token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - assumes that the base token has been already deposited in the vault
     */
    function depositFor(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev handles some of the withdrawal-related actions and returns the withdrawn base token amount
     *
     * requirements:
     *
     * - the caller must be the network contract
     * - the caller must have approved the collection to transfer/burn the pool token amount on its behalf
     */
    function withdraw(
        bytes32 contextId,
        address provider,
        Token pool,
        uint256 poolTokenAmount,
        uint256 baseTokenAmount
    ) external returns (uint256);
    /**
     * @dev returns the amounts that would be returned if the position is currently withdrawn,
     * along with the breakdown of the base token and the BNT compensation
     */
    function withdrawalAmounts(Token pool, uint256 poolTokenAmount) external view returns (WithdrawalAmounts memory);
    /**
     * @dev performs a trade by providing the source amount and returns the target amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeBySourceAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount,
        uint256 minReturnAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev performs a trade by providing the target amount and returns the required source amount and the associated fee
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function tradeByTargetAmount(
        bytes32 contextId,
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount,
        uint256 maxSourceAmount
    ) external returns (TradeAmountAndFee memory);
    /**
     * @dev returns the output amount and fee when trading by providing the source amount
     */
    function tradeOutputAndFeeBySourceAmount(
        Token sourceToken,
        Token targetToken,
        uint256 sourceAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev returns the input amount and fee when trading by providing the target amount
     */
    function tradeInputAndFeeByTargetAmount(
        Token sourceToken,
        Token targetToken,
        uint256 targetAmount
    ) external view returns (TradeAmountAndFee memory);
    /**
     * @dev notifies the pool of accrued fees
     *
     * requirements:
     *
     * - the caller must be the network contract
     */
    function onFeesCollected(Token pool, uint256 feeAmount) external;
    /**
     * @dev migrates a pool to this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolIn(Token pool, Pool calldata data) external;
    /**
     * @dev migrates a pool from this pool collection
     *
     * requirements:
     *
     * - the caller must be the pool migrator contract
     */
    function migratePoolOut(Token pool, IPoolCollection targetPoolCollection) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { IERC20Burnable } from "../../token/interfaces/IERC20Burnable.sol";
import { Token } from "../../token/Token.sol";
import { IVersioned } from "../../utility/interfaces/IVersioned.sol";
import { IOwned } from "../../utility/interfaces/IOwned.sol";
/**
 * @dev Pool Token interface
 */
interface IPoolToken is IVersioned, IOwned, IERC20, IERC20Permit, IERC20Burnable {
    /**
     * @dev returns the address of the reserve token
     */
    function reserveToken() external view returns (Token);
    /**
     * @dev increases the token supply and sends the new tokens to the given account
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     */
    function mint(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
 * @dev extends the SafeERC20 library with additional operations
 */
library SafeERC20Ex {
    using SafeERC20 for IERC20;
    /**
     * @dev ensures that the spender has sufficient allowance
     */
    function ensureApprove(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance >= amount) {
            return;
        }
        if (allowance > 0) {
            token.safeApprove(spender, 0);
        }
        token.safeApprove(spender, amount);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev the main purpose of the Token interfaces is to ensure artificially that we won't use ERC20's standard functions,
 * but only their safe versions, which are provided by SafeERC20 and SafeERC20Ex via the TokenLibrary contract
 */
interface Token {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { SafeERC20Ex } from "./SafeERC20Ex.sol";
import { Token } from "./Token.sol";
/**
 * @dev This library implements ERC20 and SafeERC20 utilities for both the native token and for ERC20 tokens
 */
library TokenLibrary {
    using SafeERC20 for IERC20;
    using SafeERC20Ex for IERC20;
    error PermitUnsupported();
    // the address that represents the native token reserve
    address private constant NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    // the symbol that represents the native token
    string private constant NATIVE_TOKEN_SYMBOL = "ETH";
    // the decimals for the native token
    uint8 private constant NATIVE_TOKEN_DECIMALS = 18;
    // the token representing the native token
    Token public constant NATIVE_TOKEN = Token(NATIVE_TOKEN_ADDRESS);
    /**
     * @dev returns whether the provided token represents an ERC20 or the native token reserve
     */
    function isNative(Token token) internal pure returns (bool) {
        return address(token) == NATIVE_TOKEN_ADDRESS;
    }
    /**
     * @dev returns the symbol of the native token/ERC20 token
     */
    function symbol(Token token) internal view returns (string memory) {
        if (isNative(token)) {
            return NATIVE_TOKEN_SYMBOL;
        }
        return toERC20(token).symbol();
    }
    /**
     * @dev returns the decimals of the native token/ERC20 token
     */
    function decimals(Token token) internal view returns (uint8) {
        if (isNative(token)) {
            return NATIVE_TOKEN_DECIMALS;
        }
        return toERC20(token).decimals();
    }
    /**
     * @dev returns the balance of the native token/ERC20 token
     */
    function balanceOf(Token token, address account) internal view returns (uint256) {
        if (isNative(token)) {
            return account.balance;
        }
        return toIERC20(token).balanceOf(account);
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token
     */
    function safeTransfer(
        Token token,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        if (isNative(token)) {
            payable(to).transfer(amount);
        } else {
            toIERC20(token).safeTransfer(to, amount);
        }
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token from a specific holder using the allowance mechanism
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeTransferFrom(
        Token token,
        address from,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0 || isNative(token)) {
            return;
        }
        toIERC20(token).safeTransferFrom(from, to, amount);
    }
    /**
     * @dev approves a specific amount of the native token/ERC20 token from a specific holder
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).safeApprove(spender, amount);
    }
    /**
     * @dev ensures that the spender has sufficient allowance
     *
     * note that the function does not perform any action if the native token is provided
     */
    function ensureApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).ensureApprove(spender, amount);
    }
    /**
     * @dev compares between a token and another raw ERC20 token
     */
    function isEqual(Token token, IERC20 erc20Token) internal pure returns (bool) {
        return toIERC20(token) == erc20Token;
    }
    /**
     * @dev utility function that converts a token to an IERC20
     */
    function toIERC20(Token token) internal pure returns (IERC20) {
        return IERC20(address(token));
    }
    /**
     * @dev utility function that converts a token to an ERC20
     */
    function toERC20(Token token) internal pure returns (ERC20) {
        return ERC20(address(token));
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev burnable ERC20 interface
 */
interface IERC20Burnable {
    /**
     * @dev Destroys tokens from the caller.
     */
    function burn(uint256 amount) external;
    /**
     * @dev Destroys tokens from a recipient, deducting from the caller's allowance
     *
     * requirements:
     *
     * - the caller must have allowance for recipient's tokens of at least the specified amount
     */
    function burnFrom(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1_000_000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
struct Fraction {
    uint256 n;
    uint256 d;
}
struct Fraction112 {
    uint112 n;
    uint112 d;
}
error InvalidFraction();
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Fraction, Fraction112, InvalidFraction } from "./Fraction.sol";
import { MathEx } from "./MathEx.sol";
// solhint-disable-next-line func-visibility
function zeroFraction() pure returns (Fraction memory) {
    return Fraction({ n: 0, d: 1 });
}
// solhint-disable-next-line func-visibility
function zeroFraction112() pure returns (Fraction112 memory) {
    return Fraction112({ n: 0, d: 1 });
}
/**
 * @dev this library provides a set of fraction operations
 */
library FractionLibrary {
    /**
     * @dev returns whether a standard fraction is valid
     */
    function isValid(Fraction memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is valid
     */
    function isValid(Fraction112 memory fraction) internal pure returns (bool) {
        return fraction.d != 0;
    }
    /**
     * @dev returns whether a standard fraction is positive
     */
    function isPositive(Fraction memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns whether a 112-bit fraction is positive
     */
    function isPositive(Fraction112 memory fraction) internal pure returns (bool) {
        return isValid(fraction) && fraction.n != 0;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction memory fraction) internal pure returns (Fraction memory) {
        Fraction memory invFraction = Fraction({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev returns the inverse of a given fraction
     */
    function inverse(Fraction112 memory fraction) internal pure returns (Fraction112 memory) {
        Fraction112 memory invFraction = Fraction112({ n: fraction.d, d: fraction.n });
        if (!isValid(invFraction)) {
            revert InvalidFraction();
        }
        return invFraction;
    }
    /**
     * @dev reduces a standard fraction to a 112-bit fraction
     */
    function toFraction112(Fraction memory fraction) internal pure returns (Fraction112 memory) {
        Fraction memory reducedFraction = MathEx.reducedFraction(fraction, type(uint112).max);
        return Fraction112({ n: uint112(reducedFraction.n), d: uint112(reducedFraction.d) });
    }
    /**
     * @dev expands a 112-bit fraction to a standard fraction
     */
    function fromFraction112(Fraction112 memory fraction) internal pure returns (Fraction memory) {
        return Fraction({ n: fraction.n, d: fraction.d });
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Fraction, InvalidFraction } from "./Fraction.sol";
import { PPM_RESOLUTION } from "./Constants.sol";
uint256 constant ONE = 0x80000000000000000000000000000000;
uint256 constant LN2 = 0x58b90bfbe8e7bcd5e4f1d9cc01f97b57;
struct Uint512 {
    uint256 hi; // 256 most significant bits
    uint256 lo; // 256 least significant bits
}
struct Sint256 {
    uint256 value;
    bool isNeg;
}
/**
 * @dev this library provides a set of complex math operations
 */
library MathEx {
    error Overflow();
    /**
     * @dev returns `2 ^ f` by calculating `e ^ (f * ln(2))`, where `e` is Euler's number:
     * - Rewrite the input as a sum of binary exponents and a single residual r, as small as possible
     * - The exponentiation of each binary exponent is given (pre-calculated)
     * - The exponentiation of r is calculated via Taylor series for e^x, where x = r
     * - The exponentiation of the input is calculated by multiplying the intermediate results above
     * - For example: e^5.521692859 = e^(4 + 1 + 0.5 + 0.021692859) = e^4 * e^1 * e^0.5 * e^0.021692859
     */
    function exp2(Fraction memory f) internal pure returns (Fraction memory) {
        uint256 x = MathEx.mulDivF(LN2, f.n, f.d);
        uint256 y;
        uint256 z;
        uint256 n;
        if (x >= (ONE << 4)) {
            revert Overflow();
        }
        unchecked {
            z = y = x % (ONE >> 3); // get the input modulo 2^(-3)
            z = (z * y) / ONE;
            n += z * 0x10e1b3be415a0000; // add y^02 * (20! / 02!)
            z = (z * y) / ONE;
            n += z * 0x05a0913f6b1e0000; // add y^03 * (20! / 03!)
            z = (z * y) / ONE;
            n += z * 0x0168244fdac78000; // add y^04 * (20! / 04!)
            z = (z * y) / ONE;
            n += z * 0x004807432bc18000; // add y^05 * (20! / 05!)
            z = (z * y) / ONE;
            n += z * 0x000c0135dca04000; // add y^06 * (20! / 06!)
            z = (z * y) / ONE;
            n += z * 0x0001b707b1cdc000; // add y^07 * (20! / 07!)
            z = (z * y) / ONE;
            n += z * 0x000036e0f639b800; // add y^08 * (20! / 08!)
            z = (z * y) / ONE;
            n += z * 0x00000618fee9f800; // add y^09 * (20! / 09!)
            z = (z * y) / ONE;
            n += z * 0x0000009c197dcc00; // add y^10 * (20! / 10!)
            z = (z * y) / ONE;
            n += z * 0x0000000e30dce400; // add y^11 * (20! / 11!)
            z = (z * y) / ONE;
            n += z * 0x000000012ebd1300; // add y^12 * (20! / 12!)
            z = (z * y) / ONE;
            n += z * 0x0000000017499f00; // add y^13 * (20! / 13!)
            z = (z * y) / ONE;
            n += z * 0x0000000001a9d480; // add y^14 * (20! / 14!)
            z = (z * y) / ONE;
            n += z * 0x00000000001c6380; // add y^15 * (20! / 15!)
            z = (z * y) / ONE;
            n += z * 0x000000000001c638; // add y^16 * (20! / 16!)
            z = (z * y) / ONE;
            n += z * 0x0000000000001ab8; // add y^17 * (20! / 17!)
            z = (z * y) / ONE;
            n += z * 0x000000000000017c; // add y^18 * (20! / 18!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000014; // add y^19 * (20! / 19!)
            z = (z * y) / ONE;
            n += z * 0x0000000000000001; // add y^20 * (20! / 20!)
            n = n / 0x21c3677c82b40000 + y + ONE; // divide by 20! and then add y^1 / 1! + y^0 / 0!
            if ((x & (ONE >> 3)) != 0)
                n = (n * 0x1c3d6a24ed82218787d624d3e5eba95f9) / 0x18ebef9eac820ae8682b9793ac6d1e776; // multiply by e^(2^-3)
            if ((x & (ONE >> 2)) != 0)
                n = (n * 0x18ebef9eac820ae8682b9793ac6d1e778) / 0x1368b2fc6f9609fe7aceb46aa619baed4; // multiply by e^(2^-2)
            if ((x & (ONE >> 1)) != 0)
                n = (n * 0x1368b2fc6f9609fe7aceb46aa619baed5) / 0x0bc5ab1b16779be3575bd8f0520a9f21f; // multiply by e^(2^-1)
            if ((x & (ONE << 0)) != 0)
                n = (n * 0x0bc5ab1b16779be3575bd8f0520a9f21e) / 0x0454aaa8efe072e7f6ddbab84b40a55c9; // multiply by e^(2^+0)
            if ((x & (ONE << 1)) != 0)
                n = (n * 0x0454aaa8efe072e7f6ddbab84b40a55c5) / 0x00960aadc109e7a3bf4578099615711ea; // multiply by e^(2^+1)
            if ((x & (ONE << 2)) != 0)
                n = (n * 0x00960aadc109e7a3bf4578099615711d7) / 0x0002bf84208204f5977f9a8cf01fdce3d; // multiply by e^(2^+2)
            if ((x & (ONE << 3)) != 0)
                n = (n * 0x0002bf84208204f5977f9a8cf01fdc307) / 0x0000003c6ab775dd0b95b4cbee7e65d11; // multiply by e^(2^+3)
        }
        return Fraction({ n: n, d: ONE });
    }
    /**
     * @dev returns a fraction with reduced components
     */
    function reducedFraction(Fraction memory fraction, uint256 max) internal pure returns (Fraction memory) {
        uint256 scale = Math.ceilDiv(Math.max(fraction.n, fraction.d), max);
        Fraction memory reduced = Fraction({ n: fraction.n / scale, d: fraction.d / scale });
        if (reduced.d == 0) {
            revert InvalidFraction();
        }
        return reduced;
    }
    /**
     * @dev returns the weighted average of two fractions
     */
    function weightedAverage(
        Fraction memory fraction1,
        Fraction memory fraction2,
        uint256 weight1,
        uint256 weight2
    ) internal pure returns (Fraction memory) {
        return
            Fraction({
                n: fraction1.n * fraction2.d * weight1 + fraction1.d * fraction2.n * weight2,
                d: fraction1.d * fraction2.d * (weight1 + weight2)
            });
    }
    /**
     * @dev returns whether or not the deviation of an offset sample from a base sample is within a permitted range
     * for example, if the maximum permitted deviation is 5%, then evaluate `95% * base <= offset <= 105% * base`
     */
    function isInRange(
        Fraction memory baseSample,
        Fraction memory offsetSample,
        uint32 maxDeviationPPM
    ) internal pure returns (bool) {
        Uint512 memory min = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION - maxDeviationPPM));
        Uint512 memory mid = mul512(baseSample.d, offsetSample.n * PPM_RESOLUTION);
        Uint512 memory max = mul512(baseSample.n, offsetSample.d * (PPM_RESOLUTION + maxDeviationPPM));
        return lte512(min, mid) && lte512(mid, max);
    }
    /**
     * @dev returns an `Sint256` positive representation of an unsigned integer
     */
    function toPos256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: false });
    }
    /**
     * @dev returns an `Sint256` negative representation of an unsigned integer
     */
    function toNeg256(uint256 n) internal pure returns (Sint256 memory) {
        return Sint256({ value: n, isNeg: true });
    }
    /**
     * @dev returns the largest integer smaller than or equal to `x * y / z`
     */
    function mulDivF(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        Uint512 memory xy = mul512(x, y);
        // if `x * y < 2 ^ 256`
        if (xy.hi == 0) {
            return xy.lo / z;
        }
        // assert `x * y / z < 2 ^ 256`
        if (xy.hi >= z) {
            revert Overflow();
        }
        uint256 m = _mulMod(x, y, z); // `m = x * y % z`
        Uint512 memory n = _sub512(xy, m); // `n = x * y - m` hence `n / z = floor(x * y / z)`
        // if `n < 2 ^ 256`
        if (n.hi == 0) {
            return n.lo / z;
        }
        uint256 p = _unsafeSub(0, z) & z; // `p` is the largest power of 2 which `z` is divisible by
        uint256 q = _div512(n, p); // `n` is divisible by `p` because `n` is divisible by `z` and `z` is divisible by `p`
        uint256 r = _inv256(z / p); // `z / p = 1 mod 2` hence `inverse(z / p) = 1 mod 2 ^ 256`
        return _unsafeMul(q, r); // `q * r = (n / p) * inverse(z / p) = n / z`
    }
    /**
     * @dev returns the smallest integer larger than or equal to `x * y / z`
     */
    function mulDivC(
        uint256 x,
        uint256 y,
        uint256 z
    ) internal pure returns (uint256) {
        uint256 w = mulDivF(x, y, z);
        if (_mulMod(x, y, z) > 0) {
            if (w >= type(uint256).max) {
                revert Overflow();
            }
            return w + 1;
        }
        return w;
    }
    /**
     * @dev returns the maximum of `n1 - n2` and 0
     */
    function subMax0(uint256 n1, uint256 n2) internal pure returns (uint256) {
        return n1 > n2 ? n1 - n2 : 0;
    }
    /**
     * @dev returns the value of `x > y`
     */
    function gt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi > y.hi || (x.hi == y.hi && x.lo > y.lo);
    }
    /**
     * @dev returns the value of `x < y`
     */
    function lt512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
    }
    /**
     * @dev returns the value of `x >= y`
     */
    function gte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !lt512(x, y);
    }
    /**
     * @dev returns the value of `x <= y`
     */
    function lte512(Uint512 memory x, Uint512 memory y) internal pure returns (bool) {
        return !gt512(x, y);
    }
    /**
     * @dev returns the value of `x * y`
     */
    function mul512(uint256 x, uint256 y) internal pure returns (Uint512 memory) {
        uint256 p = _mulModMax(x, y);
        uint256 q = _unsafeMul(x, y);
        if (p >= q) {
            return Uint512({ hi: p - q, lo: q });
        }
        return Uint512({ hi: _unsafeSub(p, q) - 1, lo: q });
    }
    /**
     * @dev returns the value of `x - y`, given that `x >= y`
     */
    function _sub512(Uint512 memory x, uint256 y) private pure returns (Uint512 memory) {
        if (x.lo >= y) {
            return Uint512({ hi: x.hi, lo: x.lo - y });
        }
        return Uint512({ hi: x.hi - 1, lo: _unsafeSub(x.lo, y) });
    }
    /**
     * @dev returns the value of `x / pow2n`, given that `x` is divisible by `pow2n`
     */
    function _div512(Uint512 memory x, uint256 pow2n) private pure returns (uint256) {
        uint256 pow2nInv = _unsafeAdd(_unsafeSub(0, pow2n) / pow2n, 1); // `1 << (256 - n)`
        return _unsafeMul(x.hi, pow2nInv) | (x.lo / pow2n); // `(x.hi << (256 - n)) | (x.lo >> n)`
    }
    /**
     * @dev returns the inverse of `d` modulo `2 ^ 256`, given that `d` is congruent to `1` modulo `2`
     */
    function _inv256(uint256 d) private pure returns (uint256) {
        // approximate the root of `f(x) = 1 / x - d` using the newton–raphson convergence method
        uint256 x = 1;
        for (uint256 i = 0; i < 8; i++) {
            x = _unsafeMul(x, _unsafeSub(2, _unsafeMul(x, d))); // `x = x * (2 - x * d) mod 2 ^ 256`
        }
        return x;
    }
    /**
     * @dev returns `(x + y) % 2 ^ 256`
     */
    function _unsafeAdd(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x + y;
        }
    }
    /**
     * @dev returns `(x - y) % 2 ^ 256`
     */
    function _unsafeSub(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x - y;
        }
    }
    /**
     * @dev returns `(x * y) % 2 ^ 256`
     */
    function _unsafeMul(uint256 x, uint256 y) private pure returns (uint256) {
        unchecked {
            return x * y;
        }
    }
    /**
     * @dev returns `x * y % (2 ^ 256 - 1)`
     */
    function _mulModMax(uint256 x, uint256 y) private pure returns (uint256) {
        return mulmod(x, y, type(uint256).max);
    }
    /**
     * @dev returns `x * y % z`
     */
    function _mulMod(
        uint256 x,
        uint256 y,
        uint256 z
    ) private pure returns (uint256) {
        return mulmod(x, y, z);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { AccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/AccessControlEnumerableUpgradeable.sol";
import { IUpgradeable } from "./interfaces/IUpgradeable.sol";
import { AccessDenied } from "./Utils.sol";
/**
 * @dev this contract provides common utilities for upgradeable contracts
 *
 * note that we're using the Transparent Upgradeable Proxy pattern and *not* the Universal Upgradeable Proxy Standard
 * (UUPS) pattern, therefore initializing the implementation contracts is not necessary or required
 */
abstract contract Upgradeable is IUpgradeable, AccessControlEnumerableUpgradeable {
    error AlreadyInitialized();
    // the admin role is used to allow a non-proxy admin to perform additional initialization/setup during contract
    // upgrades
    bytes32 internal constant ROLE_ADMIN = keccak256("ROLE_ADMIN");
    uint32 internal constant MAX_GAP = 50;
    uint16 internal _initializations;
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 1] private __gap;
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __Upgradeable_init() internal onlyInitializing {
        __AccessControl_init();
        __Upgradeable_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __Upgradeable_init_unchained() internal onlyInitializing {
        _initializations = 1;
        // set up administrative roles
        _setRoleAdmin(ROLE_ADMIN, ROLE_ADMIN);
        // allow the deployer to initially be the admin of the contract
        _setupRole(ROLE_ADMIN, msg.sender);
    }
    // solhint-enable func-name-mixedcase
    modifier onlyAdmin() {
        _hasRole(ROLE_ADMIN, msg.sender);
        _;
    }
    modifier onlyRoleMember(bytes32 role) {
        _hasRole(role, msg.sender);
        _;
    }
    function version() public view virtual override returns (uint16);
    /**
     * @dev returns the admin role
     */
    function roleAdmin() external pure returns (bytes32) {
        return ROLE_ADMIN;
    }
    /**
     * @dev performs post-upgrade initialization
     *
     * requirements:
     *
     * - this must can be called only once per-upgrade
     */
    function postUpgrade(bytes calldata data) external {
        uint16 initializations = _initializations + 1;
        if (initializations != version()) {
            revert AlreadyInitialized();
        }
        _initializations = initializations;
        _postUpgrade(data);
    }
    /**
     * @dev an optional post-upgrade callback that can be implemented by child contracts
     */
    function _postUpgrade(
        bytes calldata /* data */
    ) internal virtual {}
    function _hasRole(bytes32 role, address account) internal view {
        if (!hasRole(role, account)) {
            revert AccessDenied();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
abstract contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev Owned interface
 */
interface IOwned {
    /**
     * @dev returns the address of the current owner
     */
    function owner() external view returns (address);
    /**
     * @dev allows transferring the contract ownership
     *
     * requirements:
     *
     * - the caller must be the owner of the contract
     * - the new owner still needs to accept the transfer
     */
    function transferOwnership(address ownerCandidate) external;
    /**
     * @dev used by a new owner to accept an ownership transfer
     */
    function acceptOwnership() external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "./IVersioned.sol";
import { IAccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/IAccessControlEnumerableUpgradeable.sol";
/**
 * @dev this is the common interface for upgradeable contracts
 */
interface IUpgradeable is IAccessControlEnumerableUpgradeable, IVersioned {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev an interface for a versioned contract
 */
interface IVersioned {
    function version() external view returns (uint16);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import { PausableUpgradeable } from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import { ITokenGovernance } from "@bancor/token-governance/contracts/ITokenGovernance.sol";
import { IVault, ROLE_ASSET_MANAGER } from "./interfaces/IVault.sol";
import { Upgradeable } from "../utility/Upgradeable.sol";
import { IERC20Burnable } from "../token/interfaces/IERC20Burnable.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { Utils, AccessDenied, NotPayable, InvalidToken } from "../utility/Utils.sol";
abstract contract Vault is IVault, Upgradeable, PausableUpgradeable, ReentrancyGuardUpgradeable, Utils {
    using Address for address payable;
    using SafeERC20 for IERC20;
    using TokenLibrary for Token;
    // the address of the BNT token
    IERC20 internal immutable _bnt;
    // the address of the BNT token governance
    ITokenGovernance internal immutable _bntGovernance;
    // the address of the vBNT token
    IERC20 internal immutable _vbnt;
    // the address of the vBNT token governance
    ITokenGovernance internal immutable _vbntGovernance;
    // solhint-disable func-name-mixedcase
    /**
     * @dev a "virtual" constructor that is only used to set immutable state variables
     */
    constructor(ITokenGovernance initBNTGovernance, ITokenGovernance initVBNTGovernance)
        validAddress(address(initBNTGovernance))
        validAddress(address(initVBNTGovernance))
    {
        _bntGovernance = initBNTGovernance;
        _bnt = initBNTGovernance.token();
        _vbntGovernance = initVBNTGovernance;
        _vbnt = initVBNTGovernance.token();
    }
    /**
     * @dev initializes the contract and its parents
     */
    function __Vault_init() internal onlyInitializing {
        __Upgradeable_init();
        __Pausable_init();
        __ReentrancyGuard_init();
        __Vault_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __Vault_init_unchained() internal onlyInitializing {}
    // solhint-enable func-name-mixedcase
    /**
     * @dev returns the asset manager role
     */
    function roleAssetManager() external pure returns (bytes32) {
        return ROLE_ASSET_MANAGER;
    }
    // allows execution only by an authorized operation
    modifier whenAuthorized(
        address caller,
        Token token,
        address payable target,
        uint256 amount
    ) {
        if (!isAuthorizedWithdrawal(caller, token, target, amount)) {
            revert AccessDenied();
        }
        _;
    }
    /**
     * @dev returns whether withdrawals are currently paused
     */
    function isPaused() external view returns (bool) {
        return paused();
    }
    /**
     * @dev pauses withdrawals
     *
     * requirements:
     *
     * - the caller must have the ROLE_ADMIN privileges
     */
    function pause() external onlyAdmin {
        _pause();
    }
    /**
     * @dev unpauses withdrawals
     *
     * requirements:
     *
     * - the caller must have the ROLE_ADMIN privileges
     */
    function unpause() external onlyAdmin {
        _unpause();
    }
    /**
     * @inheritdoc IVault
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    ) external validAddress(target) nonReentrant whenNotPaused whenAuthorized(msg.sender, token, target, amount) {
        if (amount == 0) {
            return;
        }
        if (token.isNative()) {
            // using a regular transfer here would revert due to exceeding the 2300 gas limit which is why we're using
            // call instead (via sendValue), which the 2300 gas limit does not apply for
            target.sendValue(amount);
        } else {
            token.safeTransfer(target, amount);
        }
        emit FundsWithdrawn({ token: token, caller: msg.sender, target: target, amount: amount });
    }
    /**
     * @inheritdoc IVault
     */
    function burn(Token token, uint256 amount)
        external
        nonReentrant
        whenNotPaused
        whenAuthorized(msg.sender, token, payable(address(0)), amount)
    {
        if (amount == 0) {
            return;
        }
        if (token.isNative()) {
            revert InvalidToken();
        }
        // allow vaults to burn BNT and vBNT via their respective token governance modules
        if (token.isEqual(_bnt)) {
            _bntGovernance.burn(amount);
        } else if (token.isEqual(_vbnt)) {
            _vbntGovernance.burn(amount);
        } else {
            IERC20Burnable(address(token)).burn(amount);
        }
        emit FundsBurned({ token: token, caller: msg.sender, amount: amount });
    }
    /**
     * @dev returns whether the given caller is allowed access to the given token
     */
    function isAuthorizedWithdrawal(
        address caller,
        Token token,
        address target,
        uint256 amount
    ) internal view virtual returns (bool);
    /**
     * @inheritdoc IVault
     */
    function isPayable() public view virtual returns (bool);
    /**
     * @dev authorize the contract to receive the native token
     *
     * requirements:
     *
     * - isPayable must return true
     */
    receive() external payable {
        if (!isPayable()) {
            revert NotPayable();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IMasterVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
// the asset manager role is required to access all the funds
