pragma solidity =0.6.6;

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;
}

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;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

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);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// 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');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}

// 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;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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            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
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    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.

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    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: GPL-3.0
pragma solidity ^0.6.0;
/**
 * @dev Because we use the code hashes of the proxy contracts for proxy address
 * derivation, it is important that other packages have access to the correct
 * values when they import the salt library.
 */
library CodeHashes {
  bytes32 internal constant ONE_TO_ONE_CODEHASH = 0x63d9f7b5931b69188c8f6b806606f25892f1bb17b7f7e966fe3a32c04493aee4;
  bytes32 internal constant MANY_TO_ONE_CODEHASH = 0xa035ad05a1663db5bfd455b99cd7c6ac6bd49269738458eda140e0b78ed53f79;
  bytes32 internal constant IMPLEMENTATION_HOLDER_CODEHASH = 0x11c370493a726a0ffa93d42b399ad046f1b5a543b6e72f1a64f1488dc1c58f2c;
}// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
/* ==========  External Libraries  ========== */
import { Create2 } from "@openzeppelin/contracts/utils/Create2.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
/* ==========  Proxy Contracts  ========== */
import "./ManyToOneImplementationHolder.sol";
import { DelegateCallProxyManyToOne } from "./DelegateCallProxyManyToOne.sol";
import { DelegateCallProxyOneToOne } from "./DelegateCallProxyOneToOne.sol";
/* ==========  Internal Libraries  ========== */
import { SaltyLib as Salty } from "./SaltyLib.sol";
import { CodeHashes } from "./CodeHashes.sol";
/* ==========  Inheritance  ========== */
import "./interfaces/IDelegateCallProxyManager.sol";
/**
 * @dev Contract that manages deployment and upgrades of delegatecall proxies.
 *
 * An implementation identifier can be created on the proxy manager which is
 * used to specify the logic address for a particular contract type, and to
 * upgrade the implementation as needed.
 *
 * ====== Proxy Types ======
 * A one-to-one proxy is a single proxy contract with an upgradeable implementation
 * address.
 *
 * A many-to-one proxy is a single upgradeable implementation address that may be
 * used by many proxy contracts.
 *
 * ====== Access Control ======
 * The proxy manager has a single address as its owner.
 *
 * The owner is the sole account with the following permissions:
 * - Create new many-to-one implementations
 * - Create new one-to-one proxies
 * - Modify the implementation address of existing proxies
 * - Lock proxies
 * - Designate approved deployers
 * - Remove approved deployers
 * - Modify the owner address
 *
 * Approved deployers may only deploy many-to-one proxies.
 *
 * ====== Upgrades ======
 * Proxies can be upgraded by the owner if they are not locked.
 *
 * Many-to-one proxy implementations are upgraded by calling the holder contract
 * for the implementation ID being upgraded.
 * One-to-one proxies are upgraded by calling the proxy contract directly.
 *
 * The owner can lock a one-to-one proxy or many-to-one implementation ID so that
 * it becomes impossible to upgrade.
 */
contract DelegateCallProxyManager is Ownable, IDelegateCallProxyManager {
/* ==========  Events  ========== */
  event DeploymentApprovalGranted(address deployer);
  event DeploymentApprovalRevoked(address deployer);
  event ManyToOne_ImplementationCreated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationUpdated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationLocked(bytes32 implementationID);
  event ManyToOne_ProxyDeployed(
    bytes32 implementationID,
    address proxyAddress
  );
  event OneToOne_ProxyDeployed(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationUpdated(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationLocked(address proxyAddress);
/* ==========  Storage  ========== */
  // Addresses allowed to deploy many-to-one proxies.
  mapping(address => bool) internal _approvedDeployers;
  // Maps implementation holders to their implementation IDs.
  mapping(bytes32 => address) internal _implementationHolders;
  // Maps implementation holders & proxy addresses to bool stating if they are locked.
  mapping(address => bool) internal _lockedImplementations;
  // Temporary value used in the many-to-one proxy constructor.
  // The many-to-one proxy contract is deployed with create2 and
  // uses static initialization code for simple address derivation,
  // so it calls the proxy manager in the constructor to get this
  // address in order to save it as an immutable in the bytecode.
  address internal _implementationHolder;
/* ==========  Modifiers  ========== */
  modifier onlyApprovedDeployer {
    address sender = _msgSender();
    require(_approvedDeployers[sender] || sender == owner(), "ERR_NOT_APPROVED");
    _;
  }
/* ==========  Constructor  ========== */
  constructor() public Ownable() {}
/* ==========  Access Control  ========== */
  /**
   * @dev Allows `deployer` to deploy many-to-one proxies.
   */
  function approveDeployer(address deployer) external override onlyOwner {
    _approvedDeployers[deployer] = true;
    emit DeploymentApprovalGranted(deployer);
  }
  /**
   * @dev Prevents `deployer` from deploying many-to-one proxies.
   */
  function revokeDeployerApproval(address deployer) external override onlyOwner {
    _approvedDeployers[deployer] = false;
    emit DeploymentApprovalRevoked(deployer);
  }
/* ==========  Implementation Management  ========== */
  /**
   * @dev Creates a many-to-one proxy relationship.
   *
   * Deploys an implementation holder contract which stores the
   * implementation address for many proxies. The implementation
   * address can be updated on the holder to change the runtime
   * code used by all its proxies.
   *
   * @param implementationID ID for the implementation, used to identify the
   * proxies that use it. Also used as the salt in the create2 call when
   * deploying the implementation holder contract.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function createManyToOneProxyRelationship(
    bytes32 implementationID,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Deploy the implementation holder contract with the implementation
    // ID as the create2 salt.
    address implementationHolder = Create2.deploy(
      0,
      implementationID,
      type(ManyToOneImplementationHolder).creationCode
    );
    // Store the implementation holder address
    _implementationHolders[implementationID] = implementationHolder;
    // Sets the implementation address.
    _setImplementation(implementationHolder, implementation);
    emit ManyToOne_ImplementationCreated(
      implementationID,
      implementation
    );
  }
  /**
   * @dev Lock the current implementation for `implementationID` so that it can never be upgraded again.
   */
  function lockImplementationManyToOne(bytes32 implementationID) external override onlyOwner {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    _lockedImplementations[implementationHolder] = true;
    emit ManyToOne_ImplementationLocked(implementationID);
  }
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationOneToOne(address proxyAddress) external override onlyOwner {
    _lockedImplementations[proxyAddress] = true;
    emit OneToOne_ImplementationLocked(proxyAddress);
  }
  /**
   * @dev Updates the implementation address for a many-to-one
   * proxy relationship.
   *
   * @param implementationID Identifier for the implementation.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function setImplementationAddressManyToOne(
    bytes32 implementationID,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    // Verify implementation is not locked
    require(!_lockedImplementations[implementationHolder], "ERR_IMPLEMENTATION_LOCKED");
    // Set the implementation address
    _setImplementation(implementationHolder, implementation);
    emit ManyToOne_ImplementationUpdated(
      implementationID,
      implementation
    );
  }
  /**
   * @dev Updates the implementation address for a one-to-one proxy.
   *
   * Note: This could work for many-to-one as well if the caller
   * provides the implementation holder address in place of the
   * proxy address, as they use the same access control and update
   * mechanism.
   *
   * @param proxyAddress Address of the deployed proxy
   * @param implementation Address with the runtime code for
   * the proxy to use.
   */
  function setImplementationAddressOneToOne(
    address proxyAddress,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Verify proxy is not locked
    require(!_lockedImplementations[proxyAddress], "ERR_IMPLEMENTATION_LOCKED");
    // Set the implementation address
    _setImplementation(proxyAddress, implementation);
    emit OneToOne_ImplementationUpdated(proxyAddress, implementation);
  }
/* ==========  Proxy Deployment  ========== */
  /**
   * @dev Deploy a proxy contract with a one-to-one relationship
   * with its implementation.
   *
   * The proxy will have its own implementation address which can
   * be updated by the proxy manager.
   *
   * @param suppliedSalt Salt provided by the account requesting deployment.
   * @param implementation Address of the contract with the runtime
   * code that the proxy should use.
   */
  function deployProxyOneToOne(
    bytes32 suppliedSalt,
    address implementation
  )
    external
    override
    onlyOwner
    returns(address proxyAddress)
  {
    // Derive the create2 salt from the deployment requester's address
    // and the requester-supplied salt.
    bytes32 salt = Salty.deriveOneToOneSalt(_msgSender(), suppliedSalt);
    // Deploy the proxy
    proxyAddress = Create2.deploy(
      0,
      salt,
      type(DelegateCallProxyOneToOne).creationCode
    );
    // Set the implementation address on the new proxy.
    _setImplementation(proxyAddress, implementation);
    emit OneToOne_ProxyDeployed(proxyAddress, implementation);
  }
  /**
   * @dev Deploy a proxy with a many-to-one relationship with its implemenation.
   *
   * The proxy will call the implementation holder for every transaction to
   * determine the address to use in calls.
   *
   * @param implementationID Identifier for the proxy's implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deployProxyManyToOne(bytes32 implementationID, bytes32 suppliedSalt)
    external
    override
    onlyApprovedDeployer
    returns(address proxyAddress)
  {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    // Derive the create2 salt from the deployment requester's address, the
    // implementation ID and the requester-supplied salt.
    bytes32 salt = Salty.deriveManyToOneSalt(
      _msgSender(),
      implementationID,
      suppliedSalt
    );
    // Set the implementation holder address in storage so the proxy
    // constructor can query it.
    _implementationHolder = implementationHolder;
    // Deploy the proxy, which will query the implementation holder address
    // and save it as an immutable in the contract bytecode.
    proxyAddress = Create2.deploy(
      0,
      salt,
      type(DelegateCallProxyManyToOne).creationCode
    );
    // Remove the address from temporary storage.
    _implementationHolder = address(0);
    emit ManyToOne_ProxyDeployed(
      implementationID,
      proxyAddress
    );
  }
/* ==========  Queries  ========== */
  /**
   * @dev Returns a boolean stating whether `implementationID` is locked.
   */
  function isImplementationLocked(bytes32 implementationID) external override view returns (bool) {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    return _lockedImplementations[implementationHolder];
  }
  /**
   * @dev Returns a boolean stating whether `proxyAddress` is locked.
   */
  function isImplementationLocked(address proxyAddress) external override view returns (bool) {
    return _lockedImplementations[proxyAddress];
  }
  /**
   * @dev Returns a boolean stating whether `deployer` is allowed to deploy many-to-one
   * proxies.
   */
  function isApprovedDeployer(address deployer) external override view returns (bool) {
    return _approvedDeployers[deployer];
  }
  /**
   * @dev Queries the temporary storage value `_implementationHolder`.
   * This is used in the constructor of the many-to-one proxy contract
   * so that the create2 address is static (adding constructor arguments
   * would change the codehash) and the implementation holder can be
   * stored as a constant.
   */
  function getImplementationHolder()
    external
    override
    view
    returns (address)
  {
    return _implementationHolder;
  }
  /**
   * @dev Returns the address of the implementation holder contract
   * for `implementationID`.
   */
  function getImplementationHolder(
    bytes32 implementationID
  )
    external
    override
    view
    returns (address)
  {
    return _implementationHolders[implementationID];
  }
  /**
   * @dev Computes the create2 address for a one-to-one proxy requested
   * by `originator` using `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address originator,
    bytes32 suppliedSalt
  )
    external
    override
    view
    returns (address)
  {
    bytes32 salt = Salty.deriveOneToOneSalt(originator, suppliedSalt);
    return Create2.computeAddress(salt, CodeHashes.ONE_TO_ONE_CODEHASH);
  }
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` requested by `originator` using
   * `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    external
    override
    view
    returns (address)
  {
    bytes32 salt = Salty.deriveManyToOneSalt(
      originator,
      implementationID,
      suppliedSalt
    );
    return Create2.computeAddress(salt, CodeHashes.MANY_TO_ONE_CODEHASH);
  }
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(bytes32 implementationID)
    public
    override
    view
    returns (address)
  {
    return Create2.computeAddress(
      implementationID,
      CodeHashes.IMPLEMENTATION_HOLDER_CODEHASH
    );
  }
/* ==========  Internal Functions  ========== */
  /**
   * @dev Sets the implementation address for a one-to-one proxy or
   * many-to-one implementation holder. Both use the same access
   * control and update mechanism, which is the receipt of a call
   * from the proxy manager with the abi-encoded implementation address
   * as the only calldata.
   *
   * Note: Verifies that the implementation address is a contract.
   *
   * @param proxyOrHolder Address of the one-to-one proxy or
   * many-to-one implementation holder contract.
   * @param implementation Address of the contract with the runtime
   * code that the proxy or proxies should use.
   */
  function _setImplementation(
    address proxyOrHolder,
    address implementation
  ) internal {
    // Verify that the implementation address is a contract.
    require(Address.isContract(implementation), "ERR_NOT_CONTRACT");
    // Set the implementation address on the contract.
    // solium-disable-next-line security/no-low-level-calls
    (bool success,) = proxyOrHolder.call(abi.encode(implementation));
    require(success, "ERR_SET_ADDRESS_REVERT");
  }
}// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer.
 * `CREATE2` can be used to compute in advance the address where a smart
 * contract will be deployed, which allows for interesting new mechanisms known
 * as 'counterfactual interactions'.
 *
 * See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more
 * information.
 */
library Create2 {
    /**
     * @dev Deploys a contract using `CREATE2`. The address where the contract
     * will be deployed can be known in advance via {computeAddress}.
     *
     * The bytecode for a contract can be obtained from Solidity with
     * `type(contractName).creationCode`.
     *
     * Requirements:
     *
     * - `bytecode` must not be empty.
     * - `salt` must have not been used for `bytecode` already.
     * - the factory must have a balance of at least `amount`.
     * - if `amount` is non-zero, `bytecode` must have a `payable` constructor.
     */
    function deploy(uint256 amount, bytes32 salt, bytes memory bytecode) internal returns (address) {
        address addr;
        require(address(this).balance >= amount, "Create2: insufficient balance");
        require(bytecode.length != 0, "Create2: bytecode length is zero");
        // solhint-disable-next-line no-inline-assembly
        assembly {
            addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt)
        }
        require(addr != address(0), "Create2: Failed on deploy");
        return addr;
    }
    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the
     * `bytecodeHash` or `salt` will result in a new destination address.
     */
    function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) {
        return computeAddress(salt, bytecodeHash, address(this));
    }
    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at
     * `deployer`. If `deployer` is this contract's address, returns the same value as {computeAddress}.
     */
    function computeAddress(bytes32 salt, bytes32 bytecodeHash, address deployer) internal pure returns (address) {
        bytes32 _data = keccak256(
            abi.encodePacked(bytes1(0xff), deployer, salt, bytecodeHash)
        );
        return address(uint256(_data));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.2;
/**
 * @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 in 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");
        return _functionCallWithValue(target, data, value, errorMessage);
    }
    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../GSN/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/*
 * @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 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.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
/**
 * @dev The ManyToOneImplementationHolder stores an upgradeable implementation address
 * in storage, which many-to-one proxies query at execution time to determine which
 * contract to delegate to.
 *
 * The manager can upgrade the implementation address by calling the holder with the
 * abi-encoded address as calldata. If any other account calls the implementation holder,
 * it will return the implementation address.
 *
 * This pattern was inspired by the DharmaUpgradeBeacon from 0age
 * https://github.com/dharma-eng/dharma-smart-wallet/blob/master/contracts/upgradeability/smart-wallet/DharmaUpgradeBeacon.sol
 */
contract ManyToOneImplementationHolder {
/* ---  Storage  --- */
  address internal immutable _manager;
  address internal _implementation;
/* ---  Constructor  --- */
  constructor() public {
    _manager = msg.sender;
  }
  /**
   * @dev Fallback function for the contract.
