// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
pragma abicoder v2;
import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
import '@uniswap/v3-core/contracts/libraries/FixedPoint128.sol';
import '@uniswap/v3-core/contracts/libraries/FullMath.sol';
import './interfaces/INonfungiblePositionManager.sol';
import './interfaces/INonfungibleTokenPositionDescriptor.sol';
import './libraries/PositionKey.sol';
import './libraries/PoolAddress.sol';
import './base/LiquidityManagement.sol';
import './base/PeripheryImmutableState.sol';
import './base/Multicall.sol';
import './base/ERC721Permit.sol';
import './base/PeripheryValidation.sol';
import './base/SelfPermit.sol';
import './base/PoolInitializer.sol';
/// @title NFT positions
/// @notice Wraps Uniswap V3 positions in the ERC721 non-fungible token interface
contract NonfungiblePositionManager is
    INonfungiblePositionManager,
    Multicall,
    ERC721Permit,
    PeripheryImmutableState,
    PoolInitializer,
    LiquidityManagement,
    PeripheryValidation,
    SelfPermit
{
    // details about the uniswap position
    struct Position {
        // the nonce for permits
        uint96 nonce;
        // the address that is approved for spending this token
        address operator;
        // the ID of the pool with which this token is connected
        uint80 poolId;
        // the tick range of the position
        int24 tickLower;
        int24 tickUpper;
        // the liquidity of the position
        uint128 liquidity;
        // the fee growth of the aggregate position as of the last action on the individual position
        uint256 feeGrowthInside0LastX128;
        uint256 feeGrowthInside1LastX128;
        // how many uncollected tokens are owed to the position, as of the last computation
        uint128 tokensOwed0;
        uint128 tokensOwed1;
    }
    /// @dev IDs of pools assigned by this contract
    mapping(address => uint80) private _poolIds;
    /// @dev Pool keys by pool ID, to save on SSTOREs for position data
    mapping(uint80 => PoolAddress.PoolKey) private _poolIdToPoolKey;
    /// @dev The token ID position data
    mapping(uint256 => Position) private _positions;
    /// @dev The ID of the next token that will be minted. Skips 0
    uint176 private _nextId = 1;
    /// @dev The ID of the next pool that is used for the first time. Skips 0
    uint80 private _nextPoolId = 1;
    /// @dev The address of the token descriptor contract, which handles generating token URIs for position tokens
    address private immutable _tokenDescriptor;
    constructor(
        address _factory,
        address _WETH9,
        address _tokenDescriptor_
    ) ERC721Permit('Uniswap V3 Positions NFT-V1', 'UNI-V3-POS', '1') PeripheryImmutableState(_factory, _WETH9) {
        _tokenDescriptor = _tokenDescriptor_;
    }
    /// @inheritdoc INonfungiblePositionManager
    function positions(uint256 tokenId)
        external
        view
        override
        returns (
            uint96 nonce,
            address operator,
            address token0,
            address token1,
            uint24 fee,
            int24 tickLower,
            int24 tickUpper,
            uint128 liquidity,
            uint256 feeGrowthInside0LastX128,
            uint256 feeGrowthInside1LastX128,
            uint128 tokensOwed0,
            uint128 tokensOwed1
        )
    {
        Position memory position = _positions[tokenId];
        require(position.poolId != 0, 'Invalid token ID');
        PoolAddress.PoolKey memory poolKey = _poolIdToPoolKey[position.poolId];
        return (
            position.nonce,
            position.operator,
            poolKey.token0,
            poolKey.token1,
            poolKey.fee,
            position.tickLower,
            position.tickUpper,
            position.liquidity,
            position.feeGrowthInside0LastX128,
            position.feeGrowthInside1LastX128,
            position.tokensOwed0,
            position.tokensOwed1
        );
    }
    /// @dev Caches a pool key
    function cachePoolKey(address pool, PoolAddress.PoolKey memory poolKey) private returns (uint80 poolId) {
        poolId = _poolIds[pool];
        if (poolId == 0) {
            _poolIds[pool] = (poolId = _nextPoolId++);
            _poolIdToPoolKey[poolId] = poolKey;
        }
    }
    /// @inheritdoc INonfungiblePositionManager
    function mint(MintParams calldata params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (
            uint256 tokenId,
            uint128 liquidity,
            uint256 amount0,
            uint256 amount1
        )
    {
        IUniswapV3Pool pool;
        (liquidity, amount0, amount1, pool) = addLiquidity(
            AddLiquidityParams({
                token0: params.token0,
                token1: params.token1,
                fee: params.fee,
                recipient: address(this),
                tickLower: params.tickLower,
                tickUpper: params.tickUpper,
                amount0Desired: params.amount0Desired,
                amount1Desired: params.amount1Desired,
                amount0Min: params.amount0Min,
                amount1Min: params.amount1Min
            })
        );
        _mint(params.recipient, (tokenId = _nextId++));
        bytes32 positionKey = PositionKey.compute(address(this), params.tickLower, params.tickUpper);
        (, uint256 feeGrowthInside0LastX128, uint256 feeGrowthInside1LastX128, , ) = pool.positions(positionKey);
        // idempotent set
        uint80 poolId =
            cachePoolKey(
                address(pool),
                PoolAddress.PoolKey({token0: params.token0, token1: params.token1, fee: params.fee})
            );
        _positions[tokenId] = Position({
            nonce: 0,
            operator: address(0),
            poolId: poolId,
            tickLower: params.tickLower,
            tickUpper: params.tickUpper,
            liquidity: liquidity,
            feeGrowthInside0LastX128: feeGrowthInside0LastX128,
            feeGrowthInside1LastX128: feeGrowthInside1LastX128,
            tokensOwed0: 0,
            tokensOwed1: 0
        });
        emit IncreaseLiquidity(tokenId, liquidity, amount0, amount1);
    }
    modifier isAuthorizedForToken(uint256 tokenId) {
        require(_isApprovedOrOwner(msg.sender, tokenId), 'Not approved');
        _;
    }
    function tokenURI(uint256 tokenId) public view override(ERC721, IERC721Metadata) returns (string memory) {
        require(_exists(tokenId));
        return INonfungibleTokenPositionDescriptor(_tokenDescriptor).tokenURI(this, tokenId);
    }
    // save bytecode by removing implementation of unused method
    function baseURI() public pure override returns (string memory) {}
    /// @inheritdoc INonfungiblePositionManager
    function increaseLiquidity(IncreaseLiquidityParams calldata params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (
            uint128 liquidity,
            uint256 amount0,
            uint256 amount1
        )
    {
        Position storage position = _positions[params.tokenId];
        PoolAddress.PoolKey memory poolKey = _poolIdToPoolKey[position.poolId];
        IUniswapV3Pool pool;
        (liquidity, amount0, amount1, pool) = addLiquidity(
            AddLiquidityParams({
                token0: poolKey.token0,
                token1: poolKey.token1,
                fee: poolKey.fee,
                tickLower: position.tickLower,
                tickUpper: position.tickUpper,
                amount0Desired: params.amount0Desired,
                amount1Desired: params.amount1Desired,
                amount0Min: params.amount0Min,
                amount1Min: params.amount1Min,
                recipient: address(this)
            })
        );
        bytes32 positionKey = PositionKey.compute(address(this), position.tickLower, position.tickUpper);
        // this is now updated to the current transaction
        (, uint256 feeGrowthInside0LastX128, uint256 feeGrowthInside1LastX128, , ) = pool.positions(positionKey);
        position.tokensOwed0 += uint128(
            FullMath.mulDiv(
                feeGrowthInside0LastX128 - position.feeGrowthInside0LastX128,
                position.liquidity,
                FixedPoint128.Q128
            )
        );
        position.tokensOwed1 += uint128(
            FullMath.mulDiv(
                feeGrowthInside1LastX128 - position.feeGrowthInside1LastX128,
                position.liquidity,
                FixedPoint128.Q128
            )
        );
        position.feeGrowthInside0LastX128 = feeGrowthInside0LastX128;
        position.feeGrowthInside1LastX128 = feeGrowthInside1LastX128;
        position.liquidity += liquidity;
        emit IncreaseLiquidity(params.tokenId, liquidity, amount0, amount1);
    }
    /// @inheritdoc INonfungiblePositionManager
    function decreaseLiquidity(DecreaseLiquidityParams calldata params)
        external
        payable
        override
        isAuthorizedForToken(params.tokenId)
        checkDeadline(params.deadline)
        returns (uint256 amount0, uint256 amount1)
    {
        require(params.liquidity > 0);
        Position storage position = _positions[params.tokenId];
        uint128 positionLiquidity = position.liquidity;
        require(positionLiquidity >= params.liquidity);
        PoolAddress.PoolKey memory poolKey = _poolIdToPoolKey[position.poolId];
        IUniswapV3Pool pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
        (amount0, amount1) = pool.burn(position.tickLower, position.tickUpper, params.liquidity);
        require(amount0 >= params.amount0Min && amount1 >= params.amount1Min, 'Price slippage check');
        bytes32 positionKey = PositionKey.compute(address(this), position.tickLower, position.tickUpper);
        // this is now updated to the current transaction
        (, uint256 feeGrowthInside0LastX128, uint256 feeGrowthInside1LastX128, , ) = pool.positions(positionKey);
        position.tokensOwed0 +=
            uint128(amount0) +
            uint128(
                FullMath.mulDiv(
                    feeGrowthInside0LastX128 - position.feeGrowthInside0LastX128,
                    positionLiquidity,
                    FixedPoint128.Q128
                )
            );
        position.tokensOwed1 +=
            uint128(amount1) +
            uint128(
                FullMath.mulDiv(
                    feeGrowthInside1LastX128 - position.feeGrowthInside1LastX128,
                    positionLiquidity,
                    FixedPoint128.Q128
                )
            );
        position.feeGrowthInside0LastX128 = feeGrowthInside0LastX128;
        position.feeGrowthInside1LastX128 = feeGrowthInside1LastX128;
        // subtraction is safe because we checked positionLiquidity is gte params.liquidity
        position.liquidity = positionLiquidity - params.liquidity;
        emit DecreaseLiquidity(params.tokenId, params.liquidity, amount0, amount1);
    }
    /// @inheritdoc INonfungiblePositionManager
    function collect(CollectParams calldata params)
        external
        payable
        override
        isAuthorizedForToken(params.tokenId)
        returns (uint256 amount0, uint256 amount1)
    {
        require(params.amount0Max > 0 || params.amount1Max > 0);
        // allow collecting to the nft position manager address with address 0
        address recipient = params.recipient == address(0) ? address(this) : params.recipient;
        Position storage position = _positions[params.tokenId];
        PoolAddress.PoolKey memory poolKey = _poolIdToPoolKey[position.poolId];
        IUniswapV3Pool pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
        (uint128 tokensOwed0, uint128 tokensOwed1) = (position.tokensOwed0, position.tokensOwed1);
        // trigger an update of the position fees owed and fee growth snapshots if it has any liquidity
        if (position.liquidity > 0) {
            pool.burn(position.tickLower, position.tickUpper, 0);
            (, uint256 feeGrowthInside0LastX128, uint256 feeGrowthInside1LastX128, , ) =
                pool.positions(PositionKey.compute(address(this), position.tickLower, position.tickUpper));
            tokensOwed0 += uint128(
                FullMath.mulDiv(
                    feeGrowthInside0LastX128 - position.feeGrowthInside0LastX128,
                    position.liquidity,
                    FixedPoint128.Q128
                )
            );
            tokensOwed1 += uint128(
                FullMath.mulDiv(
                    feeGrowthInside1LastX128 - position.feeGrowthInside1LastX128,
                    position.liquidity,
                    FixedPoint128.Q128
                )
            );
            position.feeGrowthInside0LastX128 = feeGrowthInside0LastX128;
            position.feeGrowthInside1LastX128 = feeGrowthInside1LastX128;
        }
        // compute the arguments to give to the pool#collect method
        (uint128 amount0Collect, uint128 amount1Collect) =
            (
                params.amount0Max > tokensOwed0 ? tokensOwed0 : params.amount0Max,
                params.amount1Max > tokensOwed1 ? tokensOwed1 : params.amount1Max
            );
        // the actual amounts collected are returned
        (amount0, amount1) = pool.collect(
            recipient,
            position.tickLower,
            position.tickUpper,
            amount0Collect,
            amount1Collect
        );
        // sometimes there will be a few less wei than expected due to rounding down in core, but we just subtract the full amount expected
        // instead of the actual amount so we can burn the token
        (position.tokensOwed0, position.tokensOwed1) = (tokensOwed0 - amount0Collect, tokensOwed1 - amount1Collect);
        emit Collect(params.tokenId, recipient, amount0Collect, amount1Collect);
    }
    /// @inheritdoc INonfungiblePositionManager
    function burn(uint256 tokenId) external payable override isAuthorizedForToken(tokenId) {
        Position storage position = _positions[tokenId];
        require(position.liquidity == 0 && position.tokensOwed0 == 0 && position.tokensOwed1 == 0, 'Not cleared');
        delete _positions[tokenId];
        _burn(tokenId);
    }
    function _getAndIncrementNonce(uint256 tokenId) internal override returns (uint256) {
        return uint256(_positions[tokenId].nonce++);
    }
    /// @inheritdoc IERC721
    function getApproved(uint256 tokenId) public view override(ERC721, IERC721) returns (address) {
        require(_exists(tokenId), 'ERC721: approved query for nonexistent token');
        return _positions[tokenId].operator;
    }
    /// @dev Overrides _approve to use the operator in the position, which is packed with the position permit nonce
    function _approve(address to, uint256 tokenId) internal override(ERC721) {
        _positions[tokenId].operator = to;
        emit Approval(ownerOf(tokenId), to, tokenId);
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
import './pool/IUniswapV3PoolImmutables.sol';
import './pool/IUniswapV3PoolState.sol';
import './pool/IUniswapV3PoolDerivedState.sol';
import './pool/IUniswapV3PoolActions.sol';
import './pool/IUniswapV3PoolOwnerActions.sol';
import './pool/IUniswapV3PoolEvents.sol';
/// @title The interface for a Uniswap V3 Pool
/// @notice A Uniswap pool facilitates swapping and automated market making between any two assets that strictly conform
/// to the ERC20 specification
/// @dev The pool interface is broken up into many smaller pieces
interface IUniswapV3Pool is
    IUniswapV3PoolImmutables,
    IUniswapV3PoolState,
    IUniswapV3PoolDerivedState,
    IUniswapV3PoolActions,
    IUniswapV3PoolOwnerActions,
    IUniswapV3PoolEvents
{
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.4.0;
/// @title FixedPoint128
/// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
library FixedPoint128 {
    uint256 internal constant Q128 = 0x100000000000000000000000000000000;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.4.0;
/// @title Contains 512-bit math functions
/// @notice Facilitates multiplication and division that can have overflow of an intermediate value without any loss of precision
/// @dev Handles "phantom overflow" i.e., allows multiplication and division where an intermediate value overflows 256 bits
library FullMath {
    /// @notice Calculates floor(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
    /// @param a The multiplicand
    /// @param b The multiplier
    /// @param denominator The divisor
    /// @return result The 256-bit result
    /// @dev Credit to Remco Bloemen under MIT license https://xn--2-umb.com/21/muldiv
    function mulDiv(
        uint256 a,
        uint256 b,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        // 512-bit multiply [prod1 prod0] = a * b
        // Compute the product mod 2**256 and mod 2**256 - 1
        // then use the Chinese Remainder Theorem to reconstruct
        // the 512 bit result. The result is stored in two 256
        // variables such that product = prod1 * 2**256 + prod0
        uint256 prod0; // Least significant 256 bits of the product
        uint256 prod1; // Most significant 256 bits of the product
        assembly {
            let mm := mulmod(a, b, not(0))
            prod0 := mul(a, b)
            prod1 := sub(sub(mm, prod0), lt(mm, prod0))
        }
        // Handle non-overflow cases, 256 by 256 division
        if (prod1 == 0) {
            require(denominator > 0);
            assembly {
                result := div(prod0, denominator)
            }
            return result;
        }
        // Make sure the result is less than 2**256.
        // Also prevents denominator == 0
        require(denominator > prod1);
        ///////////////////////////////////////////////
        // 512 by 256 division.
        ///////////////////////////////////////////////
        // Make division exact by subtracting the remainder from [prod1 prod0]
        // Compute remainder using mulmod
        uint256 remainder;
        assembly {
            remainder := mulmod(a, b, denominator)
        }
        // Subtract 256 bit number from 512 bit number
        assembly {
            prod1 := sub(prod1, gt(remainder, prod0))
            prod0 := sub(prod0, remainder)
        }
        // Factor powers of two out of denominator
        // Compute largest power of two divisor of denominator.