bytes32 constant ROLE_ASSET_MANAGER = keccak256("ROLE_ASSET_MANAGER");
interface IVault is IUpgradeable {
    /**
     * @dev triggered when tokens have been withdrawn from the vault
     */
    event FundsWithdrawn(Token indexed token, address indexed caller, address indexed target, uint256 amount);
    /**
     * @dev triggered when tokens have been burned from the vault
     */
    event FundsBurned(Token indexed token, address indexed caller, uint256 amount);
    /**
     * @dev tells whether the vault accepts native token deposits
     */
    function isPayable() external view returns (bool);
    /**
     * @dev withdraws funds held by the contract and sends them to an account
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    ) external;
    /**
     * @dev burns funds held by the contract
     */
    function burn(Token token, uint256 amount) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
pragma solidity ^0.8.0;
/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822Proxiable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/ERC1967/ERC1967Proxy.sol)
pragma solidity ^0.8.0;
import "../Proxy.sol";
import "./ERC1967Upgrade.sol";
/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 */
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _upgradeToAndCall(_logic, _data, false);
    }
    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        return ERC1967Upgrade._getImplementation();
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)
pragma solidity ^0.8.2;
import "../beacon/IBeacon.sol";
import "../../interfaces/draft-IERC1822.sol";
import "../../utils/Address.sol";
import "../../utils/StorageSlot.sol";
/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);
    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }
    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }
    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }
    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }
    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);
    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }
    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }
    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);
    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }
    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/Proxy.sol)
pragma solidity ^0.8.0;
/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())
            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())
            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }
    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);
    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }
    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
pragma solidity ^0.8.0;
/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/StorageSlot.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }
    struct BooleanSlot {
        bool value;
    }
    struct Bytes32Slot {
        bytes32 value;
    }
    struct Uint256Slot {
        uint256 value;
    }
    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1000000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { ERC1967Proxy } from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
import { AccessDenied, Utils } from "./Utils.sol";
/**
 * @dev this contract is a slightly optimized version of the original TransparentUpgradeableProxy solely designed to
 * work with the ProxyAdmin contract:
 *
 * - the address of the admin is stored as an immutable state variables and as the result:
 * - the address of the admin can't be change, so the changeAdmin() function was subsequently removed
 */
contract TransparentUpgradeableProxyImmutable is ERC1967Proxy, Utils {
    address internal immutable _admin;
    /**
     * @dev initializes an upgradeable proxy managed by `initAdmin`, backed by the implementation at `logic`, and
     * optionally initialized with `data` as explained in {ERC1967Proxy-constructor}
     */
    constructor(
        address logic,
        address initAdmin,
        bytes memory data
    ) payable ERC1967Proxy(logic, data) validAddress(initAdmin) {
        _admin = initAdmin;
        // still store it to work with EIP-1967
        _changeAdmin(initAdmin);
    }
    modifier ifAdmin() {
        if (msg.sender == _admin) {
            _;
        } else {
            _fallback();
        }
    }
    /**
     * @dev returns the current admin
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function admin() external ifAdmin returns (address) {
        return _admin;
    }
    /**
     * @dev returns the current implementation.
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function implementation() external ifAdmin returns (address) {
        return _implementation();
    }
    /**
     * @dev upgrades the implementation of the proxy
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeToAndCall(newImplementation, bytes(""), false);
    }
    /**
     * @dev upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by data, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract
     *
     * requirements:
     *
     * - the caller must be the admin of the contract
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
        _upgradeToAndCall(newImplementation, data, true);
    }
    /**
     * @dev makes sure the admin cannot access the fallback function
     */
    function _beforeFallback() internal virtual override {
        if (msg.sender == _admin) {
            revert AccessDenied();
        }
        super._beforeFallback();
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidType();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
/// @title Claimable contract interface
interface IClaimable {
    function owner() external view returns (address);
    function transferOwnership(address newOwner) external;
    function acceptOwnership() external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./IClaimable.sol";
/// @title Mintable Token interface
interface IMintableToken is IERC20, IClaimable {
    function issue(address to, uint256 amount) external;
    function destroy(address from, uint256 amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "./IMintableToken.sol";
/// @title The interface for mintable/burnable token governance.
interface ITokenGovernance {
    // The address of the mintable ERC20 token.
    function token() external view returns (IMintableToken);
    /// @dev Mints new tokens.
    ///
    /// @param to Account to receive the new amount.
    /// @param amount Amount to increase the supply by.
    ///
    function mint(address to, uint256 amount) external;
    /// @dev Burns tokens from the caller.
    ///
    /// @param amount Amount to decrease the supply by.
    ///
    function burn(uint256 amount) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlEnumerableUpgradeable.sol";
import "./AccessControlUpgradeable.sol";
import "../utils/structs/EnumerableSetUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Extension of {AccessControl} that allows enumerating the members of each role.
 */
abstract contract AccessControlEnumerableUpgradeable is Initializable, IAccessControlEnumerableUpgradeable, AccessControlUpgradeable {
    function __AccessControlEnumerable_init() internal onlyInitializing {
    }
    function __AccessControlEnumerable_init_unchained() internal onlyInitializing {
    }
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    mapping(bytes32 => EnumerableSetUpgradeable.AddressSet) private _roleMembers;
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlEnumerableUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
        return _roleMembers[role].at(index);
    }
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
        return _roleMembers[role].length();
    }
    /**
     * @dev Overload {_grantRole} to track enumerable memberships
     */
    function _grantRole(bytes32 role, address account) internal virtual override {
        super._grantRole(role, account);
        _roleMembers[role].add(account);
    }
    /**
     * @dev Overload {_revokeRole} to track enumerable memberships
     */
    function _revokeRole(bytes32 role, address account) internal virtual override {
        super._revokeRole(role, account);
        _roleMembers[role].remove(account);
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "../utils/StringsUpgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
    function __AccessControl_init() internal onlyInitializing {
    }
    function __AccessControl_init_unchained() internal onlyInitializing {
    }
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }
    mapping(bytes32 => RoleData) private _roles;
    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }
    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(uint160(account), 20),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");
        _revokeRole(role, account);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }
    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlUpgradeable.sol";
/**
 * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
 */
interface IAccessControlEnumerableUpgradeable is IAccessControlUpgradeable {
    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) external view returns (address);
    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.0;
import "../../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }
    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }
    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165Upgradeable.sol";
import "../../proxy/utils/Initializable.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    function __ERC165_init() internal onlyInitializing {
    }
    function __ERC165_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165Upgradeable).interfaceId;
    }
    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;
        assembly {
            result := store
        }
        return result;
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;
        assembly {
            result := store
        }
        return result;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }
    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][spender] + addedValue);
        return true;
    }
    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }
        return true;
    }
    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        _beforeTokenTransfer(from, to, amount);
        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;
        emit Transfer(from, to, amount);
        _afterTokenTransfer(from, to, amount);
    }
    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address(0), account, amount);
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
        _afterTokenTransfer(address(0), account, amount);
    }
    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        _beforeTokenTransfer(account, address(0), amount);
        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;
        emit Transfer(account, address(0), amount);
        _afterTokenTransfer(account, address(0), amount);
    }
    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @dev Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }
    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
 * @dev extends the SafeERC20 library with additional operations
 */
library SafeERC20Ex {
    using SafeERC20 for IERC20;
    /**
     * @dev ensures that the spender has sufficient allowance
     */
    function ensureApprove(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance >= amount) {
            return;
        }
        if (allowance > 0) {
            token.safeApprove(spender, 0);
        }
        token.safeApprove(spender, amount);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev the main purpose of the Token interfaces is to ensure artificially that we won't use ERC20's standard functions,
 * but only their safe versions, which are provided by SafeERC20 and SafeERC20Ex via the TokenLibrary contract
 */
interface Token {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol";
import { SafeERC20Ex } from "./SafeERC20Ex.sol";
import { Token } from "./Token.sol";
struct Signature {
    uint8 v;
    bytes32 r;
    bytes32 s;
}
/**
 * @dev This library implements ERC20 and SafeERC20 utilities for both the native token and for ERC20 tokens
 */
library TokenLibrary {
    using SafeERC20 for IERC20;
    using SafeERC20Ex for IERC20;
    error PermitUnsupported();
    // the address that represents the native token reserve
    address public constant NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    // the symbol that represents the native token
    string private constant NATIVE_TOKEN_SYMBOL = "ETH";
    // the decimals for the native token
    uint8 private constant NATIVE_TOKEN_DECIMALS = 18;
    /**
     * @dev returns whether the provided token represents an ERC20 or the native token reserve
     */
    function isNative(Token token) internal pure returns (bool) {
        return address(token) == NATIVE_TOKEN_ADDRESS;
    }
    /**
     * @dev returns the symbol of the native token/ERC20 token
     */
    function symbol(Token token) internal view returns (string memory) {
        if (isNative(token)) {
            return NATIVE_TOKEN_SYMBOL;
        }
        return toERC20(token).symbol();
    }
    /**
     * @dev returns the decimals of the native token/ERC20 token
     */
    function decimals(Token token) internal view returns (uint8) {
        if (isNative(token)) {
            return NATIVE_TOKEN_DECIMALS;
        }
        return toERC20(token).decimals();
    }
    /**
     * @dev returns the balance of the native token/ERC20 token
     */
    function balanceOf(Token token, address account) internal view returns (uint256) {
        if (isNative(token)) {
            return account.balance;
        }
        return toIERC20(token).balanceOf(account);
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token
     */
    function safeTransfer(
        Token token,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0) {
            return;
        }
        if (isNative(token)) {
            payable(to).transfer(amount);
        } else {
            toIERC20(token).safeTransfer(to, amount);
        }
    }
    /**
     * @dev transfers a specific amount of the native token/ERC20 token from a specific holder using the allowance mechanism
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeTransferFrom(
        Token token,
        address from,
        address to,
        uint256 amount
    ) internal {
        if (amount == 0 || isNative(token)) {
            return;
        }
        toIERC20(token).safeTransferFrom(from, to, amount);
    }
    /**
     * @dev approves a specific amount of the native token/ERC20 token from a specific holder
     *
     * note that the function does not perform any action if the native token is provided
     */
    function safeApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).safeApprove(spender, amount);
    }
    /**
     * @dev ensures that the spender has sufficient allowance
     *
     * note that the function does not perform any action if the native token is provided
     */
    function ensureApprove(
        Token token,
        address spender,
        uint256 amount
    ) internal {
        if (isNative(token)) {
            return;
        }
        toIERC20(token).ensureApprove(spender, amount);
    }
    /**
     * @dev performs an EIP2612 permit
     */
    function permit(
        Token token,
        address owner,
        address spender,
        uint256 tokenAmount,
        uint256 deadline,
        Signature memory signature
    ) internal {
        if (isNative(token)) {
            revert PermitUnsupported();
        }
        // permit the amount the owner is trying to deposit. Please note, that if the base token doesn't support
        // EIP2612 permit - either this call or the inner safeTransferFrom will revert
        IERC20Permit(address(token)).permit(
            owner,
            spender,
            tokenAmount,
            deadline,
            signature.v,
            signature.r,
            signature.s
        );
    }
    /**
     * @dev compares between a token and another raw ERC20 token
     */
    function isEqual(Token token, IERC20 erc20Token) internal pure returns (bool) {
        return toIERC20(token) == erc20Token;
    }
    /**
     * @dev utility function that converts an token to an IERC20
     */
    function toIERC20(Token token) internal pure returns (IERC20) {
        return IERC20(address(token));
    }
    /**
     * @dev utility function that converts an token to an ERC20
     */
    function toERC20(Token token) internal pure returns (ERC20) {
        return ERC20(address(token));
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev burnable ERC20 interface
 */
interface IERC20Burnable {
    /**
     * @dev Destroys tokens from the caller.
     */
    function burn(uint256 amount) external;
    /**
     * @dev Destroys tokens from a recipient, deducting from the caller's allowance
     *
     * requirements:
     *
     * - the caller must have allowance for recipient's tokens of at least the specified amount
     */
    function burnFrom(address recipient, uint256 amount) external;
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
uint32 constant PPM_RESOLUTION = 1000000;
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { AccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/AccessControlEnumerableUpgradeable.sol";
import { IUpgradeable } from "./interfaces/IUpgradeable.sol";
import { AccessDenied } from "./Utils.sol";
/**
 * @dev this contract provides common utilities for upgradeable contracts
 */
abstract contract Upgradeable is IUpgradeable, AccessControlEnumerableUpgradeable {
    error AlreadyInitialized();
    // the admin role is used to allow a non-proxy admin to perform additional initialization/setup during contract
    // upgrades
    bytes32 internal constant ROLE_ADMIN = keccak256("ROLE_ADMIN");
    uint32 internal constant MAX_GAP = 50;
    uint16 internal _initializations;
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 1] private __gap;
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __Upgradeable_init() internal onlyInitializing {
        __AccessControl_init();
        __Upgradeable_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __Upgradeable_init_unchained() internal onlyInitializing {
        _initializations = 1;
        // set up administrative roles
        _setRoleAdmin(ROLE_ADMIN, ROLE_ADMIN);
        // allow the deployer to initially be the admin of the contract
        _setupRole(ROLE_ADMIN, msg.sender);
    }
    // solhint-enable func-name-mixedcase
    modifier onlyAdmin() {
        _hasRole(ROLE_ADMIN, msg.sender);
        _;
    }
    modifier onlyRoleMember(bytes32 role) {
        _hasRole(role, msg.sender);
        _;
    }
    function version() public view virtual override returns (uint16);
    /**
     * @dev returns the admin role
     */
    function roleAdmin() external pure returns (bytes32) {
        return ROLE_ADMIN;
    }
    /**
     * @dev performs post-upgrade initialization
     *
     * requirements:
     *
     * - this must can be called only once per-upgrade
     */
    function postUpgrade(bytes calldata data) external {
        uint16 initializations = _initializations + 1;
        if (initializations != version()) {
            revert AlreadyInitialized();
        }
        _initializations = initializations;
        _postUpgrade(data);
    }
    /**
     * @dev an optional post-upgrade callback that can be implemented by child contracts
     */
    function _postUpgrade(
        bytes calldata /* data */
    ) internal virtual {}
    function _hasRole(bytes32 role, address account) internal view {
        if (!hasRole(role, account)) {
            revert AccessDenied();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { PPM_RESOLUTION } from "./Constants.sol";
error AccessDenied();
error AlreadyExists();
error DoesNotExist();
error InvalidAddress();
error InvalidExternalAddress();
error InvalidFee();
error InvalidPool();
error InvalidPoolCollection();
error InvalidStakedBalance();
error InvalidToken();
error InvalidType();
error InvalidParam();
error NotEmpty();
error NotPayable();
error ZeroValue();
/**
 * @dev common utilities
 */
contract Utils {
    // allows execution by the caller only
    modifier only(address caller) {
        _only(caller);
        _;
    }
    function _only(address caller) internal view {
        if (msg.sender != caller) {
            revert AccessDenied();
        }
    }
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 value) {
        _greaterThanZero(value);
        _;
    }
    // error message binary size optimization
    function _greaterThanZero(uint256 value) internal pure {
        if (value == 0) {
            revert ZeroValue();
        }
    }
    // validates an address - currently only checks that it isn't null
    modifier validAddress(address addr) {
        _validAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validAddress(address addr) internal pure {
        if (addr == address(0)) {
            revert InvalidAddress();
        }
    }
    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address addr) {
        _validExternalAddress(addr);
        _;
    }
    // error message binary size optimization
    function _validExternalAddress(address addr) internal view {
        if (addr == address(0) || addr == address(this)) {
            revert InvalidExternalAddress();
        }
    }
    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }
    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        if (fee > PPM_RESOLUTION) {
            revert InvalidFee();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVersioned } from "./IVersioned.sol";
import { IAccessControlEnumerableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/IAccessControlEnumerableUpgradeable.sol";
/**
 * @dev this is the common interface for upgradeable contracts
 */
interface IUpgradeable is IAccessControlEnumerableUpgradeable, IVersioned {
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
/**
 * @dev an interface for a versioned contract
 */
interface IVersioned {
    function version() external view returns (uint16);
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { ITokenGovernance } from "@bancor/token-governance/contracts/ITokenGovernance.sol";
import { IVersioned } from "../utility/interfaces/IVersioned.sol";
import { Upgradeable } from "../utility/Upgradeable.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { IMasterVault } from "./interfaces/IMasterVault.sol";
import { IVault, ROLE_ASSET_MANAGER } from "./interfaces/IVault.sol";
import { Vault } from "./Vault.sol";
/**
 * @dev Master Vault contract
 */
contract MasterVault is IMasterVault, Vault {
    using SafeERC20 for IERC20;
    using TokenLibrary for Token;
    // the BNT manager role is only required to access the BNT reserve
    bytes32 private constant ROLE_BNT_MANAGER = keccak256("ROLE_BNT_MANAGER");
    // upgrade forward-compatibility storage gap
    uint256[MAX_GAP - 0] private __gap;
    /**
     * @dev a "virtual" constructor that is only used to set immutable state variables
     */
    constructor(ITokenGovernance initBNTGovernance, ITokenGovernance initVBNTGovernance)
        Vault(initBNTGovernance, initVBNTGovernance)
    {}
    /**
     * @dev fully initializes the contract and its parents
     */
    function initialize() external initializer {
        __MasterVault_init();
    }
    // solhint-disable func-name-mixedcase
    /**
     * @dev initializes the contract and its parents
     */
    function __MasterVault_init() internal onlyInitializing {
        __Vault_init();
        __MasterVault_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __MasterVault_init_unchained() internal onlyInitializing {
        // set up administrative roles
        _setRoleAdmin(ROLE_ASSET_MANAGER, ROLE_ADMIN);
        _setRoleAdmin(ROLE_BNT_MANAGER, ROLE_ADMIN);
    }
    // solhint-enable func-name-mixedcase
    /**
     * @inheritdoc Upgradeable
     */
    function version() public pure override(IVersioned, Upgradeable) returns (uint16) {
        return 1;
    }
    /**
     * @inheritdoc Vault
     */
    function isPayable() public pure override(IVault, Vault) returns (bool) {
        return true;
    }
    /**
     * @dev returns the BNT manager role
     */
    function roleBNTManager() external pure returns (bytes32) {
        return ROLE_BNT_MANAGER;
    }
    /**
     * @dev authorize the right of a caller to withdraw a specific amount of a token to a target
     *
     * requirements:
     *
     * - BNT: the caller must have the ROLE_BNT_MANAGER or ROLE_ASSET_MANAGER role
     * - other reserve token or the native token: the caller must have the ROLE_ASSET_MANAGER role
     */
    function isAuthorizedWithdrawal(
        address caller,
        Token token,
        address, /* target */
        uint256 /* amount */
    ) internal view override returns (bool) {
        return (token.isEqual(_bnt) && hasRole(ROLE_BNT_MANAGER, caller)) || hasRole(ROLE_ASSET_MANAGER, caller);
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import { PausableUpgradeable } from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import { ITokenGovernance } from "@bancor/token-governance/contracts/ITokenGovernance.sol";
import { IVault, ROLE_ASSET_MANAGER } from "./interfaces/IVault.sol";
import { Upgradeable } from "../utility/Upgradeable.sol";
import { IERC20Burnable } from "../token/interfaces/IERC20Burnable.sol";
import { Token } from "../token/Token.sol";
import { TokenLibrary } from "../token/TokenLibrary.sol";
import { Utils, AccessDenied, NotPayable, InvalidToken } from "../utility/Utils.sol";
abstract contract Vault is IVault, Upgradeable, PausableUpgradeable, ReentrancyGuardUpgradeable, Utils {
    using Address for address payable;
    using SafeERC20 for IERC20;
    using TokenLibrary for Token;
    // the address of the BNT token
    IERC20 internal immutable _bnt;
    // the address of the BNT token governance
    ITokenGovernance internal immutable _bntGovernance;
    // the address of the VBNT token
    IERC20 internal immutable _vbnt;
    // the address of the VBNT token governance
    ITokenGovernance internal immutable _vbntGovernance;
    // solhint-disable func-name-mixedcase
    /**
     * @dev a "virtual" constructor that is only used to set immutable state variables
     */
    constructor(ITokenGovernance initBNTGovernance, ITokenGovernance initVBNTGovernance)
        validAddress(address(initBNTGovernance))
        validAddress(address(initVBNTGovernance))
    {
        _bntGovernance = initBNTGovernance;
        _bnt = initBNTGovernance.token();
        _vbntGovernance = initVBNTGovernance;
        _vbnt = initVBNTGovernance.token();
    }
    /**
     * @dev initializes the contract and its parents
     */
    function __Vault_init() internal onlyInitializing {
        __Upgradeable_init();
        __Pausable_init();
        __ReentrancyGuard_init();
        __Vault_init_unchained();
    }
    /**
     * @dev performs contract-specific initialization
     */
    function __Vault_init_unchained() internal onlyInitializing {}
    // solhint-enable func-name-mixedcase
    /**
     * @dev returns the asset manager role
     */
    function roleAssetManager() external pure returns (bytes32) {
        return ROLE_ASSET_MANAGER;
    }
    // allows execution only by an authorized operation
    modifier whenAuthorized(
        address caller,
        Token token,
        address payable target,
        uint256 amount
    ) {
        if (!isAuthorizedWithdrawal(caller, token, target, amount)) {
            revert AccessDenied();
        }
        _;
    }
    /**
     * @dev returns whether withdrawals are currently paused
     */
    function isPaused() external view returns (bool) {
        return paused();
    }
    /**
     * @dev pauses withdrawals
     *
     * requirements:
     *
     * - the caller must have the ROLE_ADMIN privileges
     */
    function pause() external onlyAdmin {
        _pause();
    }
    /**
     * @dev unpauses withdrawals
     *
     * requirements:
     *
     * - the caller must have the ROLE_ADMIN privileges
     */
    function unpause() external onlyAdmin {
        _unpause();
    }
    /**
     * @inheritdoc IVault
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    )
        external
        override
        validAddress(target)
        nonReentrant
        whenNotPaused
        whenAuthorized(msg.sender, token, target, amount)
    {
        if (amount == 0) {
            return;
        }
        if (token.isNative()) {
            // using a regular transfer here would revert due to exceeding the 2300 gas limit which is why we're using
            // call instead (via sendValue), which the 2300 gas limit does not apply for
            target.sendValue(amount);
        } else {
            token.safeTransfer(target, amount);
        }
        emit FundsWithdrawn({ token: token, caller: msg.sender, target: target, amount: amount });
    }
    /**
     * @inheritdoc IVault
     */
    function burn(Token token, uint256 amount)
        external
        nonReentrant
        whenNotPaused
        whenAuthorized(msg.sender, token, payable(address(0)), amount)
    {
        if (amount == 0) {
            return;
        }
        if (token.isNative()) {
            revert InvalidToken();
        }
        // allow vaults to burn BNT and VBNT via their respective token governance modules
        if (token.isEqual(_bnt)) {
            _bntGovernance.burn(amount);
        } else if (token.isEqual(_vbnt)) {
            _vbntGovernance.burn(amount);
        } else {
            IERC20Burnable(address(token)).burn(amount);
        }
        emit FundsBurned({ token: token, caller: msg.sender, amount: amount });
    }
    /**
     * @dev returns whether the given caller is allowed access to the given token
     */
    function isAuthorizedWithdrawal(
        address caller,
        Token token,
        address target,
        uint256 amount
    ) internal view virtual returns (bool);
    /**
     * @inheritdoc IVault
     */
    function isPayable() public view virtual returns (bool);
    /**
     * @dev authorize the contract to receive the native token
     *
     * requirements:
     *
     * - isPayable must return true
     */
    receive() external payable {
        if (!isPayable()) {
            revert NotPayable();
        }
    }
}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IVault } from "./IVault.sol";
interface IMasterVault is IVault {}
// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.13;
import { IUpgradeable } from "../../utility/interfaces/IUpgradeable.sol";
import { Token } from "../../token/Token.sol";
// the asset manager role is required to access all the funds
bytes32 constant ROLE_ASSET_MANAGER = keccak256("ROLE_ASSET_MANAGER");
interface IVault is IUpgradeable {
    /**
     * @dev triggered when tokens have been withdrawn from the vault
     */
    event FundsWithdrawn(Token indexed token, address indexed caller, address indexed target, uint256 amount);
    /**
     * @dev triggered when tokens have been burned from the vault
     */
    event FundsBurned(Token indexed token, address indexed caller, uint256 amount);
    /**
     * @dev tells whether the vault accepts native token deposits
     */
    function isPayable() external view returns (bool);
    /**
     * @dev withdraws funds held by the contract and sends them to an account
     */
    function withdrawFunds(
        Token token,
        address payable target,
        uint256 amount
    ) external;
    /**
     * @dev burns funds held by the contract
     */
    function burn(Token token, uint256 amount) external;
}