   *
   * Used by proxies to read the implementation address and used
   * by the proxy manager to set the implementation address.
   *
   * If called by the owner, reads the implementation address from
   * calldata (must be abi-encoded) and stores it to the first slot.
   *
   * Otherwise, returns the stored implementation address.
   */
  fallback() external payable {
    if (msg.sender != _manager) {
      assembly {
        mstore(0, sload(0))
        return(0, 32)
      }
    }
    assembly { sstore(0, calldataload(0)) }
  }
}// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
import { Proxy } from "@openzeppelin/contracts/proxy/Proxy.sol";
/**
 * @dev Proxy contract which uses an implementation address shared with many
 * other proxies.
 *
 * An implementation holder contract stores the upgradeable implementation address.
 * When the proxy is called, it queries the implementation address from the holder
 * contract and delegatecalls the returned address, forwarding the received calldata
 * and ether.
 *
 * Note: This contract does not verify that the implementation
 * address is a valid delegation target. The manager must perform
 * this safety check before updating the implementation on the holder.
 */
contract DelegateCallProxyManyToOne is Proxy {
/* ==========  Constants  ========== */
  // Address that stores the implementation address.
  address internal immutable _implementationHolder;
/* ==========  Constructor  ========== */
  constructor() public {
    // Calls the sender rather than receiving the address in the constructor
    // arguments so that the address is computable using create2.
    _implementationHolder = ProxyDeployer(msg.sender).getImplementationHolder();
  }
/* ==========  Internal Overrides  ========== */
  /**
   * @dev Queries the implementation address from the implementation holder.
   */
  function _implementation() internal override view returns (address) {
    // Queries the implementation address from the implementation holder.
    (bool success, bytes memory data) = _implementationHolder.staticcall("");
    require(success, string(data));
    address implementation = abi.decode((data), (address));
    require(implementation != address(0), "ERR_NULL_IMPLEMENTATION");
    return implementation;
  }
}
interface ProxyDeployer {
  function getImplementationHolder() external view returns (address);
}// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @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 internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal {
        // solhint-disable-next-line no-inline-assembly
        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 virtual view 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 {
        _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 () payable external {
        _fallback();
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive () payable external {
        _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: GPL-3.0
pragma solidity =0.6.12;
import { Proxy } from "@openzeppelin/contracts/proxy/Proxy.sol";
/**
 * @dev Upgradeable delegatecall proxy for a single contract.
 *
 * This proxy stores an implementation address which can be upgraded by the proxy manager.
 *
 * To upgrade the implementation, the manager calls the proxy with the abi encoded implementation address.
 *
 * If any other account calls the proxy, it will delegatecall the implementation address with the received
 * calldata and ether. If the call succeeds, it will return with the received returndata.
 * If it reverts, it will revert with the received revert data.
 *
 * Note: The storage slot for the implementation address is:
 * `bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)`
 * This slot must not be used by the implementation contract.
 *
 * Note: This contract does not verify that the implementation address is a valid delegation target.
 * The manager must perform this safety check.
 */
contract DelegateCallProxyOneToOne is Proxy {
/* ==========  Constants  ========== */
  address internal immutable _manager;
/* ==========  Constructor  ========== */
  constructor() public {
    _manager = msg.sender ;
  }
/* ==========  Internal Overrides  ========== */
  /**
   * @dev Reads the implementation address from storage.
   */
  function _implementation() internal override view returns (address) {
    address implementation;
    assembly {
      implementation := sload(
        // bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)
        0x913bd12b32b36f36cedaeb6e043912bceb97022755958701789d3108d33a045a
      )
    }
    return implementation;
  }
  /**
    * @dev Hook that is called before falling back to the implementation.
    *
    * Checks if the call is from the owner.
    * If it is, reads the abi-encoded implementation address from calldata and stores
    * it at the slot `bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)`,
    * then returns with no data.
    * If it is not, continues execution with the fallback function.
    */
  function _beforeFallback() internal override {
    if (msg.sender != _manager) {
      super._beforeFallback();
    } else {
      assembly {
        sstore(
          // bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)
          0x913bd12b32b36f36cedaeb6e043912bceb97022755958701789d3108d33a045a,
          calldataload(0)
        )
        return(0, 0)
      }
    }
  }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/* ---  External Libraries  --- */
import { Create2 } from "@openzeppelin/contracts/utils/Create2.sol";
/* ---  Proxy Contracts  --- */
import { CodeHashes } from "./CodeHashes.sol";
/**
 * @dev Library for computing create2 salts and addresses for proxies
 * deployed by `DelegateCallProxyManager`.
 *
 * Because the proxy factory is meant to be used by multiple contracts,
 * we use a salt derivation pattern that includes the address of the
 * contract that requested the proxy deployment, a salt provided by that
 * contract and the implementation ID used (for many-to-one proxies only).
 */
library SaltyLib {
/* ---  Salt Derivation  --- */
  /**
   * @dev Derives the create2 salt for a many-to-one proxy.
   *
   * Many different contracts in the Indexed framework may use the
   * same implementation contract, and they all use the same init
   * code, so we derive the actual create2 salt from a combination
   * of the implementation ID, the address of the account requesting
   * deployment and the user-supplied salt.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deriveManyToOneSalt(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (bytes32)
  {
    return keccak256(
      abi.encodePacked(
        originator,
        implementationID,
        suppliedSalt
      )
    );
  }
  /**
   * @dev Derives the create2 salt for a one-to-one proxy.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deriveOneToOneSalt(
    address originator,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (bytes32)
  {
    return keccak256(abi.encodePacked(originator, suppliedSalt));
  }
/* ---  Address Derivation  --- */
  /**
   * @dev Computes the create2 address for a one-to-one proxy deployed
   * by `deployer` (the factory) when requested by `originator` using
   * `suppliedSalt`.
   *
   * @param deployer Address of the proxy factory.
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address deployer,
    address originator,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (address)
  {
    bytes32 salt = deriveOneToOneSalt(originator, suppliedSalt);
    return Create2.computeAddress(salt, CodeHashes.ONE_TO_ONE_CODEHASH, deployer);
  }
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` deployed by `deployer` (the factory)
   * when requested by `originator` using `suppliedSalt`.
   *
   * @param deployer Address of the proxy factory.
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address deployer,
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (address)
  {
    bytes32 salt = deriveManyToOneSalt(
      originator,
      implementationID,
      suppliedSalt
    );
    return Create2.computeAddress(salt, CodeHashes.MANY_TO_ONE_CODEHASH, deployer);
  }
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param deployer Address of the proxy factory.
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(
    address deployer,
    bytes32 implementationID
  )
    internal
    pure
    returns (address)
  {
    return Create2.computeAddress(
      implementationID,
      CodeHashes.IMPLEMENTATION_HOLDER_CODEHASH,
      deployer
    );
  }
}// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/**
 * @dev Contract that manages deployment and upgrades of delegatecall proxies.
 *
 * An implementation identifier can be created on the proxy manager which is
 * used to specify the logic address for a particular contract type, and to
 * upgrade the implementation as needed.
 *
 * A one-to-one proxy is a single proxy contract with an upgradeable implementation
 * address.
 *
 * A many-to-one proxy is a single upgradeable implementation address that may be
 * used by many proxy contracts.
 */
interface IDelegateCallProxyManager {
/* ==========  Events  ========== */
  event DeploymentApprovalGranted(address deployer);
  event DeploymentApprovalRevoked(address deployer);
  event ManyToOne_ImplementationCreated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationUpdated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ProxyDeployed(
    bytes32 implementationID,
    address proxyAddress
  );
  event OneToOne_ProxyDeployed(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationUpdated(
    address proxyAddress,
    address implementationAddress
  );
/* ==========  Controls  ========== */
  /**
   * @dev Allows `deployer` to deploy many-to-one proxies.
   */
  function approveDeployer(address deployer) external;
  /**
   * @dev Prevents `deployer` from deploying many-to-one proxies.
   */
  function revokeDeployerApproval(address deployer) external;
/* ==========  Implementation Management  ========== */
  /**
   * @dev Creates a many-to-one proxy relationship.
   *
   * Deploys an implementation holder contract which stores the
   * implementation address for many proxies. The implementation
   * address can be updated on the holder to change the runtime
   * code used by all its proxies.
   *
   * @param implementationID ID for the implementation, used to identify the
   * proxies that use it. Also used as the salt in the create2 call when
   * deploying the implementation holder contract.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function createManyToOneProxyRelationship(
    bytes32 implementationID,
    address implementation
  ) external;
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationManyToOne(bytes32 implementationID) external;
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationOneToOne(address proxyAddress) external;
  /**
   * @dev Updates the implementation address for a many-to-one
   * proxy relationship.
   *
   * @param implementationID Identifier for the implementation.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function setImplementationAddressManyToOne(
    bytes32 implementationID,
    address implementation
  ) external;
  /**
   * @dev Updates the implementation address for a one-to-one proxy.
   *
   * Note: This could work for many-to-one as well if the caller
   * provides the implementation holder address in place of the
   * proxy address, as they use the same access control and update
   * mechanism.
   *
   * @param proxyAddress Address of the deployed proxy
   * @param implementation Address with the runtime code for
   * the proxy to use.
   */
  function setImplementationAddressOneToOne(
    address proxyAddress,
    address implementation
  ) external;
/* ==========  Proxy Deployment  ========== */
  /**
   * @dev Deploy a proxy contract with a one-to-one relationship
   * with its implementation.
   *
   * The proxy will have its own implementation address which can
   * be updated by the proxy manager.
   *
   * @param suppliedSalt Salt provided by the account requesting deployment.
   * @param implementation Address of the contract with the runtime
   * code that the proxy should use.
   */
  function deployProxyOneToOne(
    bytes32 suppliedSalt,
    address implementation
  ) external returns(address proxyAddress);
  /**
   * @dev Deploy a proxy with a many-to-one relationship with its implemenation.
   *
   * The proxy will call the implementation holder for every transaction to
   * determine the address to use in calls.
   *
   * @param implementationID Identifier for the proxy's implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deployProxyManyToOne(
    bytes32 implementationID,
    bytes32 suppliedSalt
  ) external returns(address proxyAddress);
/* ==========  Queries  ========== */
  /**
   * @dev Returns a boolean stating whether `implementationID` is locked.
   */
  function isImplementationLocked(bytes32 implementationID) external view returns (bool);
  /**
   * @dev Returns a boolean stating whether `proxyAddress` is locked.
   */
  function isImplementationLocked(address proxyAddress) external view returns (bool);
  /**
   * @dev Returns a boolean stating whether `deployer` is allowed to deploy many-to-one
   * proxies.
   */
  function isApprovedDeployer(address deployer) external view returns (bool);
  /**
   * @dev Queries the temporary storage value `_implementationHolder`.
   * This is used in the constructor of the many-to-one proxy contract
   * so that the create2 address is static (adding constructor arguments
   * would change the codehash) and the implementation holder can be
   * stored as a constant.
   */
  function getImplementationHolder() external view returns (address);
  /**
   * @dev Returns the address of the implementation holder contract
   * for `implementationID`.
   */
  function getImplementationHolder(bytes32 implementationID) external view returns (address);
  /**
   * @dev Computes the create2 address for a one-to-one proxy requested
   * by `originator` using `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address originator,
    bytes32 suppliedSalt
  ) external view returns (address);
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` requested by `originator` using
   * `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  ) external view returns (address);
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(bytes32 implementationID) external view returns (address);
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/**
 * @dev Because we use the code hashes of the proxy contracts for proxy address
 * derivation, it is important that other packages have access to the correct
 * values when they import the salt library.
 */
library CodeHashes {
  bytes32 internal constant ONE_TO_ONE_CODEHASH = 0x63d9f7b5931b69188c8f6b806606f25892f1bb17b7f7e966fe3a32c04493aee4;
  bytes32 internal constant MANY_TO_ONE_CODEHASH = 0xa035ad05a1663db5bfd455b99cd7c6ac6bd49269738458eda140e0b78ed53f79;
  bytes32 internal constant IMPLEMENTATION_HOLDER_CODEHASH = 0x11c370493a726a0ffa93d42b399ad046f1b5a543b6e72f1a64f1488dc1c58f2c;
}// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
/* ==========  External Libraries  ========== */
import { Create2 } from "@openzeppelin/contracts/utils/Create2.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
/* ==========  Proxy Contracts  ========== */
import "./ManyToOneImplementationHolder.sol";
import { DelegateCallProxyManyToOne } from "./DelegateCallProxyManyToOne.sol";
import { DelegateCallProxyOneToOne } from "./DelegateCallProxyOneToOne.sol";
/* ==========  Internal Libraries  ========== */
import { SaltyLib as Salty } from "./SaltyLib.sol";
import { CodeHashes } from "./CodeHashes.sol";
/* ==========  Inheritance  ========== */
import "./interfaces/IDelegateCallProxyManager.sol";
/**
 * @dev Contract that manages deployment and upgrades of delegatecall proxies.
 *
 * An implementation identifier can be created on the proxy manager which is
 * used to specify the logic address for a particular contract type, and to
 * upgrade the implementation as needed.
 *
 * ====== Proxy Types ======
 * A one-to-one proxy is a single proxy contract with an upgradeable implementation
 * address.
 *
 * A many-to-one proxy is a single upgradeable implementation address that may be
 * used by many proxy contracts.
 *
 * ====== Access Control ======
 * The proxy manager has a single address as its owner.
 *
 * The owner is the sole account with the following permissions:
 * - Create new many-to-one implementations
 * - Create new one-to-one proxies
 * - Modify the implementation address of existing proxies
 * - Lock proxies
 * - Designate approved deployers
 * - Remove approved deployers
 * - Modify the owner address
 *
 * Approved deployers may only deploy many-to-one proxies.
 *
 * ====== Upgrades ======
 * Proxies can be upgraded by the owner if they are not locked.
 *
 * Many-to-one proxy implementations are upgraded by calling the holder contract
 * for the implementation ID being upgraded.
 * One-to-one proxies are upgraded by calling the proxy contract directly.
 *
 * The owner can lock a one-to-one proxy or many-to-one implementation ID so that
 * it becomes impossible to upgrade.
 */
contract DelegateCallProxyManager is Ownable, IDelegateCallProxyManager {
/* ==========  Events  ========== */
  event DeploymentApprovalGranted(address deployer);
  event DeploymentApprovalRevoked(address deployer);
  event ManyToOne_ImplementationCreated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationUpdated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationLocked(bytes32 implementationID);
  event ManyToOne_ProxyDeployed(
    bytes32 implementationID,
    address proxyAddress
  );
  event OneToOne_ProxyDeployed(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationUpdated(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationLocked(address proxyAddress);
/* ==========  Storage  ========== */
  // Addresses allowed to deploy many-to-one proxies.
  mapping(address => bool) internal _approvedDeployers;
  // Maps implementation holders to their implementation IDs.
  mapping(bytes32 => address) internal _implementationHolders;
  // Maps implementation holders & proxy addresses to bool stating if they are locked.
  mapping(address => bool) internal _lockedImplementations;
  // Temporary value used in the many-to-one proxy constructor.
  // The many-to-one proxy contract is deployed with create2 and
  // uses static initialization code for simple address derivation,
  // so it calls the proxy manager in the constructor to get this
  // address in order to save it as an immutable in the bytecode.
  address internal _implementationHolder;
/* ==========  Modifiers  ========== */
  modifier onlyApprovedDeployer {
    address sender = _msgSender();
    require(_approvedDeployers[sender] || sender == owner(), "ERR_NOT_APPROVED");
    _;
  }
/* ==========  Constructor  ========== */
  constructor() public Ownable() {}
/* ==========  Access Control  ========== */
  /**
   * @dev Allows `deployer` to deploy many-to-one proxies.
   */
  function approveDeployer(address deployer) external override onlyOwner {
    _approvedDeployers[deployer] = true;
    emit DeploymentApprovalGranted(deployer);
  }
  /**
   * @dev Prevents `deployer` from deploying many-to-one proxies.