        // Always >= 1.
        uint256 twos = -denominator & denominator;
        // Divide denominator by power of two
        assembly {
            denominator := div(denominator, twos)
        }
        // Divide [prod1 prod0] by the factors of two
        assembly {
            prod0 := div(prod0, twos)
        }
        // Shift in bits from prod1 into prod0. For this we need
        // to flip `twos` such that it is 2**256 / twos.
        // If twos is zero, then it becomes one
        assembly {
            twos := add(div(sub(0, twos), twos), 1)
        }
        prod0 |= prod1 * twos;
        // Invert denominator mod 2**256
        // Now that denominator is an odd number, it has an inverse
        // modulo 2**256 such that denominator * inv = 1 mod 2**256.
        // Compute the inverse by starting with a seed that is correct
        // correct for four bits. That is, denominator * inv = 1 mod 2**4
        uint256 inv = (3 * denominator) ^ 2;
        // Now use Newton-Raphson iteration to improve the precision.
        // Thanks to Hensel's lifting lemma, this also works in modular
        // arithmetic, doubling the correct bits in each step.
        inv *= 2 - denominator * inv; // inverse mod 2**8
        inv *= 2 - denominator * inv; // inverse mod 2**16
        inv *= 2 - denominator * inv; // inverse mod 2**32
        inv *= 2 - denominator * inv; // inverse mod 2**64
        inv *= 2 - denominator * inv; // inverse mod 2**128
        inv *= 2 - denominator * inv; // inverse mod 2**256
        // Because the division is now exact we can divide by multiplying
        // with the modular inverse of denominator. This will give us the
        // correct result modulo 2**256. Since the precoditions guarantee
        // that the outcome is less than 2**256, this is the final result.
        // We don't need to compute the high bits of the result and prod1
        // is no longer required.
        result = prod0 * inv;
        return result;
    }
    /// @notice Calculates ceil(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
    /// @param a The multiplicand
    /// @param b The multiplier
    /// @param denominator The divisor
    /// @return result The 256-bit result
    function mulDivRoundingUp(
        uint256 a,
        uint256 b,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        result = mulDiv(a, b, denominator);
        if (mulmod(a, b, denominator) > 0) {
            require(result < type(uint256).max);
            result++;
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;
import '@openzeppelin/contracts/token/ERC721/IERC721Metadata.sol';
import '@openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol';
import './IPoolInitializer.sol';
import './IERC721Permit.sol';
import './IPeripheryPayments.sol';
import './IPeripheryImmutableState.sol';
import '../libraries/PoolAddress.sol';
/// @title Non-fungible token for positions
/// @notice Wraps Uniswap V3 positions in a non-fungible token interface which allows for them to be transferred
/// and authorized.
interface INonfungiblePositionManager is
    IPoolInitializer,
    IPeripheryPayments,
    IPeripheryImmutableState,
    IERC721Metadata,
    IERC721Enumerable,
    IERC721Permit
{
    /// @notice Emitted when liquidity is increased for a position NFT
    /// @dev Also emitted when a token is minted
    /// @param tokenId The ID of the token for which liquidity was increased
    /// @param liquidity The amount by which liquidity for the NFT position was increased
    /// @param amount0 The amount of token0 that was paid for the increase in liquidity
    /// @param amount1 The amount of token1 that was paid for the increase in liquidity
    event IncreaseLiquidity(uint256 indexed tokenId, uint128 liquidity, uint256 amount0, uint256 amount1);
    /// @notice Emitted when liquidity is decreased for a position NFT
    /// @param tokenId The ID of the token for which liquidity was decreased
    /// @param liquidity The amount by which liquidity for the NFT position was decreased
    /// @param amount0 The amount of token0 that was accounted for the decrease in liquidity
    /// @param amount1 The amount of token1 that was accounted for the decrease in liquidity
    event DecreaseLiquidity(uint256 indexed tokenId, uint128 liquidity, uint256 amount0, uint256 amount1);
    /// @notice Emitted when tokens are collected for a position NFT
    /// @dev The amounts reported may not be exactly equivalent to the amounts transferred, due to rounding behavior
    /// @param tokenId The ID of the token for which underlying tokens were collected
    /// @param recipient The address of the account that received the collected tokens
    /// @param amount0 The amount of token0 owed to the position that was collected
    /// @param amount1 The amount of token1 owed to the position that was collected
    event Collect(uint256 indexed tokenId, address recipient, uint256 amount0, uint256 amount1);
    /// @notice Returns the position information associated with a given token ID.
    /// @dev Throws if the token ID is not valid.
    /// @param tokenId The ID of the token that represents the position
    /// @return nonce The nonce for permits
    /// @return operator The address that is approved for spending
    /// @return token0 The address of the token0 for a specific pool
    /// @return token1 The address of the token1 for a specific pool
    /// @return fee The fee associated with the pool
    /// @return tickLower The lower end of the tick range for the position
    /// @return tickUpper The higher end of the tick range for the position
    /// @return liquidity The liquidity of the position
    /// @return feeGrowthInside0LastX128 The fee growth of token0 as of the last action on the individual position
    /// @return feeGrowthInside1LastX128 The fee growth of token1 as of the last action on the individual position
    /// @return tokensOwed0 The uncollected amount of token0 owed to the position as of the last computation
    /// @return tokensOwed1 The uncollected amount of token1 owed to the position as of the last computation
    function positions(uint256 tokenId)
        external
        view
        returns (
            uint96 nonce,
            address operator,
            address token0,
            address token1,
            uint24 fee,
            int24 tickLower,
            int24 tickUpper,
            uint128 liquidity,
            uint256 feeGrowthInside0LastX128,
            uint256 feeGrowthInside1LastX128,
            uint128 tokensOwed0,
            uint128 tokensOwed1
        );
    struct MintParams {
        address token0;
        address token1;
        uint24 fee;
        int24 tickLower;
        int24 tickUpper;
        uint256 amount0Desired;
        uint256 amount1Desired;
        uint256 amount0Min;
        uint256 amount1Min;
        address recipient;
        uint256 deadline;
    }
    /// @notice Creates a new position wrapped in a NFT
    /// @dev Call this when the pool does exist and is initialized. Note that if the pool is created but not initialized
    /// a method does not exist, i.e. the pool is assumed to be initialized.
    /// @param params The params necessary to mint a position, encoded as `MintParams` in calldata
    /// @return tokenId The ID of the token that represents the minted position
    /// @return liquidity The amount of liquidity for this position
    /// @return amount0 The amount of token0
    /// @return amount1 The amount of token1
    function mint(MintParams calldata params)
        external
        payable
        returns (
            uint256 tokenId,
            uint128 liquidity,
            uint256 amount0,
            uint256 amount1
        );
    struct IncreaseLiquidityParams {
        uint256 tokenId;
        uint256 amount0Desired;
        uint256 amount1Desired;
        uint256 amount0Min;
        uint256 amount1Min;
        uint256 deadline;
    }
    /// @notice Increases the amount of liquidity in a position, with tokens paid by the `msg.sender`
    /// @param params tokenId The ID of the token for which liquidity is being increased,
    /// amount0Desired The desired amount of token0 to be spent,
    /// amount1Desired The desired amount of token1 to be spent,
    /// amount0Min The minimum amount of token0 to spend, which serves as a slippage check,
    /// amount1Min The minimum amount of token1 to spend, which serves as a slippage check,
    /// deadline The time by which the transaction must be included to effect the change
    /// @return liquidity The new liquidity amount as a result of the increase
    /// @return amount0 The amount of token0 to acheive resulting liquidity
    /// @return amount1 The amount of token1 to acheive resulting liquidity
    function increaseLiquidity(IncreaseLiquidityParams calldata params)
        external
        payable
        returns (
            uint128 liquidity,
            uint256 amount0,
            uint256 amount1
        );
    struct DecreaseLiquidityParams {
        uint256 tokenId;
        uint128 liquidity;
        uint256 amount0Min;
        uint256 amount1Min;
        uint256 deadline;
    }
    /// @notice Decreases the amount of liquidity in a position and accounts it to the position
    /// @param params tokenId The ID of the token for which liquidity is being decreased,
    /// amount The amount by which liquidity will be decreased,
    /// amount0Min The minimum amount of token0 that should be accounted for the burned liquidity,
    /// amount1Min The minimum amount of token1 that should be accounted for the burned liquidity,
    /// deadline The time by which the transaction must be included to effect the change
    /// @return amount0 The amount of token0 accounted to the position's tokens owed
    /// @return amount1 The amount of token1 accounted to the position's tokens owed
    function decreaseLiquidity(DecreaseLiquidityParams calldata params)
        external
        payable
        returns (uint256 amount0, uint256 amount1);
    struct CollectParams {
        uint256 tokenId;
        address recipient;
        uint128 amount0Max;
        uint128 amount1Max;
    }
    /// @notice Collects up to a maximum amount of fees owed to a specific position to the recipient
    /// @param params tokenId The ID of the NFT for which tokens are being collected,
    /// recipient The account that should receive the tokens,
    /// amount0Max The maximum amount of token0 to collect,
    /// amount1Max The maximum amount of token1 to collect
    /// @return amount0 The amount of fees collected in token0
    /// @return amount1 The amount of fees collected in token1
    function collect(CollectParams calldata params) external payable returns (uint256 amount0, uint256 amount1);
    /// @notice Burns a token ID, which deletes it from the NFT contract. The token must have 0 liquidity and all tokens
    /// must be collected first.
    /// @param tokenId The ID of the token that is being burned
    function burn(uint256 tokenId) external payable;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
import './INonfungiblePositionManager.sol';
/// @title Describes position NFT tokens via URI
interface INonfungibleTokenPositionDescriptor {
    /// @notice Emitted when a token is given a new priority order in the displayed price ratio
    /// @param token The token being given priority order
    /// @param priority Represents priority in ratio - higher integers get numerator priority
    event UpdateTokenRatioPriority(address token, int256 priority);
    /// @notice Produces the URI describing a particular token ID for a position manager
    /// @dev Note this URI may be a data: URI with the JSON contents directly inlined
    /// @param positionManager The position manager for which to describe the token
    /// @param tokenId The ID of the token for which to produce a description, which may not be valid
    /// @return The URI of the ERC721-compliant metadata
    function tokenURI(INonfungiblePositionManager positionManager, uint256 tokenId)
        external
        view
        returns (string memory);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
library PositionKey {
    /// @dev Returns the key of the position in the core library
    function compute(
        address owner,
        int24 tickLower,
        int24 tickUpper
    ) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked(owner, tickLower, tickUpper));
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Provides functions for deriving a pool address from the factory, tokens, and the fee
library PoolAddress {
    bytes32 internal constant POOL_INIT_CODE_HASH = 0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54;
    /// @notice The identifying key of the pool
    struct PoolKey {
        address token0;
        address token1;
        uint24 fee;
    }
    /// @notice Returns PoolKey: the ordered tokens with the matched fee levels
    /// @param tokenA The first token of a pool, unsorted
    /// @param tokenB The second token of a pool, unsorted
    /// @param fee The fee level of the pool
    /// @return Poolkey The pool details with ordered token0 and token1 assignments
    function getPoolKey(
        address tokenA,
        address tokenB,
        uint24 fee
    ) internal pure returns (PoolKey memory) {
        if (tokenA > tokenB) (tokenA, tokenB) = (tokenB, tokenA);
        return PoolKey({token0: tokenA, token1: tokenB, fee: fee});
    }
    /// @notice Deterministically computes the pool address given the factory and PoolKey
    /// @param factory The Uniswap V3 factory contract address
    /// @param key The PoolKey
    /// @return pool The contract address of the V3 pool
    function computeAddress(address factory, PoolKey memory key) internal pure returns (address pool) {
        require(key.token0 < key.token1);
        pool = address(
            uint256(
                keccak256(
                    abi.encodePacked(
                        hex'ff',
                        factory,
                        keccak256(abi.encode(key.token0, key.token1, key.fee)),
                        POOL_INIT_CODE_HASH
                    )
                )
            )
        );
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
pragma abicoder v2;
import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Factory.sol';
import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3MintCallback.sol';
import '@uniswap/v3-core/contracts/libraries/TickMath.sol';
import '../libraries/PoolAddress.sol';
import '../libraries/CallbackValidation.sol';
import '../libraries/LiquidityAmounts.sol';
import './PeripheryPayments.sol';
import './PeripheryImmutableState.sol';
/// @title Liquidity management functions
/// @notice Internal functions for safely managing liquidity in Uniswap V3
abstract contract LiquidityManagement is IUniswapV3MintCallback, PeripheryImmutableState, PeripheryPayments {
    struct MintCallbackData {
        PoolAddress.PoolKey poolKey;
        address payer;
    }
    /// @inheritdoc IUniswapV3MintCallback
    function uniswapV3MintCallback(
        uint256 amount0Owed,
        uint256 amount1Owed,
        bytes calldata data
    ) external override {
        MintCallbackData memory decoded = abi.decode(data, (MintCallbackData));
        CallbackValidation.verifyCallback(factory, decoded.poolKey);
        if (amount0Owed > 0) pay(decoded.poolKey.token0, decoded.payer, msg.sender, amount0Owed);
        if (amount1Owed > 0) pay(decoded.poolKey.token1, decoded.payer, msg.sender, amount1Owed);
    }
    struct AddLiquidityParams {
        address token0;
        address token1;
        uint24 fee;
        address recipient;
        int24 tickLower;
        int24 tickUpper;
        uint256 amount0Desired;
        uint256 amount1Desired;
        uint256 amount0Min;
        uint256 amount1Min;
    }
    /// @notice Add liquidity to an initialized pool
    function addLiquidity(AddLiquidityParams memory params)
        internal
        returns (
            uint128 liquidity,
            uint256 amount0,
            uint256 amount1,
            IUniswapV3Pool pool
        )
    {
        PoolAddress.PoolKey memory poolKey =
            PoolAddress.PoolKey({token0: params.token0, token1: params.token1, fee: params.fee});
        pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
        // compute the liquidity amount
        {
            (uint160 sqrtPriceX96, , , , , , ) = pool.slot0();
            uint160 sqrtRatioAX96 = TickMath.getSqrtRatioAtTick(params.tickLower);
            uint160 sqrtRatioBX96 = TickMath.getSqrtRatioAtTick(params.tickUpper);
            liquidity = LiquidityAmounts.getLiquidityForAmounts(
                sqrtPriceX96,
                sqrtRatioAX96,
                sqrtRatioBX96,
                params.amount0Desired,
                params.amount1Desired
            );
        }
        (amount0, amount1) = pool.mint(
            params.recipient,
            params.tickLower,
            params.tickUpper,
            liquidity,
            abi.encode(MintCallbackData({poolKey: poolKey, payer: msg.sender}))
        );
        require(amount0 >= params.amount0Min && amount1 >= params.amount1Min, 'Price slippage check');
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import '../interfaces/IPeripheryImmutableState.sol';
/// @title Immutable state
/// @notice Immutable state used by periphery contracts
abstract contract PeripheryImmutableState is IPeripheryImmutableState {
    /// @inheritdoc IPeripheryImmutableState
    address public immutable override factory;
    /// @inheritdoc IPeripheryImmutableState
    address public immutable override WETH9;
    constructor(address _factory, address _WETH9) {
        factory = _factory;
        WETH9 = _WETH9;
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
pragma abicoder v2;
import '../interfaces/IMulticall.sol';
/// @title Multicall
/// @notice Enables calling multiple methods in a single call to the contract
abstract contract Multicall is IMulticall {
    /// @inheritdoc IMulticall
    function multicall(bytes[] calldata data) external payable override returns (bytes[] memory results) {
        results = new bytes[](data.length);
        for (uint256 i = 0; i < data.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(data[i]);
            if (!success) {
                // Next 5 lines from https://ethereum.stackexchange.com/a/83577
                if (result.length < 68) revert();
                assembly {
                    result := add(result, 0x04)
                }
                revert(abi.decode(result, (string)));
            }
            results[i] = result;
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import '@openzeppelin/contracts/token/ERC721/ERC721.sol';
import '@openzeppelin/contracts/utils/Address.sol';
import '../libraries/ChainId.sol';
import '../interfaces/external/IERC1271.sol';
import '../interfaces/IERC721Permit.sol';
import './BlockTimestamp.sol';
/// @title ERC721 with permit
/// @notice Nonfungible tokens that support an approve via signature, i.e. permit
abstract contract ERC721Permit is BlockTimestamp, ERC721, IERC721Permit {
    /// @dev Gets the current nonce for a token ID and then increments it, returning the original value
    function _getAndIncrementNonce(uint256 tokenId) internal virtual returns (uint256);
    /// @dev The hash of the name used in the permit signature verification
    bytes32 private immutable nameHash;
    /// @dev The hash of the version string used in the permit signature verification
    bytes32 private immutable versionHash;
    /// @notice Computes the nameHash and versionHash
    constructor(
        string memory name_,
        string memory symbol_,
        string memory version_
    ) ERC721(name_, symbol_) {
        nameHash = keccak256(bytes(name_));
        versionHash = keccak256(bytes(version_));
    }
    /// @inheritdoc IERC721Permit
    function DOMAIN_SEPARATOR() public view override returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    // keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)')
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                    nameHash,
                    versionHash,
                    ChainId.get(),
                    address(this)
                )
            );
    }
    /// @inheritdoc IERC721Permit
    /// @dev Value is equal to keccak256("Permit(address spender,uint256 tokenId,uint256 nonce,uint256 deadline)");
    bytes32 public constant override PERMIT_TYPEHASH =
        0x49ecf333e5b8c95c40fdafc95c1ad136e8914a8fb55e9dc8bb01eaa83a2df9ad;
    /// @inheritdoc IERC721Permit
    function permit(
        address spender,
        uint256 tokenId,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable override {
        require(_blockTimestamp() <= deadline, 'Permit expired');
        bytes32 digest =
            keccak256(
                abi.encodePacked(
                    '\\x19\\x01',
                    DOMAIN_SEPARATOR(),
                    keccak256(abi.encode(PERMIT_TYPEHASH, spender, tokenId, _getAndIncrementNonce(tokenId), deadline))
                )
            );
        address owner = ownerOf(tokenId);
        require(spender != owner, 'ERC721Permit: approval to current owner');
        if (Address.isContract(owner)) {
            require(IERC1271(owner).isValidSignature(digest, abi.encodePacked(r, s, v)) == 0x1626ba7e, 'Unauthorized');
        } else {
            address recoveredAddress = ecrecover(digest, v, r, s);
            require(recoveredAddress != address(0), 'Invalid signature');
            require(recoveredAddress == owner, 'Unauthorized');
        }
        _approve(spender, tokenId);
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import './BlockTimestamp.sol';
abstract contract PeripheryValidation is BlockTimestamp {
    modifier checkDeadline(uint256 deadline) {
        require(_blockTimestamp() <= deadline, 'Transaction too old');
        _;
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/drafts/IERC20Permit.sol';
import '../interfaces/ISelfPermit.sol';
import '../interfaces/external/IERC20PermitAllowed.sol';
/// @title Self Permit
/// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
/// @dev These functions are expected to be embedded in multicalls to allow EOAs to approve a contract and call a function
/// that requires an approval in a single transaction.