// File: contracts/token/interfaces/IERC20Token.sol

pragma solidity 0.4.26;

/*
    ERC20 Standard Token interface
*/
contract IERC20Token {
    // these functions aren't abstract since the compiler emits automatically generated getter functions as external
    function name() public view returns (string) {this;}
    function symbol() public view returns (string) {this;}
    function decimals() public view returns (uint8) {this;}
    function totalSupply() public view returns (uint256) {this;}
    function balanceOf(address _owner) public view returns (uint256) {_owner; this;}
    function allowance(address _owner, address _spender) public view returns (uint256) {_owner; _spender; this;}

    function transfer(address _to, uint256 _value) public returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);
    function approve(address _spender, uint256 _value) public returns (bool success);
}

// File: contracts/IBancorNetwork.sol

pragma solidity 0.4.26;


/*
    Bancor Network interface
*/
contract IBancorNetwork {
    function convert2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _affiliateAccount,
        uint256 _affiliateFee
    ) public payable returns (uint256);

    function claimAndConvert2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _affiliateAccount,
        uint256 _affiliateFee
    ) public returns (uint256);

    function convertFor2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _for,
        address _affiliateAccount,
        uint256 _affiliateFee
    ) public payable returns (uint256);

    function claimAndConvertFor2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _for,
        address _affiliateAccount,
        uint256 _affiliateFee
    ) public returns (uint256);

    // deprecated, backward compatibility
    function convert(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn
    ) public payable returns (uint256);

    // deprecated, backward compatibility
    function claimAndConvert(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn
    ) public returns (uint256);

    // deprecated, backward compatibility
    function convertFor(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _for
    ) public payable returns (uint256);

    // deprecated, backward compatibility
    function claimAndConvertFor(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _for
    ) public returns (uint256);
}

// File: contracts/IConversionPathFinder.sol

pragma solidity 0.4.26;


/*
    Conversion Path Finder interface
*/
contract IConversionPathFinder {
    function findPath(address _sourceToken, address _targetToken) public view returns (address[] memory);
}

// File: contracts/utility/interfaces/IOwned.sol

pragma solidity 0.4.26;

/*
    Owned contract interface
*/
contract IOwned {
    // this function isn't abstract since the compiler emits automatically generated getter functions as external
    function owner() public view returns (address) {this;}

    function transferOwnership(address _newOwner) public;
    function acceptOwnership() public;
}

// File: contracts/utility/interfaces/ITokenHolder.sol

pragma solidity 0.4.26;



/*
    Token Holder interface
*/
contract ITokenHolder is IOwned {
    function withdrawTokens(IERC20Token _token, address _to, uint256 _amount) public;
}

// File: contracts/converter/interfaces/IConverterAnchor.sol

pragma solidity 0.4.26;



/*
    Converter Anchor interface
*/
contract IConverterAnchor is IOwned, ITokenHolder {
}

// File: contracts/utility/interfaces/IWhitelist.sol

pragma solidity 0.4.26;

/*
    Whitelist interface
*/
contract IWhitelist {
    function isWhitelisted(address _address) public view returns (bool);
}

// File: contracts/converter/interfaces/IConverter.sol

pragma solidity 0.4.26;





/*
    Converter interface
*/
contract IConverter is IOwned {
    function converterType() public pure returns (uint16);
    function anchor() public view returns (IConverterAnchor) {this;}
    function isActive() public view returns (bool);

    function rateAndFee(IERC20Token _sourceToken, IERC20Token _targetToken, uint256 _amount) public view returns (uint256, uint256);
    function convert(IERC20Token _sourceToken,
                     IERC20Token _targetToken,
                     uint256 _amount,
                     address _trader,
                     address _beneficiary) public payable returns (uint256);

    function conversionWhitelist() public view returns (IWhitelist) {this;}
    function conversionFee() public view returns (uint32) {this;}
    function maxConversionFee() public view returns (uint32) {this;}
    function reserveBalance(IERC20Token _reserveToken) public view returns (uint256);
    function() external payable;

    function transferAnchorOwnership(address _newOwner) public;
    function acceptAnchorOwnership() public;
    function setConversionFee(uint32 _conversionFee) public;
    function setConversionWhitelist(IWhitelist _whitelist) public;
    function withdrawTokens(IERC20Token _token, address _to, uint256 _amount) public;
    function withdrawETH(address _to) public;
    function addReserve(IERC20Token _token, uint32 _ratio) public;

    // deprecated, backward compatibility
    function token() public view returns (IConverterAnchor);
    function transferTokenOwnership(address _newOwner) public;
    function acceptTokenOwnership() public;
    function connectors(address _address) public view returns (uint256, uint32, bool, bool, bool);
    function getConnectorBalance(IERC20Token _connectorToken) public view returns (uint256);
    function connectorTokens(uint256 _index) public view returns (IERC20Token);
    function connectorTokenCount() public view returns (uint16);
}

// File: contracts/converter/interfaces/IBancorFormula.sol

pragma solidity 0.4.26;

/*
    Bancor Formula interface
*/
contract IBancorFormula {
    function purchaseRate(uint256 _supply,
                          uint256 _reserveBalance,
                          uint32 _reserveWeight,
                          uint256 _amount)
                          public view returns (uint256);

    function saleRate(uint256 _supply,
                      uint256 _reserveBalance,
                      uint32 _reserveWeight,
                      uint256 _amount)
                      public view returns (uint256);

    function crossReserveRate(uint256 _sourceReserveBalance,
                              uint32 _sourceReserveWeight,
                              uint256 _targetReserveBalance,
                              uint32 _targetReserveWeight,
                              uint256 _amount)
                              public view returns (uint256);

    function fundCost(uint256 _supply,
                      uint256 _reserveBalance,
                      uint32 _reserveRatio,
                      uint256 _amount)
                      public view returns (uint256);

    function liquidateRate(uint256 _supply,
                           uint256 _reserveBalance,
                           uint32 _reserveRatio,
                           uint256 _amount)
                           public view returns (uint256);
}

// File: contracts/utility/Owned.sol

pragma solidity 0.4.26;


/**
  * @dev Provides support and utilities for contract ownership
*/
contract Owned is IOwned {
    address public owner;
    address public newOwner;

    /**
      * @dev triggered when the owner is updated
      *
      * @param _prevOwner previous owner
      * @param _newOwner  new owner
    */
    event OwnerUpdate(address indexed _prevOwner, address indexed _newOwner);

    /**
      * @dev initializes a new Owned instance
    */
    constructor() public {
        owner = msg.sender;
    }

    // allows execution by the owner only
    modifier ownerOnly {
        _ownerOnly();
        _;
    }

    // error message binary size optimization
    function _ownerOnly() internal view {
        require(msg.sender == owner, "ERR_ACCESS_DENIED");
    }

    /**
      * @dev allows transferring the contract ownership
      * the new owner still needs to accept the transfer
      * can only be called by the contract owner
      *
      * @param _newOwner    new contract owner
    */
    function transferOwnership(address _newOwner) public ownerOnly {
        require(_newOwner != owner, "ERR_SAME_OWNER");
        newOwner = _newOwner;
    }

    /**
      * @dev used by a new owner to accept an ownership transfer
    */
    function acceptOwnership() public {
        require(msg.sender == newOwner, "ERR_ACCESS_DENIED");
        emit OwnerUpdate(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}

// File: contracts/utility/Utils.sol

pragma solidity 0.4.26;

/**
  * @dev Utilities & Common Modifiers
*/
contract Utils {
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 _value) {
        _greaterThanZero(_value);
        _;
    }

    // error message binary size optimization
    function _greaterThanZero(uint256 _value) internal pure {
        require(_value > 0, "ERR_ZERO_VALUE");
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        _validAddress(_address);
        _;
    }

    // error message binary size optimization
    function _validAddress(address _address) internal pure {
        require(_address != address(0), "ERR_INVALID_ADDRESS");
    }

    // verifies that the address is different than this contract address
    modifier notThis(address _address) {
        _notThis(_address);
        _;
    }

    // error message binary size optimization
    function _notThis(address _address) internal view {
        require(_address != address(this), "ERR_ADDRESS_IS_SELF");
    }
}

// File: contracts/utility/interfaces/IContractRegistry.sol

pragma solidity 0.4.26;

/*
    Contract Registry interface
*/
contract IContractRegistry {
    function addressOf(bytes32 _contractName) public view returns (address);

    // deprecated, backward compatibility
    function getAddress(bytes32 _contractName) public view returns (address);
}

// File: contracts/utility/ContractRegistryClient.sol

pragma solidity 0.4.26;




/**
  * @dev Base contract for ContractRegistry clients
*/
contract ContractRegistryClient is Owned, Utils {
    bytes32 internal constant CONTRACT_REGISTRY = "ContractRegistry";
    bytes32 internal constant BANCOR_NETWORK = "BancorNetwork";
    bytes32 internal constant BANCOR_FORMULA = "BancorFormula";
    bytes32 internal constant CONVERTER_FACTORY = "ConverterFactory";
    bytes32 internal constant CONVERSION_PATH_FINDER = "ConversionPathFinder";
    bytes32 internal constant CONVERTER_UPGRADER = "BancorConverterUpgrader";
    bytes32 internal constant CONVERTER_REGISTRY = "BancorConverterRegistry";
    bytes32 internal constant CONVERTER_REGISTRY_DATA = "BancorConverterRegistryData";
    bytes32 internal constant BNT_TOKEN = "BNTToken";
    bytes32 internal constant BANCOR_X = "BancorX";
    bytes32 internal constant BANCOR_X_UPGRADER = "BancorXUpgrader";

    IContractRegistry public registry;      // address of the current contract-registry
    IContractRegistry public prevRegistry;  // address of the previous contract-registry
    bool public onlyOwnerCanUpdateRegistry; // only an owner can update the contract-registry

    /**
      * @dev verifies that the caller is mapped to the given contract name
      *
      * @param _contractName    contract name
    */
    modifier only(bytes32 _contractName) {
        _only(_contractName);
        _;
    }

    // error message binary size optimization
    function _only(bytes32 _contractName) internal view {
        require(msg.sender == addressOf(_contractName), "ERR_ACCESS_DENIED");
    }

    /**
      * @dev initializes a new ContractRegistryClient instance
      *
      * @param  _registry   address of a contract-registry contract
    */
    constructor(IContractRegistry _registry) internal validAddress(_registry) {
        registry = IContractRegistry(_registry);
        prevRegistry = IContractRegistry(_registry);
    }

    /**
      * @dev updates to the new contract-registry
     */
    function updateRegistry() public {
        // verify that this function is permitted
        require(msg.sender == owner || !onlyOwnerCanUpdateRegistry, "ERR_ACCESS_DENIED");

        // get the new contract-registry
        IContractRegistry newRegistry = IContractRegistry(addressOf(CONTRACT_REGISTRY));

        // verify that the new contract-registry is different and not zero
        require(newRegistry != address(registry) && newRegistry != address(0), "ERR_INVALID_REGISTRY");

        // verify that the new contract-registry is pointing to a non-zero contract-registry
        require(newRegistry.addressOf(CONTRACT_REGISTRY) != address(0), "ERR_INVALID_REGISTRY");

        // save a backup of the current contract-registry before replacing it
        prevRegistry = registry;

        // replace the current contract-registry with the new contract-registry
        registry = newRegistry;
    }

    /**
      * @dev restores the previous contract-registry
    */
    function restoreRegistry() public ownerOnly {
        // restore the previous contract-registry
        registry = prevRegistry;
    }

    /**
      * @dev restricts the permission to update the contract-registry
      *
      * @param _onlyOwnerCanUpdateRegistry  indicates whether or not permission is restricted to owner only
    */
    function restrictRegistryUpdate(bool _onlyOwnerCanUpdateRegistry) public ownerOnly {
        // change the permission to update the contract-registry
        onlyOwnerCanUpdateRegistry = _onlyOwnerCanUpdateRegistry;
    }

    /**
      * @dev returns the address associated with the given contract name
      *
      * @param _contractName    contract name
      *
      * @return contract address
    */
    function addressOf(bytes32 _contractName) internal view returns (address) {
        return registry.addressOf(_contractName);
    }
}

// File: contracts/utility/ReentrancyGuard.sol

pragma solidity 0.4.26;

/**
  * @dev ReentrancyGuard
  *
  * The contract provides protection against re-entrancy - calling a function (directly or
  * indirectly) from within itself.
*/
contract ReentrancyGuard {
    // true while protected code is being executed, false otherwise
    bool private locked = false;

    /**
      * @dev ensures instantiation only by sub-contracts
    */
    constructor() internal {}

    // protects a function against reentrancy attacks
    modifier protected() {
        _protected();
        locked = true;
        _;
        locked = false;
    }

    // error message binary size optimization
    function _protected() internal view {
        require(!locked, "ERR_REENTRANCY");
    }
}

// File: contracts/utility/TokenHandler.sol

pragma solidity 0.4.26;


contract TokenHandler {
    bytes4 private constant APPROVE_FUNC_SELECTOR = bytes4(keccak256("approve(address,uint256)"));
    bytes4 private constant TRANSFER_FUNC_SELECTOR = bytes4(keccak256("transfer(address,uint256)"));
    bytes4 private constant TRANSFER_FROM_FUNC_SELECTOR = bytes4(keccak256("transferFrom(address,address,uint256)"));

    /**
      * @dev executes the ERC20 token's `approve` function and reverts upon failure
      * the main purpose of this function is to prevent a non standard ERC20 token
      * from failing silently
      *
      * @param _token   ERC20 token address
      * @param _spender approved address
      * @param _value   allowance amount
    */
    function safeApprove(IERC20Token _token, address _spender, uint256 _value) internal {
       execute(_token, abi.encodeWithSelector(APPROVE_FUNC_SELECTOR, _spender, _value));
    }

    /**
      * @dev executes the ERC20 token's `transfer` function and reverts upon failure
      * the main purpose of this function is to prevent a non standard ERC20 token
      * from failing silently
      *
      * @param _token   ERC20 token address
      * @param _to      target address
      * @param _value   transfer amount
    */
    function safeTransfer(IERC20Token _token, address _to, uint256 _value) internal {
       execute(_token, abi.encodeWithSelector(TRANSFER_FUNC_SELECTOR, _to, _value));
    }

    /**
      * @dev executes the ERC20 token's `transferFrom` function and reverts upon failure
      * the main purpose of this function is to prevent a non standard ERC20 token
      * from failing silently
      *
      * @param _token   ERC20 token address
      * @param _from    source address
      * @param _to      target address
      * @param _value   transfer amount
    */
    function safeTransferFrom(IERC20Token _token, address _from, address _to, uint256 _value) internal {
       execute(_token, abi.encodeWithSelector(TRANSFER_FROM_FUNC_SELECTOR, _from, _to, _value));
    }

    /**
      * @dev executes a function on the ERC20 token and reverts upon failure
      * the main purpose of this function is to prevent a non standard ERC20 token
      * from failing silently
      *
      * @param _token   ERC20 token address
      * @param _data    data to pass in to the token's contract for execution
    */
    function execute(IERC20Token _token, bytes memory _data) private {
        uint256[1] memory ret = [uint256(1)];

        assembly {
            let success := call(
                gas,            // gas remaining
                _token,         // destination address
                0,              // no ether
                add(_data, 32), // input buffer (starts after the first 32 bytes in the `data` array)
                mload(_data),   // input length (loaded from the first 32 bytes in the `data` array)
                ret,            // output buffer
                32              // output length
            )
            if iszero(success) {
                revert(0, 0)
            }
        }

        require(ret[0] != 0, "ERR_TRANSFER_FAILED");
    }
}

// File: contracts/utility/TokenHolder.sol

pragma solidity 0.4.26;






/**
  * @dev We consider every contract to be a 'token holder' since it's currently not possible
  * for a contract to deny receiving tokens.
  *
  * The TokenHolder's contract sole purpose is to provide a safety mechanism that allows
  * the owner to send tokens that were sent to the contract by mistake back to their sender.
  *
  * Note that we use the non standard ERC-20 interface which has no return value for transfer
  * in order to support both non standard as well as standard token contracts.
  * see https://github.com/ethereum/solidity/issues/4116
*/
contract TokenHolder is ITokenHolder, TokenHandler, Owned, Utils {
    /**
      * @dev withdraws tokens held by the contract and sends them to an account
      * can only be called by the owner
      *
      * @param _token   ERC20 token contract address
      * @param _to      account to receive the new amount
      * @param _amount  amount to withdraw
    */
    function withdrawTokens(IERC20Token _token, address _to, uint256 _amount)
        public
        ownerOnly
        validAddress(_token)
        validAddress(_to)
        notThis(_to)
    {
        safeTransfer(_token, _to, _amount);
    }
}

// File: contracts/utility/SafeMath.sol

pragma solidity 0.4.26;

/**
  * @dev Library for basic math operations with overflow/underflow protection
*/
library SafeMath {
    /**
      * @dev returns the sum of _x and _y, reverts if the calculation overflows
      *
      * @param _x   value 1
      * @param _y   value 2
      *
      * @return sum
    */
    function add(uint256 _x, uint256 _y) internal pure returns (uint256) {
        uint256 z = _x + _y;
        require(z >= _x, "ERR_OVERFLOW");
        return z;
    }

    /**
      * @dev returns the difference of _x minus _y, reverts if the calculation underflows
      *
      * @param _x   minuend
      * @param _y   subtrahend
      *
      * @return difference
    */
    function sub(uint256 _x, uint256 _y) internal pure returns (uint256) {
        require(_x >= _y, "ERR_UNDERFLOW");
        return _x - _y;
    }

    /**
      * @dev returns the product of multiplying _x by _y, reverts if the calculation overflows
      *
      * @param _x   factor 1
      * @param _y   factor 2
      *
      * @return product
    */
    function mul(uint256 _x, uint256 _y) internal pure returns (uint256) {
        // gas optimization
        if (_x == 0)
            return 0;

        uint256 z = _x * _y;
        require(z / _x == _y, "ERR_OVERFLOW");
        return z;
    }

    /**
      * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
      *
      * @param _x   dividend
      * @param _y   divisor
      *
      * @return quotient
    */
    function div(uint256 _x, uint256 _y) internal pure returns (uint256) {
        require(_y > 0, "ERR_DIVIDE_BY_ZERO");
        uint256 c = _x / _y;
        return c;
    }
}

// File: contracts/token/interfaces/IEtherToken.sol

pragma solidity 0.4.26;


/*
    Ether Token interface
*/
contract IEtherToken is IERC20Token {
    function deposit() public payable;
    function withdraw(uint256 _amount) public;
    function depositTo(address _to) public payable;
    function withdrawTo(address _to, uint256 _amount) public;
}

// File: contracts/token/interfaces/ISmartToken.sol

pragma solidity 0.4.26;




/*
    Smart Token interface
*/
contract ISmartToken is IConverterAnchor, IERC20Token {
    function disableTransfers(bool _disable) public;
    function issue(address _to, uint256 _amount) public;
    function destroy(address _from, uint256 _amount) public;
}

// File: contracts/bancorx/interfaces/IBancorX.sol

pragma solidity 0.4.26;


contract IBancorX {
    function token() public view returns (IERC20Token) {this;}
    function xTransfer(bytes32 _toBlockchain, bytes32 _to, uint256 _amount, uint256 _id) public;
    function getXTransferAmount(uint256 _xTransferId, address _for) public view returns (uint256);
}

// File: contracts/BancorNetwork.sol

pragma solidity 0.4.26;













// interface of older converters for backward compatibility
contract ILegacyConverter {
    function change(IERC20Token _sourceToken, IERC20Token _targetToken, uint256 _amount, uint256 _minReturn) public returns (uint256);
}

/**
  * @dev The BancorNetwork contract is the main entry point for Bancor token conversions.
  * It also allows for the conversion of any token in the Bancor Network to any other token in a single
  * transaction by providing a conversion path.
  *
  * A note on Conversion Path: Conversion path is a data structure that is used when converting a token
  * to another token in the Bancor Network, when the conversion cannot necessarily be done by a single
  * converter and might require multiple 'hops'.
  * The path defines which converters should be used and what kind of conversion should be done in each step.
  *
  * The path format doesn't include complex structure; instead, it is represented by a single array
  * in which each 'hop' is represented by a 2-tuple - converter anchor & target token.
  * In addition, the first element is always the source token.
  * The converter anchor is only used as a pointer to a converter (since converter addresses are more
  * likely to change as opposed to anchor addresses).
  *
  * Format:
  * [source token, converter anchor, target token, converter anchor, target token...]
*/
contract BancorNetwork is IBancorNetwork, TokenHolder, ContractRegistryClient, ReentrancyGuard {
    using SafeMath for uint256;

    uint256 private constant CONVERSION_FEE_RESOLUTION = 1000000;
    uint256 private constant AFFILIATE_FEE_RESOLUTION = 1000000;
    address private constant ETH_RESERVE_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    struct ConversionStep {
        IConverter converter;
        IConverterAnchor anchor;
        IERC20Token sourceToken;
        IERC20Token targetToken;
        address beneficiary;
        bool isV28OrHigherConverter;
        bool processAffiliateFee;
    }

    uint256 public maxAffiliateFee = 30000;     // maximum affiliate-fee

    mapping (address => bool) public etherTokens;       // list of all supported ether tokens

    /**
      * @dev triggered when a conversion between two tokens occurs
      *
      * @param _smartToken  anchor governed by the converter
      * @param _fromToken   source ERC20 token
      * @param _toToken     target ERC20 token
      * @param _fromAmount  amount converted, in the source token
      * @param _toAmount    amount returned, minus conversion fee
      * @param _trader      wallet that initiated the trade
    */
    event Conversion(
        address indexed _smartToken,
        address indexed _fromToken,
        address indexed _toToken,
        uint256 _fromAmount,
        uint256 _toAmount,
        address _trader
    );

    /**
      * @dev initializes a new BancorNetwork instance
      *
      * @param _registry    address of a contract registry contract
    */
    constructor(IContractRegistry _registry) ContractRegistryClient(_registry) public {
        etherTokens[ETH_RESERVE_ADDRESS] = true;
    }

    /**
      * @dev allows the owner to update the maximum affiliate-fee
      *
      * @param _maxAffiliateFee   maximum affiliate-fee
    */
    function setMaxAffiliateFee(uint256 _maxAffiliateFee)
        public
        ownerOnly
    {
        require(_maxAffiliateFee <= AFFILIATE_FEE_RESOLUTION, "ERR_INVALID_AFFILIATE_FEE");
        maxAffiliateFee = _maxAffiliateFee;
    }

    /**
      * @dev allows the owner to register/unregister ether tokens
      *
      * @param _token       ether token contract address
      * @param _register    true to register, false to unregister
    */
    function registerEtherToken(IEtherToken _token, bool _register)
        public
        ownerOnly
        validAddress(_token)
        notThis(_token)
    {
        etherTokens[_token] = _register;
    }

    /**
      * @dev returns the conversion path between two tokens in the network
      * note that this method is quite expensive in terms of gas and should generally be called off-chain
      *
      * @param _sourceToken source token address
      * @param _targetToken target token address
      *
      * @return conversion path between the two tokens
    */
    function conversionPath(IERC20Token _sourceToken, IERC20Token _targetToken) public view returns (address[]) {
        IConversionPathFinder pathFinder = IConversionPathFinder(addressOf(CONVERSION_PATH_FINDER));
        return pathFinder.findPath(_sourceToken, _targetToken);
    }