   */
  function revokeDeployerApproval(address deployer) external override onlyOwner {
    _approvedDeployers[deployer] = false;
    emit DeploymentApprovalRevoked(deployer);
  }
/* ==========  Implementation Management  ========== */
  /**
   * @dev Creates a many-to-one proxy relationship.
   *
   * Deploys an implementation holder contract which stores the
   * implementation address for many proxies. The implementation
   * address can be updated on the holder to change the runtime
   * code used by all its proxies.
   *
   * @param implementationID ID for the implementation, used to identify the
   * proxies that use it. Also used as the salt in the create2 call when
   * deploying the implementation holder contract.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function createManyToOneProxyRelationship(
    bytes32 implementationID,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Deploy the implementation holder contract with the implementation
    // ID as the create2 salt.
    address implementationHolder = Create2.deploy(
      0,
      implementationID,
      type(ManyToOneImplementationHolder).creationCode
    );
    // Store the implementation holder address
    _implementationHolders[implementationID] = implementationHolder;
    // Sets the implementation address.
    _setImplementation(implementationHolder, implementation);
    emit ManyToOne_ImplementationCreated(
      implementationID,
      implementation
    );
  }
  /**
   * @dev Lock the current implementation for `implementationID` so that it can never be upgraded again.
   */
  function lockImplementationManyToOne(bytes32 implementationID) external override onlyOwner {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    _lockedImplementations[implementationHolder] = true;
    emit ManyToOne_ImplementationLocked(implementationID);
  }
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationOneToOne(address proxyAddress) external override onlyOwner {
    _lockedImplementations[proxyAddress] = true;
    emit OneToOne_ImplementationLocked(proxyAddress);
  }
  /**
   * @dev Updates the implementation address for a many-to-one
   * proxy relationship.
   *
   * @param implementationID Identifier for the implementation.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function setImplementationAddressManyToOne(
    bytes32 implementationID,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    // Verify implementation is not locked
    require(!_lockedImplementations[implementationHolder], "ERR_IMPLEMENTATION_LOCKED");
    // Set the implementation address
    _setImplementation(implementationHolder, implementation);
    emit ManyToOne_ImplementationUpdated(
      implementationID,
      implementation
    );
  }
  /**
   * @dev Updates the implementation address for a one-to-one proxy.
   *
   * Note: This could work for many-to-one as well if the caller
   * provides the implementation holder address in place of the
   * proxy address, as they use the same access control and update
   * mechanism.
   *
   * @param proxyAddress Address of the deployed proxy
   * @param implementation Address with the runtime code for
   * the proxy to use.
   */
  function setImplementationAddressOneToOne(
    address proxyAddress,
    address implementation
  )
    external
    override
    onlyOwner
  {
    // Verify proxy is not locked
    require(!_lockedImplementations[proxyAddress], "ERR_IMPLEMENTATION_LOCKED");
    // Set the implementation address
    _setImplementation(proxyAddress, implementation);
    emit OneToOne_ImplementationUpdated(proxyAddress, implementation);
  }
/* ==========  Proxy Deployment  ========== */
  /**
   * @dev Deploy a proxy contract with a one-to-one relationship
   * with its implementation.
   *
   * The proxy will have its own implementation address which can
   * be updated by the proxy manager.
   *
   * @param suppliedSalt Salt provided by the account requesting deployment.
   * @param implementation Address of the contract with the runtime
   * code that the proxy should use.
   */
  function deployProxyOneToOne(
    bytes32 suppliedSalt,
    address implementation
  )
    external
    override
    onlyOwner
    returns(address proxyAddress)
  {
    // Derive the create2 salt from the deployment requester's address
    // and the requester-supplied salt.
    bytes32 salt = Salty.deriveOneToOneSalt(_msgSender(), suppliedSalt);
    // Deploy the proxy
    proxyAddress = Create2.deploy(
      0,
      salt,
      type(DelegateCallProxyOneToOne).creationCode
    );
    // Set the implementation address on the new proxy.
    _setImplementation(proxyAddress, implementation);
    emit OneToOne_ProxyDeployed(proxyAddress, implementation);
  }
  /**
   * @dev Deploy a proxy with a many-to-one relationship with its implemenation.
   *
   * The proxy will call the implementation holder for every transaction to
   * determine the address to use in calls.
   *
   * @param implementationID Identifier for the proxy's implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deployProxyManyToOne(bytes32 implementationID, bytes32 suppliedSalt)
    external
    override
    onlyApprovedDeployer
    returns(address proxyAddress)
  {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    // Derive the create2 salt from the deployment requester's address, the
    // implementation ID and the requester-supplied salt.
    bytes32 salt = Salty.deriveManyToOneSalt(
      _msgSender(),
      implementationID,
      suppliedSalt
    );
    // Set the implementation holder address in storage so the proxy
    // constructor can query it.
    _implementationHolder = implementationHolder;
    // Deploy the proxy, which will query the implementation holder address
    // and save it as an immutable in the contract bytecode.
    proxyAddress = Create2.deploy(
      0,
      salt,
      type(DelegateCallProxyManyToOne).creationCode
    );
    // Remove the address from temporary storage.
    _implementationHolder = address(0);
    emit ManyToOne_ProxyDeployed(
      implementationID,
      proxyAddress
    );
  }
/* ==========  Queries  ========== */
  /**
   * @dev Returns a boolean stating whether `implementationID` is locked.
   */
  function isImplementationLocked(bytes32 implementationID) external override view returns (bool) {
    // Read the implementation holder address from storage.
    address implementationHolder = _implementationHolders[implementationID];
    // Verify that the implementation exists.
    require(implementationHolder != address(0), "ERR_IMPLEMENTATION_ID");
    return _lockedImplementations[implementationHolder];
  }
  /**
   * @dev Returns a boolean stating whether `proxyAddress` is locked.
   */
  function isImplementationLocked(address proxyAddress) external override view returns (bool) {
    return _lockedImplementations[proxyAddress];
  }
  /**
   * @dev Returns a boolean stating whether `deployer` is allowed to deploy many-to-one
   * proxies.
   */
  function isApprovedDeployer(address deployer) external override view returns (bool) {
    return _approvedDeployers[deployer];
  }
  /**
   * @dev Queries the temporary storage value `_implementationHolder`.
   * This is used in the constructor of the many-to-one proxy contract
   * so that the create2 address is static (adding constructor arguments
   * would change the codehash) and the implementation holder can be
   * stored as a constant.
   */
  function getImplementationHolder()
    external
    override
    view
    returns (address)
  {
    return _implementationHolder;
  }
  /**
   * @dev Returns the address of the implementation holder contract
   * for `implementationID`.
   */
  function getImplementationHolder(
    bytes32 implementationID
  )
    external
    override
    view
    returns (address)
  {
    return _implementationHolders[implementationID];
  }
  /**
   * @dev Computes the create2 address for a one-to-one proxy requested
   * by `originator` using `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address originator,
    bytes32 suppliedSalt
  )
    external
    override
    view
    returns (address)
  {
    bytes32 salt = Salty.deriveOneToOneSalt(originator, suppliedSalt);
    return Create2.computeAddress(salt, CodeHashes.ONE_TO_ONE_CODEHASH);
  }
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` requested by `originator` using
   * `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    external
    override
    view
    returns (address)
  {
    bytes32 salt = Salty.deriveManyToOneSalt(
      originator,
      implementationID,
      suppliedSalt
    );
    return Create2.computeAddress(salt, CodeHashes.MANY_TO_ONE_CODEHASH);
  }
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(bytes32 implementationID)
    public
    override
    view
    returns (address)
  {
    return Create2.computeAddress(
      implementationID,
      CodeHashes.IMPLEMENTATION_HOLDER_CODEHASH
    );
  }
/* ==========  Internal Functions  ========== */
  /**
   * @dev Sets the implementation address for a one-to-one proxy or
   * many-to-one implementation holder. Both use the same access
   * control and update mechanism, which is the receipt of a call
   * from the proxy manager with the abi-encoded implementation address
   * as the only calldata.
   *
   * Note: Verifies that the implementation address is a contract.
   *
   * @param proxyOrHolder Address of the one-to-one proxy or
   * many-to-one implementation holder contract.
   * @param implementation Address of the contract with the runtime
   * code that the proxy or proxies should use.
   */
  function _setImplementation(
    address proxyOrHolder,
    address implementation
  ) internal {
    // Verify that the implementation address is a contract.
    require(Address.isContract(implementation), "ERR_NOT_CONTRACT");
    // Set the implementation address on the contract.
    // solium-disable-next-line security/no-low-level-calls
    (bool success,) = proxyOrHolder.call(abi.encode(implementation));
    require(success, "ERR_SET_ADDRESS_REVERT");
  }
}// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer.
 * `CREATE2` can be used to compute in advance the address where a smart
 * contract will be deployed, which allows for interesting new mechanisms known
 * as 'counterfactual interactions'.
 *
 * See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more
 * information.
 */
library Create2 {
    /**
     * @dev Deploys a contract using `CREATE2`. The address where the contract
     * will be deployed can be known in advance via {computeAddress}.
     *
     * The bytecode for a contract can be obtained from Solidity with
     * `type(contractName).creationCode`.
     *
     * Requirements:
     *
     * - `bytecode` must not be empty.
     * - `salt` must have not been used for `bytecode` already.
     * - the factory must have a balance of at least `amount`.
     * - if `amount` is non-zero, `bytecode` must have a `payable` constructor.
     */
    function deploy(uint256 amount, bytes32 salt, bytes memory bytecode) internal returns (address) {
        address addr;
        require(address(this).balance >= amount, "Create2: insufficient balance");
        require(bytecode.length != 0, "Create2: bytecode length is zero");
        // solhint-disable-next-line no-inline-assembly
        assembly {
            addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt)
        }
        require(addr != address(0), "Create2: Failed on deploy");
        return addr;
    }
    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the
     * `bytecodeHash` or `salt` will result in a new destination address.
     */
    function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) {
        return computeAddress(salt, bytecodeHash, address(this));
    }
    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at
     * `deployer`. If `deployer` is this contract's address, returns the same value as {computeAddress}.
     */
    function computeAddress(bytes32 salt, bytes32 bytecodeHash, address deployer) internal pure returns (address) {
        bytes32 _data = keccak256(
            abi.encodePacked(bytes1(0xff), deployer, salt, bytecodeHash)
        );
        return address(uint256(_data));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.2;
/**
 * @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 in 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");
        return _functionCallWithValue(target, data, value, errorMessage);
    }
    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../GSN/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/*
 * @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 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.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
/**
 * @dev The ManyToOneImplementationHolder stores an upgradeable implementation address
 * in storage, which many-to-one proxies query at execution time to determine which
 * contract to delegate to.
 *
 * The manager can upgrade the implementation address by calling the holder with the
 * abi-encoded address as calldata. If any other account calls the implementation holder,
 * it will return the implementation address.
 *
 * This pattern was inspired by the DharmaUpgradeBeacon from 0age
 * https://github.com/dharma-eng/dharma-smart-wallet/blob/master/contracts/upgradeability/smart-wallet/DharmaUpgradeBeacon.sol
 */
contract ManyToOneImplementationHolder {
/* ---  Storage  --- */
  address internal immutable _manager;
  address internal _implementation;
/* ---  Constructor  --- */
  constructor() public {
    _manager = msg.sender;
  }
  /**
   * @dev Fallback function for the contract.
   *
   * Used by proxies to read the implementation address and used
   * by the proxy manager to set the implementation address.
   *
   * If called by the owner, reads the implementation address from
   * calldata (must be abi-encoded) and stores it to the first slot.
   *
   * Otherwise, returns the stored implementation address.
   */
  fallback() external payable {
    if (msg.sender != _manager) {
      assembly {
        mstore(0, sload(0))
        return(0, 32)
      }
    }
    assembly { sstore(0, calldataload(0)) }
  }
}// SPDX-License-Identifier: GPL-3.0
pragma solidity =0.6.12;
import { Proxy } from "@openzeppelin/contracts/proxy/Proxy.sol";
/**
 * @dev Proxy contract which uses an implementation address shared with many
 * other proxies.
 *
 * An implementation holder contract stores the upgradeable implementation address.
 * When the proxy is called, it queries the implementation address from the holder
 * contract and delegatecalls the returned address, forwarding the received calldata
 * and ether.
 *
 * Note: This contract does not verify that the implementation
 * address is a valid delegation target. The manager must perform
 * this safety check before updating the implementation on the holder.
 */
contract DelegateCallProxyManyToOne is Proxy {
/* ==========  Constants  ========== */
  // Address that stores the implementation address.
  address internal immutable _implementationHolder;
/* ==========  Constructor  ========== */
  constructor() public {
    // Calls the sender rather than receiving the address in the constructor
    // arguments so that the address is computable using create2.
    _implementationHolder = ProxyDeployer(msg.sender).getImplementationHolder();
  }
/* ==========  Internal Overrides  ========== */
  /**
   * @dev Queries the implementation address from the implementation holder.
   */
  function _implementation() internal override view returns (address) {
    // Queries the implementation address from the implementation holder.
    (bool success, bytes memory data) = _implementationHolder.staticcall("");
    require(success, string(data));
    address implementation = abi.decode((data), (address));
    require(implementation != address(0), "ERR_NULL_IMPLEMENTATION");
    return implementation;
  }
}
interface ProxyDeployer {
  function getImplementationHolder() external view returns (address);
}// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @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 internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal {
        // solhint-disable-next-line no-inline-assembly
        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 virtual view 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 {
        _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 () payable external {
        _fallback();
    }
    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive () payable external {
        _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: GPL-3.0
pragma solidity =0.6.12;
import { Proxy } from "@openzeppelin/contracts/proxy/Proxy.sol";
/**
 * @dev Upgradeable delegatecall proxy for a single contract.
 *
 * This proxy stores an implementation address which can be upgraded by the proxy manager.
 *
 * To upgrade the implementation, the manager calls the proxy with the abi encoded implementation address.
 *
 * If any other account calls the proxy, it will delegatecall the implementation address with the received
 * calldata and ether. If the call succeeds, it will return with the received returndata.
 * If it reverts, it will revert with the received revert data.
 *
 * Note: The storage slot for the implementation address is:
 * `bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)`
 * This slot must not be used by the implementation contract.
 *
 * Note: This contract does not verify that the implementation address is a valid delegation target.
 * The manager must perform this safety check.
 */
contract DelegateCallProxyOneToOne is Proxy {
/* ==========  Constants  ========== */
  address internal immutable _manager;
/* ==========  Constructor  ========== */
  constructor() public {
    _manager = msg.sender ;
  }
/* ==========  Internal Overrides  ========== */
  /**
   * @dev Reads the implementation address from storage.
   */
  function _implementation() internal override view returns (address) {
    address implementation;
    assembly {
      implementation := sload(
        // bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)
        0x913bd12b32b36f36cedaeb6e043912bceb97022755958701789d3108d33a045a
      )
    }
    return implementation;
  }
  /**
    * @dev Hook that is called before falling back to the implementation.
    *
    * Checks if the call is from the owner.
    * If it is, reads the abi-encoded implementation address from calldata and stores
    * it at the slot `bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)`,
    * then returns with no data.
    * If it is not, continues execution with the fallback function.
    */
  function _beforeFallback() internal override {
    if (msg.sender != _manager) {
      super._beforeFallback();
    } else {
      assembly {
        sstore(
          // bytes32(uint256(keccak256("IMPLEMENTATION_ADDRESS")) + 1)
          0x913bd12b32b36f36cedaeb6e043912bceb97022755958701789d3108d33a045a,
          calldataload(0)
        )
        return(0, 0)
      }
    }
  }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/* ---  External Libraries  --- */
import { Create2 } from "@openzeppelin/contracts/utils/Create2.sol";
/* ---  Proxy Contracts  --- */
import { CodeHashes } from "./CodeHashes.sol";
/**
 * @dev Library for computing create2 salts and addresses for proxies
 * deployed by `DelegateCallProxyManager`.