abstract contract SelfPermit is ISelfPermit {
    /// @inheritdoc ISelfPermit
    function selfPermit(
        address token,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public payable override {
        IERC20Permit(token).permit(msg.sender, address(this), value, deadline, v, r, s);
    }
    /// @inheritdoc ISelfPermit
    function selfPermitIfNecessary(
        address token,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable override {
        if (IERC20(token).allowance(msg.sender, address(this)) < value) selfPermit(token, value, deadline, v, r, s);
    }
    /// @inheritdoc ISelfPermit
    function selfPermitAllowed(
        address token,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public payable override {
        IERC20PermitAllowed(token).permit(msg.sender, address(this), nonce, expiry, true, v, r, s);
    }
    /// @inheritdoc ISelfPermit
    function selfPermitAllowedIfNecessary(
        address token,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable override {
        if (IERC20(token).allowance(msg.sender, address(this)) < type(uint256).max)
            selfPermitAllowed(token, nonce, expiry, v, r, s);
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Factory.sol';
import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
import './PeripheryImmutableState.sol';
import '../interfaces/IPoolInitializer.sol';
/// @title Creates and initializes V3 Pools
abstract contract PoolInitializer is IPoolInitializer, PeripheryImmutableState {
    /// @inheritdoc IPoolInitializer
    function createAndInitializePoolIfNecessary(
        address token0,
        address token1,
        uint24 fee,
        uint160 sqrtPriceX96
    ) external payable override returns (address pool) {
        require(token0 < token1);
        pool = IUniswapV3Factory(factory).getPool(token0, token1, fee);
        if (pool == address(0)) {
            pool = IUniswapV3Factory(factory).createPool(token0, token1, fee);
            IUniswapV3Pool(pool).initialize(sqrtPriceX96);
        } else {
            (uint160 sqrtPriceX96Existing, , , , , , ) = IUniswapV3Pool(pool).slot0();
            if (sqrtPriceX96Existing == 0) {
                IUniswapV3Pool(pool).initialize(sqrtPriceX96);
            }
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Pool state that never changes
/// @notice These parameters are fixed for a pool forever, i.e., the methods will always return the same values
interface IUniswapV3PoolImmutables {
    /// @notice The contract that deployed the pool, which must adhere to the IUniswapV3Factory interface
    /// @return The contract address
    function factory() external view returns (address);
    /// @notice The first of the two tokens of the pool, sorted by address
    /// @return The token contract address
    function token0() external view returns (address);
    /// @notice The second of the two tokens of the pool, sorted by address
    /// @return The token contract address
    function token1() external view returns (address);
    /// @notice The pool's fee in hundredths of a bip, i.e. 1e-6
    /// @return The fee
    function fee() external view returns (uint24);
    /// @notice The pool tick spacing
    /// @dev Ticks can only be used at multiples of this value, minimum of 1 and always positive
    /// e.g.: a tickSpacing of 3 means ticks can be initialized every 3rd tick, i.e., ..., -6, -3, 0, 3, 6, ...
    /// This value is an int24 to avoid casting even though it is always positive.
    /// @return The tick spacing
    function tickSpacing() external view returns (int24);
    /// @notice The maximum amount of position liquidity that can use any tick in the range
    /// @dev This parameter is enforced per tick to prevent liquidity from overflowing a uint128 at any point, and
    /// also prevents out-of-range liquidity from being used to prevent adding in-range liquidity to a pool
    /// @return The max amount of liquidity per tick
    function maxLiquidityPerTick() external view returns (uint128);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Pool state that can change
/// @notice These methods compose the pool's state, and can change with any frequency including multiple times
/// per transaction
interface IUniswapV3PoolState {
    /// @notice The 0th storage slot in the pool stores many values, and is exposed as a single method to save gas
    /// when accessed externally.
    /// @return sqrtPriceX96 The current price of the pool as a sqrt(token1/token0) Q64.96 value
    /// tick The current tick of the pool, i.e. according to the last tick transition that was run.
    /// This value may not always be equal to SqrtTickMath.getTickAtSqrtRatio(sqrtPriceX96) if the price is on a tick
    /// boundary.
    /// observationIndex The index of the last oracle observation that was written,
    /// observationCardinality The current maximum number of observations stored in the pool,
    /// observationCardinalityNext The next maximum number of observations, to be updated when the observation.
    /// feeProtocol The protocol fee for both tokens of the pool.
    /// Encoded as two 4 bit values, where the protocol fee of token1 is shifted 4 bits and the protocol fee of token0
    /// is the lower 4 bits. Used as the denominator of a fraction of the swap fee, e.g. 4 means 1/4th of the swap fee.
    /// unlocked Whether the pool is currently locked to reentrancy
    function slot0()
        external
        view
        returns (
            uint160 sqrtPriceX96,
            int24 tick,
            uint16 observationIndex,
            uint16 observationCardinality,
            uint16 observationCardinalityNext,
            uint8 feeProtocol,
            bool unlocked
        );
    /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
    /// @dev This value can overflow the uint256
    function feeGrowthGlobal0X128() external view returns (uint256);
    /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
    /// @dev This value can overflow the uint256
    function feeGrowthGlobal1X128() external view returns (uint256);
    /// @notice The amounts of token0 and token1 that are owed to the protocol
    /// @dev Protocol fees will never exceed uint128 max in either token
    function protocolFees() external view returns (uint128 token0, uint128 token1);
    /// @notice The currently in range liquidity available to the pool
    /// @dev This value has no relationship to the total liquidity across all ticks
    function liquidity() external view returns (uint128);
    /// @notice Look up information about a specific tick in the pool
    /// @param tick The tick to look up
    /// @return liquidityGross the total amount of position liquidity that uses the pool either as tick lower or
    /// tick upper,
    /// liquidityNet how much liquidity changes when the pool price crosses the tick,
    /// feeGrowthOutside0X128 the fee growth on the other side of the tick from the current tick in token0,
    /// feeGrowthOutside1X128 the fee growth on the other side of the tick from the current tick in token1,
    /// tickCumulativeOutside the cumulative tick value on the other side of the tick from the current tick
    /// secondsPerLiquidityOutsideX128 the seconds spent per liquidity on the other side of the tick from the current tick,
    /// secondsOutside the seconds spent on the other side of the tick from the current tick,
    /// initialized Set to true if the tick is initialized, i.e. liquidityGross is greater than 0, otherwise equal to false.
    /// Outside values can only be used if the tick is initialized, i.e. if liquidityGross is greater than 0.
    /// In addition, these values are only relative and must be used only in comparison to previous snapshots for
    /// a specific position.
    function ticks(int24 tick)
        external
        view
        returns (
            uint128 liquidityGross,
            int128 liquidityNet,
            uint256 feeGrowthOutside0X128,
            uint256 feeGrowthOutside1X128,
            int56 tickCumulativeOutside,
            uint160 secondsPerLiquidityOutsideX128,
            uint32 secondsOutside,
            bool initialized
        );
    /// @notice Returns 256 packed tick initialized boolean values. See TickBitmap for more information
    function tickBitmap(int16 wordPosition) external view returns (uint256);
    /// @notice Returns the information about a position by the position's key
    /// @param key The position's key is a hash of a preimage composed by the owner, tickLower and tickUpper
    /// @return _liquidity The amount of liquidity in the position,
    /// Returns feeGrowthInside0LastX128 fee growth of token0 inside the tick range as of the last mint/burn/poke,
    /// Returns feeGrowthInside1LastX128 fee growth of token1 inside the tick range as of the last mint/burn/poke,
    /// Returns tokensOwed0 the computed amount of token0 owed to the position as of the last mint/burn/poke,
    /// Returns tokensOwed1 the computed amount of token1 owed to the position as of the last mint/burn/poke
    function positions(bytes32 key)
        external
        view
        returns (
            uint128 _liquidity,
            uint256 feeGrowthInside0LastX128,
            uint256 feeGrowthInside1LastX128,
            uint128 tokensOwed0,
            uint128 tokensOwed1
        );
    /// @notice Returns data about a specific observation index
    /// @param index The element of the observations array to fetch
    /// @dev You most likely want to use #observe() instead of this method to get an observation as of some amount of time
    /// ago, rather than at a specific index in the array.
    /// @return blockTimestamp The timestamp of the observation,
    /// Returns tickCumulative the tick multiplied by seconds elapsed for the life of the pool as of the observation timestamp,
    /// Returns secondsPerLiquidityCumulativeX128 the seconds per in range liquidity for the life of the pool as of the observation timestamp,
    /// Returns initialized whether the observation has been initialized and the values are safe to use
    function observations(uint256 index)
        external
        view
        returns (
            uint32 blockTimestamp,
            int56 tickCumulative,
            uint160 secondsPerLiquidityCumulativeX128,
            bool initialized
        );
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Pool state that is not stored
/// @notice Contains view functions to provide information about the pool that is computed rather than stored on the
/// blockchain. The functions here may have variable gas costs.
interface IUniswapV3PoolDerivedState {
    /// @notice Returns the cumulative tick and liquidity as of each timestamp `secondsAgo` from the current block timestamp
    /// @dev To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing
    /// the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick,
    /// you must call it with secondsAgos = [3600, 0].
    /// @dev The time weighted average tick represents the geometric time weighted average price of the pool, in
    /// log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.
    /// @param secondsAgos From how long ago each cumulative tick and liquidity value should be returned
    /// @return tickCumulatives Cumulative tick values as of each `secondsAgos` from the current block timestamp
    /// @return secondsPerLiquidityCumulativeX128s Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block
    /// timestamp
    function observe(uint32[] calldata secondsAgos)
        external
        view
        returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s);
    /// @notice Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range
    /// @dev Snapshots must only be compared to other snapshots, taken over a period for which a position existed.
    /// I.e., snapshots cannot be compared if a position is not held for the entire period between when the first
    /// snapshot is taken and the second snapshot is taken.
    /// @param tickLower The lower tick of the range
    /// @param tickUpper The upper tick of the range
    /// @return tickCumulativeInside The snapshot of the tick accumulator for the range
    /// @return secondsPerLiquidityInsideX128 The snapshot of seconds per liquidity for the range
    /// @return secondsInside The snapshot of seconds per liquidity for the range
    function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
        external
        view
        returns (
            int56 tickCumulativeInside,
            uint160 secondsPerLiquidityInsideX128,
            uint32 secondsInside
        );
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Permissionless pool actions
/// @notice Contains pool methods that can be called by anyone
interface IUniswapV3PoolActions {
    /// @notice Sets the initial price for the pool
    /// @dev Price is represented as a sqrt(amountToken1/amountToken0) Q64.96 value
    /// @param sqrtPriceX96 the initial sqrt price of the pool as a Q64.96
    function initialize(uint160 sqrtPriceX96) external;
    /// @notice Adds liquidity for the given recipient/tickLower/tickUpper position
    /// @dev The caller of this method receives a callback in the form of IUniswapV3MintCallback#uniswapV3MintCallback
    /// in which they must pay any token0 or token1 owed for the liquidity. The amount of token0/token1 due depends
    /// on tickLower, tickUpper, the amount of liquidity, and the current price.
    /// @param recipient The address for which the liquidity will be created
    /// @param tickLower The lower tick of the position in which to add liquidity
    /// @param tickUpper The upper tick of the position in which to add liquidity
    /// @param amount The amount of liquidity to mint
    /// @param data Any data that should be passed through to the callback
    /// @return amount0 The amount of token0 that was paid to mint the given amount of liquidity. Matches the value in the callback
    /// @return amount1 The amount of token1 that was paid to mint the given amount of liquidity. Matches the value in the callback
    function mint(
        address recipient,
        int24 tickLower,
        int24 tickUpper,
        uint128 amount,
        bytes calldata data
    ) external returns (uint256 amount0, uint256 amount1);
    /// @notice Collects tokens owed to a position
    /// @dev Does not recompute fees earned, which must be done either via mint or burn of any amount of liquidity.
    /// Collect must be called by the position owner. To withdraw only token0 or only token1, amount0Requested or
    /// amount1Requested may be set to zero. To withdraw all tokens owed, caller may pass any value greater than the
    /// actual tokens owed, e.g. type(uint128).max. Tokens owed may be from accumulated swap fees or burned liquidity.
    /// @param recipient The address which should receive the fees collected
    /// @param tickLower The lower tick of the position for which to collect fees
    /// @param tickUpper The upper tick of the position for which to collect fees
    /// @param amount0Requested How much token0 should be withdrawn from the fees owed
    /// @param amount1Requested How much token1 should be withdrawn from the fees owed
    /// @return amount0 The amount of fees collected in token0
    /// @return amount1 The amount of fees collected in token1
    function collect(
        address recipient,
        int24 tickLower,
        int24 tickUpper,
        uint128 amount0Requested,
        uint128 amount1Requested
    ) external returns (uint128 amount0, uint128 amount1);
    /// @notice Burn liquidity from the sender and account tokens owed for the liquidity to the position
    /// @dev Can be used to trigger a recalculation of fees owed to a position by calling with an amount of 0
    /// @dev Fees must be collected separately via a call to #collect
    /// @param tickLower The lower tick of the position for which to burn liquidity
    /// @param tickUpper The upper tick of the position for which to burn liquidity
    /// @param amount How much liquidity to burn
    /// @return amount0 The amount of token0 sent to the recipient
    /// @return amount1 The amount of token1 sent to the recipient
    function burn(
        int24 tickLower,
        int24 tickUpper,
        uint128 amount
    ) external returns (uint256 amount0, uint256 amount1);
    /// @notice Swap token0 for token1, or token1 for token0
    /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
    /// @param recipient The address to receive the output of the swap
    /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
    /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
    /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
    /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
    /// @param data Any data to be passed through to the callback
    /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
    /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
    function swap(
        address recipient,
        bool zeroForOne,
        int256 amountSpecified,
        uint160 sqrtPriceLimitX96,
        bytes calldata data
    ) external returns (int256 amount0, int256 amount1);
    /// @notice Receive token0 and/or token1 and pay it back, plus a fee, in the callback
    /// @dev The caller of this method receives a callback in the form of IUniswapV3FlashCallback#uniswapV3FlashCallback
    /// @dev Can be used to donate underlying tokens pro-rata to currently in-range liquidity providers by calling
    /// with 0 amount{0,1} and sending the donation amount(s) from the callback
    /// @param recipient The address which will receive the token0 and token1 amounts
    /// @param amount0 The amount of token0 to send
    /// @param amount1 The amount of token1 to send
    /// @param data Any data to be passed through to the callback
    function flash(
        address recipient,
        uint256 amount0,
        uint256 amount1,
        bytes calldata data
    ) external;
    /// @notice Increase the maximum number of price and liquidity observations that this pool will store
    /// @dev This method is no-op if the pool already has an observationCardinalityNext greater than or equal to
    /// the input observationCardinalityNext.