    /**
      * @dev returns the expected rate of converting a given amount on a given path
      * note that there is no support for circular paths
      *
      * @param _path        conversion path (see conversion path format above)
      * @param _amount      amount of _path[0] tokens received from the sender
      *
      * @return expected rate
    */
    function rateByPath(IERC20Token[] _path, uint256 _amount) public view returns (uint256) {
        uint256 amount;
        uint256 fee;
        uint256 supply;
        uint256 balance;
        uint32 weight;
        IConverter converter;
        IBancorFormula formula = IBancorFormula(addressOf(BANCOR_FORMULA));

        amount = _amount;

        // verify that the number of elements is larger than 2 and odd
        require(_path.length > 2 && _path.length % 2 == 1, "ERR_INVALID_PATH");

        // iterate over the conversion path
        for (uint256 i = 2; i < _path.length; i += 2) {
            IERC20Token sourceToken = _path[i - 2];
            IERC20Token anchor = _path[i - 1];
            IERC20Token targetToken = _path[i];

            converter = IConverter(IConverterAnchor(anchor).owner());

            // backward compatibility
            sourceToken = getConverterTokenAddress(converter, sourceToken);
            targetToken = getConverterTokenAddress(converter, targetToken);

            if (targetToken == anchor) { // buy the smart token
                // check if the current smart token has changed
                if (i < 3 || anchor != _path[i - 3])
                    supply = ISmartToken(anchor).totalSupply();

                // get the amount & the conversion fee
                balance = converter.getConnectorBalance(sourceToken);
                (, weight, , , ) = converter.connectors(sourceToken);
                amount = formula.purchaseRate(supply, balance, weight, amount);
                fee = amount.mul(converter.conversionFee()).div(CONVERSION_FEE_RESOLUTION);
                amount -= fee;

                // update the smart token supply for the next iteration
                supply = supply.add(amount);
            }
            else if (sourceToken == anchor) { // sell the smart token
                // check if the current smart token has changed
                if (i < 3 || anchor != _path[i - 3])
                    supply = ISmartToken(anchor).totalSupply();

                // get the amount & the conversion fee
                balance = converter.getConnectorBalance(targetToken);
                (, weight, , , ) = converter.connectors(targetToken);
                amount = formula.saleRate(supply, balance, weight, amount);
                fee = amount.mul(converter.conversionFee()).div(CONVERSION_FEE_RESOLUTION);
                amount -= fee;

                // update the smart token supply for the next iteration
                supply = supply.sub(amount);
            }
            else { // cross reserve conversion
                (amount, fee) = getReturn(converter, sourceToken, targetToken, amount);
            }
        }

        return amount;
    }

    /**
      * @dev converts the token to any other token in the bancor network by following
      * a predefined conversion path and transfers the result tokens to a target account
      * affiliate account/fee can also be passed in to receive a conversion fee (on top of the liquidity provider fees)
      * note that the network should already have been given allowance of the source token (if not ETH)
      *
      * @param _path                conversion path, see conversion path format above
      * @param _amount              amount to convert from, in the source token
      * @param _minReturn           if the conversion results in an amount smaller than the minimum return - it is cancelled, must be greater than zero
      * @param _beneficiary         account that will receive the conversion result or 0x0 to send the result to the sender account
      * @param _affiliateAccount    wallet address to receive the affiliate fee or 0x0 to disable affiliate fee
      * @param _affiliateFee        affiliate fee in PPM or 0 to disable affiliate fee
      *
      * @return amount of tokens received from the conversion
    */
    function convertByPath(IERC20Token[] _path, uint256 _amount, uint256 _minReturn, address _beneficiary, address _affiliateAccount, uint256 _affiliateFee)
        public
        payable
        protected
        greaterThanZero(_minReturn)
        returns (uint256)
    {
        // verify that the path contrains at least a single 'hop' and that the number of elements is odd
        require(_path.length > 2 && _path.length % 2 == 1, "ERR_INVALID_PATH");

        // validate msg.value and prepare the source token for the conversion
        handleSourceToken(_path[0], IConverterAnchor(_path[1]), _amount);

        // check if affiliate fee is enabled
        bool affiliateFeeEnabled = false;
        if (address(_affiliateAccount) == 0) {
            require(_affiliateFee == 0, "ERR_INVALID_AFFILIATE_FEE");
        }
        else {
            require(0 < _affiliateFee && _affiliateFee <= maxAffiliateFee, "ERR_INVALID_AFFILIATE_FEE");
            affiliateFeeEnabled = true;
        }

        // check if beneficiary is set
        address beneficiary = msg.sender;
        if (_beneficiary != address(0))
            beneficiary = _beneficiary;

        // convert and get the resulting amount
        ConversionStep[] memory data = createConversionData(_path, beneficiary, affiliateFeeEnabled);
        uint256 amount = doConversion(data, _amount, _minReturn, _affiliateAccount, _affiliateFee);

        // handle the conversion target tokens
        handleTargetToken(data, amount, beneficiary);

        return amount;
    }

    /**
      * @dev converts any other token to BNT in the bancor network by following
      a predefined conversion path and transfers the result to an account on a different blockchain
      * note that the network should already have been given allowance of the source token (if not ETH)
      *
      * @param _path                conversion path, see conversion path format above
      * @param _amount              amount to convert from, in the source token
      * @param _minReturn           if the conversion results in an amount smaller than the minimum return - it is cancelled, must be greater than zero
      * @param _targetBlockchain    blockchain BNT will be issued on
      * @param _targetAccount       address/account on the target blockchain to send the BNT to
      * @param _conversionId        pre-determined unique (if non zero) id which refers to this transaction
      *
      * @return the amount of BNT received from this conversion
    */
    function xConvert(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        bytes32 _targetBlockchain,
        bytes32 _targetAccount,
        uint256 _conversionId
    )
        public
        payable
        returns (uint256)
    {
        return xConvert2(_path, _amount, _minReturn, _targetBlockchain, _targetAccount, _conversionId, address(0), 0);
    }

    /**
      * @dev converts any other token to BNT in the bancor network by following
      a predefined conversion path and transfers the result to an account on a different blockchain
      * note that the network should already have been given allowance of the source token (if not ETH)
      *
      * @param _path                conversion path, see conversion path format above
      * @param _amount              amount to convert from, in the source token
      * @param _minReturn           if the conversion results in an amount smaller than the minimum return - it is cancelled, must be greater than zero
      * @param _targetBlockchain    blockchain BNT will be issued on
      * @param _targetAccount       address/account on the target blockchain to send the BNT to
      * @param _conversionId        pre-determined unique (if non zero) id which refers to this transaction
      * @param _affiliateAccount    affiliate account
      * @param _affiliateFee        affiliate fee in PPM
      *
      * @return the amount of BNT received from this conversion
    */
    function xConvert2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        bytes32 _targetBlockchain,
        bytes32 _targetAccount,
        uint256 _conversionId,
        address _affiliateAccount,
        uint256 _affiliateFee
    )
        public
        payable
        greaterThanZero(_minReturn)
        returns (uint256)
    {
        IERC20Token targetToken = _path[_path.length - 1];
        IBancorX bancorX = IBancorX(addressOf(BANCOR_X));

        // verify that the destination token is BNT
        require(targetToken == addressOf(BNT_TOKEN), "ERR_INVALID_TARGET_TOKEN");

        // convert and get the resulting amount
        uint256 amount = convertByPath(_path, _amount, _minReturn, this, _affiliateAccount, _affiliateFee);

        // grant BancorX allowance
        ensureAllowance(targetToken, bancorX, amount);

        // transfer the resulting amount to BancorX
        bancorX.xTransfer(_targetBlockchain, _targetAccount, amount, _conversionId);

        return amount;
    }

    /**
      * @dev allows a user to convert a token that was sent from another blockchain into any other
      * token on the BancorNetwork
      * ideally this transaction is created before the previous conversion is even complete, so
      * so the input amount isn't known at that point - the amount is actually take from the
      * BancorX contract directly by specifying the conversion id
      *
      * @param _path            conversion path
      * @param _bancorX         address of the BancorX contract for the source token
      * @param _conversionId    pre-determined unique (if non zero) id which refers to this conversion
      * @param _minReturn       if the conversion results in an amount smaller than the minimum return - it is cancelled, must be nonzero
      * @param _beneficiary     wallet to receive the conversion result
      *
      * @return amount of tokens received from the conversion
    */
    function completeXConversion(IERC20Token[] _path, IBancorX _bancorX, uint256 _conversionId, uint256 _minReturn, address _beneficiary)
        public returns (uint256)
    {
        // verify that the source token is the BancorX token
        require(_path[0] == _bancorX.token(), "ERR_INVALID_SOURCE_TOKEN");

        // get conversion amount from BancorX contract
        uint256 amount = _bancorX.getXTransferAmount(_conversionId, msg.sender);

        // perform the conversion
        return convertByPath(_path, amount, _minReturn, _beneficiary, address(0), 0);
    }

    /**
      * @dev executes the actual conversion by following the conversion path
      *
      * @param _data                conversion data, see ConversionStep struct above
      * @param _amount              amount to convert from, in the source token
      * @param _minReturn           if the conversion results in an amount smaller than the minimum return - it is cancelled, must be greater than zero
      * @param _affiliateAccount    affiliate account
      * @param _affiliateFee        affiliate fee in PPM
      *
      * @return amount of tokens received from the conversion
    */
    function doConversion(
        ConversionStep[] _data,
        uint256 _amount,
        uint256 _minReturn,
        address _affiliateAccount,
        uint256 _affiliateFee
    ) private returns (uint256) {
        uint256 toAmount;
        uint256 fromAmount = _amount;

        // iterate over the conversion data
        for (uint256 i = 0; i < _data.length; i++) {
            ConversionStep memory stepData = _data[i];

            // newer converter
            if (stepData.isV28OrHigherConverter) {
                // transfer the tokens to the converter only if the network contract currently holds the tokens
                // not needed with ETH or if it's the first conversion step
                if (i != 0 && _data[i - 1].beneficiary == address(this) && !etherTokens[stepData.sourceToken])
                    safeTransfer(stepData.sourceToken, stepData.converter, fromAmount);
            }
            // older converter
            // if the source token is the smart token, no need to do any transfers as the converter controls it
            else if (stepData.sourceToken != ISmartToken(stepData.anchor)) {
                // grant allowance for it to transfer the tokens from the network contract
                ensureAllowance(stepData.sourceToken, stepData.converter, fromAmount);
            }

            // do the conversion
            if (!stepData.isV28OrHigherConverter)
                toAmount = ILegacyConverter(stepData.converter).change(stepData.sourceToken, stepData.targetToken, fromAmount, 1);
            else if (etherTokens[stepData.sourceToken])
                toAmount = stepData.converter.convert.value(msg.value)(stepData.sourceToken, stepData.targetToken, fromAmount, msg.sender, stepData.beneficiary);
            else
                toAmount = stepData.converter.convert(stepData.sourceToken, stepData.targetToken, fromAmount, msg.sender, stepData.beneficiary);

            // pay affiliate-fee if needed
            if (stepData.processAffiliateFee) {
                uint256 affiliateAmount = toAmount.mul(_affiliateFee).div(AFFILIATE_FEE_RESOLUTION);
                require(stepData.targetToken.transfer(_affiliateAccount, affiliateAmount), "ERR_FEE_TRANSFER_FAILED");
                toAmount -= affiliateAmount;
            }

            emit Conversion(stepData.anchor, stepData.sourceToken, stepData.targetToken, fromAmount, toAmount, msg.sender);
            fromAmount = toAmount;
        }

        // ensure the trade meets the minimum requested amount
        require(toAmount >= _minReturn, "ERR_RETURN_TOO_LOW");

        return toAmount;
    }

    /**
      * @dev validates msg.value and prepares the conversion source token for the conversion
      *
      * @param _sourceToken source token of the first conversion step
      * @param _anchor      converter anchor of the first conversion step
      * @param _amount      amount to convert from, in the source token
    */
    function handleSourceToken(IERC20Token _sourceToken, IConverterAnchor _anchor, uint256 _amount) private {
        IConverter firstConverter = IConverter(_anchor.owner());
        bool isNewerConverter = isV28OrHigherConverter(firstConverter);

        // ETH
        if (msg.value > 0) {
            // validate msg.value
            require(msg.value == _amount, "ERR_ETH_AMOUNT_MISMATCH");

            // EtherToken converter - deposit the ETH into the EtherToken
            // note that it can still be a non ETH converter if the path is wrong
            // but such conversion will simply revert
            if (!isNewerConverter)
                IEtherToken(getConverterEtherTokenAddress(firstConverter)).deposit.value(msg.value)();
        }
        // EtherToken
        else if (etherTokens[_sourceToken]) {
            // claim the tokens - if the source token is ETH reserve, this call will fail
            // since in that case the transaction must be sent with msg.value
            safeTransferFrom(_sourceToken, msg.sender, this, _amount);

            // ETH converter - withdraw the ETH
            if (isNewerConverter)
                IEtherToken(_sourceToken).withdraw(_amount);
        }
        // other ERC20 token
        else {
            // newer converter - transfer the tokens from the sender directly to the converter
            // otherwise claim the tokens
            if (isNewerConverter)
                safeTransferFrom(_sourceToken, msg.sender, firstConverter, _amount);
            else
                safeTransferFrom(_sourceToken, msg.sender, this, _amount);
        }
    }

    /**
      * @dev handles the conversion target token if the network still holds it at the end of the conversion
      *
      * @param _data        conversion data, see ConversionStep struct above
      * @param _amount      conversion return amount, in the target token
      * @param _beneficiary wallet to receive the conversion result
    */
    function handleTargetToken(ConversionStep[] _data, uint256 _amount, address _beneficiary) private {
        ConversionStep memory stepData = _data[_data.length - 1];

        // network contract doesn't hold the tokens, do nothing
        if (stepData.beneficiary != address(this))
            return;

        IERC20Token targetToken = stepData.targetToken;

        // ETH / EtherToken
        if (etherTokens[targetToken]) {
            // newer converter should send ETH directly to the beneficiary
            assert(!stepData.isV28OrHigherConverter);

            // EtherToken converter - withdraw the ETH and transfer to the beneficiary
            IEtherToken(targetToken).withdrawTo(_beneficiary, _amount);
        }
        // other ERC20 token
        else {
            safeTransfer(targetToken, _beneficiary, _amount);
        }
    }

    /**
      * @dev creates a memory cache of all conversion steps data to minimize logic and external calls during conversions
      *
      * @param _conversionPath      conversion path, see conversion path format above
      * @param _beneficiary         wallet to receive the conversion result
      * @param _affiliateFeeEnabled true if affiliate fee was requested by the sender, false if not
      *
      * @return cached conversion data to be ingested later on by the conversion flow
    */
    function createConversionData(IERC20Token[] _conversionPath, address _beneficiary, bool _affiliateFeeEnabled) private view returns (ConversionStep[]) {
        ConversionStep[] memory data = new ConversionStep[](_conversionPath.length / 2);

        bool affiliateFeeProcessed = false;
        address bntToken = addressOf(BNT_TOKEN);
        // iterate the conversion path and create the conversion data for each step
        uint256 i;
        for (i = 0; i < _conversionPath.length - 1; i += 2) {
            IConverterAnchor anchor = IConverterAnchor(_conversionPath[i + 1]);
            IConverter converter = IConverter(anchor.owner());
            IERC20Token targetToken = _conversionPath[i + 2];

            // check if the affiliate fee should be processed in this step
            bool processAffiliateFee = _affiliateFeeEnabled && !affiliateFeeProcessed && targetToken == bntToken;
            if (processAffiliateFee)
                affiliateFeeProcessed = true;

            data[i / 2] = ConversionStep({
                // set the converter anchor
                anchor: anchor,

                // set the converter
                converter: converter,

                // set the source/target tokens
                sourceToken: _conversionPath[i],
                targetToken: targetToken,

                // requires knowledge about the next step, so initialize in the next phase
                beneficiary: address(0),

                // set flags
                isV28OrHigherConverter: isV28OrHigherConverter(converter),
                processAffiliateFee: processAffiliateFee
            });
        }

        // ETH support
        // source is ETH
        ConversionStep memory stepData = data[0];
        if (etherTokens[stepData.sourceToken]) {
            // newer converter - replace the source token address with ETH reserve address
            if (stepData.isV28OrHigherConverter)
                stepData.sourceToken = IERC20Token(ETH_RESERVE_ADDRESS);
            // older converter - replace the source token with the EtherToken address used by the converter
            else
                stepData.sourceToken = IERC20Token(getConverterEtherTokenAddress(stepData.converter));
        }

        // target is ETH
        stepData = data[data.length - 1];
        if (etherTokens[stepData.targetToken]) {
            // newer converter - replace the target token address with ETH reserve address
            if (stepData.isV28OrHigherConverter)
                stepData.targetToken = IERC20Token(ETH_RESERVE_ADDRESS);
            // older converter - replace the target token with the EtherToken address used by the converter
            else
                stepData.targetToken = IERC20Token(getConverterEtherTokenAddress(stepData.converter));
        }

        // set the beneficiary for each step
        for (i = 0; i < data.length; i++) {
            stepData = data[i];

            // first check if the converter in this step is newer as older converters don't even support the beneficiary argument
            if (stepData.isV28OrHigherConverter) {
                // if affiliate fee is processed in this step, beneficiary is the network contract
                if (stepData.processAffiliateFee)
                    stepData.beneficiary = this;
                // if it's the last step, beneficiary is the final beneficiary
                else if (i == data.length - 1)
                    stepData.beneficiary = _beneficiary;
                // if the converter in the next step is newer, beneficiary is the next converter
                else if (data[i + 1].isV28OrHigherConverter)
                    stepData.beneficiary = data[i + 1].converter;
                // the converter in the next step is older, beneficiary is the network contract
                else
                    stepData.beneficiary = this;
            }
            else {
                // converter in this step is older, beneficiary is the network contract
                stepData.beneficiary = this;
            }
        }

        return data;
    }

    /**
      * @dev utility, checks whether allowance for the given spender exists and approves one if it doesn't.
      * Note that we use the non standard erc-20 interface in which `approve` has no return value so that
      * this function will work for both standard and non standard tokens
      *
      * @param _token   token to check the allowance in
      * @param _spender approved address
      * @param _value   allowance amount
    */
    function ensureAllowance(IERC20Token _token, address _spender, uint256 _value) private {
        uint256 allowance = _token.allowance(this, _spender);
        if (allowance < _value) {
            if (allowance > 0)
                safeApprove(_token, _spender, 0);
            safeApprove(_token, _spender, _value);
        }
    }

    // legacy - returns the address of an EtherToken used by the converter
    function getConverterEtherTokenAddress(IConverter _converter) private view returns (address) {
        uint256 reserveCount = _converter.connectorTokenCount();
        for (uint256 i = 0; i < reserveCount; i++) {
            address reserveTokenAddress = _converter.connectorTokens(i);
            if (etherTokens[reserveTokenAddress])
                return reserveTokenAddress;
        }

        return ETH_RESERVE_ADDRESS;
    }

    // legacy - if the token is an ether token, returns the ETH reserve address
    // used by the converter, otherwise returns the input token address
    function getConverterTokenAddress(IConverter _converter, IERC20Token _token) private view returns (IERC20Token) {
        if (!etherTokens[_token])
            return _token;

        if (isV28OrHigherConverter(_converter))
            return IERC20Token(ETH_RESERVE_ADDRESS);

        return IERC20Token(getConverterEtherTokenAddress(_converter));
    }

    bytes4 private constant GET_RETURN_FUNC_SELECTOR = bytes4(keccak256("getReturn(address,address,uint256)"));

    // using assembly code since older converter versions have different return values
    function getReturn(address _dest, address _sourceToken, address _targetToken, uint256 _amount) internal view returns (uint256, uint256) {
        uint256[2] memory ret;
        bytes memory data = abi.encodeWithSelector(GET_RETURN_FUNC_SELECTOR, _sourceToken, _targetToken, _amount);

        assembly {
            let success := staticcall(
                gas,           // gas remaining
                _dest,         // destination address
                add(data, 32), // input buffer (starts after the first 32 bytes in the `data` array)
                mload(data),   // input length (loaded from the first 32 bytes in the `data` array)
                ret,           // output buffer
                64             // output length
            )
            if iszero(success) {
                revert(0, 0)
            }
        }

        return (ret[0], ret[1]);
    }

    bytes4 private constant IS_V28_OR_HIGHER_FUNC_SELECTOR = bytes4(keccak256("isV28OrHigher()"));

    // using assembly code to identify converter version
    // can't rely on the version number since the function had a different signature in older converters
    function isV28OrHigherConverter(IConverter _converter) internal view returns (bool) {
        bool success;
        uint256[1] memory ret;
        bytes memory data = abi.encodeWithSelector(IS_V28_OR_HIGHER_FUNC_SELECTOR);

        assembly {
            success := staticcall(
                5000,          // isV28OrHigher consumes 190 gas, but just for extra safety
                _converter,    // destination address
                add(data, 32), // input buffer (starts after the first 32 bytes in the `data` array)
                mload(data),   // input length (loaded from the first 32 bytes in the `data` array)
                ret,           // output buffer
                32             // output length
            )
        }

        return success && ret[0] != 0;
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function getReturnByPath(IERC20Token[] _path, uint256 _amount) public view returns (uint256, uint256) {
        return (rateByPath(_path, _amount), 0);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function convert(IERC20Token[] _path, uint256 _amount, uint256 _minReturn) public payable returns (uint256) {
        return convertByPath(_path, _amount, _minReturn, address(0), address(0), 0);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function convert2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _affiliateAccount,
        uint256 _affiliateFee
    )
        public
        payable
        returns (uint256)
    {
        return convertByPath(_path, _amount, _minReturn, address(0), _affiliateAccount, _affiliateFee);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function convertFor(IERC20Token[] _path, uint256 _amount, uint256 _minReturn, address _beneficiary) public payable returns (uint256) {
        return convertByPath(_path, _amount, _minReturn, _beneficiary, address(0), 0);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function convertFor2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _beneficiary,
        address _affiliateAccount,
        uint256 _affiliateFee
    )
        public
        payable
        greaterThanZero(_minReturn)
        returns (uint256)
    {
        return convertByPath(_path, _amount, _minReturn, _beneficiary, _affiliateAccount, _affiliateFee);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function claimAndConvert(IERC20Token[] _path, uint256 _amount, uint256 _minReturn) public returns (uint256) {
        return convertByPath(_path, _amount, _minReturn, address(0), address(0), 0);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function claimAndConvert2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _affiliateAccount,
        uint256 _affiliateFee
    )
        public
        returns (uint256)
    {
        return convertByPath(_path, _amount, _minReturn, address(0), _affiliateAccount, _affiliateFee);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function claimAndConvertFor(IERC20Token[] _path, uint256 _amount, uint256 _minReturn, address _beneficiary) public returns (uint256) {
        return convertByPath(_path, _amount, _minReturn, _beneficiary, address(0), 0);
    }

    /**
      * @dev deprecated, backward compatibility
    */
    function claimAndConvertFor2(
        IERC20Token[] _path,
        uint256 _amount,
        uint256 _minReturn,
        address _beneficiary,
        address _affiliateAccount,
        uint256 _affiliateFee
    )
        public
        returns (uint256)
    {
        return convertByPath(_path, _amount, _minReturn, _beneficiary, _affiliateAccount, _affiliateFee);
    }
}

// File: solidity/contracts/token/interfaces/IERC20Token.sol

// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.6.12;

/*
    ERC20 Standard Token interface
*/
interface IERC20Token {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint256);
    function balanceOf(address _owner) external view returns (uint256);
    function allowance(address _owner, address _spender) external view returns (uint256);

    function transfer(address _to, uint256 _value) external returns (bool);
    function transferFrom(address _from, address _to, uint256 _value) external returns (bool);
    function approve(address _spender, uint256 _value) external returns (bool);
}

// File: solidity/contracts/utility/Utils.sol


pragma solidity 0.6.12;

/**
  * @dev Utilities & Common Modifiers
*/
contract Utils {
    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 _value) {
        _greaterThanZero(_value);
        _;
    }

    // error message binary size optimization
    function _greaterThanZero(uint256 _value) internal pure {
        require(_value > 0, "ERR_ZERO_VALUE");
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        _validAddress(_address);
        _;
    }

    // error message binary size optimization
    function _validAddress(address _address) internal pure {
        require(_address != address(0), "ERR_INVALID_ADDRESS");
    }

    // verifies that the address is different than this contract address
    modifier notThis(address _address) {
        _notThis(_address);
        _;
    }

    // error message binary size optimization
    function _notThis(address _address) internal view {
        require(_address != address(this), "ERR_ADDRESS_IS_SELF");
    }
}

// File: solidity/contracts/utility/SafeMath.sol


pragma solidity 0.6.12;

/**
  * @dev Library for basic math operations with overflow/underflow protection
*/
library SafeMath {
    /**
      * @dev returns the sum of _x and _y, reverts if the calculation overflows
      *
      * @param _x   value 1
      * @param _y   value 2
      *
      * @return sum
    */
    function add(uint256 _x, uint256 _y) internal pure returns (uint256) {
        uint256 z = _x + _y;
        require(z >= _x, "ERR_OVERFLOW");
        return z;
    }

    /**
      * @dev returns the difference of _x minus _y, reverts if the calculation underflows
      *
      * @param _x   minuend
      * @param _y   subtrahend
      *
      * @return difference
    */
    function sub(uint256 _x, uint256 _y) internal pure returns (uint256) {
        require(_x >= _y, "ERR_UNDERFLOW");
        return _x - _y;
    }

    /**
      * @dev returns the product of multiplying _x by _y, reverts if the calculation overflows
      *
      * @param _x   factor 1
      * @param _y   factor 2
      *
      * @return product
    */
    function mul(uint256 _x, uint256 _y) internal pure returns (uint256) {
        // gas optimization
        if (_x == 0)
            return 0;

        uint256 z = _x * _y;
        require(z / _x == _y, "ERR_OVERFLOW");
        return z;
    }