 *
 * Because the proxy factory is meant to be used by multiple contracts,
 * we use a salt derivation pattern that includes the address of the
 * contract that requested the proxy deployment, a salt provided by that
 * contract and the implementation ID used (for many-to-one proxies only).
 */
library SaltyLib {
/* ---  Salt Derivation  --- */
  /**
   * @dev Derives the create2 salt for a many-to-one proxy.
   *
   * Many different contracts in the Indexed framework may use the
   * same implementation contract, and they all use the same init
   * code, so we derive the actual create2 salt from a combination
   * of the implementation ID, the address of the account requesting
   * deployment and the user-supplied salt.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deriveManyToOneSalt(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (bytes32)
  {
    return keccak256(
      abi.encodePacked(
        originator,
        implementationID,
        suppliedSalt
      )
    );
  }
  /**
   * @dev Derives the create2 salt for a one-to-one proxy.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deriveOneToOneSalt(
    address originator,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (bytes32)
  {
    return keccak256(abi.encodePacked(originator, suppliedSalt));
  }
/* ---  Address Derivation  --- */
  /**
   * @dev Computes the create2 address for a one-to-one proxy deployed
   * by `deployer` (the factory) when requested by `originator` using
   * `suppliedSalt`.
   *
   * @param deployer Address of the proxy factory.
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address deployer,
    address originator,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (address)
  {
    bytes32 salt = deriveOneToOneSalt(originator, suppliedSalt);
    return Create2.computeAddress(salt, CodeHashes.ONE_TO_ONE_CODEHASH, deployer);
  }
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` deployed by `deployer` (the factory)
   * when requested by `originator` using `suppliedSalt`.
   *
   * @param deployer Address of the proxy factory.
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address deployer,
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  )
    internal
    pure
    returns (address)
  {
    bytes32 salt = deriveManyToOneSalt(
      originator,
      implementationID,
      suppliedSalt
    );
    return Create2.computeAddress(salt, CodeHashes.MANY_TO_ONE_CODEHASH, deployer);
  }
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param deployer Address of the proxy factory.
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(
    address deployer,
    bytes32 implementationID
  )
    internal
    pure
    returns (address)
  {
    return Create2.computeAddress(
      implementationID,
      CodeHashes.IMPLEMENTATION_HOLDER_CODEHASH,
      deployer
    );
  }
}// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/**
 * @dev Contract that manages deployment and upgrades of delegatecall proxies.
 *
 * An implementation identifier can be created on the proxy manager which is
 * used to specify the logic address for a particular contract type, and to
 * upgrade the implementation as needed.
 *
 * A one-to-one proxy is a single proxy contract with an upgradeable implementation
 * address.
 *
 * A many-to-one proxy is a single upgradeable implementation address that may be
 * used by many proxy contracts.
 */
interface IDelegateCallProxyManager {
/* ==========  Events  ========== */
  event DeploymentApprovalGranted(address deployer);
  event DeploymentApprovalRevoked(address deployer);
  event ManyToOne_ImplementationCreated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ImplementationUpdated(
    bytes32 implementationID,
    address implementationAddress
  );
  event ManyToOne_ProxyDeployed(
    bytes32 implementationID,
    address proxyAddress
  );
  event OneToOne_ProxyDeployed(
    address proxyAddress,
    address implementationAddress
  );
  event OneToOne_ImplementationUpdated(
    address proxyAddress,
    address implementationAddress
  );
/* ==========  Controls  ========== */
  /**
   * @dev Allows `deployer` to deploy many-to-one proxies.
   */
  function approveDeployer(address deployer) external;
  /**
   * @dev Prevents `deployer` from deploying many-to-one proxies.
   */
  function revokeDeployerApproval(address deployer) external;
/* ==========  Implementation Management  ========== */
  /**
   * @dev Creates a many-to-one proxy relationship.
   *
   * Deploys an implementation holder contract which stores the
   * implementation address for many proxies. The implementation
   * address can be updated on the holder to change the runtime
   * code used by all its proxies.
   *
   * @param implementationID ID for the implementation, used to identify the
   * proxies that use it. Also used as the salt in the create2 call when
   * deploying the implementation holder contract.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function createManyToOneProxyRelationship(
    bytes32 implementationID,
    address implementation
  ) external;
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationManyToOne(bytes32 implementationID) external;
  /**
   * @dev Lock the current implementation for `proxyAddress` so that it can never be upgraded again.
   */
  function lockImplementationOneToOne(address proxyAddress) external;
  /**
   * @dev Updates the implementation address for a many-to-one
   * proxy relationship.
   *
   * @param implementationID Identifier for the implementation.
   * @param implementation Address with the runtime code the proxies
   * should use.
   */
  function setImplementationAddressManyToOne(
    bytes32 implementationID,
    address implementation
  ) external;
  /**
   * @dev Updates the implementation address for a one-to-one proxy.
   *
   * Note: This could work for many-to-one as well if the caller
   * provides the implementation holder address in place of the
   * proxy address, as they use the same access control and update
   * mechanism.
   *
   * @param proxyAddress Address of the deployed proxy
   * @param implementation Address with the runtime code for
   * the proxy to use.
   */
  function setImplementationAddressOneToOne(
    address proxyAddress,
    address implementation
  ) external;
/* ==========  Proxy Deployment  ========== */
  /**
   * @dev Deploy a proxy contract with a one-to-one relationship
   * with its implementation.
   *
   * The proxy will have its own implementation address which can
   * be updated by the proxy manager.
   *
   * @param suppliedSalt Salt provided by the account requesting deployment.
   * @param implementation Address of the contract with the runtime
   * code that the proxy should use.
   */
  function deployProxyOneToOne(
    bytes32 suppliedSalt,
    address implementation
  ) external returns(address proxyAddress);
  /**
   * @dev Deploy a proxy with a many-to-one relationship with its implemenation.
   *
   * The proxy will call the implementation holder for every transaction to
   * determine the address to use in calls.
   *
   * @param implementationID Identifier for the proxy's implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function deployProxyManyToOne(
    bytes32 implementationID,
    bytes32 suppliedSalt
  ) external returns(address proxyAddress);
/* ==========  Queries  ========== */
  /**
   * @dev Returns a boolean stating whether `implementationID` is locked.
   */
  function isImplementationLocked(bytes32 implementationID) external view returns (bool);
  /**
   * @dev Returns a boolean stating whether `proxyAddress` is locked.
   */
  function isImplementationLocked(address proxyAddress) external view returns (bool);
  /**
   * @dev Returns a boolean stating whether `deployer` is allowed to deploy many-to-one
   * proxies.
   */
  function isApprovedDeployer(address deployer) external view returns (bool);
  /**
   * @dev Queries the temporary storage value `_implementationHolder`.
   * This is used in the constructor of the many-to-one proxy contract
   * so that the create2 address is static (adding constructor arguments
   * would change the codehash) and the implementation holder can be
   * stored as a constant.
   */
  function getImplementationHolder() external view returns (address);
  /**
   * @dev Returns the address of the implementation holder contract
   * for `implementationID`.
   */
  function getImplementationHolder(bytes32 implementationID) external view returns (address);
  /**
   * @dev Computes the create2 address for a one-to-one proxy requested
   * by `originator` using `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param suppliedSalt Salt provided by the account requesting deployment.
   */
  function computeProxyAddressOneToOne(
    address originator,
    bytes32 suppliedSalt
  ) external view returns (address);
  /**
   * @dev Computes the create2 address for a many-to-one proxy for the
   * implementation `implementationID` requested by `originator` using
   * `suppliedSalt`.
   *
   * @param originator Address of the account requesting deployment.
   * @param implementationID The identifier for the contract implementation.
   * @param suppliedSalt Salt provided by the account requesting deployment.
  */
  function computeProxyAddressManyToOne(
    address originator,
    bytes32 implementationID,
    bytes32 suppliedSalt
  ) external view returns (address);
  /**
   * @dev Computes the create2 address of the implementation holder
   * for `implementationID`.
   *
   * @param implementationID The identifier for the contract implementation.
  */
  function computeHolderAddressManyToOne(bytes32 implementationID) external view returns (address);
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
/************************************************************************************************
Originally from https://github.com/balancer-labs/balancer-core/blob/master/contracts/BConst.sol
This source code has been modified from the original, which was copied from the github repository
at commit hash f4ed5d65362a8d6cec21662fb6eae233b0babc1f.
Subject to the GPL-3.0 license
*************************************************************************************************/
contract BConst {
  uint256 public constant VERSION_NUMBER = 1;
/* ---  Weight Updates  --- */
  // Minimum time passed between each weight update for a token.
  uint256 internal constant WEIGHT_UPDATE_DELAY = 1 hours;
  // Maximum percent by which a weight can adjust at a time
  // relative to the current weight.
  // The number of iterations needed to move from weight A to weight B is the floor of:
  // (A > B): (ln(A) - ln(B)) / ln(1.01)
  // (B > A): (ln(A) - ln(B)) / ln(0.99)
  uint256 internal constant WEIGHT_CHANGE_PCT = BONE/100;
  uint256 internal constant BONE = 10**18;
  uint256 internal constant MIN_BOUND_TOKENS = 2;
  uint256 internal constant MAX_BOUND_TOKENS = 10;
  // Minimum swap fee.
  uint256 internal constant MIN_FEE = BONE / 10**6;
  // Maximum swap or exit fee.
  uint256 internal constant MAX_FEE = BONE / 10;
  // Actual exit fee.
  uint256 internal constant EXIT_FEE = 5e15;
  // Default total of all desired weights. Can differ by up to BONE.
  uint256 internal constant DEFAULT_TOTAL_WEIGHT = BONE * 25;
  // Minimum weight for any token (1/100).
  uint256 internal constant MIN_WEIGHT = BONE / 4;
  uint256 internal constant MAX_WEIGHT = BONE * 25;
  // Maximum total weight.
  uint256 internal constant MAX_TOTAL_WEIGHT = BONE * 26;
  // Minimum balance for a token (only applied at initialization)
  uint256 internal constant MIN_BALANCE = BONE / 10**12;
  // Initial pool tokens
  uint256 internal constant INIT_POOL_SUPPLY = BONE * 100;
  uint256 internal constant MIN_BPOW_BASE = 1 wei;
  uint256 internal constant MAX_BPOW_BASE = (2 * BONE) - 1 wei;
  uint256 internal constant BPOW_PRECISION = BONE / 10**10;
  // Maximum ratio of input tokens to balance for swaps.
  uint256 internal constant MAX_IN_RATIO = BONE / 2;
  // Maximum ratio of output tokens to balance for swaps.
  uint256 internal constant MAX_OUT_RATIO = (BONE / 3) + 1 wei;
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
import "./BNum.sol";
/************************************************************************************************
Originally from https://github.com/balancer-labs/balancer-core/blob/master/contracts/BMath.sol
This source code has been modified from the original, which was copied from the github repository
at commit hash f4ed5d65362a8d6cec21662fb6eae233b0babc1f.
Subject to the GPL-3.0 license
*************************************************************************************************/
contract BMath is BConst, BNum {
  /**********************************************************************************************
    // calcSpotPrice                                                                             //
    // sP = spotPrice                                                                            //
    // bI = tokenBalanceIn                ( bI / wI )         1                                  //
    // bO = tokenBalanceOut         sP =  -----------  *  ----------                             //
    // wI = tokenWeightIn                 ( bO / wO )     ( 1 - sF )                             //
    // wO = tokenWeightOut                                                                       //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
  function calcSpotPrice(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 swapFee
  ) internal pure returns (uint256 spotPrice) {
    uint256 numer = bdiv(tokenBalanceIn, tokenWeightIn);
    uint256 denom = bdiv(tokenBalanceOut, tokenWeightOut);
    uint256 ratio = bdiv(numer, denom);
    uint256 scale = bdiv(BONE, bsub(BONE, swapFee));
    return (spotPrice = bmul(ratio, scale));
  }
  /**********************************************************************************************
    // calcOutGivenIn                                                                            //
    // aO = tokenAmountOut                                                                       //
    // bO = tokenBalanceOut                                                                      //
    // bI = tokenBalanceIn              /      /            bI             \\    (wI / wO) \\      //
    // aI = tokenAmountIn    aO = bO * |  1 - | --------------------------  | ^            |     //
    // wI = tokenWeightIn               \\      \\ ( bI + ( aI * ( 1 - sF )) /              /      //
    // wO = tokenWeightOut                                                                       //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
  function calcOutGivenIn(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 tokenAmountIn,
    uint256 swapFee
  ) internal pure returns (uint256 tokenAmountOut) {
    uint256 weightRatio = bdiv(tokenWeightIn, tokenWeightOut);
    uint256 adjustedIn = bsub(BONE, swapFee);
    adjustedIn = bmul(tokenAmountIn, adjustedIn);
    uint256 y = bdiv(tokenBalanceIn, badd(tokenBalanceIn, adjustedIn));
    uint256 foo = bpow(y, weightRatio);
    uint256 bar = bsub(BONE, foo);
    tokenAmountOut = bmul(tokenBalanceOut, bar);
    return tokenAmountOut;
  }
  /**********************************************************************************************
    // calcInGivenOut                                                                            //
    // aI = tokenAmountIn                                                                        //
    // bO = tokenBalanceOut               /  /     bO      \\    (wO / wI)      \\                 //
    // bI = tokenBalanceIn          bI * |  | ------------  | ^            - 1  |                //
    // aO = tokenAmountOut    aI =        \\  \\ ( bO - aO ) /                   /                 //
    // wI = tokenWeightIn           --------------------------------------------                 //
    // wO = tokenWeightOut                          ( 1 - sF )                                   //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
  function calcInGivenOut(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 tokenAmountOut,
    uint256 swapFee
  ) internal pure returns (uint256 tokenAmountIn) {
    uint256 weightRatio = bdiv(tokenWeightOut, tokenWeightIn);
    uint256 diff = bsub(tokenBalanceOut, tokenAmountOut);
    uint256 y = bdiv(tokenBalanceOut, diff);
    uint256 foo = bpow(y, weightRatio);
    foo = bsub(foo, BONE);
    tokenAmountIn = bsub(BONE, swapFee);
    tokenAmountIn = bdiv(bmul(tokenBalanceIn, foo), tokenAmountIn);
    return tokenAmountIn;
  }
  /**********************************************************************************************
    // calcPoolOutGivenSingleIn                                                                  //
    // pAo = poolAmountOut         /                                              \\              //
    // tAi = tokenAmountIn        ///      /     //    wI \\      \\\\       \\     wI \\             //
    // wI = tokenWeightIn        //| tAi *| 1 - || 1 - --  | * sF || + tBi \\    --  \\            //
    // tW = totalWeight     pAo=||  \\      \\     \\\\    tW /      //         | ^ tW   | * pS - pS //
    // tBi = tokenBalanceIn      \\\\  ------------------------------------- /        /            //
    // pS = poolSupply            \\\\                    tBi               /        /             //
    // sF = swapFee                \\                                              /              //
    **********************************************************************************************/
  function calcPoolOutGivenSingleIn(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 poolSupply,
    uint256 totalWeight,
    uint256 tokenAmountIn,
    uint256 swapFee
  ) internal pure returns (uint256 poolAmountOut) {
    // Charge the trading fee for the proportion of tokenAi
    ///  which is implicitly traded to the other pool tokens.