    /// @param observationCardinalityNext The desired minimum number of observations for the pool to store
    function increaseObservationCardinalityNext(uint16 observationCardinalityNext) external;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Permissioned pool actions
/// @notice Contains pool methods that may only be called by the factory owner
interface IUniswapV3PoolOwnerActions {
    /// @notice Set the denominator of the protocol's % share of the fees
    /// @param feeProtocol0 new protocol fee for token0 of the pool
    /// @param feeProtocol1 new protocol fee for token1 of the pool
    function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external;
    /// @notice Collect the protocol fee accrued to the pool
    /// @param recipient The address to which collected protocol fees should be sent
    /// @param amount0Requested The maximum amount of token0 to send, can be 0 to collect fees in only token1
    /// @param amount1Requested The maximum amount of token1 to send, can be 0 to collect fees in only token0
    /// @return amount0 The protocol fee collected in token0
    /// @return amount1 The protocol fee collected in token1
    function collectProtocol(
        address recipient,
        uint128 amount0Requested,
        uint128 amount1Requested
    ) external returns (uint128 amount0, uint128 amount1);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Events emitted by a pool
/// @notice Contains all events emitted by the pool
interface IUniswapV3PoolEvents {
    /// @notice Emitted exactly once by a pool when #initialize is first called on the pool
    /// @dev Mint/Burn/Swap cannot be emitted by the pool before Initialize
    /// @param sqrtPriceX96 The initial sqrt price of the pool, as a Q64.96
    /// @param tick The initial tick of the pool, i.e. log base 1.0001 of the starting price of the pool
    event Initialize(uint160 sqrtPriceX96, int24 tick);
    /// @notice Emitted when liquidity is minted for a given position
    /// @param sender The address that minted the liquidity
    /// @param owner The owner of the position and recipient of any minted liquidity
    /// @param tickLower The lower tick of the position
    /// @param tickUpper The upper tick of the position
    /// @param amount The amount of liquidity minted to the position range
    /// @param amount0 How much token0 was required for the minted liquidity
    /// @param amount1 How much token1 was required for the minted liquidity
    event Mint(
        address sender,
        address indexed owner,
        int24 indexed tickLower,
        int24 indexed tickUpper,
        uint128 amount,
        uint256 amount0,
        uint256 amount1
    );
    /// @notice Emitted when fees are collected by the owner of a position
    /// @dev Collect events may be emitted with zero amount0 and amount1 when the caller chooses not to collect fees
    /// @param owner The owner of the position for which fees are collected
    /// @param tickLower The lower tick of the position
    /// @param tickUpper The upper tick of the position
    /// @param amount0 The amount of token0 fees collected
    /// @param amount1 The amount of token1 fees collected
    event Collect(
        address indexed owner,
        address recipient,
        int24 indexed tickLower,
        int24 indexed tickUpper,
        uint128 amount0,
        uint128 amount1
    );
    /// @notice Emitted when a position's liquidity is removed
    /// @dev Does not withdraw any fees earned by the liquidity position, which must be withdrawn via #collect
    /// @param owner The owner of the position for which liquidity is removed
    /// @param tickLower The lower tick of the position
    /// @param tickUpper The upper tick of the position
    /// @param amount The amount of liquidity to remove
    /// @param amount0 The amount of token0 withdrawn
    /// @param amount1 The amount of token1 withdrawn
    event Burn(
        address indexed owner,
        int24 indexed tickLower,
        int24 indexed tickUpper,
        uint128 amount,
        uint256 amount0,
        uint256 amount1
    );
    /// @notice Emitted by the pool for any swaps between token0 and token1
    /// @param sender The address that initiated the swap call, and that received the callback
    /// @param recipient The address that received the output of the swap
    /// @param amount0 The delta of the token0 balance of the pool
    /// @param amount1 The delta of the token1 balance of the pool
    /// @param sqrtPriceX96 The sqrt(price) of the pool after the swap, as a Q64.96
    /// @param liquidity The liquidity of the pool after the swap
    /// @param tick The log base 1.0001 of price of the pool after the swap
    event Swap(
        address indexed sender,
        address indexed recipient,
        int256 amount0,
        int256 amount1,
        uint160 sqrtPriceX96,
        uint128 liquidity,
        int24 tick
    );
    /// @notice Emitted by the pool for any flashes of token0/token1
    /// @param sender The address that initiated the swap call, and that received the callback
    /// @param recipient The address that received the tokens from flash
    /// @param amount0 The amount of token0 that was flashed
    /// @param amount1 The amount of token1 that was flashed
    /// @param paid0 The amount of token0 paid for the flash, which can exceed the amount0 plus the fee
    /// @param paid1 The amount of token1 paid for the flash, which can exceed the amount1 plus the fee
    event Flash(
        address indexed sender,
        address indexed recipient,
        uint256 amount0,
        uint256 amount1,
        uint256 paid0,
        uint256 paid1
    );
    /// @notice Emitted by the pool for increases to the number of observations that can be stored
    /// @dev observationCardinalityNext is not the observation cardinality until an observation is written at the index
    /// just before a mint/swap/burn.
    /// @param observationCardinalityNextOld The previous value of the next observation cardinality
    /// @param observationCardinalityNextNew The updated value of the next observation cardinality
    event IncreaseObservationCardinalityNext(
        uint16 observationCardinalityNextOld,
        uint16 observationCardinalityNextNew
    );
    /// @notice Emitted when the protocol fee is changed by the pool
    /// @param feeProtocol0Old The previous value of the token0 protocol fee
    /// @param feeProtocol1Old The previous value of the token1 protocol fee
    /// @param feeProtocol0New The updated value of the token0 protocol fee
    /// @param feeProtocol1New The updated value of the token1 protocol fee
    event SetFeeProtocol(uint8 feeProtocol0Old, uint8 feeProtocol1Old, uint8 feeProtocol0New, uint8 feeProtocol1New);
    /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
    /// @param sender The address that collects the protocol fees
    /// @param recipient The address that receives the collected protocol fees
    /// @param amount0 The amount of token0 protocol fees that is withdrawn
    /// @param amount0 The amount of token1 protocol fees that is withdrawn
    event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;
/// @title Creates and initializes V3 Pools
/// @notice Provides a method for creating and initializing a pool, if necessary, for bundling with other methods that
/// require the pool to exist.
interface IPoolInitializer {
    /// @notice Creates a new pool if it does not exist, then initializes if not initialized
    /// @dev This method can be bundled with others via IMulticall for the first action (e.g. mint) performed against a pool
    /// @param token0 The contract address of token0 of the pool
    /// @param token1 The contract address of token1 of the pool
    /// @param fee The fee amount of the v3 pool for the specified token pair
    /// @param sqrtPriceX96 The initial square root price of the pool as a Q64.96 value
    /// @return pool Returns the pool address based on the pair of tokens and fee, will return the newly created pool address if necessary
    function createAndInitializePoolIfNecessary(
        address token0,
        address token1,
        uint24 fee,
        uint160 sqrtPriceX96
    ) external payable returns (address pool);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
/// @title ERC721 with permit
/// @notice Extension to ERC721 that includes a permit function for signature based approvals
interface IERC721Permit is IERC721 {
    /// @notice The permit typehash used in the permit signature
    /// @return The typehash for the permit
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    /// @notice The domain separator used in the permit signature
    /// @return The domain seperator used in encoding of permit signature
    function DOMAIN_SEPARATOR() external view returns (bytes32);
    /// @notice Approve of a specific token ID for spending by spender via signature
    /// @param spender The account that is being approved
    /// @param tokenId The ID of the token that is being approved for spending
    /// @param deadline The deadline timestamp by which the call must be mined for the approve to work
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function permit(
        address spender,
        uint256 tokenId,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
/// @title Periphery Payments
/// @notice Functions to ease deposits and withdrawals of ETH
interface IPeripheryPayments {
    /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH.
    /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
    /// @param amountMinimum The minimum amount of WETH9 to unwrap
    /// @param recipient The address receiving ETH
    function unwrapWETH9(uint256 amountMinimum, address recipient) external payable;
    /// @notice Refunds any ETH balance held by this contract to the `msg.sender`
    /// @dev Useful for bundling with mint or increase liquidity that uses ether, or exact output swaps
    /// that use ether for the input amount
    function refundETH() external payable;
    /// @notice Transfers the full amount of a token held by this contract to recipient
    /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
    /// @param token The contract address of the token which will be transferred to `recipient`
    /// @param amountMinimum The minimum amount of token required for a transfer
    /// @param recipient The destination address of the token
    function sweepToken(
        address token,
        uint256 amountMinimum,
        address recipient
    ) external payable;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Immutable state
/// @notice Functions that return immutable state of the router
interface IPeripheryImmutableState {
    /// @return Returns the address of the Uniswap V3 factory
    function factory() external view returns (address);
    /// @return Returns the address of WETH9
    function WETH9() external view returns (address);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../introspection/IERC165.sol";
/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);
    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);
    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId) external;
    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 tokenId) external;
    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;
    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);
    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;
    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
    /**
      * @dev Safely transfers `tokenId` token from `from` to `to`.
      *
      * Requirements:
      *
      * - `from` cannot be the zero address.
      * - `to` cannot be the zero address.
      * - `tokenId` token must exist and be owned by `from`.
      * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
      * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
      *
      * Emits a {Transfer} event.
      */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title The interface for the Uniswap V3 Factory
/// @notice The Uniswap V3 Factory facilitates creation of Uniswap V3 pools and control over the protocol fees
interface IUniswapV3Factory {
    /// @notice Emitted when the owner of the factory is changed
    /// @param oldOwner The owner before the owner was changed
    /// @param newOwner The owner after the owner was changed
    event OwnerChanged(address indexed oldOwner, address indexed newOwner);
    /// @notice Emitted when a pool is created
    /// @param token0 The first token of the pool by address sort order
    /// @param token1 The second token of the pool by address sort order
    /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
    /// @param tickSpacing The minimum number of ticks between initialized ticks
    /// @param pool The address of the created pool
    event PoolCreated(
        address indexed token0,
        address indexed token1,
        uint24 indexed fee,
        int24 tickSpacing,
        address pool
    );
    /// @notice Emitted when a new fee amount is enabled for pool creation via the factory
    /// @param fee The enabled fee, denominated in hundredths of a bip
    /// @param tickSpacing The minimum number of ticks between initialized ticks for pools created with the given fee
    event FeeAmountEnabled(uint24 indexed fee, int24 indexed tickSpacing);
    /// @notice Returns the current owner of the factory
    /// @dev Can be changed by the current owner via setOwner
    /// @return The address of the factory owner
    function owner() external view returns (address);
    /// @notice Returns the tick spacing for a given fee amount, if enabled, or 0 if not enabled
    /// @dev A fee amount can never be removed, so this value should be hard coded or cached in the calling context
    /// @param fee The enabled fee, denominated in hundredths of a bip. Returns 0 in case of unenabled fee
    /// @return The tick spacing
    function feeAmountTickSpacing(uint24 fee) external view returns (int24);
    /// @notice Returns the pool address for a given pair of tokens and a fee, or address 0 if it does not exist
    /// @dev tokenA and tokenB may be passed in either token0/token1 or token1/token0 order
    /// @param tokenA The contract address of either token0 or token1
    /// @param tokenB The contract address of the other token
    /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
    /// @return pool The pool address
    function getPool(
        address tokenA,
        address tokenB,
        uint24 fee
    ) external view returns (address pool);
    /// @notice Creates a pool for the given two tokens and fee
    /// @param tokenA One of the two tokens in the desired pool
    /// @param tokenB The other of the two tokens in the desired pool
    /// @param fee The desired fee for the pool
    /// @dev tokenA and tokenB may be passed in either order: token0/token1 or token1/token0. tickSpacing is retrieved
    /// from the fee. The call will revert if the pool already exists, the fee is invalid, or the token arguments
    /// are invalid.
    /// @return pool The address of the newly created pool
    function createPool(
        address tokenA,
        address tokenB,
        uint24 fee
    ) external returns (address pool);
    /// @notice Updates the owner of the factory
    /// @dev Must be called by the current owner
    /// @param _owner The new owner of the factory
    function setOwner(address _owner) external;
    /// @notice Enables a fee amount with the given tickSpacing
    /// @dev Fee amounts may never be removed once enabled
    /// @param fee The fee amount to enable, denominated in hundredths of a bip (i.e. 1e-6)
    /// @param tickSpacing The spacing between ticks to be enforced for all pools created with the given fee amount
    function enableFeeAmount(uint24 fee, int24 tickSpacing) external;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Callback for IUniswapV3PoolActions#mint
/// @notice Any contract that calls IUniswapV3PoolActions#mint must implement this interface
interface IUniswapV3MintCallback {
    /// @notice Called to `msg.sender` after minting liquidity to a position from IUniswapV3Pool#mint.
    /// @dev In the implementation you must pay the pool tokens owed for the minted liquidity.
    /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
    /// @param amount0Owed The amount of token0 due to the pool for the minted liquidity
    /// @param amount1Owed The amount of token1 due to the pool for the minted liquidity
    /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#mint call
    function uniswapV3MintCallback(
        uint256 amount0Owed,
        uint256 amount1Owed,
        bytes calldata data
    ) external;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Math library for computing sqrt prices from ticks and vice versa
/// @notice Computes sqrt price for ticks of size 1.0001, i.e. sqrt(1.0001^tick) as fixed point Q64.96 numbers. Supports
/// prices between 2**-128 and 2**128
library TickMath {
    /// @dev The minimum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**-128
    int24 internal constant MIN_TICK = -887272;
    /// @dev The maximum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**128
    int24 internal constant MAX_TICK = -MIN_TICK;
    /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
    uint160 internal constant MIN_SQRT_RATIO = 4295128739;
    /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
    uint160 internal constant MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
    /// @notice Calculates sqrt(1.0001^tick) * 2^96
    /// @dev Throws if |tick| > max tick
    /// @param tick The input tick for the above formula
    /// @return sqrtPriceX96 A Fixed point Q64.96 number representing the sqrt of the ratio of the two assets (token1/token0)
    /// at the given tick
    function getSqrtRatioAtTick(int24 tick) internal pure returns (uint160 sqrtPriceX96) {
        uint256 absTick = tick < 0 ? uint256(-int256(tick)) : uint256(int256(tick));
        require(absTick <= uint256(MAX_TICK), 'T');
        uint256 ratio = absTick & 0x1 != 0 ? 0xfffcb933bd6fad37aa2d162d1a594001 : 0x100000000000000000000000000000000;
        if (absTick & 0x2 != 0) ratio = (ratio * 0xfff97272373d413259a46990580e213a) >> 128;
        if (absTick & 0x4 != 0) ratio = (ratio * 0xfff2e50f5f656932ef12357cf3c7fdcc) >> 128;
        if (absTick & 0x8 != 0) ratio = (ratio * 0xffe5caca7e10e4e61c3624eaa0941cd0) >> 128;
        if (absTick & 0x10 != 0) ratio = (ratio * 0xffcb9843d60f6159c9db58835c926644) >> 128;
        if (absTick & 0x20 != 0) ratio = (ratio * 0xff973b41fa98c081472e6896dfb254c0) >> 128;
        if (absTick & 0x40 != 0) ratio = (ratio * 0xff2ea16466c96a3843ec78b326b52861) >> 128;
        if (absTick & 0x80 != 0) ratio = (ratio * 0xfe5dee046a99a2a811c461f1969c3053) >> 128;
        if (absTick & 0x100 != 0) ratio = (ratio * 0xfcbe86c7900a88aedcffc83b479aa3a4) >> 128;
        if (absTick & 0x200 != 0) ratio = (ratio * 0xf987a7253ac413176f2b074cf7815e54) >> 128;
        if (absTick & 0x400 != 0) ratio = (ratio * 0xf3392b0822b70005940c7a398e4b70f3) >> 128;
        if (absTick & 0x800 != 0) ratio = (ratio * 0xe7159475a2c29b7443b29c7fa6e889d9) >> 128;
        if (absTick & 0x1000 != 0) ratio = (ratio * 0xd097f3bdfd2022b8845ad8f792aa5825) >> 128;
        if (absTick & 0x2000 != 0) ratio = (ratio * 0xa9f746462d870fdf8a65dc1f90e061e5) >> 128;
        if (absTick & 0x4000 != 0) ratio = (ratio * 0x70d869a156d2a1b890bb3df62baf32f7) >> 128;
        if (absTick & 0x8000 != 0) ratio = (ratio * 0x31be135f97d08fd981231505542fcfa6) >> 128;
        if (absTick & 0x10000 != 0) ratio = (ratio * 0x9aa508b5b7a84e1c677de54f3e99bc9) >> 128;
        if (absTick & 0x20000 != 0) ratio = (ratio * 0x5d6af8dedb81196699c329225ee604) >> 128;
        if (absTick & 0x40000 != 0) ratio = (ratio * 0x2216e584f5fa1ea926041bedfe98) >> 128;
        if (absTick & 0x80000 != 0) ratio = (ratio * 0x48a170391f7dc42444e8fa2) >> 128;
        if (tick > 0) ratio = type(uint256).max / ratio;
        // this divides by 1<<32 rounding up to go from a Q128.128 to a Q128.96.