    /**
      * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
      *
      * @param _x   dividend
      * @param _y   divisor
      *
      * @return quotient
    */
    function div(uint256 _x, uint256 _y) internal pure returns (uint256) {
        require(_y > 0, "ERR_DIVIDE_BY_ZERO");
        uint256 c = _x / _y;
        return c;
    }
}

// File: solidity/contracts/token/ERC20Token.sol


pragma solidity 0.6.12;




/**
  * @dev ERC20 Standard Token implementation
*/
contract ERC20Token is IERC20Token, Utils {
    using SafeMath for uint256;


    string public override name;
    string public override symbol;
    uint8 public override decimals;
    uint256 public override totalSupply;
    mapping (address => uint256) public override balanceOf;
    mapping (address => mapping (address => uint256)) public override allowance;

    /**
      * @dev triggered when tokens are transferred between wallets
      *
      * @param _from    source address
      * @param _to      target address
      * @param _value   transfer amount
    */
    event Transfer(address indexed _from, address indexed _to, uint256 _value);

    /**
      * @dev triggered when a wallet allows another wallet to transfer tokens from on its behalf
      *
      * @param _owner   wallet that approves the allowance
      * @param _spender wallet that receives the allowance
      * @param _value   allowance amount
    */
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    /**
      * @dev initializes a new ERC20Token instance
      *
      * @param _name        token name
      * @param _symbol      token symbol
      * @param _decimals    decimal points, for display purposes
      * @param _totalSupply total supply of token units
    */
    constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _totalSupply) public {
        // validate input
        require(bytes(_name).length > 0, "ERR_INVALID_NAME");
        require(bytes(_symbol).length > 0, "ERR_INVALID_SYMBOL");

        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        totalSupply = _totalSupply;
        balanceOf[msg.sender] = _totalSupply;
    }

    /**
      * @dev transfers tokens to a given address
      * throws on any error rather then return a false flag to minimize user errors
      *
      * @param _to      target address
      * @param _value   transfer amount
      *
      * @return true if the transfer was successful, false if it wasn't
    */
    function transfer(address _to, uint256 _value)
        public
        virtual
        override
        validAddress(_to)
        returns (bool)
    {
        balanceOf[msg.sender] = balanceOf[msg.sender].sub(_value);
        balanceOf[_to] = balanceOf[_to].add(_value);
        emit Transfer(msg.sender, _to, _value);
        return true;
    }

    /**
      * @dev transfers tokens to a given address on behalf of another address
      * throws on any error rather then return a false flag to minimize user errors
      *
      * @param _from    source address
      * @param _to      target address
      * @param _value   transfer amount
      *
      * @return true if the transfer was successful, false if it wasn't
    */
    function transferFrom(address _from, address _to, uint256 _value)
        public
        virtual
        override
        validAddress(_from)
        validAddress(_to)
        returns (bool)
    {
        allowance[_from][msg.sender] = allowance[_from][msg.sender].sub(_value);
        balanceOf[_from] = balanceOf[_from].sub(_value);
        balanceOf[_to] = balanceOf[_to].add(_value);
        emit Transfer(_from, _to, _value);
        return true;
    }

    /**
      * @dev allows another account/contract to transfers tokens on behalf of the caller
      * throws on any error rather then return a false flag to minimize user errors
      *
      * @param _spender approved address
      * @param _value   allowance amount
      *
      * @return true if the approval was successful, false if it wasn't
    */
    function approve(address _spender, uint256 _value)
        public
        virtual
        override
        validAddress(_spender)
        returns (bool)
    {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }
}

// File: solidity/contracts/utility/interfaces/IOwned.sol


pragma solidity 0.6.12;

/*
    Owned contract interface
*/
interface IOwned {
    // this function isn't since the compiler emits automatically generated getter functions as external
    function owner() external view returns (address);

    function transferOwnership(address _newOwner) external;
    function acceptOwnership() external;
}

// File: solidity/contracts/converter/interfaces/IConverterAnchor.sol


pragma solidity 0.6.12;


/*
    Converter Anchor interface
*/
interface IConverterAnchor is IOwned {
}

// File: solidity/contracts/token/interfaces/IDSToken.sol


pragma solidity 0.6.12;




/*
    DSToken interface
*/
interface IDSToken is IConverterAnchor, IERC20Token {
    function issue(address _to, uint256 _amount) external;
    function destroy(address _from, uint256 _amount) external;
}

// File: solidity/contracts/utility/Owned.sol


pragma solidity 0.6.12;


/**
  * @dev Provides support and utilities for contract ownership
*/
contract Owned is IOwned {
    address public override owner;
    address public newOwner;

    /**
      * @dev triggered when the owner is updated
      *
      * @param _prevOwner previous owner
      * @param _newOwner  new owner
    */
    event OwnerUpdate(address indexed _prevOwner, address indexed _newOwner);

    /**
      * @dev initializes a new Owned instance
    */
    constructor() public {
        owner = msg.sender;
    }

    // allows execution by the owner only
    modifier ownerOnly {
        _ownerOnly();
        _;
    }

    // error message binary size optimization
    function _ownerOnly() internal view {
        require(msg.sender == owner, "ERR_ACCESS_DENIED");
    }

    /**
      * @dev allows transferring the contract ownership
      * the new owner still needs to accept the transfer
      * can only be called by the contract owner
      *
      * @param _newOwner    new contract owner
    */
    function transferOwnership(address _newOwner) public override ownerOnly {
        require(_newOwner != owner, "ERR_SAME_OWNER");
        newOwner = _newOwner;
    }

    /**
      * @dev used by a new owner to accept an ownership transfer
    */
    function acceptOwnership() override public {
        require(msg.sender == newOwner, "ERR_ACCESS_DENIED");
        emit OwnerUpdate(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}

// File: solidity/contracts/token/DSToken.sol


pragma solidity 0.6.12;




/**
  * @dev DSToken represents a token with dynamic supply.
  * The owner of the token can mint/burn tokens to/from any account.
  *
*/
contract DSToken is IDSToken, ERC20Token, Owned {
    using SafeMath for uint256;

    /**
      * @dev triggered when the total supply is increased
      *
      * @param _amount  amount that gets added to the supply
    */
    event Issuance(uint256 _amount);

    /**
      * @dev triggered when the total supply is decreased
      *
      * @param _amount  amount that gets removed from the supply
    */
    event Destruction(uint256 _amount);

    /**
      * @dev initializes a new DSToken instance
      *
      * @param _name       token name
      * @param _symbol     token short symbol, minimum 1 character
      * @param _decimals   for display purposes only
    */
    constructor(string memory _name, string memory _symbol, uint8 _decimals)
        public
        ERC20Token(_name, _symbol, _decimals, 0)
    {
    }

    /**
      * @dev increases the token supply and sends the new tokens to the given account
      * can only be called by the contract owner
      *
      * @param _to      account to receive the new amount
      * @param _amount  amount to increase the supply by
    */
    function issue(address _to, uint256 _amount)
        public
        override
        ownerOnly
        validAddress(_to)
        notThis(_to)
    {
        totalSupply = totalSupply.add(_amount);
        balanceOf[_to] = balanceOf[_to].add(_amount);

        emit Issuance(_amount);
        emit Transfer(address(0), _to, _amount);
    }

    /**
      * @dev removes tokens from the given account and decreases the token supply
      * can only be called by the contract owner
      *
      * @param _from    account to remove the amount from
      * @param _amount  amount to decrease the supply by
    */
    function destroy(address _from, uint256 _amount) public override ownerOnly {
        balanceOf[_from] = balanceOf[_from].sub(_amount);
        totalSupply = totalSupply.sub(_amount);

        emit Transfer(_from, address(0), _amount);
        emit Destruction(_amount);
    }

    // ERC20 standard method overrides with some extra functionality

    /**
      * @dev send coins
      * throws on any error rather then return a false flag to minimize user errors
      * in addition to the standard checks, the function throws if transfers are disabled
      *
      * @param _to      target address
      * @param _value   transfer amount
      *
      * @return true if the transfer was successful, false if it wasn't
    */
    function transfer(address _to, uint256 _value)
        public
        override(IERC20Token, ERC20Token)
        returns (bool)
    {
        return super.transfer(_to, _value);
    }

    /**
      * @dev an account/contract attempts to get the coins
      * throws on any error rather then return a false flag to minimize user errors
      * in addition to the standard checks, the function throws if transfers are disabled
      *
      * @param _from    source address
      * @param _to      target address
      * @param _value   transfer amount
      *
      * @return true if the transfer was successful, false if it wasn't
    */
    function transferFrom(address _from, address _to, uint256 _value)
        public
        override(IERC20Token, ERC20Token)
        returns (bool) 
    {
        return super.transferFrom(_from, _to, _value);
    }
}

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/utils/Address.sol



pragma solidity >=0.6.2 <0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol



pragma solidity >=0.6.0 <0.8.0;




/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: solidity/contracts/converter/ConverterVersion.sol


pragma solidity 0.6.12;

contract ConverterVersion {
    uint16 public constant version = 46;
}

// File: solidity/contracts/utility/interfaces/IOwned.sol


pragma solidity 0.6.12;

/*
    Owned contract interface
*/
interface IOwned {
    // this function isn't since the compiler emits automatically generated getter functions as external
    function owner() external view returns (address);

    function transferOwnership(address _newOwner) external;

    function acceptOwnership() external;
}

// File: solidity/contracts/converter/interfaces/IConverterAnchor.sol


pragma solidity 0.6.12;


/*
    Converter Anchor interface
*/
interface IConverterAnchor is IOwned {

}

// File: solidity/contracts/converter/interfaces/IConverter.sol


pragma solidity 0.6.12;




/*
    Converter interface
*/
interface IConverter is IOwned {
    function converterType() external pure returns (uint16);

    function anchor() external view returns (IConverterAnchor);

    function isActive() external view returns (bool);

    function targetAmountAndFee(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount
    ) external view returns (uint256, uint256);

    function convert(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount,
        address _trader,
        address payable _beneficiary
    ) external payable returns (uint256);

    function conversionFee() external view returns (uint32);

    function maxConversionFee() external view returns (uint32);

    function reserveBalance(IERC20 _reserveToken) external view returns (uint256);

    receive() external payable;

    function transferAnchorOwnership(address _newOwner) external;

    function acceptAnchorOwnership() external;

    function setConversionFee(uint32 _conversionFee) external;

    function addReserve(IERC20 _token, uint32 _weight) external;

    function transferReservesOnUpgrade(address _newConverter) external;

    function onUpgradeComplete() external;

    // deprecated, backward compatibility
    function token() external view returns (IConverterAnchor);

    function transferTokenOwnership(address _newOwner) external;

    function acceptTokenOwnership() external;

    function connectors(IERC20 _address)
        external
        view
        returns (
            uint256,
            uint32,
            bool,
            bool,
            bool
        );

    function getConnectorBalance(IERC20 _connectorToken) external view returns (uint256);

    function connectorTokens(uint256 _index) external view returns (IERC20);

    function connectorTokenCount() external view returns (uint16);

    /**
     * @dev triggered when the converter is activated
     *
     * @param _type        converter type
     * @param _anchor      converter anchor
     * @param _activated   true if the converter was activated, false if it was deactivated
     */
    event Activation(uint16 indexed _type, IConverterAnchor indexed _anchor, bool indexed _activated);

    /**
     * @dev triggered when a conversion between two tokens occurs
     *
     * @param _fromToken       source ERC20 token
     * @param _toToken         target ERC20 token
     * @param _trader          wallet that initiated the trade
     * @param _amount          input amount in units of the source token
     * @param _return          output amount minus conversion fee in units of the target token
     * @param _conversionFee   conversion fee in units of the target token
     */
    event Conversion(
        IERC20 indexed _fromToken,
        IERC20 indexed _toToken,
        address indexed _trader,
        uint256 _amount,
        uint256 _return,
        int256 _conversionFee
    );

    /**
     * @dev triggered when the rate between two tokens in the converter changes
     * note that the event might be dispatched for rate updates between any two tokens in the converter
     *
     * @param  _token1 address of the first token
     * @param  _token2 address of the second token
     * @param  _rateN  rate of 1 unit of `_token1` in `_token2` (numerator)
     * @param  _rateD  rate of 1 unit of `_token1` in `_token2` (denominator)
     */
    event TokenRateUpdate(IERC20 indexed _token1, IERC20 indexed _token2, uint256 _rateN, uint256 _rateD);

    /**
     * @dev triggered when the conversion fee is updated
     *
     * @param  _prevFee    previous fee percentage, represented in ppm
     * @param  _newFee     new fee percentage, represented in ppm
     */
    event ConversionFeeUpdate(uint32 _prevFee, uint32 _newFee);
}

// File: solidity/contracts/converter/interfaces/IConverterUpgrader.sol


pragma solidity 0.6.12;

/*
    Converter Upgrader interface
*/
interface IConverterUpgrader {
    function upgrade(bytes32 _version) external;

    function upgrade(uint16 _version) external;
}

// File: solidity/contracts/utility/interfaces/ITokenHolder.sol


pragma solidity 0.6.12;



/*
    Token Holder interface
*/
interface ITokenHolder is IOwned {
    receive() external payable;

    function withdrawTokens(
        IERC20 token,
        address payable to,
        uint256 amount
    ) external;

    function withdrawTokensMultiple(
        IERC20[] calldata tokens,
        address payable to,
        uint256[] calldata amounts
    ) external;
}

// File: solidity/contracts/INetworkSettings.sol


pragma solidity 0.6.12;


interface INetworkSettings {
    function networkFeeParams() external view returns (ITokenHolder, uint32);

    function networkFeeWallet() external view returns (ITokenHolder);

    function networkFee() external view returns (uint32);
}

// File: solidity/contracts/token/interfaces/IDSToken.sol


pragma solidity 0.6.12;




/*
    DSToken interface
*/
interface IDSToken is IConverterAnchor, IERC20 {
    function issue(address _to, uint256 _amount) external;

    function destroy(address _from, uint256 _amount) external;
}

// File: solidity/contracts/utility/MathEx.sol


pragma solidity 0.6.12;

/**
 * @dev This library provides a set of complex math operations.
 */
library MathEx {
    uint256 private constant MAX_EXP_BIT_LEN = 4;
    uint256 private constant MAX_EXP = 2**MAX_EXP_BIT_LEN - 1;
    uint256 private constant MAX_UINT128 = 2**128 - 1;

    /**
     * @dev returns the largest integer smaller than or equal to the square root of a positive integer
     *
     * @param _num a positive integer
     *
     * @return the largest integer smaller than or equal to the square root of the positive integer
     */
    function floorSqrt(uint256 _num) internal pure returns (uint256) {
        uint256 x = _num / 2 + 1;
        uint256 y = (x + _num / x) / 2;
        while (x > y) {
            x = y;
            y = (x + _num / x) / 2;
        }
        return x;
    }

    /**
     * @dev returns the smallest integer larger than or equal to the square root of a positive integer
     *
     * @param _num a positive integer
     *
     * @return the smallest integer larger than or equal to the square root of the positive integer
     */
    function ceilSqrt(uint256 _num) internal pure returns (uint256) {
        uint256 x = floorSqrt(_num);
        return x * x == _num ? x : x + 1;
    }

    /**
     * @dev computes a powered ratio
     *
     * @param _n   ratio numerator
     * @param _d   ratio denominator
     * @param _exp ratio exponent
     *
     * @return powered ratio's numerator and denominator
     */
    function poweredRatio(
        uint256 _n,
        uint256 _d,
        uint256 _exp
    ) internal pure returns (uint256, uint256) {
        require(_exp <= MAX_EXP, "ERR_EXP_TOO_LARGE");

        uint256[MAX_EXP_BIT_LEN] memory ns;
        uint256[MAX_EXP_BIT_LEN] memory ds;

        (ns[0], ds[0]) = reducedRatio(_n, _d, MAX_UINT128);
        for (uint256 i = 0; (_exp >> i) > 1; i++) {
            (ns[i + 1], ds[i + 1]) = reducedRatio(ns[i] ** 2, ds[i] ** 2, MAX_UINT128);
        }

        uint256 n = 1;
        uint256 d = 1;

        for (uint256 i = 0; (_exp >> i) > 0; i++) {
            if (((_exp >> i) & 1) > 0) {
                (n, d) = reducedRatio(n * ns[i], d * ds[i], MAX_UINT128);
            }
        }

        return (n, d);
    }

    /**
     * @dev computes a reduced-scalar ratio
     *
     * @param _n   ratio numerator
     * @param _d   ratio denominator
     * @param _max maximum desired scalar
     *
     * @return ratio's numerator and denominator
     */
    function reducedRatio(
        uint256 _n,
        uint256 _d,
        uint256 _max
    ) internal pure returns (uint256, uint256) {
        (uint256 n, uint256 d) = (_n, _d);
        if (n > _max || d > _max) {
            (n, d) = normalizedRatio(n, d, _max);
        }
        if (n != d) {
            return (n, d);
        }
        return (1, 1);
    }

    /**
     * @dev computes "scale * a / (a + b)" and "scale * b / (a + b)".
     */
    function normalizedRatio(
        uint256 _a,
        uint256 _b,
        uint256 _scale
    ) internal pure returns (uint256, uint256) {
        if (_a <= _b) {
            return accurateRatio(_a, _b, _scale);
        }
        (uint256 y, uint256 x) = accurateRatio(_b, _a, _scale);
        return (x, y);
    }

    /**
     * @dev computes "scale * a / (a + b)" and "scale * b / (a + b)", assuming that "a <= b".
     */
    function accurateRatio(
        uint256 _a,
        uint256 _b,
        uint256 _scale
    ) internal pure returns (uint256, uint256) {
        uint256 maxVal = uint256(-1) / _scale;
        if (_a > maxVal) {
            uint256 c = _a / (maxVal + 1) + 1;
            _a /= c; // we can now safely compute `_a * _scale`
            _b /= c;
        }
        if (_a != _b) {
            uint256 n = _a * _scale;
            uint256 d = _a + _b; // can overflow
            if (d >= _a) {
                // no overflow in `_a + _b`
                uint256 x = roundDiv(n, d); // we can now safely compute `_scale - x`
                uint256 y = _scale - x;
                return (x, y);
            }
            if (n < _b - (_b - _a) / 2) {
                return (0, _scale); // `_a * _scale < (_a + _b) / 2 < MAX_UINT256 < _a + _b`
            }
            return (1, _scale - 1); // `(_a + _b) / 2 < _a * _scale < MAX_UINT256 < _a + _b`
        }
        return (_scale / 2, _scale / 2); // allow reduction to `(1, 1)` in the calling function
    }

    /**
     * @dev computes the nearest integer to a given quotient without overflowing or underflowing.
     */
    function roundDiv(uint256 _n, uint256 _d) internal pure returns (uint256) {
        return _n / _d + (_n % _d) / (_d - _d / 2);
    }

    /**
     * @dev returns the average number of decimal digits in a given list of positive integers
     *
     * @param _values  list of positive integers
     *
     * @return the average number of decimal digits in the given list of positive integers
     */
    function geometricMean(uint256[] memory _values) internal pure returns (uint256) {
        uint256 numOfDigits = 0;
        uint256 length = _values.length;
        for (uint256 i = 0; i < length; i++) {
            numOfDigits += decimalLength(_values[i]);
        }
        return uint256(10)**(roundDivUnsafe(numOfDigits, length) - 1);
    }

    /**
     * @dev returns the number of decimal digits in a given positive integer
     *
     * @param _x   positive integer
     *
     * @return the number of decimal digits in the given positive integer
     */
    function decimalLength(uint256 _x) internal pure returns (uint256) {
        uint256 y = 0;
        for (uint256 x = _x; x > 0; x /= 10) {
            y++;
        }
        return y;
    }

    /**
     * @dev returns the nearest integer to a given quotient
     * the computation is overflow-safe assuming that the input is sufficiently small
     *
     * @param _n   quotient numerator
     * @param _d   quotient denominator
     *
     * @return the nearest integer to the given quotient
     */
    function roundDivUnsafe(uint256 _n, uint256 _d) internal pure returns (uint256) {
        return (_n + _d / 2) / _d;
    }

    /**
     * @dev returns the larger of two values
     *
     * @param _val1 the first value
     * @param _val2 the second value
     */
    function max(uint256 _val1, uint256 _val2) internal pure returns (uint256) {
        return _val1 > _val2 ? _val1 : _val2;
    }
}

// File: solidity/contracts/utility/Owned.sol


pragma solidity 0.6.12;


/**
 * @dev This contract provides support and utilities for contract ownership.
 */
contract Owned is IOwned {
    address public override owner;
    address public newOwner;

    /**
     * @dev triggered when the owner is updated
     *
     * @param _prevOwner previous owner
     * @param _newOwner  new owner
     */
    event OwnerUpdate(address indexed _prevOwner, address indexed _newOwner);

    /**
     * @dev initializes a new Owned instance
     */
    constructor() public {
        owner = msg.sender;
    }

    // allows execution by the owner only
    modifier ownerOnly {
        _ownerOnly();
        _;
    }

    // error message binary size optimization
    function _ownerOnly() internal view {
        require(msg.sender == owner, "ERR_ACCESS_DENIED");
    }

    /**
     * @dev allows transferring the contract ownership
     * the new owner still needs to accept the transfer
     * can only be called by the contract owner
     *
     * @param _newOwner    new contract owner
     */
    function transferOwnership(address _newOwner) public override ownerOnly {
        require(_newOwner != owner, "ERR_SAME_OWNER");
        newOwner = _newOwner;
    }

    /**
     * @dev used by a new owner to accept an ownership transfer
     */
    function acceptOwnership() public override {
        require(msg.sender == newOwner, "ERR_ACCESS_DENIED");
        emit OwnerUpdate(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}

// File: solidity/contracts/utility/Utils.sol


pragma solidity 0.6.12;


/**
 * @dev Utilities & Common Modifiers
 */
contract Utils {
    uint32 internal constant PPM_RESOLUTION = 1000000;
    IERC20 internal constant NATIVE_TOKEN_ADDRESS = IERC20(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);

    // verifies that a value is greater than zero
    modifier greaterThanZero(uint256 _value) {
        _greaterThanZero(_value);
        _;
    }

    // error message binary size optimization
    function _greaterThanZero(uint256 _value) internal pure {
        require(_value > 0, "ERR_ZERO_VALUE");
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        _validAddress(_address);
        _;
    }

    // error message binary size optimization
    function _validAddress(address _address) internal pure {
        require(_address != address(0), "ERR_INVALID_ADDRESS");
    }

    // ensures that the portion is valid
    modifier validPortion(uint32 _portion) {
        _validPortion(_portion);
        _;
    }

    // error message binary size optimization
    function _validPortion(uint32 _portion) internal pure {
        require(_portion > 0 && _portion <= PPM_RESOLUTION, "ERR_INVALID_PORTION");
    }

    // validates an external address - currently only checks that it isn't null or this
    modifier validExternalAddress(address _address) {
        _validExternalAddress(_address);
        _;
    }

    // error message binary size optimization
    function _validExternalAddress(address _address) internal view {
        require(_address != address(0) && _address != address(this), "ERR_INVALID_EXTERNAL_ADDRESS");
    }

    // ensures that the fee is valid
    modifier validFee(uint32 fee) {
        _validFee(fee);
        _;
    }

    // error message binary size optimization
    function _validFee(uint32 fee) internal pure {
        require(fee <= PPM_RESOLUTION, "ERR_INVALID_FEE");
    }
}

// File: solidity/contracts/utility/interfaces/IContractRegistry.sol


pragma solidity 0.6.12;

/*
    Contract Registry interface
*/
interface IContractRegistry {
    function addressOf(bytes32 _contractName) external view returns (address);
}

// File: solidity/contracts/utility/ContractRegistryClient.sol


pragma solidity 0.6.12;




/**
 * @dev This is the base contract for ContractRegistry clients.
 */
contract ContractRegistryClient is Owned, Utils {
    bytes32 internal constant CONTRACT_REGISTRY = "ContractRegistry";
    bytes32 internal constant BANCOR_NETWORK = "BancorNetwork";
    bytes32 internal constant BANCOR_FORMULA = "BancorFormula";
    bytes32 internal constant CONVERTER_FACTORY = "ConverterFactory";
    bytes32 internal constant CONVERSION_PATH_FINDER = "ConversionPathFinder";
    bytes32 internal constant CONVERTER_UPGRADER = "BancorConverterUpgrader";
    bytes32 internal constant CONVERTER_REGISTRY = "BancorConverterRegistry";
    bytes32 internal constant CONVERTER_REGISTRY_DATA = "BancorConverterRegistryData";
    bytes32 internal constant BNT_TOKEN = "BNTToken";
    bytes32 internal constant BANCOR_X = "BancorX";
    bytes32 internal constant BANCOR_X_UPGRADER = "BancorXUpgrader";
    bytes32 internal constant LIQUIDITY_PROTECTION = "LiquidityProtection";
    bytes32 internal constant NETWORK_SETTINGS = "NetworkSettings";

    IContractRegistry public registry; // address of the current contract-registry
    IContractRegistry public prevRegistry; // address of the previous contract-registry
    bool public onlyOwnerCanUpdateRegistry; // only an owner can update the contract-registry

    /**
     * @dev verifies that the caller is mapped to the given contract name
     *
     * @param _contractName    contract name
     */
    modifier only(bytes32 _contractName) {
        _only(_contractName);
        _;
    }

    // error message binary size optimization
    function _only(bytes32 _contractName) internal view {
        require(msg.sender == addressOf(_contractName), "ERR_ACCESS_DENIED");
    }

    /**
     * @dev initializes a new ContractRegistryClient instance
     *
     * @param  _registry   address of a contract-registry contract
     */
    constructor(IContractRegistry _registry) internal validAddress(address(_registry)) {
        registry = IContractRegistry(_registry);
        prevRegistry = IContractRegistry(_registry);
    }