    // That proportion is (1- weightTokenIn)
    // tokenAiAfterFee = tAi * (1 - (1-weightTi) * poolFee);
    uint256 normalizedWeight = bdiv(tokenWeightIn, totalWeight);
    uint256 zaz = bmul(bsub(BONE, normalizedWeight), swapFee);
    uint256 tokenAmountInAfterFee = bmul(tokenAmountIn, bsub(BONE, zaz));
    uint256 newTokenBalanceIn = badd(tokenBalanceIn, tokenAmountInAfterFee);
    uint256 tokenInRatio = bdiv(newTokenBalanceIn, tokenBalanceIn);
    // uint newPoolSupply = (ratioTi ^ weightTi) * poolSupply;
    uint256 poolRatio = bpow(tokenInRatio, normalizedWeight);
    uint256 newPoolSupply = bmul(poolRatio, poolSupply);
    poolAmountOut = bsub(newPoolSupply, poolSupply);
    return poolAmountOut;
  }
  /**********************************************************************************************
    // calcSingleInGivenPoolOut                                                                  //
    // tAi = tokenAmountIn              //(pS + pAo)\\     /    1    \\\\                           //
    // pS = poolSupply                 || ---------  | ^ | --------- || * bI - bI                //
    // pAo = poolAmountOut              \\\\    pS    /     \\(wI / tW)//                           //
    // bI = balanceIn          tAi =  --------------------------------------------               //
    // wI = weightIn                              /      wI  \\                                   //
    // tW = totalWeight                          |  1 - ----  |  * sF                            //
    // sF = swapFee                               \\      tW  /                                   //
    **********************************************************************************************/
  function calcSingleInGivenPoolOut(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 poolSupply,
    uint256 totalWeight,
    uint256 poolAmountOut,
    uint256 swapFee
  ) internal pure returns (uint256 tokenAmountIn) {
    uint256 normalizedWeight = bdiv(tokenWeightIn, totalWeight);
    uint256 newPoolSupply = badd(poolSupply, poolAmountOut);
    uint256 poolRatio = bdiv(newPoolSupply, poolSupply);
    //uint newBalTi = poolRatio^(1/weightTi) * balTi;
    uint256 boo = bdiv(BONE, normalizedWeight);
    uint256 tokenInRatio = bpow(poolRatio, boo);
    uint256 newTokenBalanceIn = bmul(tokenInRatio, tokenBalanceIn);
    uint256 tokenAmountInAfterFee = bsub(newTokenBalanceIn, tokenBalanceIn);
    // Do reverse order of fees charged in joinswap_ExternAmountIn, this way
    //     ``` pAo == joinswap_ExternAmountIn(Ti, joinswap_PoolAmountOut(pAo, Ti)) ```
    //uint tAi = tAiAfterFee / (1 - (1-weightTi) * swapFee) ;
    uint256 zar = bmul(bsub(BONE, normalizedWeight), swapFee);
    tokenAmountIn = bdiv(tokenAmountInAfterFee, bsub(BONE, zar));
    return tokenAmountIn;
  }
  /**********************************************************************************************
    // calcSingleOutGivenPoolIn                                                                  //
    // tAo = tokenAmountOut            /      /                                             \\\\   //
    // bO = tokenBalanceOut           /      // pS - (pAi * (1 - eF)) \\     /    1    \\      \\\\  //
    // pAi = poolAmountIn            | bO - || ----------------------- | ^ | --------- | * b0 || //
    // ps = poolSupply                \\      \\\\          pS           /     \\(wO / tW)/      //  //
    // wI = tokenWeightIn      tAo =   \\      \\                                             //   //
    // tW = totalWeight                    /     /      wO \\       \\                             //
    // sF = swapFee                    *  | 1 - |  1 - ---- | * sF  |                            //
    // eF = exitFee                        \\     \\      tW /       /                             //
    **********************************************************************************************/
  function calcSingleOutGivenPoolIn(
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 poolSupply,
    uint256 totalWeight,
    uint256 poolAmountIn,
    uint256 swapFee
  ) internal pure returns (uint256 tokenAmountOut) {
    uint256 normalizedWeight = bdiv(tokenWeightOut, totalWeight);
    // charge exit fee on the pool token side
    // pAiAfterExitFee = pAi*(1-exitFee)
    uint256 poolAmountInAfterExitFee = bmul(poolAmountIn, bsub(BONE, EXIT_FEE));
    uint256 newPoolSupply = bsub(poolSupply, poolAmountInAfterExitFee);
    uint256 poolRatio = bdiv(newPoolSupply, poolSupply);
    // newBalTo = poolRatio^(1/weightTo) * balTo;
    uint256 tokenOutRatio = bpow(poolRatio, bdiv(BONE, normalizedWeight));
    uint256 newTokenBalanceOut = bmul(tokenOutRatio, tokenBalanceOut);
    uint256 tokenAmountOutBeforeSwapFee = bsub(
      tokenBalanceOut,
      newTokenBalanceOut
    );
    // charge swap fee on the output token side
    //uint tAo = tAoBeforeSwapFee * (1 - (1-weightTo) * swapFee)
    uint256 zaz = bmul(bsub(BONE, normalizedWeight), swapFee);
    tokenAmountOut = bmul(tokenAmountOutBeforeSwapFee, bsub(BONE, zaz));
    return tokenAmountOut;
  }
  /**********************************************************************************************
    // calcPoolInGivenSingleOut                                                                  //
    // pAi = poolAmountIn               // /               tAo             \\\\     / wO \\     \\   //
    // bO = tokenBalanceOut            // | bO - -------------------------- |\\   | ---- |     \\  //
    // tAo = tokenAmountOut      pS - ||   \\     1 - ((1 - (tO / tW)) * sF)/  | ^ \\ tW /  * pS | //
    // ps = poolSupply                 \\\\ -----------------------------------/                /  //
    // wO = tokenWeightOut  pAi =       \\\\               bO                 /                /   //
    // tW = totalWeight           -------------------------------------------------------------  //
    // sF = swapFee                                        ( 1 - eF )                            //
    // eF = exitFee                                                                              //
    **********************************************************************************************/
  function calcPoolInGivenSingleOut(
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 poolSupply,
    uint256 totalWeight,
    uint256 tokenAmountOut,
    uint256 swapFee
  ) internal pure returns (uint256 poolAmountIn) {
    // charge swap fee on the output token side
    uint256 normalizedWeight = bdiv(tokenWeightOut, totalWeight);
    //uint tAoBeforeSwapFee = tAo / (1 - (1-weightTo) * swapFee) ;
    uint256 zoo = bsub(BONE, normalizedWeight);
    uint256 zar = bmul(zoo, swapFee);
    uint256 tokenAmountOutBeforeSwapFee = bdiv(tokenAmountOut, bsub(BONE, zar));
    uint256 newTokenBalanceOut = bsub(
      tokenBalanceOut,
      tokenAmountOutBeforeSwapFee
    );
    uint256 tokenOutRatio = bdiv(newTokenBalanceOut, tokenBalanceOut);
    //uint newPoolSupply = (ratioTo ^ weightTo) * poolSupply;
    uint256 poolRatio = bpow(tokenOutRatio, normalizedWeight);
    uint256 newPoolSupply = bmul(poolRatio, poolSupply);
    uint256 poolAmountInAfterExitFee = bsub(poolSupply, newPoolSupply);
    // charge exit fee on the pool token side
    // pAi = pAiAfterExitFee/(1-exitFee)
    poolAmountIn = bdiv(poolAmountInAfterExitFee, bsub(BONE, EXIT_FEE));
    return poolAmountIn;
  }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
import "./BConst.sol";
/************************************************************************************************
Originally from https://github.com/balancer-labs/balancer-core/blob/master/contracts/BNum.sol
This source code has been modified from the original, which was copied from the github repository
at commit hash f4ed5d65362a8d6cec21662fb6eae233b0babc1f.
Subject to the GPL-3.0 license
*************************************************************************************************/
contract BNum is BConst {
  function btoi(uint256 a) internal pure returns (uint256) {
    return a / BONE;
  }
  function bfloor(uint256 a) internal pure returns (uint256) {
    return btoi(a) * BONE;
  }
  function badd(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a, "ERR_ADD_OVERFLOW");
    return c;
  }
  function bsub(uint256 a, uint256 b) internal pure returns (uint256) {
    (uint256 c, bool flag) = bsubSign(a, b);
    require(!flag, "ERR_SUB_UNDERFLOW");
    return c;
  }
  function bsubSign(uint256 a, uint256 b)
    internal
    pure
    returns (uint256, bool)
  {
    if (a >= b) {
      return (a - b, false);
    } else {
      return (b - a, true);
    }
  }
  function bmul(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c0 = a * b;
    require(a == 0 || c0 / a == b, "ERR_MUL_OVERFLOW");
    uint256 c1 = c0 + (BONE / 2);
    require(c1 >= c0, "ERR_MUL_OVERFLOW");
    uint256 c2 = c1 / BONE;
    return c2;
  }
  function bdiv(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0, "ERR_DIV_ZERO");
    uint256 c0 = a * BONE;
    require(a == 0 || c0 / a == BONE, "ERR_DIV_INTERNAL"); // bmul overflow
    uint256 c1 = c0 + (b / 2);
    require(c1 >= c0, "ERR_DIV_INTERNAL"); //  badd require
    uint256 c2 = c1 / b;
    return c2;
  }
  // DSMath.wpow
  function bpowi(uint256 a, uint256 n) internal pure returns (uint256) {
    uint256 z = n % 2 != 0 ? a : BONE;
    for (n /= 2; n != 0; n /= 2) {
      a = bmul(a, a);
      if (n % 2 != 0) {
        z = bmul(z, a);
      }
    }
    return z;
  }
  // Compute b^(e.w) by splitting it into (b^e)*(b^0.w).
  // Use `bpowi` for `b^e` and `bpowK` for k iterations
  // of approximation of b^0.w
  function bpow(uint256 base, uint256 exp) internal pure returns (uint256) {
    require(base >= MIN_BPOW_BASE, "ERR_BPOW_BASE_TOO_LOW");
    require(base <= MAX_BPOW_BASE, "ERR_BPOW_BASE_TOO_HIGH");
    uint256 whole = bfloor(exp);
    uint256 remain = bsub(exp, whole);
    uint256 wholePow = bpowi(base, btoi(whole));
    if (remain == 0) {
      return wholePow;
    }
    uint256 partialResult = bpowApprox(base, remain, BPOW_PRECISION);
    return bmul(wholePow, partialResult);
  }
  function bpowApprox(
    uint256 base,
    uint256 exp,
    uint256 precision
  ) internal pure returns (uint256) {
    // term 0:
    uint256 a = exp;
    (uint256 x, bool xneg) = bsubSign(base, BONE);
    uint256 term = BONE;
    uint256 sum = term;
    bool negative = false;
    // term(k) = numer / denom
    //         = (product(a - i - 1, i=1-->k) * x^k) / (k!)
    // each iteration, multiply previous term by (a-(k-1)) * x / k
    // continue until term is less than precision
    for (uint256 i = 1; term >= precision; i++) {
      uint256 bigK = i * BONE;
      (uint256 c, bool cneg) = bsubSign(a, bsub(bigK, BONE));
      term = bmul(term, bmul(c, x));
      term = bdiv(term, bigK);
      if (term == 0) break;
      if (xneg) negative = !negative;
      if (cneg) negative = !negative;
      if (negative) {
        sum = bsub(sum, term);
      } else {
        sum = badd(sum, term);
      }
    }
    return sum;
  }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
import "./BNum.sol";
/************************************************************************************************
Originally from https://github.com/balancer-labs/balancer-core/blob/master/contracts/BToken.sol
This source code has been modified from the original, which was copied from the github repository
at commit hash f4ed5d65362a8d6cec21662fb6eae233b0babc1f.
Subject to the GPL-3.0 license
*************************************************************************************************/
// Highly opinionated token implementation
interface IERC20 {
  event Approval(address indexed src, address indexed dst, uint256 amt);
  event Transfer(address indexed src, address indexed dst, uint256 amt);
  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 whom) external view returns (uint256);
  function allowance(address src, address dst) external view returns (uint256);
  function approve(address dst, uint256 amt) external returns (bool);
  function transfer(address dst, uint256 amt) external returns (bool);
  function transferFrom(
    address src,
    address dst,
    uint256 amt
  ) external returns (bool);
}
contract BTokenBase is BNum {
  mapping(address => uint256) internal _balance;
  mapping(address => mapping(address => uint256)) internal _allowance;
  uint256 internal _totalSupply;
  event Approval(address indexed src, address indexed dst, uint256 amt);
  event Transfer(address indexed src, address indexed dst, uint256 amt);
  function _mint(uint256 amt) internal {
    _balance[address(this)] = badd(_balance[address(this)], amt);
    _totalSupply = badd(_totalSupply, amt);
    emit Transfer(address(0), address(this), amt);
  }
  function _burn(uint256 amt) internal {
    require(_balance[address(this)] >= amt, "ERR_INSUFFICIENT_BAL");
    _balance[address(this)] = bsub(_balance[address(this)], amt);
    _totalSupply = bsub(_totalSupply, amt);
    emit Transfer(address(this), address(0), amt);
  }
  function _move(
    address src,
    address dst,
    uint256 amt
  ) internal {
    require(_balance[src] >= amt, "ERR_INSUFFICIENT_BAL");
    _balance[src] = bsub(_balance[src], amt);
    _balance[dst] = badd(_balance[dst], amt);
    emit Transfer(src, dst, amt);
  }
  function _push(address to, uint256 amt) internal {
    _move(address(this), to, amt);
  }
  function _pull(address from, uint256 amt) internal {
    _move(from, address(this), amt);
  }
}
contract BToken is BTokenBase, IERC20 {
  uint8 private constant DECIMALS = 18;
  string private _name;
  string private _symbol;
  function _initializeToken(string memory name, string memory symbol) internal {
    require(
      bytes(_name).length == 0 &&
      bytes(name).length != 0 &&
      bytes(symbol).length != 0,
      "ERR_BTOKEN_INITIALIZED"
    );
    _name = name;
    _symbol = symbol;
  }
  function name()
    external
    override
    view
    returns (string memory)
  {
    return _name;
  }
  function symbol()
    external
    override
    view
    returns (string memory)
  {
    return _symbol;
  }
  function decimals()
    external
    override
    view
    returns (uint8)
  {
    return DECIMALS;
  }
  function allowance(address src, address dst)
    external
    override
    view
    returns (uint256)
  {
    return _allowance[src][dst];
  }
  function balanceOf(address whom) external override view returns (uint256) {
    return _balance[whom];
  }
  function totalSupply() public override view returns (uint256) {
    return _totalSupply;
  }
  function approve(address dst, uint256 amt) external override returns (bool) {
    _allowance[msg.sender][dst] = amt;
    emit Approval(msg.sender, dst, amt);
    return true;
  }
  function increaseApproval(address dst, uint256 amt) external returns (bool) {
    _allowance[msg.sender][dst] = badd(_allowance[msg.sender][dst], amt);
    emit Approval(msg.sender, dst, _allowance[msg.sender][dst]);
    return true;
  }
  function decreaseApproval(address dst, uint256 amt) external returns (bool) {
    uint256 oldValue = _allowance[msg.sender][dst];
    if (amt > oldValue) {
      _allowance[msg.sender][dst] = 0;
    } else {
      _allowance[msg.sender][dst] = bsub(oldValue, amt);
    }
    emit Approval(msg.sender, dst, _allowance[msg.sender][dst]);
    return true;
  }
  function transfer(address dst, uint256 amt) external override returns (bool) {
    _move(msg.sender, dst, amt);
    return true;
  }
  function transferFrom(
    address src,
    address dst,
    uint256 amt
  ) external override returns (bool) {
    require(
      msg.sender == src || amt <= _allowance[src][msg.sender],
      "ERR_BTOKEN_BAD_CALLER"
    );
    _move(src, dst, amt);
    if (msg.sender != src && _allowance[src][msg.sender] != uint256(-1)) {
      _allowance[src][msg.sender] = bsub(_allowance[src][msg.sender], amt);
      emit Approval(msg.sender, dst, _allowance[src][msg.sender]);
    }
    return true;
  }
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;
/* ========== Internal Inheritance ========== */
import "./BToken.sol";
import "./BMath.sol";
/* ========== Internal Interfaces ========== */
import "../interfaces/IIndexPool.sol";
import "../interfaces/ICompLikeToken.sol";
/************************************************************************************************
Originally from https://github.com/balancer-labs/balancer-core/blob/master/contracts/BPool.sol
This source code has been modified from the original, which was copied from the github repository
at commit hash f4ed5d65362a8d6cec21662fb6eae233b0babc1f.