        // we then downcast because we know the result always fits within 160 bits due to our tick input constraint
        // we round up in the division so getTickAtSqrtRatio of the output price is always consistent
        sqrtPriceX96 = uint160((ratio >> 32) + (ratio % (1 << 32) == 0 ? 0 : 1));
    }
    /// @notice Calculates the greatest tick value such that getRatioAtTick(tick) <= ratio
    /// @dev Throws in case sqrtPriceX96 < MIN_SQRT_RATIO, as MIN_SQRT_RATIO is the lowest value getRatioAtTick may
    /// ever return.
    /// @param sqrtPriceX96 The sqrt ratio for which to compute the tick as a Q64.96
    /// @return tick The greatest tick for which the ratio is less than or equal to the input ratio
    function getTickAtSqrtRatio(uint160 sqrtPriceX96) internal pure returns (int24 tick) {
        // second inequality must be < because the price can never reach the price at the max tick
        require(sqrtPriceX96 >= MIN_SQRT_RATIO && sqrtPriceX96 < MAX_SQRT_RATIO, 'R');
        uint256 ratio = uint256(sqrtPriceX96) << 32;
        uint256 r = ratio;
        uint256 msb = 0;
        assembly {
            let f := shl(7, gt(r, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(6, gt(r, 0xFFFFFFFFFFFFFFFF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(5, gt(r, 0xFFFFFFFF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(4, gt(r, 0xFFFF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(3, gt(r, 0xFF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(2, gt(r, 0xF))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := shl(1, gt(r, 0x3))
            msb := or(msb, f)
            r := shr(f, r)
        }
        assembly {
            let f := gt(r, 0x1)
            msb := or(msb, f)
        }
        if (msb >= 128) r = ratio >> (msb - 127);
        else r = ratio << (127 - msb);
        int256 log_2 = (int256(msb) - 128) << 64;
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(63, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(62, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(61, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(60, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(59, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(58, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(57, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(56, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(55, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(54, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(53, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(52, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(51, f))
            r := shr(f, r)
        }
        assembly {
            r := shr(127, mul(r, r))
            let f := shr(128, r)
            log_2 := or(log_2, shl(50, f))
        }
        int256 log_sqrt10001 = log_2 * 255738958999603826347141; // 128.128 number
        int24 tickLow = int24((log_sqrt10001 - 3402992956809132418596140100660247210) >> 128);
        int24 tickHi = int24((log_sqrt10001 + 291339464771989622907027621153398088495) >> 128);
        tick = tickLow == tickHi ? tickLow : getSqrtRatioAtTick(tickHi) <= sqrtPriceX96 ? tickHi : tickLow;
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
import './PoolAddress.sol';
/// @notice Provides validation for callbacks from Uniswap V3 Pools
library CallbackValidation {
    /// @notice Returns the address of a valid Uniswap V3 Pool
    /// @param factory The contract address of the Uniswap V3 factory
    /// @param tokenA The contract address of either token0 or token1
    /// @param tokenB The contract address of the other token
    /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
    /// @return pool The V3 pool contract address
    function verifyCallback(
        address factory,
        address tokenA,
        address tokenB,
        uint24 fee
    ) internal view returns (IUniswapV3Pool pool) {
        return verifyCallback(factory, PoolAddress.getPoolKey(tokenA, tokenB, fee));
    }
    /// @notice Returns the address of a valid Uniswap V3 Pool
    /// @param factory The contract address of the Uniswap V3 factory
    /// @param poolKey The identifying key of the V3 pool
    /// @return pool The V3 pool contract address
    function verifyCallback(address factory, PoolAddress.PoolKey memory poolKey)
        internal
        view
        returns (IUniswapV3Pool pool)
    {
        pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
        require(msg.sender == address(pool));
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
import '@uniswap/v3-core/contracts/libraries/FullMath.sol';
import '@uniswap/v3-core/contracts/libraries/FixedPoint96.sol';
/// @title Liquidity amount functions
/// @notice Provides functions for computing liquidity amounts from token amounts and prices
library LiquidityAmounts {
    /// @notice Downcasts uint256 to uint128
    /// @param x The uint258 to be downcasted
    /// @return y The passed value, downcasted to uint128
    function toUint128(uint256 x) private pure returns (uint128 y) {
        require((y = uint128(x)) == x);
    }
    /// @notice Computes the amount of liquidity received for a given amount of token0 and price range
    /// @dev Calculates amount0 * (sqrt(upper) * sqrt(lower)) / (sqrt(upper) - sqrt(lower))
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param amount0 The amount0 being sent in
    /// @return liquidity The amount of returned liquidity
    function getLiquidityForAmount0(
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint256 amount0
    ) internal pure returns (uint128 liquidity) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        uint256 intermediate = FullMath.mulDiv(sqrtRatioAX96, sqrtRatioBX96, FixedPoint96.Q96);
        return toUint128(FullMath.mulDiv(amount0, intermediate, sqrtRatioBX96 - sqrtRatioAX96));
    }
    /// @notice Computes the amount of liquidity received for a given amount of token1 and price range
    /// @dev Calculates amount1 / (sqrt(upper) - sqrt(lower)).
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param amount1 The amount1 being sent in
    /// @return liquidity The amount of returned liquidity
    function getLiquidityForAmount1(
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint256 amount1
    ) internal pure returns (uint128 liquidity) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        return toUint128(FullMath.mulDiv(amount1, FixedPoint96.Q96, sqrtRatioBX96 - sqrtRatioAX96));
    }
    /// @notice Computes the maximum amount of liquidity received for a given amount of token0, token1, the current
    /// pool prices and the prices at the tick boundaries
    /// @param sqrtRatioX96 A sqrt price representing the current pool prices
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param amount0 The amount of token0 being sent in
    /// @param amount1 The amount of token1 being sent in
    /// @return liquidity The maximum amount of liquidity received
    function getLiquidityForAmounts(
        uint160 sqrtRatioX96,
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint256 amount0,
        uint256 amount1
    ) internal pure returns (uint128 liquidity) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        if (sqrtRatioX96 <= sqrtRatioAX96) {
            liquidity = getLiquidityForAmount0(sqrtRatioAX96, sqrtRatioBX96, amount0);
        } else if (sqrtRatioX96 < sqrtRatioBX96) {
            uint128 liquidity0 = getLiquidityForAmount0(sqrtRatioX96, sqrtRatioBX96, amount0);
            uint128 liquidity1 = getLiquidityForAmount1(sqrtRatioAX96, sqrtRatioX96, amount1);
            liquidity = liquidity0 < liquidity1 ? liquidity0 : liquidity1;
        } else {
            liquidity = getLiquidityForAmount1(sqrtRatioAX96, sqrtRatioBX96, amount1);
        }
    }
    /// @notice Computes the amount of token0 for a given amount of liquidity and a price range
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param liquidity The liquidity being valued
    /// @return amount0 The amount of token0
    function getAmount0ForLiquidity(
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint128 liquidity
    ) internal pure returns (uint256 amount0) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        return
            FullMath.mulDiv(
                uint256(liquidity) << FixedPoint96.RESOLUTION,
                sqrtRatioBX96 - sqrtRatioAX96,
                sqrtRatioBX96
            ) / sqrtRatioAX96;
    }
    /// @notice Computes the amount of token1 for a given amount of liquidity and a price range
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param liquidity The liquidity being valued
    /// @return amount1 The amount of token1
    function getAmount1ForLiquidity(
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint128 liquidity
    ) internal pure returns (uint256 amount1) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        return FullMath.mulDiv(liquidity, sqrtRatioBX96 - sqrtRatioAX96, FixedPoint96.Q96);
    }
    /// @notice Computes the token0 and token1 value for a given amount of liquidity, the current
    /// pool prices and the prices at the tick boundaries
    /// @param sqrtRatioX96 A sqrt price representing the current pool prices
    /// @param sqrtRatioAX96 A sqrt price representing the first tick boundary
    /// @param sqrtRatioBX96 A sqrt price representing the second tick boundary
    /// @param liquidity The liquidity being valued
    /// @return amount0 The amount of token0
    /// @return amount1 The amount of token1
    function getAmountsForLiquidity(
        uint160 sqrtRatioX96,
        uint160 sqrtRatioAX96,
        uint160 sqrtRatioBX96,
        uint128 liquidity
    ) internal pure returns (uint256 amount0, uint256 amount1) {
        if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
        if (sqrtRatioX96 <= sqrtRatioAX96) {
            amount0 = getAmount0ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity);
        } else if (sqrtRatioX96 < sqrtRatioBX96) {
            amount0 = getAmount0ForLiquidity(sqrtRatioX96, sqrtRatioBX96, liquidity);
            amount1 = getAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioX96, liquidity);
        } else {
            amount1 = getAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity);
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '../interfaces/IPeripheryPayments.sol';
import '../interfaces/external/IWETH9.sol';
import '../libraries/TransferHelper.sol';
import './PeripheryImmutableState.sol';
abstract contract PeripheryPayments is IPeripheryPayments, PeripheryImmutableState {
    receive() external payable {
        require(msg.sender == WETH9, 'Not WETH9');
    }
    /// @inheritdoc IPeripheryPayments
    function unwrapWETH9(uint256 amountMinimum, address recipient) external payable override {
        uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
        require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');
        if (balanceWETH9 > 0) {
            IWETH9(WETH9).withdraw(balanceWETH9);
            TransferHelper.safeTransferETH(recipient, balanceWETH9);
        }
    }
    /// @inheritdoc IPeripheryPayments
    function sweepToken(
        address token,
        uint256 amountMinimum,
        address recipient
    ) external payable override {
        uint256 balanceToken = IERC20(token).balanceOf(address(this));
        require(balanceToken >= amountMinimum, 'Insufficient token');
        if (balanceToken > 0) {
            TransferHelper.safeTransfer(token, recipient, balanceToken);
        }
    }
    /// @inheritdoc IPeripheryPayments
    function refundETH() external payable override {
        if (address(this).balance > 0) TransferHelper.safeTransferETH(msg.sender, address(this).balance);
    }
    /// @param token The token to pay
    /// @param payer The entity that must pay
    /// @param recipient The entity that will receive payment
    /// @param value The amount to pay
    function pay(
        address token,
        address payer,
        address recipient,
        uint256 value
    ) internal {
        if (token == WETH9 && address(this).balance >= value) {
            // pay with WETH9
            IWETH9(WETH9).deposit{value: value}(); // wrap only what is needed to pay
            IWETH9(WETH9).transfer(recipient, value);
        } else if (payer == address(this)) {
            // pay with tokens already in the contract (for the exact input multihop case)
            TransferHelper.safeTransfer(token, recipient, value);
        } else {
            // pull payment
            TransferHelper.safeTransferFrom(token, payer, recipient, value);
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.4.0;
/// @title FixedPoint96
/// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
/// @dev Used in SqrtPriceMath.sol
library FixedPoint96 {
    uint8 internal constant RESOLUTION = 96;
    uint256 internal constant Q96 = 0x1000000000000000000000000;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
/// @title Interface for WETH9
interface IWETH9 is IERC20 {
    /// @notice Deposit ether to get wrapped ether
    function deposit() external payable;
    /// @notice Withdraw wrapped ether to get ether
    function withdraw(uint256) external;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.0;
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
library TransferHelper {
    /// @notice Transfers tokens from the targeted address to the given destination
    /// @notice Errors with 'STF' if transfer fails
    /// @param token The contract address of the token to be transferred
    /// @param from The originating address from which the tokens will be transferred
    /// @param to The destination address of the transfer
    /// @param value The amount to be transferred
    function safeTransferFrom(
        address token,
        address from,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) =
            token.call(abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'STF');
    }
    /// @notice Transfers tokens from msg.sender to a recipient
    /// @dev Errors with ST if transfer fails
    /// @param token The contract address of the token which will be transferred
    /// @param to The recipient of the transfer
    /// @param value The value of the transfer
    function safeTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'ST');
    }
    /// @notice Approves the stipulated contract to spend the given allowance in the given token
    /// @dev Errors with 'SA' if transfer fails
    /// @param token The contract address of the token to be approved
    /// @param to The target of the approval
    /// @param value The amount of the given token the target will be allowed to spend
    function safeApprove(
        address token,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.approve.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'SA');
    }
    /// @notice Transfers ETH to the recipient address
    /// @dev Fails with `STE`
    /// @param to The destination of the transfer
    /// @param value The value to be transferred
    function safeTransferETH(address to, uint256 value) internal {
        (bool success, ) = to.call{value: value}(new bytes(0));
        require(success, 'STE');
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;
/// @title Multicall interface
/// @notice Enables calling multiple methods in a single call to the contract
interface IMulticall {
    /// @notice Call multiple functions in the current contract and return the data from all of them if they all succeed
    /// @dev The `msg.value` should not be trusted for any method callable from multicall.
    /// @param data The encoded function data for each of the calls to make to this contract
    /// @return results The results from each of the calls passed in via data
    function multicall(bytes[] calldata data) external payable returns (bytes[] memory results);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../utils/Context.sol";
import "./IERC721.sol";
import "./IERC721Metadata.sol";
import "./IERC721Enumerable.sol";
import "./IERC721Receiver.sol";
import "../../introspection/ERC165.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
import "../../utils/EnumerableSet.sol";
import "../../utils/EnumerableMap.sol";
import "../../utils/Strings.sol";
/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev see https://eips.ethereum.org/EIPS/eip-721
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable {
    using SafeMath for uint256;
    using Address for address;
    using EnumerableSet for EnumerableSet.UintSet;
    using EnumerableMap for EnumerableMap.UintToAddressMap;
    using Strings for uint256;
    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
    // Mapping from holder address to their (enumerable) set of owned tokens
    mapping (address => EnumerableSet.UintSet) private _holderTokens;
    // Enumerable mapping from token ids to their owners
    EnumerableMap.UintToAddressMap private _tokenOwners;
    // Mapping from token ID to approved address
    mapping (uint256 => address) private _tokenApprovals;
    // Mapping from owner to operator approvals
    mapping (address => mapping (address => bool)) private _operatorApprovals;
    // Token name
    string private _name;
    // Token symbol
    string private _symbol;
    // Optional mapping for token URIs
    mapping (uint256 => string) private _tokenURIs;
    // Base URI
    string private _baseURI;
    /*
     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231
     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
     *
     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
     *        0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
     */
    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
    /*
     *     bytes4(keccak256('name()')) == 0x06fdde03
     *     bytes4(keccak256('symbol()')) == 0x95d89b41
     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
     *
     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
     */
    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
    /*
     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd
     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
     *
     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
     */
    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor (string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_INTERFACE_ID_ERC721);
        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
    }
    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _holderTokens[owner].length();
    }
    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
    }
    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
        string memory _tokenURI = _tokenURIs[tokenId];
        string memory base = baseURI();
        // If there is no base URI, return the token URI.
        if (bytes(base).length == 0) {
            return _tokenURI;
        }
        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
        if (bytes(_tokenURI).length > 0) {
            return string(abi.encodePacked(base, _tokenURI));
        }
        // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
        return string(abi.encodePacked(base, tokenId.toString()));
    }
    /**
    * @dev Returns the base URI set via {_setBaseURI}. This will be
    * automatically added as a prefix in {tokenURI} to each token's URI, or
    * to the token ID if no specific URI is set for that token ID.