    /**
     * @dev updates to the new contract-registry
     */
    function updateRegistry() public {
        // verify that this function is permitted
        require(msg.sender == owner || !onlyOwnerCanUpdateRegistry, "ERR_ACCESS_DENIED");

        // get the new contract-registry
        IContractRegistry newRegistry = IContractRegistry(addressOf(CONTRACT_REGISTRY));

        // verify that the new contract-registry is different and not zero
        require(newRegistry != registry && address(newRegistry) != address(0), "ERR_INVALID_REGISTRY");

        // verify that the new contract-registry is pointing to a non-zero contract-registry
        require(newRegistry.addressOf(CONTRACT_REGISTRY) != address(0), "ERR_INVALID_REGISTRY");

        // save a backup of the current contract-registry before replacing it
        prevRegistry = registry;

        // replace the current contract-registry with the new contract-registry
        registry = newRegistry;
    }

    /**
     * @dev restores the previous contract-registry
     */
    function restoreRegistry() public ownerOnly {
        // restore the previous contract-registry
        registry = prevRegistry;
    }

    /**
     * @dev restricts the permission to update the contract-registry
     *
     * @param _onlyOwnerCanUpdateRegistry  indicates whether or not permission is restricted to owner only
     */
    function restrictRegistryUpdate(bool _onlyOwnerCanUpdateRegistry) public ownerOnly {
        // change the permission to update the contract-registry
        onlyOwnerCanUpdateRegistry = _onlyOwnerCanUpdateRegistry;
    }

    /**
     * @dev returns the address associated with the given contract name
     *
     * @param _contractName    contract name
     *
     * @return contract address
     */
    function addressOf(bytes32 _contractName) internal view returns (address) {
        return registry.addressOf(_contractName);
    }
}

// File: solidity/contracts/utility/ReentrancyGuard.sol


pragma solidity 0.6.12;

/**
 * @dev This contract provides protection against calling a function
 * (directly or indirectly) from within itself.
 */
contract ReentrancyGuard {
    uint256 private constant UNLOCKED = 1;
    uint256 private constant LOCKED = 2;

    // LOCKED while protected code is being executed, UNLOCKED otherwise
    uint256 private state = UNLOCKED;

    /**
     * @dev ensures instantiation only by sub-contracts
     */
    constructor() internal {}

    // protects a function against reentrancy attacks
    modifier protected() {
        _protected();
        state = LOCKED;
        _;
        state = UNLOCKED;
    }

    // error message binary size optimization
    function _protected() internal view {
        require(state == UNLOCKED, "ERR_REENTRANCY");
    }
}

// File: solidity/contracts/utility/Time.sol


pragma solidity 0.6.12;

/*
    Time implementing contract
*/
contract Time {
    /**
     * @dev returns the current time
     */
    function time() internal view virtual returns (uint256) {
        return block.timestamp;
    }
}

// File: solidity/contracts/converter/types/standard-pool/StandardPoolConverter.sol


pragma solidity 0.6.12;













/**
 * @dev This contract is a specialized version of the converter, which is
 * optimized for a liquidity pool that has 2 reserves with 50%/50% weights.
 */
contract StandardPoolConverter is ConverterVersion, IConverter, ContractRegistryClient, ReentrancyGuard, Time {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    using MathEx for *;

    uint256 private constant MAX_UINT128 = 2**128 - 1;
    uint256 private constant MAX_UINT112 = 2**112 - 1;
    uint256 private constant MAX_UINT32 = 2**32 - 1;
    uint256 private constant AVERAGE_RATE_PERIOD = 10 minutes;

    uint256 private __reserveBalances;
    uint256 private _reserveBalancesProduct;
    IERC20[] private __reserveTokens;
    mapping(IERC20 => uint256) private __reserveIds;

    IConverterAnchor public override anchor; // converter anchor contract
    uint32 public override maxConversionFee; // maximum conversion fee, represented in ppm, 0...1000000
    uint32 public override conversionFee; // current conversion fee, represented in ppm, 0...maxConversionFee

    // average rate details:
    // bits 0...111 represent the numerator of the rate between reserve token 0 and reserve token 1
    // bits 111...223 represent the denominator of the rate between reserve token 0 and reserve token 1
    // bits 224...255 represent the update-time of the rate between reserve token 0 and reserve token 1
    // where `numerator / denominator` gives the worth of one reserve token 0 in units of reserve token 1
    uint256 public averageRateInfo;

    /**
     * @dev triggered after liquidity is added
     *
     * @param  _provider       liquidity provider
     * @param  _reserveToken   reserve token address
     * @param  _amount         reserve token amount
     * @param  _newBalance     reserve token new balance
     * @param  _newSupply      pool token new supply
     */
    event LiquidityAdded(
        address indexed _provider,
        IERC20 indexed _reserveToken,
        uint256 _amount,
        uint256 _newBalance,
        uint256 _newSupply
    );

    /**
     * @dev triggered after liquidity is removed
     *
     * @param  _provider       liquidity provider
     * @param  _reserveToken   reserve token address
     * @param  _amount         reserve token amount
     * @param  _newBalance     reserve token new balance
     * @param  _newSupply      pool token new supply
     */
    event LiquidityRemoved(
        address indexed _provider,
        IERC20 indexed _reserveToken,
        uint256 _amount,
        uint256 _newBalance,
        uint256 _newSupply
    );

    /**
     * @dev initializes a new StandardPoolConverter instance
     *
     * @param  _anchor             anchor governed by the converter
     * @param  _registry           address of a contract registry contract
     * @param  _maxConversionFee   maximum conversion fee, represented in ppm
     */
    constructor(
        IConverterAnchor _anchor,
        IContractRegistry _registry,
        uint32 _maxConversionFee
    ) public ContractRegistryClient(_registry) validAddress(address(_anchor)) validConversionFee(_maxConversionFee) {
        anchor = _anchor;
        maxConversionFee = _maxConversionFee;
    }

    // ensures that the converter is active
    modifier active() {
        _active();
        _;
    }

    // error message binary size optimization
    function _active() internal view {
        require(isActive(), "ERR_INACTIVE");
    }

    // ensures that the converter is not active
    modifier inactive() {
        _inactive();
        _;
    }

    // error message binary size optimization
    function _inactive() internal view {
        require(!isActive(), "ERR_ACTIVE");
    }

    // validates a reserve token address - verifies that the address belongs to one of the reserve tokens
    modifier validReserve(IERC20 _address) {
        _validReserve(_address);
        _;
    }

    // error message binary size optimization
    function _validReserve(IERC20 _address) internal view {
        require(__reserveIds[_address] != 0, "ERR_INVALID_RESERVE");
    }

    // validates conversion fee
    modifier validConversionFee(uint32 _conversionFee) {
        _validConversionFee(_conversionFee);
        _;
    }

    // error message binary size optimization
    function _validConversionFee(uint32 _conversionFee) internal pure {
        require(_conversionFee <= PPM_RESOLUTION, "ERR_INVALID_CONVERSION_FEE");
    }

    // validates reserve weight
    modifier validReserveWeight(uint32 _weight) {
        _validReserveWeight(_weight);
        _;
    }

    // error message binary size optimization
    function _validReserveWeight(uint32 _weight) internal pure {
        require(_weight == PPM_RESOLUTION / 2, "ERR_INVALID_RESERVE_WEIGHT");
    }

    /**
     * @dev returns the converter type
     *
     * @return see the converter types in the the main contract doc
     */
    function converterType() public pure virtual override returns (uint16) {
        return 3;
    }

    /**
     * @dev deposits ether
     * can only be called if the converter has an ETH reserve
     */
    receive() external payable override(IConverter) validReserve(NATIVE_TOKEN_ADDRESS) {}

    /**
     * @dev checks whether or not the converter version is 28 or higher
     *
     * @return true, since the converter version is 28 or higher
     */
    function isV28OrHigher() public pure returns (bool) {
        return true;
    }

    /**
     * @dev returns true if the converter is active, false otherwise
     *
     * @return true if the converter is active, false otherwise
     */
    function isActive() public view virtual override returns (bool) {
        return anchor.owner() == address(this);
    }

    /**
     * @dev transfers the anchor ownership
     * the new owner needs to accept the transfer
     * can only be called by the converter upgrader while the upgrader is the owner
     * note that prior to version 28, you should use 'transferAnchorOwnership' instead
     *
     * @param _newOwner    new token owner
     */
    function transferAnchorOwnership(address _newOwner) public override ownerOnly only(CONVERTER_UPGRADER) {
        anchor.transferOwnership(_newOwner);
    }

    /**
     * @dev accepts ownership of the anchor after an ownership transfer
     * most converters are also activated as soon as they accept the anchor ownership
     * can only be called by the contract owner
     * note that prior to version 28, you should use 'acceptTokenOwnership' instead
     */
    function acceptAnchorOwnership() public virtual override ownerOnly {
        // verify the the converter has exactly two reserves
        require(reserveTokenCount() == 2, "ERR_INVALID_RESERVE_COUNT");
        anchor.acceptOwnership();
        syncReserveBalances(0);
        emit Activation(converterType(), anchor, true);
    }

    /**
     * @dev updates the current conversion fee
     * can only be called by the contract owner
     *
     * @param _conversionFee new conversion fee, represented in ppm
     */
    function setConversionFee(uint32 _conversionFee) public override ownerOnly {
        require(_conversionFee <= maxConversionFee, "ERR_INVALID_CONVERSION_FEE");
        emit ConversionFeeUpdate(conversionFee, _conversionFee);
        conversionFee = _conversionFee;
    }

    /**
     * @dev transfers reserve balances to a new converter during an upgrade
     * can only be called by the converter upgraded which should be set at its owner
     *
     * @param _newConverter address of the converter to receive the new amount
     */
    function transferReservesOnUpgrade(address _newConverter)
        external
        override
        protected
        ownerOnly
        only(CONVERTER_UPGRADER)
    {
        uint256 reserveCount = __reserveTokens.length;
        for (uint256 i = 0; i < reserveCount; ++i) {
            IERC20 reserveToken = __reserveTokens[i];

            uint256 amount;
            if (reserveToken == NATIVE_TOKEN_ADDRESS) {
                amount = address(this).balance;
            } else {
                amount = reserveToken.balanceOf(address(this));
            }

            safeTransfer(reserveToken, _newConverter, amount);

            syncReserveBalance(reserveToken);
        }
    }

    /**
     * @dev upgrades the converter to the latest version
     * can only be called by the owner
     * note that the owner needs to call acceptOwnership on the new converter after the upgrade
     */
    function upgrade() public ownerOnly {
        IConverterUpgrader converterUpgrader = IConverterUpgrader(addressOf(CONVERTER_UPGRADER));

        // trigger de-activation event
        emit Activation(converterType(), anchor, false);

        transferOwnership(address(converterUpgrader));
        converterUpgrader.upgrade(version);
        acceptOwnership();
    }

    /**
     * @dev executed by the upgrader at the end of the upgrade process to handle custom pool logic
     */
    function onUpgradeComplete()
        external
        override
        protected
        ownerOnly
        only(CONVERTER_UPGRADER)
    {
        (uint256 reserveBalance0, uint256 reserveBalance1) = reserveBalances(1, 2);
        _reserveBalancesProduct = reserveBalance0 * reserveBalance1;
    }

    /**
     * @dev returns the number of reserve tokens
     * note that prior to version 17, you should use 'connectorTokenCount' instead
     *
     * @return number of reserve tokens
     */
    function reserveTokenCount() public view returns (uint16) {
        return uint16(__reserveTokens.length);
    }

    /**
     * @dev returns the array of reserve tokens
     *
     * @return array of reserve tokens
     */
    function reserveTokens() public view returns (IERC20[] memory) {
        return __reserveTokens;
    }

    /**
     * @dev defines a new reserve token for the converter
     * can only be called by the owner while the converter is inactive
     *
     * @param _token   address of the reserve token
     * @param _weight  reserve weight, represented in ppm, 1-1000000
     */
    function addReserve(IERC20 _token, uint32 _weight)
        public
        virtual
        override
        ownerOnly
        inactive
        validExternalAddress(address(_token))
        validReserveWeight(_weight)
    {
        // validate input
        require(address(_token) != address(anchor) && __reserveIds[_token] == 0, "ERR_INVALID_RESERVE");
        require(reserveTokenCount() < 2, "ERR_INVALID_RESERVE_COUNT");

        __reserveTokens.push(_token);
        __reserveIds[_token] = __reserveTokens.length;
    }

    /**
     * @dev returns the reserve's weight
     * added in version 28
     *
     * @param _reserveToken    reserve token contract address
     *
     * @return reserve weight
     */
    function reserveWeight(IERC20 _reserveToken) public view validReserve(_reserveToken) returns (uint32) {
        return PPM_RESOLUTION / 2;
    }

    /**
     * @dev returns the balance of a given reserve token
     *
     * @param _reserveToken    reserve token contract address
     *
     * @return the balance of the given reserve token
     */
    function reserveBalance(IERC20 _reserveToken) public view override returns (uint256) {
        uint256 reserveId = __reserveIds[_reserveToken];
        require(reserveId != 0, "ERR_INVALID_RESERVE");
        return reserveBalance(reserveId);
    }

    /**
     * @dev returns the balances of both reserve tokens
     *
     * @return the balances of both reserve tokens
     */
    function reserveBalances() public view returns (uint256, uint256) {
        return reserveBalances(1, 2);
    }

    /**
     * @dev syncs all stored reserve balances
     */
    function syncReserveBalances() external {
        syncReserveBalances(0);
    }

    /**
     * @dev calculates the accumulated network fee and transfers it to the network fee wallet
     */
    function processNetworkFees() external protected {
        (uint256 reserveBalance0, uint256 reserveBalance1) = processNetworkFees(0);
        _reserveBalancesProduct = reserveBalance0 * reserveBalance1;
    }

    /**
     * @dev calculates the accumulated network fee and transfers it to the network fee wallet
     *
     * @param _value amount of ether to exclude from the ether reserve balance (if relevant)
     *
     * @return new reserve balances
     */
    function processNetworkFees(uint256 _value) internal returns (uint256, uint256) {
        syncReserveBalances(_value);
        (uint256 reserveBalance0, uint256 reserveBalance1) = reserveBalances(1, 2);
        (ITokenHolder wallet, uint256 fee0, uint256 fee1) = networkWalletAndFees(reserveBalance0, reserveBalance1);
        reserveBalance0 -= fee0;
        reserveBalance1 -= fee1;
        setReserveBalances(1, 2, reserveBalance0, reserveBalance1);
        safeTransfer(__reserveTokens[0], address(wallet), fee0);
        safeTransfer(__reserveTokens[1], address(wallet), fee1);
        return (reserveBalance0, reserveBalance1);
    }

    /**
     * @dev returns the reserve balances of the given reserve tokens minus their corresponding fees
     *
     * @param _reserveTokens reserve tokens
     *
     * @return reserve balances minus their corresponding fees
     */
    function baseReserveBalances(IERC20[] memory _reserveTokens) internal view returns (uint256[2] memory) {
        uint256 reserveId0 = __reserveIds[_reserveTokens[0]];
        uint256 reserveId1 = __reserveIds[_reserveTokens[1]];
        (uint256 reserveBalance0, uint256 reserveBalance1) = reserveBalances(reserveId0, reserveId1);
        (, uint256 fee0, uint256 fee1) = networkWalletAndFees(reserveBalance0, reserveBalance1);
        return [reserveBalance0 - fee0, reserveBalance1 - fee1];
    }

    /**
     * @dev converts a specific amount of source tokens to target tokens
     * can only be called by the bancor network contract
     *
     * @param _sourceToken source ERC20 token
     * @param _targetToken target ERC20 token
     * @param _amount      amount of tokens to convert (in units of the source token)
     * @param _trader      address of the caller who executed the conversion
     * @param _beneficiary wallet to receive the conversion result
     *
     * @return amount of tokens received (in units of the target token)
     */
    function convert(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount,
        address _trader,
        address payable _beneficiary
    ) public payable override protected only(BANCOR_NETWORK) returns (uint256) {
        // validate input
        require(_sourceToken != _targetToken, "ERR_SAME_SOURCE_TARGET");

        return doConvert(_sourceToken, _targetToken, _amount, _trader, _beneficiary);
    }

    /**
     * @dev returns the conversion fee for a given target amount
     *
     * @param _targetAmount  target amount
     *
     * @return conversion fee
     */
    function calculateFee(uint256 _targetAmount) internal view returns (uint256) {
        return _targetAmount.mul(conversionFee) / PPM_RESOLUTION;
    }

    /**
     * @dev returns the conversion fee taken from a given target amount
     *
     * @param _targetAmount  target amount
     *
     * @return conversion fee
     */
    function calculateFeeInv(uint256 _targetAmount) internal view returns (uint256) {
        return _targetAmount.mul(conversionFee).div(PPM_RESOLUTION - conversionFee);
    }

    /**
     * @dev loads the stored reserve balance for a given reserve id
     *
     * @param _reserveId   reserve id
     */
    function reserveBalance(uint256 _reserveId) internal view returns (uint256) {
        return decodeReserveBalance(__reserveBalances, _reserveId);
    }

    /**
     * @dev loads the stored reserve balances
     *
     * @param _sourceId    source reserve id
     * @param _targetId    target reserve id
     */
    function reserveBalances(uint256 _sourceId, uint256 _targetId) internal view returns (uint256, uint256) {
        require((_sourceId == 1 && _targetId == 2) || (_sourceId == 2 && _targetId == 1), "ERR_INVALID_RESERVES");
        return decodeReserveBalances(__reserveBalances, _sourceId, _targetId);
    }

    /**
     * @dev stores the stored reserve balance for a given reserve id
     *
     * @param _reserveId       reserve id
     * @param _reserveBalance  reserve balance
     */
    function setReserveBalance(uint256 _reserveId, uint256 _reserveBalance) internal {
        require(_reserveBalance <= MAX_UINT128, "ERR_RESERVE_BALANCE_OVERFLOW");
        uint256 otherBalance = decodeReserveBalance(__reserveBalances, 3 - _reserveId);
        __reserveBalances = encodeReserveBalances(_reserveBalance, _reserveId, otherBalance, 3 - _reserveId);
    }

    /**
     * @dev stores the stored reserve balances
     *
     * @param _sourceId        source reserve id
     * @param _targetId        target reserve id
     * @param _sourceBalance   source reserve balance
     * @param _targetBalance   target reserve balance
     */
    function setReserveBalances(
        uint256 _sourceId,
        uint256 _targetId,
        uint256 _sourceBalance,
        uint256 _targetBalance
    ) internal {
        require(_sourceBalance <= MAX_UINT128 && _targetBalance <= MAX_UINT128, "ERR_RESERVE_BALANCE_OVERFLOW");
        __reserveBalances = encodeReserveBalances(_sourceBalance, _sourceId, _targetBalance, _targetId);
    }

    /**
     * @dev syncs the stored reserve balance for a given reserve with the real reserve balance
     *
     * @param _reserveToken    address of the reserve token
     */
    function syncReserveBalance(IERC20 _reserveToken) internal {
        uint256 reserveId = __reserveIds[_reserveToken];
        uint256 balance =
            _reserveToken == NATIVE_TOKEN_ADDRESS ? address(this).balance : _reserveToken.balanceOf(address(this));
        setReserveBalance(reserveId, balance);
    }

    /**
     * @dev syncs all stored reserve balances, excluding a given amount of ether from the ether reserve balance (if relevant)
     *
     * @param _value   amount of ether to exclude from the ether reserve balance (if relevant)
     */
    function syncReserveBalances(uint256 _value) internal {
        IERC20 _reserveToken0 = __reserveTokens[0];
        IERC20 _reserveToken1 = __reserveTokens[1];
        uint256 balance0 =
            _reserveToken0 == NATIVE_TOKEN_ADDRESS
                ? address(this).balance - _value
                : _reserveToken0.balanceOf(address(this));
        uint256 balance1 =
            _reserveToken1 == NATIVE_TOKEN_ADDRESS
                ? address(this).balance - _value
                : _reserveToken1.balanceOf(address(this));
        setReserveBalances(1, 2, balance0, balance1);
    }

    /**
     * @dev helper, dispatches the Conversion event
     *
     * @param _sourceToken     source ERC20 token
     * @param _targetToken     target ERC20 token
     * @param _trader          address of the caller who executed the conversion
     * @param _amount          amount purchased/sold (in the source token)
     * @param _returnAmount    amount returned (in the target token)
     */
    function dispatchConversionEvent(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        address _trader,
        uint256 _amount,
        uint256 _returnAmount,
        uint256 _feeAmount
    ) internal {
        emit Conversion(_sourceToken, _targetToken, _trader, _amount, _returnAmount, int256(_feeAmount));
    }

    /**
     * @dev returns the expected amount and expected fee for converting one reserve to another
     *
     * @param _sourceToken address of the source reserve token contract
     * @param _targetToken address of the target reserve token contract
     * @param _amount      amount of source reserve tokens converted
     *
     * @return expected amount in units of the target reserve token
     * @return expected fee in units of the target reserve token
     */
    function targetAmountAndFee(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount
    ) public view virtual override active returns (uint256, uint256) {
        uint256 sourceId = __reserveIds[_sourceToken];
        uint256 targetId = __reserveIds[_targetToken];

        (uint256 sourceBalance, uint256 targetBalance) = reserveBalances(sourceId, targetId);

        return targetAmountAndFee(_sourceToken, _targetToken, sourceBalance, targetBalance, _amount);
    }

    /**
     * @dev returns the expected amount and expected fee for converting one reserve to another
     *
     * @param _sourceBalance    balance in the source reserve token contract
     * @param _targetBalance    balance in the target reserve token contract
     * @param _amount           amount of source reserve tokens converted
     *
     * @return expected amount in units of the target reserve token
     * @return expected fee in units of the target reserve token
     */
    function targetAmountAndFee(
        IERC20, /* _sourceToken */
        IERC20, /* _targetToken */
        uint256 _sourceBalance,
        uint256 _targetBalance,
        uint256 _amount
    ) internal view virtual returns (uint256, uint256) {
        uint256 amount = crossReserveTargetAmount(_sourceBalance, _targetBalance, _amount);

        uint256 fee = calculateFee(amount);

        return (amount - fee, fee);
    }

    /**
     * @dev returns the required amount and expected fee for converting one reserve to another
     *
     * @param _sourceToken address of the source reserve token contract
     * @param _targetToken address of the target reserve token contract
     * @param _amount      amount of target reserve tokens desired
     *
     * @return required amount in units of the source reserve token
     * @return expected fee in units of the target reserve token
     */
    function sourceAmountAndFee(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount
    ) public view virtual active returns (uint256, uint256) {
        uint256 sourceId = __reserveIds[_sourceToken];
        uint256 targetId = __reserveIds[_targetToken];

        (uint256 sourceBalance, uint256 targetBalance) = reserveBalances(sourceId, targetId);

        uint256 fee = calculateFeeInv(_amount);

        uint256 amount = crossReserveSourceAmount(sourceBalance, targetBalance, _amount.add(fee));

        return (amount, fee);
    }

    /**
     * @dev converts a specific amount of source tokens to target tokens
     *
     * @param _sourceToken source ERC20 token
     * @param _targetToken target ERC20 token
     * @param _amount      amount of tokens to convert (in units of the source token)
     * @param _trader      address of the caller who executed the conversion
     * @param _beneficiary wallet to receive the conversion result
     *
     * @return amount of tokens received (in units of the target token)
     */
    function doConvert(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount,
        address _trader,
        address payable _beneficiary
    ) internal returns (uint256) {
        // update the recent average rate
        updateRecentAverageRate();

        uint256 sourceId = __reserveIds[_sourceToken];
        uint256 targetId = __reserveIds[_targetToken];

        (uint256 sourceBalance, uint256 targetBalance) = reserveBalances(sourceId, targetId);

        // get the target amount minus the conversion fee and the conversion fee
        (uint256 amount, uint256 fee) =
            targetAmountAndFee(_sourceToken, _targetToken, sourceBalance, targetBalance, _amount);

        // ensure that the trade gives something in return
        require(amount != 0, "ERR_ZERO_TARGET_AMOUNT");

        // ensure that the trade won't deplete the reserve balance
        assert(amount < targetBalance);

        // ensure that the input amount was already deposited
        uint256 actualSourceBalance;
        if (_sourceToken == NATIVE_TOKEN_ADDRESS) {
            actualSourceBalance = address(this).balance;
            require(msg.value == _amount, "ERR_ETH_AMOUNT_MISMATCH");
        } else {
            actualSourceBalance = _sourceToken.balanceOf(address(this));
            require(msg.value == 0 && actualSourceBalance.sub(sourceBalance) >= _amount, "ERR_INVALID_AMOUNT");
        }

        // sync the reserve balances
        setReserveBalances(sourceId, targetId, actualSourceBalance, targetBalance - amount);

        // transfer funds to the beneficiary in the to reserve token
        safeTransfer(_targetToken, _beneficiary, amount);

        // dispatch the conversion event
        dispatchConversionEvent(_sourceToken, _targetToken, _trader, _amount, amount, fee);