Subject to the GPL-3.0 license
*************************************************************************************************/
contract SigmaIndexPoolV1 is BToken, BMath, IIndexPool {
/* ==========  EVENTS  ========== */
  /** @dev Emitted when tokens are swapped. */
  event LOG_SWAP(
    address indexed caller,
    address indexed tokenIn,
    address indexed tokenOut,
    uint256 tokenAmountIn,
    uint256 tokenAmountOut
  );
  /** @dev Emitted when underlying tokens are deposited for pool tokens. */
  event LOG_JOIN(
    address indexed caller,
    address indexed tokenIn,
    uint256 tokenAmountIn
  );
  /** @dev Emitted when pool tokens are burned for underlying. */
  event LOG_EXIT(
    address indexed caller,
    address indexed tokenOut,
    uint256 tokenAmountOut
  );
  /** @dev Emitted when a token's weight updates. */
  event LOG_DENORM_UPDATED(address indexed token, uint256 newDenorm);
  /** @dev Emitted when a token's desired weight is set. */
  event LOG_DESIRED_DENORM_SET(address indexed token, uint256 desiredDenorm);
  /** @dev Emitted when a token is unbound from the pool. */
  event LOG_TOKEN_REMOVED(address token);
  /** @dev Emitted when a token is unbound from the pool. */
  event LOG_TOKEN_ADDED(
    address indexed token,
    uint256 desiredDenorm,
    uint256 minimumBalance
  );
  /** @dev Emitted when a token's minimum balance is updated. */
  event LOG_MINIMUM_BALANCE_UPDATED(address token, uint256 minimumBalance);
  /** @dev Emitted when a token reaches its minimum balance. */
  event LOG_TOKEN_READY(address indexed token);
  /** @dev Emitted when public trades are disabled. */
  event LOG_PUBLIC_SWAP_TOGGLED(bool enabled);
  /** @dev Emitted when the swap fee is updated. */
  event LOG_SWAP_FEE_UPDATED(uint256 swapFee);
/* ==========  Modifiers  ========== */
  modifier _lock_ {
    require(!_mutex, "ERR_REENTRY");
    _mutex = true;
    _;
    _mutex = false;
  }
  modifier _viewlock_() {
    require(!_mutex, "ERR_REENTRY");
    _;
  }
  modifier _control_ {
    require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
    _;
  }
  modifier _public_ {
    require(_publicSwap, "ERR_NOT_PUBLIC");
    _;
  }
/* ==========  Storage  ========== */
  bool internal _mutex;
  // Account with CONTROL role. Able to modify the swap fee,
  // adjust token weights, bind and unbind tokens and lock
  // public swaps & joins.
  address internal _controller;
  // Contract that handles unbound tokens.
  TokenUnbindHandler internal _unbindHandler;
  // True if PUBLIC can call SWAP & JOIN functions
  bool internal _publicSwap;
  // `setSwapFee` requires CONTROL
  uint256 internal _swapFee;
  // Array of underlying tokens in the pool.
  address[] internal _tokens;
  // Internal records of the pool's underlying tokens
  mapping(address => Record) internal _records;
  // Total denormalized weight of the pool.
  uint256 internal _totalWeight;
  // Minimum balances for tokens which have been added without the
  // requisite initial balance.
  mapping(address => uint256) internal _minimumBalances;
  // Recipient for exit fees
  address internal _exitFeeRecipient;
/* ==========  Controls  ========== */
  /**
   * @dev Sets the controller address and the token name & symbol.
   *
   * Note: This saves on storage costs for multi-step pool deployment.
   *
   * @param controller Controller of the pool
   * @param name Name of the pool token
   * @param symbol Symbol of the pool token
   */
  function configure(
    address controller,
    string calldata name,
    string calldata symbol
  ) external override {
    require(_controller == address(0), "ERR_CONFIGURED");
    require(controller != address(0), "ERR_NULL_ADDRESS");
    _controller = controller;
    // default fee is 2.5%
    _swapFee = BONE / 40;
    _initializeToken(name, symbol);
  }
  /**
   * @dev Sets up the initial assets for the pool.
   *
   * Note: `tokenProvider` must have approved the pool to transfer the
   * corresponding `balances` of `tokens`.
   *
   * @param tokens Underlying tokens to initialize the pool with
   * @param balances Initial balances to transfer
   * @param denorms Initial denormalized weights for the tokens
   * @param tokenProvider Address to transfer the balances from
   * @param unbindHandler Address that receives tokens removed from the pool
   * @param exitFeeRecipient Address that receives exit fees
   */
  function initialize(
    address[] calldata tokens,
    uint256[] calldata balances,
    uint96[] calldata denorms,
    address tokenProvider,
    address unbindHandler,
    address exitFeeRecipient
  )
    external
    override
    _control_
  {
    require(_tokens.length == 0, "ERR_INITIALIZED");
    uint256 len = tokens.length;
    require(len >= MIN_BOUND_TOKENS, "ERR_MIN_TOKENS");
    require(len <= MAX_BOUND_TOKENS, "ERR_MAX_TOKENS");
    require(balances.length == len && denorms.length == len, "ERR_ARR_LEN");
    uint256 totalWeight = 0;
    for (uint256 i = 0; i < len; i++) {
      address token = tokens[i];
      uint96 denorm = denorms[i];
      uint256 balance = balances[i];
      require(denorm >= MIN_WEIGHT, "ERR_MIN_WEIGHT");
      require(denorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");
      require(balance >= MIN_BALANCE, "ERR_MIN_BALANCE");
      _records[token] = Record({
        bound: true,
        ready: true,
        lastDenormUpdate: uint40(now),
        denorm: denorm,
        desiredDenorm: denorm,
        index: uint8(i),
        balance: balance
      });
      _tokens.push(token);
      totalWeight = badd(totalWeight, denorm);
      _pullUnderlying(token, tokenProvider, balance);
    }
    require(totalWeight <= MAX_TOTAL_WEIGHT, "ERR_MAX_TOTAL_WEIGHT");
    _totalWeight = totalWeight;
    _publicSwap = true;
    emit LOG_PUBLIC_SWAP_TOGGLED(true);
    _mintPoolShare(INIT_POOL_SUPPLY);
    _pushPoolShare(tokenProvider, INIT_POOL_SUPPLY);
    _unbindHandler = TokenUnbindHandler(unbindHandler);
    _exitFeeRecipient = exitFeeRecipient;
  }
  /**
   * @dev Set the swap fee.
   * Note: Swap fee must be between 0.0001% and 10%
   */
  function setSwapFee(uint256 swapFee) external override _control_ {
    require(swapFee >= MIN_FEE && swapFee <= MAX_FEE, "ERR_INVALID_FEE");
    _swapFee = swapFee;
    emit LOG_SWAP_FEE_UPDATED(swapFee);
  }
  /**
   * @dev Delegate a comp-like governance token to an address
   * specified by the controller.
   */
  function delegateCompLikeToken(address token, address delegatee)
    external
    override
    _control_
  {
    ICompLikeToken(token).delegate(delegatee);
  }
  /**
   * @dev Set the exit fee recipient address. Can only be called
   * by the current exit fee recipient.
   */
  function setExitFeeRecipient(address exitFeeRecipient) external override {
    require(msg.sender == _exitFeeRecipient, "ERR_NOT_FEE_RECIPIENT");
    _exitFeeRecipient = exitFeeRecipient;
  }
  /**
   * @dev Toggle public trading for the index pool.
   * This will enable or disable swaps and single-token joins and exits.
   */
  function setPublicSwap(bool enabled) external override _control_ {
    _publicSwap = enabled;
    emit LOG_PUBLIC_SWAP_TOGGLED(enabled);
  }
/* ==========  Token Management Actions  ========== */
  /**
   * @dev Sets the desired weights for the pool tokens, which
   * will be adjusted over time as they are swapped.
   *
   * Note: This does not check for duplicate tokens or that the total
   * of the desired weights is equal to the target total weight (25).
   * Those assumptions should be met in the controller. Further, the
   * provided tokens should only include the tokens which are not set
   * for removal.
   */
  function reweighTokens(
    address[] calldata tokens,
    uint96[] calldata desiredDenorms
  )
    external
    override
    _lock_
    _control_
  {
    require(desiredDenorms.length == tokens.length, "ERR_ARR_LEN");
    for (uint256 i = 0; i < tokens.length; i++)
      _setDesiredDenorm(tokens[i], desiredDenorms[i]);
  }
  /**
   * @dev Update the underlying assets held by the pool and their associated
   * weights. Tokens which are not currently bound will be gradually added
   * as they are swapped in to reach the provided minimum balances, which must
   * be an amount of tokens worth the minimum weight of the total pool value.
   * If a currently bound token is not received in this call, the token's
   * desired weight will be set to 0.
   */
  function reindexTokens(
    address[] calldata tokens,
    uint96[] calldata desiredDenorms,
    uint256[] calldata minimumBalances
  )
    external
    override
    _lock_
    _control_
  {
    require(
      desiredDenorms.length == tokens.length && minimumBalances.length == tokens.length,
      "ERR_ARR_LEN"
    );
    // This size may not be the same as the input size, as it is possible
    // to temporarily exceed the index size while tokens are being phased in
    // or out.
    uint256 tLen = _tokens.length;
    bool[] memory receivedIndices = new bool[](tLen);
    // We need to read token records in two separate loops, so
    // write them to memory to avoid duplicate storage reads.
    Record[] memory records = new Record[](tokens.length);
    // Read all the records from storage and mark which of the existing tokens
    // were represented in the reindex call.
    for (uint256 i = 0; i < tokens.length; i++) {
      records[i] = _records[tokens[i]];
      if (records[i].bound) receivedIndices[records[i].index] = true;
    }
    // If any bound tokens were not sent in this call, set their desired weights to 0.
    for (uint256 i = 0; i < tLen; i++) {
      if (!receivedIndices[i]) {
        _setDesiredDenorm(_tokens[i], 0);
      }
    }
    for (uint256 i = 0; i < tokens.length; i++) {
      address token = tokens[i];
      // If an input weight is less than the minimum weight, use that instead.
      uint96 denorm = desiredDenorms[i];
      if (denorm < MIN_WEIGHT) denorm = uint96(MIN_WEIGHT);
      if (!records[i].bound) {
        // If the token is not bound, bind it.
        _bind(token, minimumBalances[i], denorm);
      } else {
        _setDesiredDenorm(token, denorm);
      }
    }
  }
  /**
   * @dev Updates the minimum balance for an uninitialized token.
   * This becomes useful if a token's external price significantly
   * rises after being bound, since the pool can not send a token
   * out until it reaches the minimum balance.
   */
  function setMinimumBalance(
    address token,
    uint256 minimumBalance
  )
    external
    override
    _control_
  {
    Record storage record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    require(!record.ready, "ERR_READY");
    _minimumBalances[token] = minimumBalance;
    emit LOG_MINIMUM_BALANCE_UPDATED(token, minimumBalance);
  }
/* ==========  Liquidity Provider Actions  ========== */
  /**
   * @dev Mint new pool tokens by providing the proportional amount of each
   * underlying token's balance relative to the proportion of pool tokens minted.
   *
   * For any underlying tokens which are not initialized, the caller must provide
   * the proportional share of the minimum balance for the token rather than the
   * actual balance.
   *
   * @param poolAmountOut Amount of pool tokens to mint
   * @param maxAmountsIn Maximum amount of each token to pay in the same
   * order as the pool's _tokens list.
   */
  function joinPool(uint256 poolAmountOut, uint256[] calldata maxAmountsIn)
    external
    override
    _lock_
    _public_
  {
    uint256 poolTotal = totalSupply();
    uint256 ratio = bdiv(poolAmountOut, poolTotal);
    require(ratio != 0, "ERR_MATH_APPROX");
    require(maxAmountsIn.length == _tokens.length, "ERR_ARR_LEN");
    for (uint256 i = 0; i < maxAmountsIn.length; i++) {
      address t = _tokens[i];
      (Record memory record, uint256 realBalance) = _getInputToken(t);
      uint256 tokenAmountIn = bmul(ratio, record.balance);
      require(tokenAmountIn != 0, "ERR_MATH_APPROX");
      require(tokenAmountIn <= maxAmountsIn[i], "ERR_LIMIT_IN");
      _updateInputToken(t, record, badd(realBalance, tokenAmountIn));
      emit LOG_JOIN(msg.sender, t, tokenAmountIn);
      _pullUnderlying(t, msg.sender, tokenAmountIn);
    }
    _mintPoolShare(poolAmountOut);
    _pushPoolShare(msg.sender, poolAmountOut);
  }
  /**
   * @dev Pay `tokenAmountIn` of `tokenIn` to mint at least `minPoolAmountOut`
   * pool tokens.
   *
   * The pool implicitly swaps `(1- weightTokenIn) * tokenAmountIn` to the other
   * underlying tokens. Thus a swap fee is charged against the input tokens.
   *
   * @param tokenIn Token to send the pool
   * @param tokenAmountIn Exact amount of `tokenIn` to pay
   * @param minPoolAmountOut Minimum amount of pool tokens to mint
   * @return poolAmountOut - Amount of pool tokens minted
   */
  function joinswapExternAmountIn(
    address tokenIn,
    uint256 tokenAmountIn,
    uint256 minPoolAmountOut
  )
    external
    override
    _lock_
    _public_
    returns (uint256/* poolAmountOut */)
  {
    (Record memory inRecord, uint256 realInBalance) = _getInputToken(tokenIn);
    require(tokenAmountIn != 0, "ERR_ZERO_IN");
    require(
      tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO),
      "ERR_MAX_IN_RATIO"
    );
    uint256 poolAmountOut = calcPoolOutGivenSingleIn(
      inRecord.balance,
      inRecord.denorm,
      _totalSupply,
      _totalWeight,
      tokenAmountIn,
      _swapFee
    );
    require(poolAmountOut >= minPoolAmountOut, "ERR_LIMIT_OUT");
    _updateInputToken(tokenIn, inRecord, badd(realInBalance, tokenAmountIn));
    emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);
    _mintPoolShare(poolAmountOut);
    _pushPoolShare(msg.sender, poolAmountOut);
    _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
    return poolAmountOut;
  }
  /**
   * @dev Pay up to `maxAmountIn` of `tokenIn` to mint exactly `poolAmountOut`.
   *
   * The pool implicitly swaps `(1- weightTokenIn) * tokenAmountIn` to the other
   * underlying tokens. Thus a swap fee is charged against the input tokens.
   *
   * @param tokenIn Token to send the pool
   * @param poolAmountOut Exact amount of pool tokens to mint
   * @param maxAmountIn Maximum amount of `tokenIn` to pay
   * @return tokenAmountIn - Amount of `tokenIn` paid
   */
  function joinswapPoolAmountOut(
    address tokenIn,
    uint256 poolAmountOut,
    uint256 maxAmountIn
  )
    external
    override
    _lock_
    _public_
    returns (uint256/* tokenAmountIn */)
  {
    (Record memory inRecord, uint256 realInBalance) = _getInputToken(tokenIn);
    uint256 tokenAmountIn = calcSingleInGivenPoolOut(
      inRecord.balance,
      inRecord.denorm,
      _totalSupply,
      _totalWeight,
      poolAmountOut,
      _swapFee
    );
    require(tokenAmountIn != 0, "ERR_MATH_APPROX");
    require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");
    require(
      tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO),
      "ERR_MAX_IN_RATIO"
    );
    _updateInputToken(tokenIn, inRecord, badd(realInBalance, tokenAmountIn));
    emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);
    _mintPoolShare(poolAmountOut);
    _pushPoolShare(msg.sender, poolAmountOut);
    _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
    return tokenAmountIn;
  }
  /**
   * @dev Burns `poolAmountIn` pool tokens in exchange for the amounts of each
   * underlying token's balance proportional to the ratio of tokens burned to
   * total pool supply. The amount of each token transferred to the caller must
   * be greater than or equal to the associated minimum output amount from the
   * `minAmountsOut` array.