    */
    function baseURI() public view virtual returns (string memory) {
        return _baseURI;
    }
    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        return _holderTokens[owner].at(index);
    }
    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
        return _tokenOwners.length();
    }
    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        (uint256 tokenId, ) = _tokenOwners.at(index);
        return tokenId;
    }
    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");
        require(_msgSender() == owner || ERC721.isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );
        _approve(to, tokenId);
    }
    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");
        return _tokenApprovals[tokenId];
    }
    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        require(operator != _msgSender(), "ERC721: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
    }
    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }
    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(address from, address to, uint256 tokenId) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _transfer(from, to, tokenId);
    }
    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }
    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }
    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(address from, address to, uint256 tokenId, bytes memory _data) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }
    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _tokenOwners.contains(tokenId);
    }
    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || ERC721.isApprovedForAll(owner, spender));
    }
    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     d*
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }
    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(address to, uint256 tokenId, bytes memory _data) internal virtual {
        _mint(to, tokenId);
        require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }
    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");
        _beforeTokenTransfer(address(0), to, tokenId);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(tokenId, to);
        emit Transfer(address(0), to, tokenId);
    }
    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId); // internal owner
        _beforeTokenTransfer(owner, address(0), tokenId);
        // Clear approvals
        _approve(address(0), tokenId);
        // Clear metadata (if any)
        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
        _holderTokens[owner].remove(tokenId);
        _tokenOwners.remove(tokenId);
        emit Transfer(owner, address(0), tokenId);
    }
    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(address from, address to, uint256 tokenId) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); // internal owner
        require(to != address(0), "ERC721: transfer to the zero address");
        _beforeTokenTransfer(from, to, tokenId);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId);
        _holderTokens[from].remove(tokenId);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(tokenId, to);
        emit Transfer(from, to, tokenId);
    }
    /**
     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
        require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }
    /**
     * @dev Internal function to set the base URI for all token IDs. It is
     * automatically added as a prefix to the value returned in {tokenURI},
     * or to the token ID if {tokenURI} is empty.
     */
    function _setBaseURI(string memory baseURI_) internal virtual {
        _baseURI = baseURI_;
    }
    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
        private returns (bool)
    {
        if (!to.isContract()) {
            return true;
        }
        bytes memory returndata = to.functionCall(abi.encodeWithSelector(
            IERC721Receiver(to).onERC721Received.selector,
            _msgSender(),
            from,
            tokenId,
            _data
        ), "ERC721: transfer to non ERC721Receiver implementer");
        bytes4 retval = abi.decode(returndata, (bytes4));
        return (retval == _ERC721_RECEIVED);
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId); // internal owner
    }
    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual { }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.0;
/// @title Function for getting the current chain ID
library ChainId {
    /// @dev Gets the current chain ID
    /// @return chainId The current chain ID
    function get() internal pure returns (uint256 chainId) {
        assembly {
            chainId := chainid()
        }
    }
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Interface for verifying contract-based account signatures
/// @notice Interface that verifies provided signature for the data
/// @dev Interface defined by EIP-1271
interface IERC1271 {
    /// @notice Returns whether the provided signature is valid for the provided data
    /// @dev MUST return the bytes4 magic value 0x1626ba7e when function passes.
    /// MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5).
    /// MUST allow external calls.
    /// @param hash Hash of the data to be signed
    /// @param signature Signature byte array associated with _data
    /// @return magicValue The bytes4 magic value 0x1626ba7e
    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
/// @title Function for getting block timestamp
/// @dev Base contract that is overridden for tests
abstract contract BlockTimestamp {
    /// @dev Method that exists purely to be overridden for tests
    /// @return The current block timestamp
    function _blockTimestamp() internal view virtual returns (uint256) {
        return block.timestamp;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with 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: MIT
pragma solidity ^0.7.0;
/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC165.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts may inherit from this and call {_registerInterface} to declare
 * their support of an interface.
 */
abstract contract ERC165 is IERC165 {
    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
    /**
     * @dev Mapping of interface ids to whether or not it's supported.
     */
    mapping(bytes4 => bool) private _supportedInterfaces;
    constructor () {
        // Derived contracts need only register support for their own interfaces,
        // we register support for ERC165 itself here
        _registerInterface(_INTERFACE_ID_ERC165);
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     *
     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return _supportedInterfaces[interfaceId];
    }
    /**
     * @dev Registers the contract as an implementer of the interface defined by
     * `interfaceId`. Support of the actual ERC165 interface is automatic and
     * registering its interface id is not required.
     *
     * See {IERC165-supportsInterface}.
     *
     * Requirements:
     *
     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
     */
    function _registerInterface(bytes4 interfaceId) internal virtual {
        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
        _supportedInterfaces[interfaceId] = true;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) { // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            bytes32 lastvalue = set._values[lastIndex];
            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        require(set._values.length > index, "EnumerableSet: index out of bounds");
        return set._values[index];
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing an enumerable variant of Solidity's
 * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
 * type.
 *
 * Maps have the following properties:
 *
 * - Entries are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Entries are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableMap for EnumerableMap.UintToAddressMap;
 *
 *     // Declare a set state variable
 *     EnumerableMap.UintToAddressMap private myMap;
 * }
 * ```
 *
 * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
 * supported.
 */
library EnumerableMap {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Map type with
    // bytes32 keys and values.
    // The Map implementation uses private functions, and user-facing
    // implementations (such as Uint256ToAddressMap) are just wrappers around
    // the underlying Map.
    // This means that we can only create new EnumerableMaps for types that fit
    // in bytes32.
    struct MapEntry {
        bytes32 _key;
        bytes32 _value;
    }
    struct Map {
        // Storage of map keys and values
        MapEntry[] _entries;
        // Position of the entry defined by a key in the `entries` array, plus 1
        // because index 0 means a key is not in the map.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) { // Equivalent to !contains(map, key)
            map._entries.push(MapEntry({ _key: key, _value: value }));
            // The entry is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            map._indexes[key] = map._entries.length;
            return true;
        } else {
            map._entries[keyIndex - 1]._value = value;
            return false;
        }
    }
    /**
     * @dev Removes a key-value pair from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function _remove(Map storage map, bytes32 key) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex != 0) { // Equivalent to contains(map, key)
            // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one
            // in the array, and then remove the last entry (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = keyIndex - 1;
            uint256 lastIndex = map._entries.length - 1;
            // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            MapEntry storage lastEntry = map._entries[lastIndex];
            // Move the last entry to the index where the entry to delete is
            map._entries[toDeleteIndex] = lastEntry;
            // Update the index for the moved entry
            map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved entry was stored
            map._entries.pop();
            // Delete the index for the deleted slot
            delete map._indexes[key];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function _contains(Map storage map, bytes32 key) private view returns (bool) {
        return map._indexes[key] != 0;
    }
    /**
     * @dev Returns the number of key-value pairs in the map. O(1).
     */
    function _length(Map storage map) private view returns (uint256) {
        return map._entries.length;
    }
   /**
    * @dev Returns the key-value pair stored at position `index` in the map. O(1).
    *
    * Note that there are no guarantees on the ordering of entries inside the
    * array, and it may change when more entries are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {
        require(map._entries.length > index, "EnumerableMap: index out of bounds");
        MapEntry storage entry = map._entries[index];
        return (entry._key, entry._value);
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     */
    function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) return (false, 0); // Equivalent to contains(map, key)
        return (true, map._entries[keyIndex - 1]._value); // All indexes are 1-based
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function _get(Map storage map, bytes32 key) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, "EnumerableMap: nonexistent key"); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    /**
     * @dev Same as {_get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {_tryGet}.
     */
    function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    // UintToAddressMap
    struct UintToAddressMap {
        Map _inner;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {
        return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
        return _remove(map._inner, bytes32(key));
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
        return _contains(map._inner, bytes32(key));
    }
    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToAddressMap storage map) internal view returns (uint256) {
        return _length(map._inner);
    }
   /**
    * @dev Returns the element stored at position `index` in the set. O(1).
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
        (bytes32 key, bytes32 value) = _at(map._inner, index);
        return (uint256(key), address(uint160(uint256(value))));
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     *
     * _Available since v3.4._
     */
    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));
        return (success, address(uint160(uint256(value))));
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key)))));
    }
    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev String operations.
 */
library Strings {
    /**
     * @dev Converts a `uint256` to its ASCII `string` representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = bytes1(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,
     * given `owner`'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
/// @title Self Permit
/// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
interface ISelfPermit {
    /// @notice Permits this contract to spend a given token from `msg.sender`
    /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
    /// @param token The address of the token spent
    /// @param value The amount that can be spent of token
    /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function selfPermit(
        address token,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable;
    /// @notice Permits this contract to spend a given token from `msg.sender`
    /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
    /// Can be used instead of #selfPermit to prevent calls from failing due to a frontrun of a call to #selfPermit
    /// @param token The address of the token spent
    /// @param value The amount that can be spent of token
    /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function selfPermitIfNecessary(
        address token,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable;
    /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
    /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
    /// @param token The address of the token spent
    /// @param nonce The current nonce of the owner
    /// @param expiry The timestamp at which the permit is no longer valid
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function selfPermitAllowed(
        address token,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable;
    /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
    /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
    /// Can be used instead of #selfPermitAllowed to prevent calls from failing due to a frontrun of a call to #selfPermitAllowed.
    /// @param token The address of the token spent
    /// @param nonce The current nonce of the owner
    /// @param expiry The timestamp at which the permit is no longer valid
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function selfPermitAllowedIfNecessary(
        address token,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external payable;
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Interface for permit
/// @notice Interface used by DAI/CHAI for permit
interface IERC20PermitAllowed {
    /// @notice Approve the spender to spend some tokens via the holder signature
    /// @dev This is the permit interface used by DAI and CHAI
    /// @param holder The address of the token holder, the token owner
    /// @param spender The address of the token spender
    /// @param nonce The holder's nonce, increases at each call to permit
    /// @param expiry The timestamp at which the permit is no longer valid
    /// @param allowed Boolean that sets approval amount, true for type(uint256).max and false for 0
    /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
    /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
    /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
    function permit(
        address holder,
        address spender,
        uint256 nonce,
        uint256 expiry,
        bool allowed,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}

pragma solidity 0.5.13;

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

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

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

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

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

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

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

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

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

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

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

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

        return c;
    }

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

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

        return c;
    }

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

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

        return c;
    }

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

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

        return c;
    }

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

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

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

    mapping (address => uint256) private _balances;

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

    uint256 private _totalSupply;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

contract GlobalsAndUtility is ERC20 {
    /*  XfLobbyEnter      (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        address  indexed  memberAddr
        uint256  indexed  entryId
        uint96            rawAmount       -->  data0 [135: 40]
        address  indexed  referrerAddr
    */
    event XfLobbyEnter(
        uint256 data0,
        address indexed memberAddr,
        uint256 indexed entryId,
        address indexed referrerAddr
    );

    /*  XfLobbyExit       (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        address  indexed  memberAddr
        uint256  indexed  entryId
        uint72            xfAmount        -->  data0 [111: 40]
        address  indexed  referrerAddr
    */
    event XfLobbyExit(
        uint256 data0,
        address indexed memberAddr,
        uint256 indexed entryId,
        address indexed referrerAddr
    );

    /*  DailyDataUpdate   (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        uint16            beginDay        -->  data0 [ 55: 40]
        uint16            endDay          -->  data0 [ 71: 56]
        bool              isAutoUpdate    -->  data0 [ 79: 72]
        address  indexed  updaterAddr
    */
    event DailyDataUpdate(
        uint256 data0,
        address indexed updaterAddr
    );

    /*  Claim             (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        bytes20  indexed  btcAddr
        uint56            rawSatoshis     -->  data0 [ 95: 40]
        uint56            adjSatoshis     -->  data0 [151: 96]
        address  indexed  claimToAddr
        uint8             claimFlags      -->  data0 [159:152]
        uint72            claimedHearts   -->  data0 [231:160]
        address  indexed  referrerAddr
        address           senderAddr      -->  data1 [159:  0]
    */
    event Claim(
        uint256 data0,
        uint256 data1,
        bytes20 indexed btcAddr,
        address indexed claimToAddr,
        address indexed referrerAddr
    );

    /*  ClaimAssist       (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        bytes20           btcAddr         -->  data0 [199: 40]