        // dispatch rate updates
        dispatchTokenRateUpdateEvents(_sourceToken, _targetToken, actualSourceBalance, targetBalance - amount);

        return amount;
    }

    /**
     * @dev returns the recent average rate of 1 `_token` in the other reserve token units
     *
     * @param _token   token to get the rate for
     *
     * @return recent average rate between the reserves (numerator)
     * @return recent average rate between the reserves (denominator)
     */
    function recentAverageRate(IERC20 _token) external view validReserve(_token) returns (uint256, uint256) {
        // get the recent average rate of reserve 0
        uint256 rate = calcRecentAverageRate(averageRateInfo);

        uint256 rateN = decodeAverageRateN(rate);
        uint256 rateD = decodeAverageRateD(rate);

        if (_token == __reserveTokens[0]) {
            return (rateN, rateD);
        }

        return (rateD, rateN);
    }

    /**
     * @dev updates the recent average rate if needed
     */
    function updateRecentAverageRate() internal {
        uint256 averageRateInfo1 = averageRateInfo;
        uint256 averageRateInfo2 = calcRecentAverageRate(averageRateInfo1);
        if (averageRateInfo1 != averageRateInfo2) {
            averageRateInfo = averageRateInfo2;
        }
    }

    /**
     * @dev returns the recent average rate of 1 reserve token 0 in reserve token 1 units
     *
     * @param _averageRateInfo a local copy of the `averageRateInfo` state-variable
     *
     * @return recent average rate between the reserves
     */
    function calcRecentAverageRate(uint256 _averageRateInfo) internal view returns (uint256) {
        // get the previous average rate and its update-time
        uint256 prevAverageRateT = decodeAverageRateT(_averageRateInfo);
        uint256 prevAverageRateN = decodeAverageRateN(_averageRateInfo);
        uint256 prevAverageRateD = decodeAverageRateD(_averageRateInfo);

        // get the elapsed time since the previous average rate was calculated
        uint256 currentTime = time();
        uint256 timeElapsed = currentTime - prevAverageRateT;

        // if the previous average rate was calculated in the current block, the average rate remains unchanged
        if (timeElapsed == 0) {
            return _averageRateInfo;
        }

        // get the current rate between the reserves
        (uint256 currentRateD, uint256 currentRateN) = reserveBalances();

        // if the previous average rate was calculated a while ago or never, the average rate is equal to the current rate
        if (timeElapsed >= AVERAGE_RATE_PERIOD || prevAverageRateT == 0) {
            (currentRateN, currentRateD) = MathEx.reducedRatio(currentRateN, currentRateD, MAX_UINT112);
            return encodeAverageRateInfo(currentTime, currentRateN, currentRateD);
        }

        uint256 x = prevAverageRateD.mul(currentRateN);
        uint256 y = prevAverageRateN.mul(currentRateD);

        // since we know that timeElapsed < AVERAGE_RATE_PERIOD, we can avoid using SafeMath:
        uint256 newRateN = y.mul(AVERAGE_RATE_PERIOD - timeElapsed).add(x.mul(timeElapsed));
        uint256 newRateD = prevAverageRateD.mul(currentRateD).mul(AVERAGE_RATE_PERIOD);

        (newRateN, newRateD) = MathEx.reducedRatio(newRateN, newRateD, MAX_UINT112);
        return encodeAverageRateInfo(currentTime, newRateN, newRateD);
    }

    /**
     * @dev increases the pool's liquidity and mints new shares in the pool to the caller
     *
     * @param _reserveTokens   address of each reserve token
     * @param _reserveAmounts  amount of each reserve token
     * @param _minReturn       token minimum return-amount
     *
     * @return amount of pool tokens issued
     */
    function addLiquidity(
        IERC20[] memory _reserveTokens,
        uint256[] memory _reserveAmounts,
        uint256 _minReturn
    ) public payable protected active returns (uint256) {
        // verify the user input
        verifyLiquidityInput(_reserveTokens, _reserveAmounts, _minReturn);

        // if one of the reserves is ETH, then verify that the input amount of ETH is equal to the input value of ETH
        for (uint256 i = 0; i < 2; i++) {
            if (_reserveTokens[i] == NATIVE_TOKEN_ADDRESS) {
                require(_reserveAmounts[i] == msg.value, "ERR_ETH_AMOUNT_MISMATCH");
            }
        }

        // if the input value of ETH is larger than zero, then verify that one of the reserves is ETH
        if (msg.value > 0) {
            require(__reserveIds[NATIVE_TOKEN_ADDRESS] != 0, "ERR_NO_ETH_RESERVE");
        }

        // save a local copy of the pool token
        IDSToken poolToken = IDSToken(address(anchor));

        // get the total supply
        uint256 totalSupply = poolToken.totalSupply();

        uint256[2] memory prevReserveBalances;
        uint256[2] memory newReserveBalances;

        // process the network fees and get the reserve balances
        (prevReserveBalances[0], prevReserveBalances[1]) = processNetworkFees(msg.value);

        uint256 amount;
        uint256[2] memory reserveAmounts;

        // calculate the amount of pool tokens to mint for the caller
        // and the amount of reserve tokens to transfer from the caller
        if (totalSupply == 0) {
            amount = MathEx.geometricMean(_reserveAmounts);
            reserveAmounts[0] = _reserveAmounts[0];
            reserveAmounts[1] = _reserveAmounts[1];
        } else {
            (amount, reserveAmounts) = addLiquidityAmounts(
                _reserveTokens,
                _reserveAmounts,
                prevReserveBalances,
                totalSupply
            );
        }

        uint256 newPoolTokenSupply = totalSupply.add(amount);
        for (uint256 i = 0; i < 2; i++) {
            IERC20 reserveToken = _reserveTokens[i];
            uint256 reserveAmount = reserveAmounts[i];
            require(reserveAmount > 0, "ERR_ZERO_TARGET_AMOUNT");
            assert(reserveAmount <= _reserveAmounts[i]);

            // transfer each one of the reserve amounts from the user to the pool
            if (reserveToken != NATIVE_TOKEN_ADDRESS) {
                // ETH has already been transferred as part of the transaction
                reserveToken.safeTransferFrom(msg.sender, address(this), reserveAmount);
            } else if (_reserveAmounts[i] > reserveAmount) {
                // transfer the extra amount of ETH back to the user
                msg.sender.transfer(_reserveAmounts[i] - reserveAmount);
            }

            // save the new reserve balance
            newReserveBalances[i] = prevReserveBalances[i].add(reserveAmount);

            emit LiquidityAdded(msg.sender, reserveToken, reserveAmount, newReserveBalances[i], newPoolTokenSupply);

            // dispatch the `TokenRateUpdate` event for the pool token
            emit TokenRateUpdate(poolToken, reserveToken, newReserveBalances[i], newPoolTokenSupply);
        }

        // set the reserve balances
        setReserveBalances(1, 2, newReserveBalances[0], newReserveBalances[1]);

        // set the reserve balances product
        _reserveBalancesProduct = newReserveBalances[0] * newReserveBalances[1];

        // verify that the equivalent amount of tokens is equal to or larger than the user's expectation
        require(amount >= _minReturn, "ERR_RETURN_TOO_LOW");

        // issue the tokens to the user
        poolToken.issue(msg.sender, amount);

        // return the amount of pool tokens issued
        return amount;
    }

    /**
     * @dev get the amount of pool tokens to mint for the caller
     * and the amount of reserve tokens to transfer from the caller
     *
     * @param _reserveAmounts   amount of each reserve token
     * @param _reserveBalances  balance of each reserve token
     * @param _totalSupply      total supply of pool tokens
     *
     * @return amount of pool tokens to mint for the caller
     * @return amount of reserve tokens to transfer from the caller
     */
    function addLiquidityAmounts(
        IERC20[] memory, /* _reserveTokens */
        uint256[] memory _reserveAmounts,
        uint256[2] memory _reserveBalances,
        uint256 _totalSupply
    ) internal view virtual returns (uint256, uint256[2] memory) {
        this;

        uint256 index =
            _reserveAmounts[0].mul(_reserveBalances[1]) < _reserveAmounts[1].mul(_reserveBalances[0]) ? 0 : 1;
        uint256 amount = fundSupplyAmount(_totalSupply, _reserveBalances[index], _reserveAmounts[index]);

        uint256[2] memory reserveAmounts =
            [fundCost(_totalSupply, _reserveBalances[0], amount), fundCost(_totalSupply, _reserveBalances[1], amount)];

        return (amount, reserveAmounts);
    }

    /**
     * @dev decreases the pool's liquidity and burns the caller's shares in the pool
     *
     * @param _amount                  token amount
     * @param _reserveTokens           address of each reserve token
     * @param _reserveMinReturnAmounts minimum return-amount of each reserve token
     *
     * @return the amount of each reserve token granted for the given amount of pool tokens
     */
    function removeLiquidity(
        uint256 _amount,
        IERC20[] memory _reserveTokens,
        uint256[] memory _reserveMinReturnAmounts
    ) public protected active returns (uint256[] memory) {
        // verify the user input
        bool inputRearranged = verifyLiquidityInput(_reserveTokens, _reserveMinReturnAmounts, _amount);

        // save a local copy of the pool token
        IDSToken poolToken = IDSToken(address(anchor));

        // get the total supply BEFORE destroying the user tokens
        uint256 totalSupply = poolToken.totalSupply();

        // destroy the user tokens
        poolToken.destroy(msg.sender, _amount);

        uint256 newPoolTokenSupply = totalSupply.sub(_amount);

        uint256[2] memory prevReserveBalances;
        uint256[2] memory newReserveBalances;

        // process the network fees and get the reserve balances
        (prevReserveBalances[0], prevReserveBalances[1]) = processNetworkFees(0);

        uint256[] memory reserveAmounts = removeLiquidityReserveAmounts(_amount, totalSupply, prevReserveBalances);

        for (uint256 i = 0; i < 2; i++) {
            IERC20 reserveToken = _reserveTokens[i];
            uint256 reserveAmount = reserveAmounts[i];
            require(reserveAmount >= _reserveMinReturnAmounts[i], "ERR_ZERO_TARGET_AMOUNT");

            // save the new reserve balance
            newReserveBalances[i] = prevReserveBalances[i].sub(reserveAmount);

            // transfer each one of the reserve amounts from the pool to the user
            safeTransfer(reserveToken, msg.sender, reserveAmount);

            emit LiquidityRemoved(msg.sender, reserveToken, reserveAmount, newReserveBalances[i], newPoolTokenSupply);

            // dispatch the `TokenRateUpdate` event for the pool token
            emit TokenRateUpdate(poolToken, reserveToken, newReserveBalances[i], newPoolTokenSupply);
        }

        // set the reserve balances
        setReserveBalances(1, 2, newReserveBalances[0], newReserveBalances[1]);

        // set the reserve balances product
        _reserveBalancesProduct = newReserveBalances[0] * newReserveBalances[1];

        if (inputRearranged) {
            uint256 tempReserveAmount = reserveAmounts[0];
            reserveAmounts[0] = reserveAmounts[1];
            reserveAmounts[1] = tempReserveAmount;
        }

        // return the amount of each reserve token granted for the given amount of pool tokens
        return reserveAmounts;
    }

    /**
     * @dev given the amount of one of the reserve tokens to add liquidity of,
     * returns the required amount of each one of the other reserve tokens
     * since an empty pool can be funded with any list of non-zero input amounts,
     * this function assumes that the pool is not empty (has already been funded)
     *
     * @param _reserveTokens       address of each reserve token
     * @param _reserveTokenIndex   index of the relevant reserve token
     * @param _reserveAmount       amount of the relevant reserve token
     *
     * @return the required amount of each one of the reserve tokens
     */
    function addLiquidityCost(
        IERC20[] memory _reserveTokens,
        uint256 _reserveTokenIndex,
        uint256 _reserveAmount
    ) public view returns (uint256[] memory) {
        uint256 totalSupply = IDSToken(address(anchor)).totalSupply();
        uint256[2] memory baseBalances = baseReserveBalances(_reserveTokens);
        uint256 amount = fundSupplyAmount(totalSupply, baseBalances[_reserveTokenIndex], _reserveAmount);

        uint256[] memory reserveAmounts = new uint256[](2);
        reserveAmounts[0] = fundCost(totalSupply, baseBalances[0], amount);
        reserveAmounts[1] = fundCost(totalSupply, baseBalances[1], amount);
        return reserveAmounts;
    }

    /**
     * @dev returns the amount of pool tokens entitled for given amounts of reserve tokens
     * since an empty pool can be funded with any list of non-zero input amounts,
     * this function assumes that the pool is not empty (has already been funded)
     *
     * @param _reserveTokens   address of each reserve token
     * @param _reserveAmounts  amount of each reserve token
     *
     * @return the amount of pool tokens entitled for the given amounts of reserve tokens
     */
    function addLiquidityReturn(IERC20[] memory _reserveTokens, uint256[] memory _reserveAmounts)
        public
        view
        returns (uint256)
    {
        uint256 totalSupply = IDSToken(address(anchor)).totalSupply();
        uint256[2] memory baseBalances = baseReserveBalances(_reserveTokens);
        (uint256 amount, ) = addLiquidityAmounts(_reserveTokens, _reserveAmounts, baseBalances, totalSupply);
        return amount;
    }

    /**
     * @dev returns the amount of each reserve token entitled for a given amount of pool tokens
     *
     * @param _amount          amount of pool tokens
     * @param _reserveTokens   address of each reserve token
     *
     * @return the amount of each reserve token entitled for the given amount of pool tokens
     */
    function removeLiquidityReturn(uint256 _amount, IERC20[] memory _reserveTokens)
        public
        view
        returns (uint256[] memory)
    {
        uint256 totalSupply = IDSToken(address(anchor)).totalSupply();
        uint256[2] memory baseBalances = baseReserveBalances(_reserveTokens);
        return removeLiquidityReserveAmounts(_amount, totalSupply, baseBalances);
    }

    /**
     * @dev verifies that a given array of tokens is identical to the converter's array of reserve tokens
     * we take this input in order to allow specifying the corresponding reserve amounts in any order
     * this function rearranges the input arrays according to the converter's array of reserve tokens
     *
     * @param _reserveTokens   array of reserve tokens
     * @param _reserveAmounts  array of reserve amounts
     * @param _amount          token amount
     *
     * @return true if the function has rearranged the input arrays; false otherwise
     */
    function verifyLiquidityInput(
        IERC20[] memory _reserveTokens,
        uint256[] memory _reserveAmounts,
        uint256 _amount
    ) private view returns (bool) {
        require(validReserveAmounts(_reserveAmounts) && _amount > 0, "ERR_ZERO_AMOUNT");

        uint256 reserve0Id = __reserveIds[_reserveTokens[0]];
        uint256 reserve1Id = __reserveIds[_reserveTokens[1]];

        if (reserve0Id == 2 && reserve1Id == 1) {
            IERC20 tempReserveToken = _reserveTokens[0];
            _reserveTokens[0] = _reserveTokens[1];
            _reserveTokens[1] = tempReserveToken;
            uint256 tempReserveAmount = _reserveAmounts[0];
            _reserveAmounts[0] = _reserveAmounts[1];
            _reserveAmounts[1] = tempReserveAmount;
            return true;
        }

        require(reserve0Id == 1 && reserve1Id == 2, "ERR_INVALID_RESERVE");
        return false;
    }

    /**
     * @dev checks whether or not both reserve amounts are larger than zero
     *
     * @param _reserveAmounts  array of reserve amounts
     *
     * @return true if both reserve amounts are larger than zero; false otherwise
     */
    function validReserveAmounts(uint256[] memory _reserveAmounts) internal pure virtual returns (bool) {
        return _reserveAmounts[0] > 0 && _reserveAmounts[1] > 0;
    }

    /**
     * @dev returns the amount of each reserve token entitled for a given amount of pool tokens
     *
     * @param _amount          amount of pool tokens
     * @param _totalSupply     total supply of pool tokens
     * @param _reserveBalances balance of each reserve token
     *
     * @return the amount of each reserve token entitled for the given amount of pool tokens
     */
    function removeLiquidityReserveAmounts(
        uint256 _amount,
        uint256 _totalSupply,
        uint256[2] memory _reserveBalances
    ) private pure returns (uint256[] memory) {
        uint256[] memory reserveAmounts = new uint256[](2);
        reserveAmounts[0] = liquidateReserveAmount(_totalSupply, _reserveBalances[0], _amount);
        reserveAmounts[1] = liquidateReserveAmount(_totalSupply, _reserveBalances[1], _amount);
        return reserveAmounts;
    }

    /**
     * @dev dispatches token rate update events for the reserve tokens and the pool token
     *
     * @param _sourceToken     address of the source reserve token
     * @param _targetToken     address of the target reserve token
     * @param _sourceBalance   balance of the source reserve token
     * @param _targetBalance   balance of the target reserve token
     */
    function dispatchTokenRateUpdateEvents(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _sourceBalance,
        uint256 _targetBalance
    ) private {
        // save a local copy of the pool token
        IDSToken poolToken = IDSToken(address(anchor));

        // get the total supply of pool tokens
        uint256 poolTokenSupply = poolToken.totalSupply();

        // dispatch token rate update event for the reserve tokens
        emit TokenRateUpdate(_sourceToken, _targetToken, _targetBalance, _sourceBalance);

        // dispatch token rate update events for the pool token
        emit TokenRateUpdate(poolToken, _sourceToken, _sourceBalance, poolTokenSupply);
        emit TokenRateUpdate(poolToken, _targetToken, _targetBalance, poolTokenSupply);
    }

    function encodeReserveBalance(uint256 _balance, uint256 _id) private pure returns (uint256) {
        assert(_balance <= MAX_UINT128 && (_id == 1 || _id == 2));
        return _balance << ((_id - 1) * 128);
    }

    function decodeReserveBalance(uint256 _balances, uint256 _id) private pure returns (uint256) {
        assert(_id == 1 || _id == 2);
        return (_balances >> ((_id - 1) * 128)) & MAX_UINT128;
    }

    function encodeReserveBalances(
        uint256 _balance0,
        uint256 _id0,
        uint256 _balance1,
        uint256 _id1
    ) private pure returns (uint256) {
        return encodeReserveBalance(_balance0, _id0) | encodeReserveBalance(_balance1, _id1);
    }

    function decodeReserveBalances(
        uint256 _balances,
        uint256 _id0,
        uint256 _id1
    ) private pure returns (uint256, uint256) {
        return (decodeReserveBalance(_balances, _id0), decodeReserveBalance(_balances, _id1));
    }

    function encodeAverageRateInfo(
        uint256 _averageRateT,
        uint256 _averageRateN,
        uint256 _averageRateD
    ) private pure returns (uint256) {
        assert(_averageRateT <= MAX_UINT32 && _averageRateN <= MAX_UINT112 && _averageRateD <= MAX_UINT112);
        return (_averageRateT << 224) | (_averageRateN << 112) | _averageRateD;
    }

    function decodeAverageRateT(uint256 _averageRateInfo) private pure returns (uint256) {
        return _averageRateInfo >> 224;
    }

    function decodeAverageRateN(uint256 _averageRateInfo) private pure returns (uint256) {
        return (_averageRateInfo >> 112) & MAX_UINT112;
    }

    function decodeAverageRateD(uint256 _averageRateInfo) private pure returns (uint256) {
        return _averageRateInfo & MAX_UINT112;
    }

    /**
     * @dev returns the largest integer smaller than or equal to the square root of a given value
     *
     * @param x the given value
     *
     * @return the largest integer smaller than or equal to the square root of the given value
     */
    function floorSqrt(uint256 x) private pure returns (uint256) {
        return x > 0 ? MathEx.floorSqrt(x) : 0;
    }

    function crossReserveTargetAmount(
        uint256 _sourceReserveBalance,
        uint256 _targetReserveBalance,
        uint256 _amount
    ) private pure returns (uint256) {
        // validate input
        require(_sourceReserveBalance > 0 && _targetReserveBalance > 0, "ERR_INVALID_RESERVE_BALANCE");

        return _targetReserveBalance.mul(_amount) / _sourceReserveBalance.add(_amount);
    }

    function crossReserveSourceAmount(
        uint256 _sourceReserveBalance,
        uint256 _targetReserveBalance,
        uint256 _amount
    ) private pure returns (uint256) {
        // validate input
        require(_sourceReserveBalance > 0, "ERR_INVALID_RESERVE_BALANCE");
        require(_amount < _targetReserveBalance, "ERR_INVALID_AMOUNT");

        if (_amount == 0) {
            return 0;
        }

        return (_sourceReserveBalance.mul(_amount) - 1) / (_targetReserveBalance - _amount) + 1;
    }

    function fundCost(
        uint256 _supply,
        uint256 _reserveBalance,
        uint256 _amount
    ) private pure returns (uint256) {
        // validate input
        require(_supply > 0, "ERR_INVALID_SUPPLY");
        require(_reserveBalance > 0, "ERR_INVALID_RESERVE_BALANCE");

        // special case for 0 amount
        if (_amount == 0) {
            return 0;
        }

        return (_amount.mul(_reserveBalance) - 1) / _supply + 1;
    }

    function fundSupplyAmount(
        uint256 _supply,
        uint256 _reserveBalance,
        uint256 _amount
    ) private pure returns (uint256) {
        // validate input
        require(_supply > 0, "ERR_INVALID_SUPPLY");
        require(_reserveBalance > 0, "ERR_INVALID_RESERVE_BALANCE");

        // special case for 0 amount
        if (_amount == 0) {
            return 0;
        }

        return _amount.mul(_supply) / _reserveBalance;
    }

    function liquidateReserveAmount(
        uint256 _supply,
        uint256 _reserveBalance,
        uint256 _amount
    ) private pure returns (uint256) {
        // validate input
        require(_supply > 0, "ERR_INVALID_SUPPLY");
        require(_reserveBalance > 0, "ERR_INVALID_RESERVE_BALANCE");
        require(_amount <= _supply, "ERR_INVALID_AMOUNT");

        // special case for 0 amount
        if (_amount == 0) {
            return 0;
        }

        // special case for liquidating the entire supply
        if (_amount == _supply) {
            return _reserveBalance;
        }

        return _amount.mul(_reserveBalance) / _supply;
    }

    /**
     * @dev returns the network wallet and fees
     *
     * @param reserveBalance0 1st reserve balance
     * @param reserveBalance1 2nd reserve balance
     *
     * @return the network wallet
     * @return the network fee on the 1st reserve
     * @return the network fee on the 2nd reserve
     */
    function networkWalletAndFees(uint256 reserveBalance0, uint256 reserveBalance1)
        private
        view
        returns (
            ITokenHolder,
            uint256,
            uint256
        )
    {
        uint256 prevPoint = floorSqrt(_reserveBalancesProduct);
        uint256 currPoint = floorSqrt(reserveBalance0 * reserveBalance1);

        if (prevPoint >= currPoint) {
            return (ITokenHolder(address(0)), 0, 0);
        }

        (ITokenHolder networkFeeWallet, uint32 networkFee) =
            INetworkSettings(addressOf(NETWORK_SETTINGS)).networkFeeParams();
        uint256 n = (currPoint - prevPoint) * networkFee;
        uint256 d = currPoint * PPM_RESOLUTION;
        return (networkFeeWallet, reserveBalance0.mul(n).div(d), reserveBalance1.mul(n).div(d));
    }

    /**
     * @dev transfers funds held by the contract and sends them to an account
     *
     * @param token ERC20 token contract address
     * @param to account to receive the new amount
     * @param amount amount to withdraw
     */
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 amount
    ) private {
        if (amount == 0) {
            return;
        }

        if (token == NATIVE_TOKEN_ADDRESS) {
            payable(to).transfer(amount);
        } else {
            token.safeTransfer(to, amount);
        }
    }

    /**
     * @dev deprecated since version 28, backward compatibility - use only for earlier versions
     */
    function token() public view override returns (IConverterAnchor) {
        return anchor;
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function transferTokenOwnership(address _newOwner) public override ownerOnly {
        transferAnchorOwnership(_newOwner);
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function acceptTokenOwnership() public override ownerOnly {
        acceptAnchorOwnership();
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function connectors(IERC20 _address)
        public
        view
        override
        returns (
            uint256,
            uint32,
            bool,
            bool,
            bool
        )
    {
        uint256 reserveId = __reserveIds[_address];
        if (reserveId != 0) {
            return (reserveBalance(reserveId), PPM_RESOLUTION / 2, false, false, true);
        }
        return (0, 0, false, false, false);
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function connectorTokens(uint256 _index) public view override returns (IERC20) {
        return __reserveTokens[_index];
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function connectorTokenCount() public view override returns (uint16) {
        return reserveTokenCount();
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function getConnectorBalance(IERC20 _connectorToken) public view override returns (uint256) {
        return reserveBalance(_connectorToken);
    }

    /**
     * @dev deprecated, backward compatibility
     */
    function getReturn(
        IERC20 _sourceToken,
        IERC20 _targetToken,
        uint256 _amount
    ) public view returns (uint256, uint256) {
        return targetAmountAndFee(_sourceToken, _targetToken, _amount);
    }
}

pragma solidity ^0.4.11;

/*
    Overflow protected math functions
*/
contract SafeMath {
    /**
        constructor
    */
    function SafeMath() {
    }

    /**
        @dev returns the sum of _x and _y, asserts if the calculation overflows

        @param _x   value 1
        @param _y   value 2

        @return sum
    */
    function safeAdd(uint256 _x, uint256 _y) internal returns (uint256) {
        uint256 z = _x + _y;
        assert(z >= _x);
        return z;
    }

    /**
        @dev returns the difference of _x minus _y, asserts if the subtraction results in a negative number

        @param _x   minuend
        @param _y   subtrahend

        @return difference
    */
    function safeSub(uint256 _x, uint256 _y) internal returns (uint256) {
        assert(_x >= _y);
        return _x - _y;
    }

    /**
        @dev returns the product of multiplying _x by _y, asserts if the calculation overflows

        @param _x   factor 1
        @param _y   factor 2

        @return product
    */
    function safeMul(uint256 _x, uint256 _y) internal returns (uint256) {
        uint256 z = _x * _y;
        assert(_x == 0 || z / _x == _y);
        return z;
    }
} 

/*
    Owned contract interface
*/
contract IOwned {
    // this function isn't abstract since the compiler emits automatically generated getter functions as external
    function owner() public constant returns (address owner) { owner; }

    function transferOwnership(address _newOwner) public;
    function acceptOwnership() public;
}

/*
    Provides support and utilities for contract ownership
*/
contract Owned is IOwned {
    address public owner;
    address public newOwner;

    event OwnerUpdate(address _prevOwner, address _newOwner);

    /**
        @dev constructor
    */
    function Owned() {
        owner = msg.sender;
    }

    // allows execution by the owner only
    modifier ownerOnly {
        assert(msg.sender == owner);
        _;
    }

    /**
        @dev allows transferring the contract ownership
        the new owner still need to accept the transfer
        can only be called by the contract owner

        @param _newOwner    new contract owner
    */
    function transferOwnership(address _newOwner) public ownerOnly {
        require(_newOwner != owner);
        newOwner = _newOwner;
    }

    /**
        @dev used by a new owner to accept an ownership transfer
    */
    function acceptOwnership() public {
        require(msg.sender == newOwner);
        OwnerUpdate(owner, newOwner);
        owner = newOwner;
        newOwner = 0x0;
    }
}

/*
    Token Holder interface
*/
contract ITokenHolder is IOwned {
    function withdrawTokens(IERC20Token _token, address _to, uint256 _amount) public;
}

/*
    We consider every contract to be a 'token holder' since it's currently not possible
    for a contract to deny receiving tokens.