   *
   * @param poolAmountIn Exact amount of pool tokens to burn
   * @param minAmountsOut Minimum amount of each token to receive, in the same
   * order as the pool's _tokens list.
   */
  function exitPool(uint256 poolAmountIn, uint256[] calldata minAmountsOut)
    external
    override
    _lock_
  {
    require(minAmountsOut.length == _tokens.length, "ERR_ARR_LEN");
    uint256 poolTotal = totalSupply();
    uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);
    uint256 pAiAfterExitFee = bsub(poolAmountIn, exitFee);
    uint256 ratio = bdiv(pAiAfterExitFee, poolTotal);
    require(ratio != 0, "ERR_MATH_APPROX");
    _pullPoolShare(msg.sender, poolAmountIn);
    _pushPoolShare(_exitFeeRecipient, exitFee);
    _burnPoolShare(pAiAfterExitFee);
    for (uint256 i = 0; i < minAmountsOut.length; i++) {
      address t = _tokens[i];
      Record memory record = _records[t];
      if (record.ready) {
        uint256 tokenAmountOut = bmul(ratio, record.balance);
        require(tokenAmountOut != 0, "ERR_MATH_APPROX");
        require(tokenAmountOut >= minAmountsOut[i], "ERR_LIMIT_OUT");
        _records[t].balance = bsub(record.balance, tokenAmountOut);
        emit LOG_EXIT(msg.sender, t, tokenAmountOut);
        _pushUnderlying(t, msg.sender, tokenAmountOut);
      } else {
        // If the token is not initialized, it can not exit the pool.
        require(minAmountsOut[i] == 0, "ERR_OUT_NOT_READY");
      }
    }
  }
  /**
   * @dev Burns `poolAmountIn` pool tokens in exchange for at least `minAmountOut`
   * of `tokenOut`. Returns the number of tokens sent to the caller.
   *
   * The pool implicitly burns the tokens for all underlying tokens and swaps them
   * to the desired output token. A swap fee is charged against the output tokens.
   *
   * @param tokenOut Token to receive
   * @param poolAmountIn Exact amount of pool tokens to burn
   * @param minAmountOut Minimum amount of `tokenOut` to receive
   * @return tokenAmountOut - Amount of `tokenOut` received
   */
  function exitswapPoolAmountIn(
    address tokenOut,
    uint256 poolAmountIn,
    uint256 minAmountOut
  )
    external
    override
    _lock_
    returns (uint256/* tokenAmountOut */)
  {
    Record memory outRecord = _getOutputToken(tokenOut);
    uint256 tokenAmountOut = calcSingleOutGivenPoolIn(
      outRecord.balance,
      outRecord.denorm,
      _totalSupply,
      _totalWeight,
      poolAmountIn,
      _swapFee
    );
    require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");
    require(
      tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO),
      "ERR_MAX_OUT_RATIO"
    );
    _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);
    _records[tokenOut].balance = bsub(outRecord.balance, tokenAmountOut);
    _decreaseDenorm(outRecord, tokenOut);
    uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);
    emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);
    _pullPoolShare(msg.sender, poolAmountIn);
    _burnPoolShare(bsub(poolAmountIn, exitFee));
    _pushPoolShare(_exitFeeRecipient, exitFee);
    return tokenAmountOut;
  }
  /**
   * @dev Burn up to `maxPoolAmountIn` for exactly `tokenAmountOut` of `tokenOut`.
   * Returns the number of pool tokens burned.
   *
   * The pool implicitly burns the tokens for all underlying tokens and swaps them
   * to the desired output token. A swap fee is charged against the output tokens.
   *
   * @param tokenOut Token to receive
   * @param tokenAmountOut Exact amount of `tokenOut` to receive
   * @param maxPoolAmountIn Maximum amount of pool tokens to burn
   * @return poolAmountIn - Amount of pool tokens burned
   */
  function exitswapExternAmountOut(
    address tokenOut,
    uint256 tokenAmountOut,
    uint256 maxPoolAmountIn
  )
    external
    override
    _lock_
    returns (uint256/* poolAmountIn */)
  {
    Record memory outRecord = _getOutputToken(tokenOut);
    require(
      tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO),
      "ERR_MAX_OUT_RATIO"
    );
    uint256 poolAmountIn = calcPoolInGivenSingleOut(
      outRecord.balance,
      outRecord.denorm,
      _totalSupply,
      _totalWeight,
      tokenAmountOut,
      _swapFee
    );
    require(poolAmountIn != 0, "ERR_MATH_APPROX");
    require(poolAmountIn <= maxPoolAmountIn, "ERR_LIMIT_IN");
    _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);
    _records[tokenOut].balance = bsub(outRecord.balance, tokenAmountOut);
    _decreaseDenorm(outRecord, tokenOut);
    uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);
    emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);
    _pullPoolShare(msg.sender, poolAmountIn);
    _burnPoolShare(bsub(poolAmountIn, exitFee));
    _pushPoolShare(_exitFeeRecipient, exitFee);
    return poolAmountIn;
  }
/* ==========  Other  ========== */
  /**
   * @dev Absorb any tokens that have been sent to the pool.
   * If the token is not bound, it will be sent to the unbound
   * token handler.
   */
  function gulp(address token) external override _lock_ {
    Record storage record = _records[token];
    uint256 balance = IERC20(token).balanceOf(address(this));
    if (record.bound) {
      if (!record.ready) {
        uint256 minimumBalance = _minimumBalances[token];
        if (balance >= minimumBalance) {
          _minimumBalances[token] = 0;
          record.ready = true;
          emit LOG_TOKEN_READY(token);
          uint256 additionalBalance = bsub(balance, minimumBalance);
          uint256 balRatio = bdiv(additionalBalance, minimumBalance);
          uint96 newDenorm = uint96(badd(MIN_WEIGHT, bmul(MIN_WEIGHT, balRatio)));
          record.denorm = newDenorm;
          record.lastDenormUpdate = uint40(now);
          _totalWeight = badd(_totalWeight, newDenorm);
          emit LOG_DENORM_UPDATED(token, record.denorm);
        }
      }
      _records[token].balance = balance;
    } else {
      _pushUnderlying(token, address(_unbindHandler), balance);
      _unbindHandler.handleUnbindToken(token, balance);
    }
  }
/* ==========  Token Swaps  ========== */
  /**
   * @dev Execute a token swap with a specified amount of input
   * tokens and a minimum amount of output tokens.
   *
   * Note: Will revert if `tokenOut` is uninitialized.
   *
   * @param tokenIn Token to swap in
   * @param tokenAmountIn Exact amount of `tokenIn` to swap in
   * @param tokenOut Token to swap out
   * @param minAmountOut Minimum amount of `tokenOut` to receive
   * @param maxPrice Maximum ratio of input to output tokens
   * @return (tokenAmountOut, spotPriceAfter)
   */
  function swapExactAmountIn(
    address tokenIn,
    uint256 tokenAmountIn,
    address tokenOut,
    uint256 minAmountOut,
    uint256 maxPrice
  )
    external
    override
    _lock_
    _public_
    returns (uint256/* tokenAmountOut */, uint256/* spotPriceAfter */)
  {
    (Record memory inRecord, uint256 realInBalance) = _getInputToken(tokenIn);
    Record memory outRecord = _getOutputToken(tokenOut);
    require(
      tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO),
      "ERR_MAX_IN_RATIO"
    );
    uint256 spotPriceBefore = calcSpotPrice(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      _swapFee
    );
    require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");
    uint256 tokenAmountOut = calcOutGivenIn(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      tokenAmountIn,
      _swapFee
    );
    require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");
    _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
    _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);
    realInBalance = badd(realInBalance, tokenAmountIn);
    _updateInputToken(tokenIn, inRecord, realInBalance);
    if (inRecord.ready) {
      inRecord.balance = realInBalance;
    }
    // Update the in-memory record for the spotPriceAfter calculation,
    // then update the storage record with the local balance.
    outRecord.balance = bsub(outRecord.balance, tokenAmountOut);
    _records[tokenOut].balance = outRecord.balance;
    // If needed, update the output token's weight.
    _decreaseDenorm(outRecord, tokenOut);
    uint256 spotPriceAfter = calcSpotPrice(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      _swapFee
    );
    require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX_2");
    require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
    require(
      spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut),
      "ERR_MATH_APPROX"
    );
    emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);
    return (tokenAmountOut, spotPriceAfter);
  }
  /**
   * @dev Trades at most `maxAmountIn` of `tokenIn` for exactly `tokenAmountOut`
   * of `tokenOut`.
   *
   * Returns the actual input amount and the new spot price after the swap,
   * which can not exceed `maxPrice`.
   *
   * @param tokenIn Token to swap in
   * @param maxAmountIn Maximum amount of `tokenIn` to pay
   * @param tokenOut Token to swap out
   * @param tokenAmountOut Exact amount of `tokenOut` to receive
   * @param maxPrice Maximum ratio of input to output tokens
   * @return (tokenAmountIn, spotPriceAfter)
   */
  function swapExactAmountOut(
    address tokenIn,
    uint256 maxAmountIn,
    address tokenOut,
    uint256 tokenAmountOut,
    uint256 maxPrice
  )
    external
    override
    _lock_
    _public_
    returns (uint256 /* tokenAmountIn */, uint256 /* spotPriceAfter */)
  {
    (Record memory inRecord, uint256 realInBalance) = _getInputToken(tokenIn);
    Record memory outRecord = _getOutputToken(tokenOut);
    require(
      tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO),
      "ERR_MAX_OUT_RATIO"
    );
    uint256 spotPriceBefore = calcSpotPrice(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      _swapFee
    );
    require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");
    uint256 tokenAmountIn = calcInGivenOut(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      tokenAmountOut,
      _swapFee
    );
    require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");
    _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
    _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);
    // Update the balance and (if necessary) weight of the input token.
    realInBalance = badd(realInBalance, tokenAmountIn);
    _updateInputToken(tokenIn, inRecord, realInBalance);
    if (inRecord.ready) {
      inRecord.balance = realInBalance;
    }
    // Update the in-memory record for the spotPriceAfter calculation,
    // then update the storage record with the local balance.
    outRecord.balance = bsub(outRecord.balance, tokenAmountOut);
    _records[tokenOut].balance = outRecord.balance;
    // If needed, update the output token's weight.
    _decreaseDenorm(outRecord, tokenOut);
    uint256 spotPriceAfter = calcSpotPrice(
      inRecord.balance,
      inRecord.denorm,
      outRecord.balance,
      outRecord.denorm,
      _swapFee
    );
    require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
    require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
    require(
      spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut),
      "ERR_MATH_APPROX"
    );
    emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);
    return (tokenAmountIn, spotPriceAfter);
  }
/* ==========  Config Queries  ========== */
  /**
   * @dev Check if swapping tokens and joining the pool is allowed.
   */
  function isPublicSwap() external view override returns (bool) {
    return _publicSwap;
  }
  function getSwapFee() external view override _viewlock_ returns (uint256/* swapFee */) {
    return _swapFee;
  }
  /**
   * @dev Returns the controller address.
   */
  function getController() external view override returns (address) {
    return _controller;
  }
  /**
   * @dev Returns the exit fee recipient address.
   */
  function getExitFeeRecipient() external view override returns (address) {
    return _exitFeeRecipient;
  }
/* ==========  Token Queries  ========== */
  /**
   * @dev Check if a token is bound to the pool.
   */
  function isBound(address t) external view override returns (bool) {
    return _records[t].bound;
  }
  /**
   * @dev Get the number of tokens bound to the pool.
   */
  function getNumTokens() external view override returns (uint256) {
    return _tokens.length;
  }
  /**
   * @dev Get all bound tokens.
   */
  function getCurrentTokens()
    external
    view
    override
    _viewlock_
    returns (address[] memory tokens)
  {
    tokens = _tokens;
  }
  /**
   * @dev Returns the list of tokens which have a desired weight above 0.
   * Tokens with a desired weight of 0 are set to be phased out of the pool.
   */
  function getCurrentDesiredTokens()
    external
    view
    override
    _viewlock_
    returns (address[] memory tokens)
  {
    address[] memory tempTokens = _tokens;
    tokens = new address[](tempTokens.length);
    uint256 usedIndex = 0;
    for (uint256 i = 0; i < tokens.length; i++) {
      address token = tempTokens[i];
      if (_records[token].desiredDenorm > 0) {
        tokens[usedIndex++] = token;
      }
    }
    assembly { mstore(tokens, usedIndex) }
  }
  /**
   * @dev Returns the denormalized weight of a bound token.
   */
  function getDenormalizedWeight(address token)
    external
    view
    override
    _viewlock_
    returns (uint256/* denorm */)
  {
    require(_records[token].bound, "ERR_NOT_BOUND");
    return _records[token].denorm;
  }
  /**
   * @dev Returns the record for a token bound to the pool.
   */
  function getTokenRecord(address token)
    external
    view
    override
    _viewlock_
    returns (Record memory record)
  {
    record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
  }
  /**
   * @dev Finds the first token which is both initialized and has a
   * desired weight above 0, then returns the address of that token
   * and the extrapolated value of the pool in terms of that token.
   *
   * The value is extrapolated by multiplying the token's
   * balance by the reciprocal of its normalized weight.
   * @return (token, extrapolatedValue)
   */
  function extrapolatePoolValueFromToken()
    external
    view
    override
    _viewlock_
    returns (address/* token */, uint256/* extrapolatedValue */)
  {
    address token;
    uint256 extrapolatedValue;
    uint256 len = _tokens.length;
    for (uint256 i = 0; i < len; i++) {
      token = _tokens[i];
      Record storage record = _records[token];
      if (record.ready && record.desiredDenorm > 0) {
        extrapolatedValue = bmul(
          record.balance,
          bdiv(_totalWeight, record.denorm)
        );
        break;
      }
    }
    require(extrapolatedValue > 0, "ERR_NONE_READY");
    return (token, extrapolatedValue);
  }
  /**
   * @dev Get the total denormalized weight of the pool.
   */
  function getTotalDenormalizedWeight()
    external
    view
    override
    _viewlock_
    returns (uint256)
  {
    return _totalWeight;
  }
  /**
   * @dev Returns the stored balance of a bound token.
   */
  function getBalance(address token) external view override _viewlock_ returns (uint256) {
    Record storage record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    return record.balance;
  }
  /**
   * @dev Get the minimum balance of an uninitialized token.
   * Note: Throws if the token is initialized.
   */
  function getMinimumBalance(address token) external view override _viewlock_ returns (uint256) {
    Record memory record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    require(!record.ready, "ERR_READY");
    return _minimumBalances[token];
  }
  /**
   * @dev Returns the balance of a token which is used in price
   * calculations. If the token is initialized, this is the
   * stored balance; if not, this is the minimum balance.
   */
  function getUsedBalance(address token) external view override _viewlock_ returns (uint256) {
    Record memory record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    if (!record.ready) {
      return _minimumBalances[token];
    }
    return record.balance;
  }
/* ==========  Price Queries  ========== */
  /**
   * @dev Returns the spot price for `tokenOut` in terms of `tokenIn`.