        uint56            rawSatoshis     -->  data0 [255:200]
        uint56            adjSatoshis     -->  data1 [ 55:  0]
        address           claimToAddr     -->  data1 [215: 56]
        uint8             claimFlags      -->  data1 [223:216]
        uint72            claimedHearts   -->  data2 [ 71:  0]
        address           referrerAddr    -->  data2 [231: 72]
        address  indexed  senderAddr
    */
    event ClaimAssist(
        uint256 data0,
        uint256 data1,
        uint256 data2,
        address indexed senderAddr
    );

    /*  StakeStart        (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        address  indexed  stakerAddr
        uint40   indexed  stakeId
        uint72            stakedHearts    -->  data0 [111: 40]
        uint72            stakeShares     -->  data0 [183:112]
        uint16            stakedDays      -->  data0 [199:184]
        bool              isAutoStake     -->  data0 [207:200]
    */
    event StakeStart(
        uint256 data0,
        address indexed stakerAddr,
        uint40 indexed stakeId
    );

    /*  StakeGoodAccounting(auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        address  indexed  stakerAddr
        uint40   indexed  stakeId
        uint72            stakedHearts    -->  data0 [111: 40]
        uint72            stakeShares     -->  data0 [183:112]
        uint72            payout          -->  data0 [255:184]
        uint72            penalty         -->  data1 [ 71:  0]
        address  indexed  senderAddr
    */
    event StakeGoodAccounting(
        uint256 data0,
        uint256 data1,
        address indexed stakerAddr,
        uint40 indexed stakeId,
        address indexed senderAddr
    );

    /*  StakeEnd          (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        address  indexed  stakerAddr
        uint40   indexed  stakeId
        uint72            stakedHearts    -->  data0 [111: 40]
        uint72            stakeShares     -->  data0 [183:112]
        uint72            payout          -->  data0 [255:184]
        uint72            penalty         -->  data1 [ 71:  0]
        uint16            servedDays      -->  data1 [ 87: 72]
        bool              prevUnlocked    -->  data1 [ 95: 88]
    */
    event StakeEnd(
        uint256 data0,
        uint256 data1,
        address indexed stakerAddr,
        uint40 indexed stakeId
    );

    /*  ShareRateChange   (auto-generated event)

        uint40            timestamp       -->  data0 [ 39:  0]
        uint40            shareRate       -->  data0 [ 79: 40]
        uint40   indexed  stakeId
    */
    event ShareRateChange(
        uint256 data0,
        uint40 indexed stakeId
    );

    /* Origin address */
    address internal constant ORIGIN_ADDR = 0x9A6a414D6F3497c05E3b1De90520765fA1E07c03;

    /* Flush address */
    address payable internal constant FLUSH_ADDR = 0xDEC9f2793e3c17cd26eeFb21C4762fA5128E0399;

    /* ERC20 constants */
    string public constant name = "HEX";
    string public constant symbol = "HEX";
    uint8 public constant decimals = 8;

    /* Hearts per Satoshi = 10,000 * 1e8 / 1e8 = 1e4 */
    uint256 private constant HEARTS_PER_HEX = 10 ** uint256(decimals); // 1e8
    uint256 private constant HEX_PER_BTC = 1e4;
    uint256 private constant SATOSHIS_PER_BTC = 1e8;
    uint256 internal constant HEARTS_PER_SATOSHI = HEARTS_PER_HEX / SATOSHIS_PER_BTC * HEX_PER_BTC;

    /* Time of contract launch (2019-12-03T00:00:00Z) */
    uint256 internal constant LAUNCH_TIME = 1575331200;

    /* Size of a Hearts or Shares uint */
    uint256 internal constant HEART_UINT_SIZE = 72;

    /* Size of a transform lobby entry index uint */
    uint256 internal constant XF_LOBBY_ENTRY_INDEX_SIZE = 40;
    uint256 internal constant XF_LOBBY_ENTRY_INDEX_MASK = (1 << XF_LOBBY_ENTRY_INDEX_SIZE) - 1;

    /* Seed for WAAS Lobby */
    uint256 internal constant WAAS_LOBBY_SEED_HEX = 1e9;
    uint256 internal constant WAAS_LOBBY_SEED_HEARTS = WAAS_LOBBY_SEED_HEX * HEARTS_PER_HEX;

    /* Start of claim phase */
    uint256 internal constant PRE_CLAIM_DAYS = 1;
    uint256 internal constant CLAIM_PHASE_START_DAY = PRE_CLAIM_DAYS;

    /* Length of claim phase */
    uint256 private constant CLAIM_PHASE_WEEKS = 50;
    uint256 internal constant CLAIM_PHASE_DAYS = CLAIM_PHASE_WEEKS * 7;

    /* End of claim phase */
    uint256 internal constant CLAIM_PHASE_END_DAY = CLAIM_PHASE_START_DAY + CLAIM_PHASE_DAYS;

    /* Number of words to hold 1 bit for each transform lobby day */
    uint256 internal constant XF_LOBBY_DAY_WORDS = (CLAIM_PHASE_END_DAY + 255) >> 8;

    /* BigPayDay */
    uint256 internal constant BIG_PAY_DAY = CLAIM_PHASE_END_DAY + 1;

    /* Root hash of the UTXO Merkle tree */
    bytes32 internal constant MERKLE_TREE_ROOT = 0x4e831acb4223b66de3b3d2e54a2edeefb0de3d7916e2886a4b134d9764d41bec;

    /* Size of a Satoshi claim uint in a Merkle leaf */
    uint256 internal constant MERKLE_LEAF_SATOSHI_SIZE = 45;

    /* Zero-fill between BTC address and Satoshis in a Merkle leaf */
    uint256 internal constant MERKLE_LEAF_FILL_SIZE = 256 - 160 - MERKLE_LEAF_SATOSHI_SIZE;
    uint256 internal constant MERKLE_LEAF_FILL_BASE = (1 << MERKLE_LEAF_FILL_SIZE) - 1;
    uint256 internal constant MERKLE_LEAF_FILL_MASK = MERKLE_LEAF_FILL_BASE << MERKLE_LEAF_SATOSHI_SIZE;

    /* Size of a Satoshi total uint */
    uint256 internal constant SATOSHI_UINT_SIZE = 51;
    uint256 internal constant SATOSHI_UINT_MASK = (1 << SATOSHI_UINT_SIZE) - 1;

    /* Total Satoshis from all BTC addresses in UTXO snapshot */
    uint256 internal constant FULL_SATOSHIS_TOTAL = 1807766732160668;

    /* Total Satoshis from supported BTC addresses in UTXO snapshot after applying Silly Whale */
    uint256 internal constant CLAIMABLE_SATOSHIS_TOTAL = 910087996911001;

    /* Number of claimable BTC addresses in UTXO snapshot */
    uint256 internal constant CLAIMABLE_BTC_ADDR_COUNT = 27997742;

    /* Largest BTC address Satoshis balance in UTXO snapshot (sanity check) */
    uint256 internal constant MAX_BTC_ADDR_BALANCE_SATOSHIS = 25550214098481;

    /* Percentage of total claimed Hearts that will be auto-staked from a claim */
    uint256 internal constant AUTO_STAKE_CLAIM_PERCENT = 90;

    /* Stake timing parameters */
    uint256 internal constant MIN_STAKE_DAYS = 1;
    uint256 internal constant MIN_AUTO_STAKE_DAYS = 350;

    uint256 internal constant MAX_STAKE_DAYS = 5555; // Approx 15 years

    uint256 internal constant EARLY_PENALTY_MIN_DAYS = 90;

    uint256 private constant LATE_PENALTY_GRACE_WEEKS = 2;
    uint256 internal constant LATE_PENALTY_GRACE_DAYS = LATE_PENALTY_GRACE_WEEKS * 7;

    uint256 private constant LATE_PENALTY_SCALE_WEEKS = 100;
    uint256 internal constant LATE_PENALTY_SCALE_DAYS = LATE_PENALTY_SCALE_WEEKS * 7;

    /* Stake shares Longer Pays Better bonus constants used by _stakeStartBonusHearts() */
    uint256 private constant LPB_BONUS_PERCENT = 20;
    uint256 private constant LPB_BONUS_MAX_PERCENT = 200;
    uint256 internal constant LPB = 364 * 100 / LPB_BONUS_PERCENT;
    uint256 internal constant LPB_MAX_DAYS = LPB * LPB_BONUS_MAX_PERCENT / 100;

    /* Stake shares Bigger Pays Better bonus constants used by _stakeStartBonusHearts() */
    uint256 private constant BPB_BONUS_PERCENT = 10;
    uint256 private constant BPB_MAX_HEX = 150 * 1e6;
    uint256 internal constant BPB_MAX_HEARTS = BPB_MAX_HEX * HEARTS_PER_HEX;
    uint256 internal constant BPB = BPB_MAX_HEARTS * 100 / BPB_BONUS_PERCENT;

    /* Share rate is scaled to increase precision */
    uint256 internal constant SHARE_RATE_SCALE = 1e5;

    /* Share rate max (after scaling) */
    uint256 internal constant SHARE_RATE_UINT_SIZE = 40;
    uint256 internal constant SHARE_RATE_MAX = (1 << SHARE_RATE_UINT_SIZE) - 1;

    /* Constants for preparing the claim message text */
    uint8 internal constant ETH_ADDRESS_BYTE_LEN = 20;
    uint8 internal constant ETH_ADDRESS_HEX_LEN = ETH_ADDRESS_BYTE_LEN * 2;

    uint8 internal constant CLAIM_PARAM_HASH_BYTE_LEN = 12;
    uint8 internal constant CLAIM_PARAM_HASH_HEX_LEN = CLAIM_PARAM_HASH_BYTE_LEN * 2;

    uint8 internal constant BITCOIN_SIG_PREFIX_LEN = 24;
    bytes24 internal constant BITCOIN_SIG_PREFIX_STR = "Bitcoin Signed Message:\n";

    bytes internal constant STD_CLAIM_PREFIX_STR = "Claim_HEX_to_0x";
    bytes internal constant OLD_CLAIM_PREFIX_STR = "Claim_BitcoinHEX_to_0x";

    bytes16 internal constant HEX_DIGITS = "0123456789abcdef";

    /* Claim flags passed to btcAddressClaim()  */
    uint8 internal constant CLAIM_FLAG_MSG_PREFIX_OLD = 1 << 0;
    uint8 internal constant CLAIM_FLAG_BTC_ADDR_COMPRESSED = 1 << 1;
    uint8 internal constant CLAIM_FLAG_BTC_ADDR_P2WPKH_IN_P2SH = 1 << 2;
    uint8 internal constant CLAIM_FLAG_BTC_ADDR_BECH32 = 1 << 3;
    uint8 internal constant CLAIM_FLAG_ETH_ADDR_LOWERCASE = 1 << 4;

    /* Globals expanded for memory (except _latestStakeId) and compact for storage */
    struct GlobalsCache {
        // 1
        uint256 _lockedHeartsTotal;
        uint256 _nextStakeSharesTotal;
        uint256 _shareRate;
        uint256 _stakePenaltyTotal;
        // 2
        uint256 _dailyDataCount;
        uint256 _stakeSharesTotal;
        uint40 _latestStakeId;
        uint256 _unclaimedSatoshisTotal;
        uint256 _claimedSatoshisTotal;
        uint256 _claimedBtcAddrCount;
        //
        uint256 _currentDay;
    }

    struct GlobalsStore {
        // 1
        uint72 lockedHeartsTotal;
        uint72 nextStakeSharesTotal;
        uint40 shareRate;
        uint72 stakePenaltyTotal;
        // 2
        uint16 dailyDataCount;
        uint72 stakeSharesTotal;
        uint40 latestStakeId;
        uint128 claimStats;
    }

    GlobalsStore public globals;

    /* Claimed BTC addresses */
    mapping(bytes20 => bool) public btcAddressClaims;

    /* Daily data */
    struct DailyDataStore {
        uint72 dayPayoutTotal;
        uint72 dayStakeSharesTotal;
        uint56 dayUnclaimedSatoshisTotal;
    }

    mapping(uint256 => DailyDataStore) public dailyData;

    /* Stake expanded for memory (except _stakeId) and compact for storage */
    struct StakeCache {
        uint40 _stakeId;
        uint256 _stakedHearts;
        uint256 _stakeShares;
        uint256 _lockedDay;
        uint256 _stakedDays;
        uint256 _unlockedDay;
        bool _isAutoStake;
    }

    struct StakeStore {
        uint40 stakeId;
        uint72 stakedHearts;
        uint72 stakeShares;
        uint16 lockedDay;
        uint16 stakedDays;
        uint16 unlockedDay;
        bool isAutoStake;
    }

    mapping(address => StakeStore[]) public stakeLists;

    /* Temporary state for calculating daily rounds */
    struct DailyRoundState {
        uint256 _allocSupplyCached;
        uint256 _mintOriginBatch;
        uint256 _payoutTotal;
    }

    struct XfLobbyEntryStore {
        uint96 rawAmount;
        address referrerAddr;
    }

    struct XfLobbyQueueStore {
        uint40 headIndex;
        uint40 tailIndex;
        mapping(uint256 => XfLobbyEntryStore) entries;
    }

    mapping(uint256 => uint256) public xfLobby;
    mapping(uint256 => mapping(address => XfLobbyQueueStore)) public xfLobbyMembers;

    /**
     * @dev PUBLIC FACING: Optionally update daily data for a smaller
     * range to reduce gas cost for a subsequent operation
     * @param beforeDay Only update days before this day number (optional; 0 for current day)
     */
    function dailyDataUpdate(uint256 beforeDay)
        external
    {
        GlobalsCache memory g;
        GlobalsCache memory gSnapshot;
        _globalsLoad(g, gSnapshot);

        /* Skip pre-claim period */
        require(g._currentDay > CLAIM_PHASE_START_DAY, "HEX: Too early");

        if (beforeDay != 0) {
            require(beforeDay <= g._currentDay, "HEX: beforeDay cannot be in the future");

            _dailyDataUpdate(g, beforeDay, false);
        } else {
            /* Default to updating before current day */
            _dailyDataUpdate(g, g._currentDay, false);
        }

        _globalsSync(g, gSnapshot);
    }

    /**
     * @dev PUBLIC FACING: External helper to return multiple values of daily data with
     * a single call. Ugly implementation due to limitations of the standard ABI encoder.
     * @param beginDay First day of data range
     * @param endDay Last day (non-inclusive) of data range
     * @return Fixed array of packed values
     */
    function dailyDataRange(uint256 beginDay, uint256 endDay)
        external
        view
        returns (uint256[] memory list)
    {
        require(beginDay < endDay && endDay <= globals.dailyDataCount, "HEX: range invalid");

        list = new uint256[](endDay - beginDay);

        uint256 src = beginDay;
        uint256 dst = 0;
        uint256 v;
        do {
            v = uint256(dailyData[src].dayUnclaimedSatoshisTotal) << (HEART_UINT_SIZE * 2);
            v |= uint256(dailyData[src].dayStakeSharesTotal) << HEART_UINT_SIZE;
            v |= uint256(dailyData[src].dayPayoutTotal);

            list[dst++] = v;
        } while (++src < endDay);

        return list;
    }

    /**
     * @dev PUBLIC FACING: External helper to return most global info with a single call.
     * Ugly implementation due to limitations of the standard ABI encoder.
     * @return Fixed array of values
     */
    function globalInfo()
        external
        view
        returns (uint256[13] memory)
    {
        uint256 _claimedBtcAddrCount;
        uint256 _claimedSatoshisTotal;
        uint256 _unclaimedSatoshisTotal;

        (_claimedBtcAddrCount, _claimedSatoshisTotal, _unclaimedSatoshisTotal) = _claimStatsDecode(
            globals.claimStats
        );

        return [
            // 1
            globals.lockedHeartsTotal,
            globals.nextStakeSharesTotal,
            globals.shareRate,
            globals.stakePenaltyTotal,
            // 2
            globals.dailyDataCount,
            globals.stakeSharesTotal,
            globals.latestStakeId,
            _unclaimedSatoshisTotal,
            _claimedSatoshisTotal,
            _claimedBtcAddrCount,
            //
            block.timestamp,
            totalSupply(),
            xfLobby[_currentDay()]
        ];
    }

    /**
     * @dev PUBLIC FACING: ERC20 totalSupply() is the circulating supply and does not include any
     * staked Hearts. allocatedSupply() includes both.
     * @return Allocated Supply in Hearts
     */
    function allocatedSupply()
        external
        view
        returns (uint256)
    {
        return totalSupply() + globals.lockedHeartsTotal;
    }

    /**
     * @dev PUBLIC FACING: External helper for the current day number since launch time
     * @return Current day number (zero-based)
     */
    function currentDay()
        external
        view
        returns (uint256)
    {
        return _currentDay();
    }

    function _currentDay()
        internal
        view
        returns (uint256)
    {
        return (block.timestamp - LAUNCH_TIME) / 1 days;
    }

    function _dailyDataUpdateAuto(GlobalsCache memory g)
        internal
    {
        _dailyDataUpdate(g, g._currentDay, true);
    }

    function _globalsLoad(GlobalsCache memory g, GlobalsCache memory gSnapshot)
        internal
        view
    {
        // 1
        g._lockedHeartsTotal = globals.lockedHeartsTotal;
        g._nextStakeSharesTotal = globals.nextStakeSharesTotal;
        g._shareRate = globals.shareRate;
        g._stakePenaltyTotal = globals.stakePenaltyTotal;
        // 2
        g._dailyDataCount = globals.dailyDataCount;
        g._stakeSharesTotal = globals.stakeSharesTotal;
        g._latestStakeId = globals.latestStakeId;
        (g._claimedBtcAddrCount, g._claimedSatoshisTotal, g._unclaimedSatoshisTotal) = _claimStatsDecode(
            globals.claimStats
        );
        //
        g._currentDay = _currentDay();

        _globalsCacheSnapshot(g, gSnapshot);
    }

    function _globalsCacheSnapshot(GlobalsCache memory g, GlobalsCache memory gSnapshot)
        internal
        pure
    {
        // 1
        gSnapshot._lockedHeartsTotal = g._lockedHeartsTotal;
        gSnapshot._nextStakeSharesTotal = g._nextStakeSharesTotal;
        gSnapshot._shareRate = g._shareRate;
        gSnapshot._stakePenaltyTotal = g._stakePenaltyTotal;
        // 2
        gSnapshot._dailyDataCount = g._dailyDataCount;
        gSnapshot._stakeSharesTotal = g._stakeSharesTotal;
        gSnapshot._latestStakeId = g._latestStakeId;
        gSnapshot._unclaimedSatoshisTotal = g._unclaimedSatoshisTotal;
        gSnapshot._claimedSatoshisTotal = g._claimedSatoshisTotal;
        gSnapshot._claimedBtcAddrCount = g._claimedBtcAddrCount;
    }

    function _globalsSync(GlobalsCache memory g, GlobalsCache memory gSnapshot)
        internal
    {
        if (g._lockedHeartsTotal != gSnapshot._lockedHeartsTotal
            || g._nextStakeSharesTotal != gSnapshot._nextStakeSharesTotal
            || g._shareRate != gSnapshot._shareRate
            || g._stakePenaltyTotal != gSnapshot._stakePenaltyTotal) {
            // 1
            globals.lockedHeartsTotal = uint72(g._lockedHeartsTotal);
            globals.nextStakeSharesTotal = uint72(g._nextStakeSharesTotal);
            globals.shareRate = uint40(g._shareRate);
            globals.stakePenaltyTotal = uint72(g._stakePenaltyTotal);
        }
        if (g._dailyDataCount != gSnapshot._dailyDataCount
            || g._stakeSharesTotal != gSnapshot._stakeSharesTotal
            || g._latestStakeId != gSnapshot._latestStakeId
            || g._unclaimedSatoshisTotal != gSnapshot._unclaimedSatoshisTotal
            || g._claimedSatoshisTotal != gSnapshot._claimedSatoshisTotal
            || g._claimedBtcAddrCount != gSnapshot._claimedBtcAddrCount) {
            // 2
            globals.dailyDataCount = uint16(g._dailyDataCount);
            globals.stakeSharesTotal = uint72(g._stakeSharesTotal);
            globals.latestStakeId = g._latestStakeId;
            globals.claimStats = _claimStatsEncode(
                g._claimedBtcAddrCount,
                g._claimedSatoshisTotal,
                g._unclaimedSatoshisTotal
            );
        }
    }

    function _stakeLoad(StakeStore storage stRef, uint40 stakeIdParam, StakeCache memory st)
        internal
        view
    {
        /* Ensure caller's stakeIndex is still current */
        require(stakeIdParam == stRef.stakeId, "HEX: stakeIdParam not in stake");

        st._stakeId = stRef.stakeId;
        st._stakedHearts = stRef.stakedHearts;
        st._stakeShares = stRef.stakeShares;
        st._lockedDay = stRef.lockedDay;
        st._stakedDays = stRef.stakedDays;
        st._unlockedDay = stRef.unlockedDay;
        st._isAutoStake = stRef.isAutoStake;
    }

    function _stakeUpdate(StakeStore storage stRef, StakeCache memory st)
        internal
    {
        stRef.stakeId = st._stakeId;
        stRef.stakedHearts = uint72(st._stakedHearts);
        stRef.stakeShares = uint72(st._stakeShares);
        stRef.lockedDay = uint16(st._lockedDay);
        stRef.stakedDays = uint16(st._stakedDays);
        stRef.unlockedDay = uint16(st._unlockedDay);
        stRef.isAutoStake = st._isAutoStake;
    }

    function _stakeAdd(
        StakeStore[] storage stakeListRef,
        uint40 newStakeId,
        uint256 newStakedHearts,
        uint256 newStakeShares,
        uint256 newLockedDay,
        uint256 newStakedDays,
        bool newAutoStake
    )
        internal
    {
        stakeListRef.push(
            StakeStore(
                newStakeId,
                uint72(newStakedHearts),
                uint72(newStakeShares),
                uint16(newLockedDay),
                uint16(newStakedDays),
                uint16(0), // unlockedDay
                newAutoStake
            )
        );
    }

    /**
     * @dev Efficiently delete from an unordered array by moving the last element
     * to the "hole" and reducing the array length. Can change the order of the list
     * and invalidate previously held indexes.