    The TokenHolder's contract sole purpose is to provide a safety mechanism that allows
    the owner to send tokens that were sent to the contract by mistake back to their sender.
*/
contract TokenHolder is ITokenHolder, Owned {
    /**
        @dev constructor
    */
    function TokenHolder() {
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        require(_address != 0x0);
        _;
    }

    // verifies that the address is different than this contract address
    modifier notThis(address _address) {
        require(_address != address(this));
        _;
    }

    /**
        @dev withdraws tokens held by the contract and sends them to an account
        can only be called by the owner

        @param _token   ERC20 token contract address
        @param _to      account to receive the new amount
        @param _amount  amount to withdraw
    */
    function withdrawTokens(IERC20Token _token, address _to, uint256 _amount)
        public
        ownerOnly
        validAddress(_token)
        validAddress(_to)
        notThis(_to)
    {
        assert(_token.transfer(_to, _amount));
    }
}

/*
    ERC20 Standard Token interface
*/
contract IERC20Token {
    // these functions aren't abstract since the compiler emits automatically generated getter functions as external
    function name() public constant returns (string name) { name; }
    function symbol() public constant returns (string symbol) { symbol; }
    function decimals() public constant returns (uint8 decimals) { decimals; }
    function totalSupply() public constant returns (uint256 totalSupply) { totalSupply; }
    function balanceOf(address _owner) public constant returns (uint256 balance) { _owner; balance; }
    function allowance(address _owner, address _spender) public constant returns (uint256 remaining) { _owner; _spender; remaining; }

    function transfer(address _to, uint256 _value) public returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);
    function approve(address _spender, uint256 _value) public returns (bool success);
}

/**
    ERC20 Standard Token implementation
*/
contract ERC20Token is IERC20Token, SafeMath {
    string public standard = 'Token 0.1';
    string public name = '';
    string public symbol = '';
    uint8 public decimals = 0;
    uint256 public totalSupply = 0;
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    /**
        @dev constructor

        @param _name        token name
        @param _symbol      token symbol
        @param _decimals    decimal points, for display purposes
    */
    function ERC20Token(string _name, string _symbol, uint8 _decimals) {
        require(bytes(_name).length > 0 && bytes(_symbol).length > 0); // validate input

        name = _name;
        symbol = _symbol;
        decimals = _decimals;
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        require(_address != 0x0);
        _;
    }

    /**
        @dev send coins
        throws on any error rather then return a false flag to minimize user errors

        @param _to      target address
        @param _value   transfer amount

        @return true if the transfer was successful, false if it wasn't
    */
    function transfer(address _to, uint256 _value)
        public
        validAddress(_to)
        returns (bool success)
    {
        balanceOf[msg.sender] = safeSub(balanceOf[msg.sender], _value);
        balanceOf[_to] = safeAdd(balanceOf[_to], _value);
        Transfer(msg.sender, _to, _value);
        return true;
    }

    /**
        @dev an account/contract attempts to get the coins
        throws on any error rather then return a false flag to minimize user errors

        @param _from    source address
        @param _to      target address
        @param _value   transfer amount

        @return true if the transfer was successful, false if it wasn't
    */
    function transferFrom(address _from, address _to, uint256 _value)
        public
        validAddress(_from)
        validAddress(_to)
        returns (bool success)
    {
        allowance[_from][msg.sender] = safeSub(allowance[_from][msg.sender], _value);
        balanceOf[_from] = safeSub(balanceOf[_from], _value);
        balanceOf[_to] = safeAdd(balanceOf[_to], _value);
        Transfer(_from, _to, _value);
        return true;
    }

    /**
        @dev allow another account/contract to spend some tokens on your behalf
        throws on any error rather then return a false flag to minimize user errors

        also, to minimize the risk of the approve/transferFrom attack vector
        (see https://docs.google.com/document/d/1YLPtQxZu1UAvO9cZ1O2RPXBbT0mooh4DYKjA_jp-RLM/), approve has to be called twice
        in 2 separate transactions - once to change the allowance to 0 and secondly to change it to the new allowance value

        @param _spender approved address
        @param _value   allowance amount

        @return true if the approval was successful, false if it wasn't
    */
    function approve(address _spender, uint256 _value)
        public
        validAddress(_spender)
        returns (bool success)
    {
        // if the allowance isn't 0, it can only be updated to 0 to prevent an allowance change immediately after withdrawal
        require(_value == 0 || allowance[msg.sender][_spender] == 0);

        allowance[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }
}

/*
    Smart Token interface
*/
contract ISmartToken is ITokenHolder, IERC20Token {
    function disableTransfers(bool _disable) public;
    function issue(address _to, uint256 _amount) public;
    function destroy(address _from, uint256 _amount) public;
}

/*
    Smart Token v0.2

    'Owned' is specified here for readability reasons
*/
contract SmartToken is ISmartToken, ERC20Token, Owned, TokenHolder {
    string public version = '0.2';

    bool public transfersEnabled = true;    // true if transfer/transferFrom are enabled, false if not

    // triggered when a smart token is deployed - the _token address is defined for forward compatibility, in case we want to trigger the event from a factory
    event NewSmartToken(address _token);
    // triggered when the total supply is increased
    event Issuance(uint256 _amount);
    // triggered when the total supply is decreased
    event Destruction(uint256 _amount);

    /**
        @dev constructor

        @param _name       token name
        @param _symbol     token short symbol, 1-6 characters
        @param _decimals   for display purposes only
    */
    function SmartToken(string _name, string _symbol, uint8 _decimals)
        ERC20Token(_name, _symbol, _decimals)
    {
        require(bytes(_symbol).length <= 6); // validate input
        NewSmartToken(address(this));
    }

    // allows execution only when transfers aren't disabled
    modifier transfersAllowed {
        assert(transfersEnabled);
        _;
    }

    /**
        @dev disables/enables transfers
        can only be called by the contract owner

        @param _disable    true to disable transfers, false to enable them
    */
    function disableTransfers(bool _disable) public ownerOnly {
        transfersEnabled = !_disable;
    }

    /**
        @dev increases the token supply and sends the new tokens to an account
        can only be called by the contract owner

        @param _to         account to receive the new amount
        @param _amount     amount to increase the supply by
    */
    function issue(address _to, uint256 _amount)
        public
        ownerOnly
        validAddress(_to)
        notThis(_to)
    {
        totalSupply = safeAdd(totalSupply, _amount);
        balanceOf[_to] = safeAdd(balanceOf[_to], _amount);

        Issuance(_amount);
        Transfer(this, _to, _amount);
    }

    /**
        @dev removes tokens from an account and decreases the token supply
        can only be called by the contract owner

        @param _from       account to remove the amount from
        @param _amount     amount to decrease the supply by
    */
    function destroy(address _from, uint256 _amount)
        public
        ownerOnly
    {
        balanceOf[_from] = safeSub(balanceOf[_from], _amount);
        totalSupply = safeSub(totalSupply, _amount);

        Transfer(_from, this, _amount);
        Destruction(_amount);
    }

    // ERC20 standard method overrides with some extra functionality

    /**
        @dev send coins
        throws on any error rather then return a false flag to minimize user errors
        note that when transferring to the smart token's address, the coins are actually destroyed

        @param _to      target address
        @param _value   transfer amount

        @return true if the transfer was successful, false if it wasn't
    */
    function transfer(address _to, uint256 _value) public transfersAllowed returns (bool success) {
        assert(super.transfer(_to, _value));

        // transferring to the contract address destroys tokens
        if (_to == address(this)) {
            balanceOf[_to] -= _value;
            totalSupply -= _value;
            Destruction(_value);
        }

        return true;
    }

    /**
        @dev an account/contract attempts to get the coins
        throws on any error rather then return a false flag to minimize user errors
        note that when transferring to the smart token's address, the coins are actually destroyed

        @param _from    source address
        @param _to      target address
        @param _value   transfer amount

        @return true if the transfer was successful, false if it wasn't
    */
    function transferFrom(address _from, address _to, uint256 _value) public transfersAllowed returns (bool success) {
        assert(super.transferFrom(_from, _to, _value));

        // transferring to the contract address destroys tokens
        if (_to == address(this)) {
            balanceOf[_to] -= _value;
            totalSupply -= _value;
            Destruction(_value);
        }

        return true;
    }
}

pragma solidity ^0.4.24;

// File: contracts/utility/interfaces/IOwned.sol

/*
    Owned contract interface
*/
contract IOwned {
    // this function isn't abstract since the compiler emits automatically generated getter functions as external
    function owner() public view returns (address) {}

    function transferOwnership(address _newOwner) public;
    function acceptOwnership() public;
}

// File: contracts/utility/Owned.sol

/*
    Provides support and utilities for contract ownership
*/
contract Owned is IOwned {
    address public owner;
    address public newOwner;

    event OwnerUpdate(address indexed _prevOwner, address indexed _newOwner);

    /**
        @dev constructor
    */
    constructor() public {
        owner = msg.sender;
    }

    // allows execution by the owner only
    modifier ownerOnly {
        require(msg.sender == owner);
        _;
    }

    /**
        @dev allows transferring the contract ownership
        the new owner still needs to accept the transfer
        can only be called by the contract owner

        @param _newOwner    new contract owner
    */
    function transferOwnership(address _newOwner) public ownerOnly {
        require(_newOwner != owner);
        newOwner = _newOwner;
    }

    /**
        @dev used by a new owner to accept an ownership transfer
    */
    function acceptOwnership() public {
        require(msg.sender == newOwner);
        emit OwnerUpdate(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}

// File: contracts/utility/Utils.sol

/*
    Utilities & Common Modifiers
*/
contract Utils {
    /**
        constructor
    */
    constructor() public {
    }

    // verifies that an amount is greater than zero
    modifier greaterThanZero(uint256 _amount) {
        require(_amount > 0);
        _;
    }

    // validates an address - currently only checks that it isn't null
    modifier validAddress(address _address) {
        require(_address != address(0));
        _;
    }

    // verifies that the address is different than this contract address
    modifier notThis(address _address) {
        require(_address != address(this));
        _;
    }

    // Overflow protected math functions

    /**
        @dev returns the sum of _x and _y, asserts if the calculation overflows

        @param _x   value 1
        @param _y   value 2

        @return sum
    */
    function safeAdd(uint256 _x, uint256 _y) internal pure returns (uint256) {
        uint256 z = _x + _y;
        assert(z >= _x);
        return z;
    }

    /**
        @dev returns the difference of _x minus _y, asserts if the subtraction results in a negative number

        @param _x   minuend
        @param _y   subtrahend

        @return difference
    */
    function safeSub(uint256 _x, uint256 _y) internal pure returns (uint256) {
        assert(_x >= _y);
        return _x - _y;
    }

    /**
        @dev returns the product of multiplying _x by _y, asserts if the calculation overflows

        @param _x   factor 1
        @param _y   factor 2

        @return product
    */
    function safeMul(uint256 _x, uint256 _y) internal pure returns (uint256) {
        uint256 z = _x * _y;
        assert(_x == 0 || z / _x == _y);
        return z;
    }
}

// File: contracts/utility/interfaces/IContractRegistry.sol

/*
    Contract Registry interface
*/
contract IContractRegistry {
    function addressOf(bytes32 _contractName) public view returns (address);

    // deprecated, backward compatibility
    function getAddress(bytes32 _contractName) public view returns (address);
}

// File: contracts/ContractIds.sol

/**
    Id definitions for bancor contracts

    Can be used in conjunction with the contract registry to get contract addresses
*/
contract ContractIds {
    // generic
    bytes32 public constant CONTRACT_FEATURES = "ContractFeatures";
    bytes32 public constant CONTRACT_REGISTRY = "ContractRegistry";

    // bancor logic
    bytes32 public constant BANCOR_NETWORK = "BancorNetwork";
    bytes32 public constant BANCOR_FORMULA = "BancorFormula";
    bytes32 public constant BANCOR_GAS_PRICE_LIMIT = "BancorGasPriceLimit";
    bytes32 public constant BANCOR_CONVERTER_UPGRADER = "BancorConverterUpgrader";
    bytes32 public constant BANCOR_CONVERTER_FACTORY = "BancorConverterFactory";

    // Ids of BNT converter and BNT token
    bytes32 public constant BNT_TOKEN = "BNTToken";
    bytes32 public constant BNT_CONVERTER = "BNTConverter";

    // Id of BancorX contract
    bytes32 public constant BANCOR_X = "BancorX";
}

// File: contracts/utility/ContractRegistry.sol

/**
    Contract Registry

    The contract registry keeps contract addresses by name.
    The owner can update contract addresses so that a contract name always points to the latest version
    of the given contract.
    Other contracts can query the registry to get updated addresses instead of depending on specific
    addresses.

    Note that contract names are limited to 32 bytes UTF8 encoded ASCII strings to optimize gas costs
*/
contract ContractRegistry is IContractRegistry, Owned, Utils, ContractIds {
    struct RegistryItem {
        address contractAddress;    // contract address
        uint256 nameIndex;          // index of the item in the list of contract names
        bool isSet;                 // used to tell if the mapping element is defined
    }

    mapping (bytes32 => RegistryItem) private items;    // name -> RegistryItem mapping
    string[] public contractNames;                      // list of all registered contract names

    // triggered when an address pointed to by a contract name is modified
    event AddressUpdate(bytes32 indexed _contractName, address _contractAddress);

    /**
        @dev constructor
    */
    constructor() public {
        registerAddress(ContractIds.CONTRACT_REGISTRY, address(this));
    }

    /**
        @dev returns the number of items in the registry

        @return number of items
    */
    function itemCount() public view returns (uint256) {
        return contractNames.length;
    }

    /**
        @dev returns the address associated with the given contract name

        @param _contractName    contract name

        @return contract address
    */
    function addressOf(bytes32 _contractName) public view returns (address) {
        return items[_contractName].contractAddress;
    }

    /**
        @dev registers a new address for the contract name in the registry

        @param _contractName     contract name
        @param _contractAddress  contract address
    */
    function registerAddress(bytes32 _contractName, address _contractAddress)
        public
        ownerOnly
        validAddress(_contractAddress)
    {
        require(_contractName.length > 0); // validate input

        // update the address in the registry
        items[_contractName].contractAddress = _contractAddress;

        if (!items[_contractName].isSet) {
            // mark the item as set
            items[_contractName].isSet = true;
            // add the contract name to the name list
            uint256 i = contractNames.push(bytes32ToString(_contractName));
            // update the item's index in the list
            items[_contractName].nameIndex = i - 1;
        }

        // dispatch the address update event
        emit AddressUpdate(_contractName, _contractAddress);
    }

    /**
        @dev removes an existing contract address from the registry

        @param _contractName contract name
    */
    function unregisterAddress(bytes32 _contractName) public ownerOnly {
        require(_contractName.length > 0); // validate input

        // remove the address from the registry
        items[_contractName].contractAddress = address(0);

        // if there are multiple items in the registry, move the last element to the deleted element's position
        // and modify last element's registryItem.nameIndex in the items collection to point to the right position in contractNames
        if (contractNames.length > 1) {
            string memory lastContractNameString = contractNames[contractNames.length - 1];
            uint256 unregisterIndex = items[_contractName].nameIndex;

            contractNames[unregisterIndex] = lastContractNameString;
            bytes32 lastContractName = stringToBytes32(lastContractNameString);
            RegistryItem storage registryItem = items[lastContractName];
            registryItem.nameIndex = unregisterIndex;
        }

        // remove the last element from the name list
        contractNames.length--;
        // zero the deleted element's index
        items[_contractName].nameIndex = 0;

        // dispatch the address update event
        emit AddressUpdate(_contractName, address(0));
    }

    /**
        @dev utility, converts bytes32 to a string
        note that the bytes32 argument is assumed to be UTF8 encoded ASCII string

        @return string representation of the given bytes32 argument
    */
    function bytes32ToString(bytes32 _bytes) private pure returns (string) {
        bytes memory byteArray = new bytes(32);
        for (uint256 i; i < 32; i++) {
            byteArray[i] = _bytes[i];
        }

        return string(byteArray);
    }

    // @dev utility, converts string to bytes32
    function stringToBytes32(string memory _string) private pure returns (bytes32) {
        bytes32 result;
        assembly {
            result := mload(add(_string,32))
        }
        return result;
    }

    // deprecated, backward compatibility
    function getAddress(bytes32 _contractName) public view returns (address) {
        return addressOf(_contractName);
    }
}

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*/
// Made by https://peppersec.com

pragma solidity 0.5.17;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.5.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/math/SafeMath.sol

pragma solidity ^0.5.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     *
     * _Available since v2.4.0._
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.5.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20Mintable}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20};
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for `sender`'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`.`amount` is then deducted
     * from the caller's allowance.
     *
     * See {_burn} and {_approve}.
     */
    function _burnFrom(address account, uint256 amount) internal {
        _burn(account, amount);
        _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, "ERC20: burn amount exceeds allowance"));
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20Detailed.sol

pragma solidity ^0.5.0;


/**
 * @dev Optional functions from the ERC20 standard.
 */
contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
     * these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

// File: @openzeppelin/contracts/math/Math.sol

pragma solidity ^0.5.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }
}

// File: @openzeppelin/contracts/utils/Address.sol

pragma solidity ^0.5.5;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Converts an `address` into `address payable`. Note that this is
     * simply a type cast: the actual underlying value is not changed.
     *
     * _Available since v2.4.0._
     */
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     *
     * _Available since v2.4.0._
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-call-value
        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol

pragma solidity ^0.5.0;




/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/INXM.sol

pragma solidity 0.5.17;


contract INXM is IERC20 {
    function whiteListed(address owner) external view returns (bool);
    function isLockedForMV(address owner) external view returns (uint256);
}

// File: contracts/ECDSA.sol

pragma solidity ^0.5.0;

// A copy from https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2237/files

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        // Check the signature length
        if (signature.length != 65) {
            revert("ECDSA: invalid signature length");
        }

        // Divide the signature in r, s and v variables
        bytes32 r;
        bytes32 s;
        uint8 v;

        // ecrecover takes the signature parameters, and the only way to get them
        // currently is to use assembly.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            r := mload(add(signature, 0x20))
            s := mload(add(signature, 0x40))
            v := byte(0, mload(add(signature, 0x60)))
        }

        return recover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover-bytes32-bytes-} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            revert("ECDSA: invalid signature 's' value");
        }

        if (v != 27 && v != 28) {
            revert("ECDSA: invalid signature 'v' value");
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        require(signer != address(0), "ECDSA: invalid signature");

        return signer;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * replicates the behavior of the
     * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]
     * JSON-RPC method.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }
}

// File: contracts/ERC20Permit.sol

pragma solidity ^0.5.0;

// Adapted copy from https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2237/files





/**
 * @dev Extension of {ERC20} that allows token holders to use their tokens
 * without sending any transactions by setting {IERC20-allowance} with a
 * signature using the {permit} method, and then spend them via
 * {IERC20-transferFrom}.
 *
 * The {permit} signature mechanism conforms to the {IERC2612Permit} interface.
 */
contract ERC20Permit is ERC20, ERC20Detailed {
    mapping(address => uint256) private _nonces;

    bytes32 private constant _PERMIT_TYPEHASH = keccak256(
        "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
    );

    // Mapping of ChainID to domain separators. This is a very gas efficient way
    // to not recalculate the domain separator on every call, while still
    // automatically detecting ChainID changes.
    mapping(uint256 => bytes32) private _domainSeparators;

    constructor() internal {
        _updateDomainSeparator();
    }

    /**
     * @dev See {IERC2612Permit-permit}.
     *
     * If https://eips.ethereum.org/EIPS/eip-1344[ChainID] ever changes, the
     * EIP712 Domain Separator is automatically recalculated.
     */
    function permit(
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public {
        require(blockTimestamp() <= deadline, "ERC20Permit: expired deadline");

        bytes32 hashStruct = keccak256(
            abi.encode(_PERMIT_TYPEHASH, owner, spender, amount, _nonces[owner], deadline)
        );

        bytes32 hash = keccak256(abi.encodePacked(uint16(0x1901), _domainSeparator(), hashStruct));

        address signer = ECDSA.recover(hash, v, r, s);
        require(signer == owner, "ERC20Permit: invalid signature");

        _nonces[owner]++;
        _approve(owner, spender, amount);
    }

    /**
     * @dev See {IERC2612Permit-nonces}.
     */
    function nonces(address owner) public view returns (uint256) {
        return _nonces[owner];
    }

    function _updateDomainSeparator() private returns (bytes32) {
        uint256 _chainID = chainID();

        bytes32 newDomainSeparator = keccak256(
            abi.encode(
                keccak256(
                    "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
                ),
                keccak256(bytes(name())),
                keccak256(bytes("1")), // Version
                _chainID,
                address(this)
            )
        );

        _domainSeparators[_chainID] = newDomainSeparator;

        return newDomainSeparator;
    }

    // Returns the domain separator, updating it if chainID changes
    function _domainSeparator() private returns (bytes32) {
        bytes32 domainSeparator = _domainSeparators[chainID()];
        if (domainSeparator != 0x00) {
            return domainSeparator;
        } else {
            return _updateDomainSeparator();
        }
    }

    function chainID() public view returns (uint256 _chainID) {
        assembly {
            _chainID := chainid()
        }
    }

    function blockTimestamp() public view returns (uint256) {
        return block.timestamp;
    }
}

// File: contracts/wNXM.sol

pragma solidity 0.5.17;

contract wNXM is ERC20, ERC20Detailed, ERC20Permit {
    using SafeERC20 for ERC20;
    using SafeMath for uint256;

    INXM public NXM;

    modifier notwNXM(address recipient) {
        require(recipient != address(this), "wNXM: can not send to self");
        _;
    }

    constructor(INXM _nxm) public ERC20Detailed("Wrapped NXM", "wNXM", 18) {
        NXM = _nxm;
    }

    function _transfer(address sender, address recipient, uint256 amount)
        internal
        notwNXM(recipient)
    {
        super._transfer(sender, recipient, amount);
    }

    function wrap(uint256 _amount) external {
        require(NXM.transferFrom(msg.sender, address(this), _amount), "wNXM: transferFrom failed");
        _mint(msg.sender, _amount);
    }

    function unwrap(uint256 _amount) external {
        unwrapTo(msg.sender, _amount);
    }

    function unwrapTo(address _to, uint256 _amount) public notwNXM(_to) {
        _burn(msg.sender, _amount);
        require(NXM.transfer(_to, _amount), "wNXM: transfer failed");
    }

    function canWrap(address _owner, uint256 _amount)
        external
        view
        returns (bool success, string memory reason)
    {
        if (NXM.allowance(_owner, address(this)) < _amount) {
            return (false, "insufficient allowance");
        }

        if (NXM.balanceOf(_owner) < _amount) {
            return (false, "insufficient NXM balance");
        }

        if (NXM.isLockedForMV(_owner) > now) {
            return (false, "NXM balance lockedForMv");
        }

        if (!NXM.whiteListed(address(this))) {
            return (false, "wNXM is not whitelisted");
        }

        return (true, "");
    }

    function canUnwrap(address _owner, address _recipient, uint256 _amount)
        external
        view
        returns (bool success, string memory reason)
    {
        if (balanceOf(_owner) < _amount) {
            return (false, "insufficient wNXM balance");
        }

        if (!NXM.whiteListed(_recipient)) {
            return (false, "recipient is not whitelisted");
        }

        if (NXM.isLockedForMV(address(this)) > now) {
            return (false, "wNXM is lockedForMv");
        }

        return (true, "");
    }

    /// @dev Method to claim junk and accidentally sent tokens
    function claimTokens(ERC20 _token, address payable _to, uint256 _balance) external {
        require(_to != address(0), "wNXM: can not send to zero address");

        if (_token == ERC20(address(NXM))) {
            uint256 surplusBalance = _token.balanceOf(address(this)).sub(totalSupply());
            require(surplusBalance > 0, "wNXM: there is no accidentally sent NXM");
            uint256 balance = _balance == 0 ? surplusBalance : Math.min(surplusBalance, _balance);
            _token.safeTransfer(_to, balance);
        } else if (_token == ERC20(0)) {
            // for Ether
            uint256 totalBalance = address(this).balance;
            uint256 balance = _balance == 0 ? totalBalance : Math.min(totalBalance, _balance);
            _to.transfer(balance);
        } else {
            // any other erc20
            uint256 totalBalance = _token.balanceOf(address(this));
            uint256 balance = _balance == 0 ? totalBalance : Math.min(totalBalance, _balance);
            require(balance > 0, "wNXM: trying to send 0 balance");
            _token.safeTransfer(_to, balance);
        }
    }
}