   */
  function getSpotPrice(address tokenIn, address tokenOut)
    external
    view
    override
    _viewlock_
    returns (uint256)
  {
    (Record memory inRecord,) = _getInputToken(tokenIn);
    Record memory outRecord = _getOutputToken(tokenOut);
    return
      calcSpotPrice(
        inRecord.balance,
        inRecord.denorm,
        outRecord.balance,
        outRecord.denorm,
        _swapFee
      );
  }
/* ==========  Pool Share Internal Functions  ========== */
  function _pullPoolShare(address from, uint256 amount) internal {
    _pull(from, amount);
  }
  function _pushPoolShare(address to, uint256 amount) internal {
    _push(to, amount);
  }
  function _mintPoolShare(uint256 amount) internal {
    _mint(amount);
  }
  function _burnPoolShare(uint256 amount) internal {
    _burn(amount);
  }
/* ==========  Underlying Token Internal Functions  ========== */
  // 'Underlying' token-manipulation functions make external calls but are NOT locked
  // You must `_lock_` or otherwise ensure reentry-safety
  function _pullUnderlying(
    address erc20,
    address from,
    uint256 amount
  ) internal {
    (bool success, bytes memory data) = erc20.call(
      abi.encodeWithSelector(
        IERC20.transferFrom.selector,
        from,
        address(this),
        amount
      )
    );
    require(
      success && (data.length == 0 || abi.decode(data, (bool))),
      "ERR_ERC20_FALSE"
    );
  }
  function _pushUnderlying(
    address erc20,
    address to,
    uint256 amount
  ) internal {
    (bool success, bytes memory data) = erc20.call(
      abi.encodeWithSelector(
        IERC20.transfer.selector,
        to,
        amount
      )
    );
    require(
      success && (data.length == 0 || abi.decode(data, (bool))),
      "ERR_ERC20_FALSE"
    );
  }
/* ==========  Token Management Internal Functions  ========== */
  /**
   * @dev Bind a token by address without actually depositing a balance.
   * The token will be unable to be swapped out until it reaches the minimum balance.
   * Note: Token must not already be bound.
   * Note: `minimumBalance` should represent an amount of the token which is worth
   * the portion of the current pool value represented by the minimum weight.
   * @param token Address of the token to bind
   * @param minimumBalance minimum balance to reach before the token can be swapped out
   * @param desiredDenorm Desired weight for the token.
   */
  function _bind(
    address token,
    uint256 minimumBalance,
    uint96 desiredDenorm
  ) internal {
    require(!_records[token].bound, "ERR_IS_BOUND");
    require(desiredDenorm >= MIN_WEIGHT, "ERR_MIN_WEIGHT");
    require(desiredDenorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");
    require(minimumBalance >= MIN_BALANCE, "ERR_MIN_BALANCE");
    _records[token] = Record({
      bound: true,
      ready: false,
      lastDenormUpdate: 0,
      denorm: 0,
      desiredDenorm: desiredDenorm,
      index: uint8(_tokens.length),
      balance: 0
    });
    _tokens.push(token);
    _minimumBalances[token] = minimumBalance;
    emit LOG_TOKEN_ADDED(token, desiredDenorm, minimumBalance);
  }
  /**
   * @dev Remove a token from the pool.
   * Replaces the address in the tokens array with the last address,
   * then removes it from the array.
   * Note: This should only be called after the total weight has been adjusted.
   * Note: Must be called in a function with:
   * - _lock_ modifier to prevent reentrance
   * - requirement that the token is bound
   */
  function _unbind(address token) internal {
    Record memory record = _records[token];
    uint256 tokenBalance = record.balance;
    // Swap the token-to-unbind with the last token,
    // then delete the last token
    uint256 index = record.index;
    uint256 last = _tokens.length - 1;
    // Only swap the token with the last token if it is not
    // already at the end of the array.
    if (index != last) {
      _tokens[index] = _tokens[last];
      _records[_tokens[index]].index = uint8(index);
    }
    _tokens.pop();
    _records[token] = Record({
      bound: false,
      ready: false,
      lastDenormUpdate: 0,
      denorm: 0,
      desiredDenorm: 0,
      index: 0,
      balance: 0
    });
    // transfer any remaining tokens out
    _pushUnderlying(token, address(_unbindHandler), tokenBalance);
    _unbindHandler.handleUnbindToken(token, tokenBalance);
    emit LOG_TOKEN_REMOVED(token);
  }
  function _setDesiredDenorm(address token, uint96 desiredDenorm) internal {
    Record storage record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    // If the desired weight is 0, this will trigger a gradual unbinding of the token.
    // Therefore the weight only needs to be above the minimum weight if it isn't 0.
    require(
      desiredDenorm >= MIN_WEIGHT || desiredDenorm == 0,
      "ERR_MIN_WEIGHT"
    );
    require(desiredDenorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");
    record.desiredDenorm = desiredDenorm;
    emit LOG_DESIRED_DENORM_SET(token, desiredDenorm);
  }
  function _increaseDenorm(Record memory record, address token) internal {
    // If the weight does not need to increase or the token is not
    // initialized, don't do anything.
    if (
      record.denorm >= record.desiredDenorm ||
      !record.ready ||
      now - record.lastDenormUpdate < WEIGHT_UPDATE_DELAY
    ) return;
    uint96 oldWeight = record.denorm;
    uint96 denorm = record.desiredDenorm;
    uint256 maxDiff = bmul(oldWeight, WEIGHT_CHANGE_PCT);
    uint256 diff = bsub(denorm, oldWeight);
    if (diff > maxDiff) {
      denorm = uint96(badd(oldWeight, maxDiff));
      diff = maxDiff;
    }
    _totalWeight = badd(_totalWeight, diff);
    require(_totalWeight <= MAX_TOTAL_WEIGHT, "ERR_MAX_TOTAL_WEIGHT");
    // Update the in-memory denorm value for spot-price computations.
    record.denorm = denorm;
    // Update the storage record
    _records[token].denorm = denorm;
    _records[token].lastDenormUpdate = uint40(now);
    emit LOG_DENORM_UPDATED(token, denorm);
  }
  function _decreaseDenorm(Record memory record, address token) internal {
    // If the weight does not need to decrease, don't do anything.
    if (
      record.denorm <= record.desiredDenorm ||
      !record.ready ||
      now - record.lastDenormUpdate < WEIGHT_UPDATE_DELAY
    ) return;
    uint96 oldWeight = record.denorm;
    uint96 denorm = record.desiredDenorm;
    uint256 maxDiff = bmul(oldWeight, WEIGHT_CHANGE_PCT);
    uint256 diff = bsub(oldWeight, denorm);
    if (diff > maxDiff) {
      denorm = uint96(bsub(oldWeight, maxDiff));
      diff = maxDiff;
    }
    if (denorm <= MIN_WEIGHT) {
      denorm = 0;
      _totalWeight = bsub(_totalWeight, denorm);
      // Because this is removing the token from the pool, the
      // in-memory denorm value is irrelevant, as it is only used
      // to calculate the new spot price, but the spot price calc
      // will throw if it is passed 0 for the denorm.
      _unbind(token);
    } else {
      _totalWeight = bsub(_totalWeight, diff);
      // Update the in-memory denorm value for spot-price computations.
      record.denorm = denorm;
      // Update the stored denorm value
      _records[token].denorm = denorm;
      _records[token].lastDenormUpdate = uint40(now);
      emit LOG_DENORM_UPDATED(token, denorm);
    }
  }
  /**
   * @dev Handles weight changes and initialization of an
   * input token.
   *
   * If the token is not initialized and the new balance is
   * still below the minimum, this will not do anything.
   *
   * If the token is not initialized but the new balance will
   * bring the token above the minimum balance, this will
   * mark the token as initialized, remove the minimum
   * balance and set the weight to the minimum weight plus
   * 1%.
   *
   *
   * @param token Address of the input token
   * @param record Token record with minimums applied to the balance
   * and weight if the token was uninitialized.
   */
  function _updateInputToken(
    address token,
    Record memory record,
    uint256 realBalance
  )
    internal
  {
    if (!record.ready) {
      // Check if the minimum balance has been reached
      if (realBalance >= record.balance) {
        // Remove the minimum balance record
        _minimumBalances[token] = 0;
        // Mark the token as initialized
        _records[token].ready = true;
        record.ready = true;
        emit LOG_TOKEN_READY(token);
        // Set the initial denorm value to the minimum weight times one plus
        // the ratio of the increase in balance over the minimum to the minimum
        // balance.
        // weight = (1 + ((bal - min_bal) / min_bal)) * min_weight
        uint256 additionalBalance = bsub(realBalance, record.balance);
        uint256 balRatio = bdiv(additionalBalance, record.balance);
        record.denorm = uint96(badd(MIN_WEIGHT, bmul(MIN_WEIGHT, balRatio)));
        _records[token].denorm = record.denorm;
        _records[token].lastDenormUpdate = uint40(now);
        _totalWeight = badd(_totalWeight, record.denorm);
        emit LOG_DENORM_UPDATED(token, record.denorm);
      } else {
        uint256 realToMinRatio = bdiv(
          bsub(record.balance, realBalance),
          record.balance
        );
        uint256 weightPremium = bmul(MIN_WEIGHT / 10, realToMinRatio);
        record.denorm = uint96(badd(MIN_WEIGHT, weightPremium));
      }
      // If the token is still not ready, do not adjust the weight.
    } else {
      // If the token is already initialized, update the weight (if any adjustment
      // is needed).
      _increaseDenorm(record, token);
    }
    // Regardless of whether the token is initialized, store the actual new balance.
    _records[token].balance = realBalance;
  }
/* ==========  Token Query Internal Functions  ========== */
  /**
   * @dev Get the record for a token which is being swapped in.
   * The token must be bound to the pool. If the token is not
   * initialized (meaning it does not have the minimum balance)
   * this function will return the actual balance of the token
   * which the pool holds, but set the record's balance and weight
   * to the token's minimum balance and the pool's minimum weight.
   * This allows the token swap to be priced correctly even if the
   * pool does not own any of the tokens.
   */
  function _getInputToken(address token)
    internal
    view
    returns (Record memory record, uint256 realBalance)
  {
    record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    realBalance = record.balance;
    // If the input token is not initialized, we use the minimum
    // initial weight and minimum initial balance instead of the
    // real values for price and output calculations.
    if (!record.ready) {
      record.balance = _minimumBalances[token];
      uint256 realToMinRatio = bdiv(
        bsub(record.balance, realBalance),
        record.balance
      );
      uint256 weightPremium = bmul(MIN_WEIGHT / 10, realToMinRatio);
      record.denorm = uint96(badd(MIN_WEIGHT, weightPremium));
    }
  }
  function _getOutputToken(address token)
    internal
    view
    returns (Record memory record)
  {
    record = _records[token];
    require(record.bound, "ERR_NOT_BOUND");
    // Tokens which have not reached their minimum balance can not be
    // swapped out.
    require(record.ready, "ERR_OUT_NOT_READY");
  }
}
interface TokenUnbindHandler {
  /**
   * @dev Receive `amount` of `token` from the pool.
   */
  function handleUnbindToken(address token, uint256 amount) external;
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;
interface IIndexPool {
  /**
   * @dev Token record data structure
   * @param bound is token bound to pool
   * @param ready has token been initialized
   * @param lastDenormUpdate timestamp of last denorm change
   * @param denorm denormalized weight
   * @param desiredDenorm desired denormalized weight (used for incremental changes)
   * @param index index of address in tokens array
   * @param balance token balance
   */
  struct Record {
    bool bound;
    bool ready;
    uint40 lastDenormUpdate;
    uint96 denorm;
    uint96 desiredDenorm;
    uint8 index;
    uint256 balance;
  }
  event LOG_SWAP(
    address indexed caller,
    address indexed tokenIn,
    address indexed tokenOut,
    uint256 tokenAmountIn,
    uint256 tokenAmountOut
  );
  event LOG_JOIN(
    address indexed caller,
    address indexed tokenIn,
    uint256 tokenAmountIn
  );
  event LOG_EXIT(
    address indexed caller,
    address indexed tokenOut,
    uint256 tokenAmountOut
  );
  event LOG_DENORM_UPDATED(address indexed token, uint256 newDenorm);
  event LOG_DESIRED_DENORM_SET(address indexed token, uint256 desiredDenorm);
  event LOG_TOKEN_REMOVED(address token);
  event LOG_TOKEN_ADDED(
    address indexed token,
    uint256 desiredDenorm,
    uint256 minimumBalance
  );
  event LOG_MINIMUM_BALANCE_UPDATED(address token, uint256 minimumBalance);
  event LOG_TOKEN_READY(address indexed token);
  event LOG_PUBLIC_SWAP_TOGGLED(bool enabled);
  event LOG_MAX_TOKENS_UPDATED(uint256 maxPoolTokens);
  event LOG_SWAP_FEE_UPDATED(uint256 swapFee);
  function configure(
    address controller,
    string calldata name,
    string calldata symbol
  ) external;
  function initialize(
    address[] calldata tokens,
    uint256[] calldata balances,
    uint96[] calldata denorms,
    address tokenProvider,
    address unbindHandler,
    address exitFeeRecipient
  ) external;
  function setSwapFee(uint256 swapFee) external;
  function delegateCompLikeToken(address token, address delegatee) external;
  function setExitFeeRecipient(address) external;
  function setPublicSwap(bool enabled) external;
  function reweighTokens(
    address[] calldata tokens,
    uint96[] calldata desiredDenorms
  ) external;
  function reindexTokens(
    address[] calldata tokens,
    uint96[] calldata desiredDenorms,
    uint256[] calldata minimumBalances
  ) external;
  function setMinimumBalance(address token, uint256 minimumBalance) external;
  function joinPool(uint256 poolAmountOut, uint256[] calldata maxAmountsIn) external;
  function joinswapExternAmountIn(
    address tokenIn,
    uint256 tokenAmountIn,
    uint256 minPoolAmountOut
  ) external returns (uint256/* poolAmountOut */);
  function joinswapPoolAmountOut(
    address tokenIn,
    uint256 poolAmountOut,
    uint256 maxAmountIn
  ) external returns (uint256/* tokenAmountIn */);
  function exitPool(uint256 poolAmountIn, uint256[] calldata minAmountsOut) external;
  function exitswapPoolAmountIn(
    address tokenOut,
    uint256 poolAmountIn,
    uint256 minAmountOut
  )
    external returns (uint256/* tokenAmountOut */);
  function exitswapExternAmountOut(
    address tokenOut,
    uint256 tokenAmountOut,
    uint256 maxPoolAmountIn
  ) external returns (uint256/* poolAmountIn */);
  function gulp(address token) external;
  function swapExactAmountIn(
    address tokenIn,
    uint256 tokenAmountIn,
    address tokenOut,
    uint256 minAmountOut,
    uint256 maxPrice
  ) external returns (uint256/* tokenAmountOut */, uint256/* spotPriceAfter */);
  function swapExactAmountOut(
    address tokenIn,
    uint256 maxAmountIn,
    address tokenOut,
    uint256 tokenAmountOut,
    uint256 maxPrice
  ) external returns (uint256 /* tokenAmountIn */, uint256 /* spotPriceAfter */);
  function isPublicSwap() external view returns (bool);
  function getSwapFee() external view returns (uint256/* swapFee */);
  function getController() external view returns (address);
  function getExitFeeRecipient() external view returns (address);
  function isBound(address t) external view returns (bool);
  function getNumTokens() external view returns (uint256);
  function getCurrentTokens() external view returns (address[] memory tokens);
  function getCurrentDesiredTokens() external view returns (address[] memory tokens);
  function getDenormalizedWeight(address token) external view returns (uint256/* denorm */);
  function getTokenRecord(address token) external view returns (Record memory record);
  function extrapolatePoolValueFromToken() external view returns (address/* token */, uint256/* extrapolatedValue */);
  function getTotalDenormalizedWeight() external view returns (uint256);
  function getBalance(address token) external view returns (uint256);
  function getMinimumBalance(address token) external view returns (uint256);
  function getUsedBalance(address token) external view returns (uint256);
  function getSpotPrice(address tokenIn, address tokenOut) external view returns (uint256);
}// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
interface ICompLikeToken {
  function delegate(address delegatee) external;
}