     * @notice stakeListRef length and stakeIndex are already ensured valid in stakeEnd()
     * @param stakeListRef Reference to stakeLists[stakerAddr] array in storage
     * @param stakeIndex Index of the element to delete
     */
    function _stakeRemove(StakeStore[] storage stakeListRef, uint256 stakeIndex)
        internal
    {
        uint256 lastIndex = stakeListRef.length - 1;

        /* Skip the copy if element to be removed is already the last element */
        if (stakeIndex != lastIndex) {
            /* Copy last element to the requested element's "hole" */
            stakeListRef[stakeIndex] = stakeListRef[lastIndex];
        }

        /*
            Reduce the array length now that the array is contiguous.
            Surprisingly, 'pop()' uses less gas than 'stakeListRef.length = lastIndex'
        */
        stakeListRef.pop();
    }

    function _claimStatsEncode(
        uint256 _claimedBtcAddrCount,
        uint256 _claimedSatoshisTotal,
        uint256 _unclaimedSatoshisTotal
    )
        internal
        pure
        returns (uint128)
    {
        uint256 v = _claimedBtcAddrCount << (SATOSHI_UINT_SIZE * 2);
        v |= _claimedSatoshisTotal << SATOSHI_UINT_SIZE;
        v |= _unclaimedSatoshisTotal;

        return uint128(v);
    }

    function _claimStatsDecode(uint128 v)
        internal
        pure
        returns (uint256 _claimedBtcAddrCount, uint256 _claimedSatoshisTotal, uint256 _unclaimedSatoshisTotal)
    {
        _claimedBtcAddrCount = v >> (SATOSHI_UINT_SIZE * 2);
        _claimedSatoshisTotal = (v >> SATOSHI_UINT_SIZE) & SATOSHI_UINT_MASK;
        _unclaimedSatoshisTotal = v & SATOSHI_UINT_MASK;

        return (_claimedBtcAddrCount, _claimedSatoshisTotal, _unclaimedSatoshisTotal);
    }

    /**
     * @dev Estimate the stake payout for an incomplete day
     * @param g Cache of stored globals
     * @param stakeSharesParam Param from stake to calculate bonuses for
     * @param day Day to calculate bonuses for
     * @return Payout in Hearts
     */
    function _estimatePayoutRewardsDay(GlobalsCache memory g, uint256 stakeSharesParam, uint256 day)
        internal
        view
        returns (uint256 payout)
    {
        /* Prevent updating state for this estimation */
        GlobalsCache memory gTmp;
        _globalsCacheSnapshot(g, gTmp);

        DailyRoundState memory rs;
        rs._allocSupplyCached = totalSupply() + g._lockedHeartsTotal;

        _dailyRoundCalc(gTmp, rs, day);

        /* Stake is no longer locked so it must be added to total as if it were */
        gTmp._stakeSharesTotal += stakeSharesParam;

        payout = rs._payoutTotal * stakeSharesParam / gTmp._stakeSharesTotal;

        if (day == BIG_PAY_DAY) {
            uint256 bigPaySlice = gTmp._unclaimedSatoshisTotal * HEARTS_PER_SATOSHI * stakeSharesParam
                / gTmp._stakeSharesTotal;
            payout += bigPaySlice + _calcAdoptionBonus(gTmp, bigPaySlice);
        }

        return payout;
    }

    function _calcAdoptionBonus(GlobalsCache memory g, uint256 payout)
        internal
        pure
        returns (uint256)
    {
        /*
            VIRAL REWARDS: Add adoption percentage bonus to payout

            viral = payout * (claimedBtcAddrCount / CLAIMABLE_BTC_ADDR_COUNT)
        */
        uint256 viral = payout * g._claimedBtcAddrCount / CLAIMABLE_BTC_ADDR_COUNT;

        /*
            CRIT MASS REWARDS: Add adoption percentage bonus to payout

            crit  = payout * (claimedSatoshisTotal / CLAIMABLE_SATOSHIS_TOTAL)
        */
        uint256 crit = payout * g._claimedSatoshisTotal / CLAIMABLE_SATOSHIS_TOTAL;

        return viral + crit;
    }

    function _dailyRoundCalc(GlobalsCache memory g, DailyRoundState memory rs, uint256 day)
        private
        pure
    {
        /*
            Calculate payout round

            Inflation of 3.69% inflation per 364 days             (approx 1 year)
            dailyInterestRate   = exp(log(1 + 3.69%)  / 364) - 1
                                = exp(log(1 + 0.0369) / 364) - 1
                                = exp(log(1.0369) / 364) - 1
                                = 0.000099553011616349            (approx)

            payout  = allocSupply * dailyInterestRate
                    = allocSupply / (1 / dailyInterestRate)
                    = allocSupply / (1 / 0.000099553011616349)
                    = allocSupply / 10044.899534066692            (approx)
                    = allocSupply * 10000 / 100448995             (* 10000/10000 for int precision)
        */
        rs._payoutTotal = rs._allocSupplyCached * 10000 / 100448995;

        if (day < CLAIM_PHASE_END_DAY) {
            uint256 bigPaySlice = g._unclaimedSatoshisTotal * HEARTS_PER_SATOSHI / CLAIM_PHASE_DAYS;

            uint256 originBonus = bigPaySlice + _calcAdoptionBonus(g, rs._payoutTotal + bigPaySlice);
            rs._mintOriginBatch += originBonus;
            rs._allocSupplyCached += originBonus;

            rs._payoutTotal += _calcAdoptionBonus(g, rs._payoutTotal);
        }

        if (g._stakePenaltyTotal != 0) {
            rs._payoutTotal += g._stakePenaltyTotal;
            g._stakePenaltyTotal = 0;
        }
    }

    function _dailyRoundCalcAndStore(GlobalsCache memory g, DailyRoundState memory rs, uint256 day)
        private
    {
        _dailyRoundCalc(g, rs, day);

        dailyData[day].dayPayoutTotal = uint72(rs._payoutTotal);
        dailyData[day].dayStakeSharesTotal = uint72(g._stakeSharesTotal);
        dailyData[day].dayUnclaimedSatoshisTotal = uint56(g._unclaimedSatoshisTotal);
    }

    function _dailyDataUpdate(GlobalsCache memory g, uint256 beforeDay, bool isAutoUpdate)
        private
    {
        if (g._dailyDataCount >= beforeDay) {
            /* Already up-to-date */
            return;
        }

        DailyRoundState memory rs;
        rs._allocSupplyCached = totalSupply() + g._lockedHeartsTotal;

        uint256 day = g._dailyDataCount;

        _dailyRoundCalcAndStore(g, rs, day);

        /* Stakes started during this day are added to the total the next day */
        if (g._nextStakeSharesTotal != 0) {
            g._stakeSharesTotal += g._nextStakeSharesTotal;
            g._nextStakeSharesTotal = 0;
        }

        while (++day < beforeDay) {
            _dailyRoundCalcAndStore(g, rs, day);
        }

        _emitDailyDataUpdate(g._dailyDataCount, day, isAutoUpdate);
        g._dailyDataCount = day;

        if (rs._mintOriginBatch != 0) {
            _mint(ORIGIN_ADDR, rs._mintOriginBatch);
        }
    }

    function _emitDailyDataUpdate(uint256 beginDay, uint256 endDay, bool isAutoUpdate)
        private
    {
        emit DailyDataUpdate( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint16(beginDay)) << 40)
                | (uint256(uint16(endDay)) << 56)
                | (isAutoUpdate ? (1 << 72) : 0),
            msg.sender
        );
    }
}

contract StakeableToken is GlobalsAndUtility {
    /**
     * @dev PUBLIC FACING: Open a stake.
     * @param newStakedHearts Number of Hearts to stake
     * @param newStakedDays Number of days to stake
     */
    function stakeStart(uint256 newStakedHearts, uint256 newStakedDays)
        external
    {
        GlobalsCache memory g;
        GlobalsCache memory gSnapshot;
        _globalsLoad(g, gSnapshot);

        /* Enforce the minimum stake time */
        require(newStakedDays >= MIN_STAKE_DAYS, "HEX: newStakedDays lower than minimum");

        /* Check if log data needs to be updated */
        _dailyDataUpdateAuto(g);

        _stakeStart(g, newStakedHearts, newStakedDays, false);

        /* Remove staked Hearts from balance of staker */
        _burn(msg.sender, newStakedHearts);

        _globalsSync(g, gSnapshot);
    }

    /**
     * @dev PUBLIC FACING: Unlocks a completed stake, distributing the proceeds of any penalty
     * immediately. The staker must still call stakeEnd() to retrieve their stake return (if any).
     * @param stakerAddr Address of staker
     * @param stakeIndex Index of stake within stake list
     * @param stakeIdParam The stake's id
     */
    function stakeGoodAccounting(address stakerAddr, uint256 stakeIndex, uint40 stakeIdParam)
        external
    {
        GlobalsCache memory g;
        GlobalsCache memory gSnapshot;
        _globalsLoad(g, gSnapshot);

        /* require() is more informative than the default assert() */
        require(stakeLists[stakerAddr].length != 0, "HEX: Empty stake list");
        require(stakeIndex < stakeLists[stakerAddr].length, "HEX: stakeIndex invalid");

        StakeStore storage stRef = stakeLists[stakerAddr][stakeIndex];

        /* Get stake copy */
        StakeCache memory st;
        _stakeLoad(stRef, stakeIdParam, st);

        /* Stake must have served full term */
        require(g._currentDay >= st._lockedDay + st._stakedDays, "HEX: Stake not fully served");

        /* Stake must still be locked */
        require(st._unlockedDay == 0, "HEX: Stake already unlocked");

        /* Check if log data needs to be updated */
        _dailyDataUpdateAuto(g);

        /* Unlock the completed stake */
        _stakeUnlock(g, st);

        /* stakeReturn value is unused here */
        (, uint256 payout, uint256 penalty, uint256 cappedPenalty) = _stakePerformance(
            g,
            st,
            st._stakedDays
        );

        _emitStakeGoodAccounting(
            stakerAddr,
            stakeIdParam,
            st._stakedHearts,
            st._stakeShares,
            payout,
            penalty
        );

        if (cappedPenalty != 0) {
            _splitPenaltyProceeds(g, cappedPenalty);
        }

        /* st._unlockedDay has changed */
        _stakeUpdate(stRef, st);

        _globalsSync(g, gSnapshot);
    }

    /**
     * @dev PUBLIC FACING: Closes a stake. The order of the stake list can change so
     * a stake id is used to reject stale indexes.
     * @param stakeIndex Index of stake within stake list
     * @param stakeIdParam The stake's id
     */
    function stakeEnd(uint256 stakeIndex, uint40 stakeIdParam)
        external
    {
        GlobalsCache memory g;
        GlobalsCache memory gSnapshot;
        _globalsLoad(g, gSnapshot);

        StakeStore[] storage stakeListRef = stakeLists[msg.sender];

        /* require() is more informative than the default assert() */
        require(stakeListRef.length != 0, "HEX: Empty stake list");
        require(stakeIndex < stakeListRef.length, "HEX: stakeIndex invalid");

        /* Get stake copy */
        StakeCache memory st;
        _stakeLoad(stakeListRef[stakeIndex], stakeIdParam, st);

        /* Check if log data needs to be updated */
        _dailyDataUpdateAuto(g);

        uint256 servedDays = 0;

        bool prevUnlocked = (st._unlockedDay != 0);
        uint256 stakeReturn;
        uint256 payout = 0;
        uint256 penalty = 0;
        uint256 cappedPenalty = 0;

        if (g._currentDay >= st._lockedDay) {
            if (prevUnlocked) {
                /* Previously unlocked in stakeGoodAccounting(), so must have served full term */
                servedDays = st._stakedDays;
            } else {
                _stakeUnlock(g, st);

                servedDays = g._currentDay - st._lockedDay;
                if (servedDays > st._stakedDays) {
                    servedDays = st._stakedDays;
                } else {
                    /* Deny early-unstake before an auto-stake minimum has been served */
                    if (servedDays < MIN_AUTO_STAKE_DAYS) {
                        require(!st._isAutoStake, "HEX: Auto-stake still locked");
                    }
                }
            }

            (stakeReturn, payout, penalty, cappedPenalty) = _stakePerformance(g, st, servedDays);
        } else {
            /* Deny early-unstake before an auto-stake minimum has been served */
            require(!st._isAutoStake, "HEX: Auto-stake still locked");

            /* Stake hasn't been added to the total yet, so no penalties or rewards apply */
            g._nextStakeSharesTotal -= st._stakeShares;

            stakeReturn = st._stakedHearts;
        }

        _emitStakeEnd(
            stakeIdParam,
            st._stakedHearts,
            st._stakeShares,
            payout,
            penalty,
            servedDays,
            prevUnlocked
        );

        if (cappedPenalty != 0 && !prevUnlocked) {
            /* Split penalty proceeds only if not previously unlocked by stakeGoodAccounting() */
            _splitPenaltyProceeds(g, cappedPenalty);
        }

        /* Pay the stake return, if any, to the staker */
        if (stakeReturn != 0) {
            _mint(msg.sender, stakeReturn);

            /* Update the share rate if necessary */
            _shareRateUpdate(g, st, stakeReturn);
        }
        g._lockedHeartsTotal -= st._stakedHearts;

        _stakeRemove(stakeListRef, stakeIndex);

        _globalsSync(g, gSnapshot);
    }

    /**
     * @dev PUBLIC FACING: Return the current stake count for a staker address
     * @param stakerAddr Address of staker
     */
    function stakeCount(address stakerAddr)
        external
        view
        returns (uint256)
    {
        return stakeLists[stakerAddr].length;
    }

    /**
     * @dev Open a stake.
     * @param g Cache of stored globals
     * @param newStakedHearts Number of Hearts to stake
     * @param newStakedDays Number of days to stake
     * @param newAutoStake Stake is automatic directly from a new claim
     */
    function _stakeStart(
        GlobalsCache memory g,
        uint256 newStakedHearts,
        uint256 newStakedDays,
        bool newAutoStake
    )
        internal
    {
        /* Enforce the maximum stake time */
        require(newStakedDays <= MAX_STAKE_DAYS, "HEX: newStakedDays higher than maximum");

        uint256 bonusHearts = _stakeStartBonusHearts(newStakedHearts, newStakedDays);
        uint256 newStakeShares = (newStakedHearts + bonusHearts) * SHARE_RATE_SCALE / g._shareRate;

        /* Ensure newStakedHearts is enough for at least one stake share */
        require(newStakeShares != 0, "HEX: newStakedHearts must be at least minimum shareRate");

        /*
            The stakeStart timestamp will always be part-way through the current
            day, so it needs to be rounded-up to the next day to ensure all
            stakes align with the same fixed calendar days. The current day is
            already rounded-down, so rounded-up is current day + 1.
        */
        uint256 newLockedDay = g._currentDay < CLAIM_PHASE_START_DAY
            ? CLAIM_PHASE_START_DAY + 1
            : g._currentDay + 1;

        /* Create Stake */
        uint40 newStakeId = ++g._latestStakeId;
        _stakeAdd(
            stakeLists[msg.sender],
            newStakeId,
            newStakedHearts,
            newStakeShares,
            newLockedDay,
            newStakedDays,
            newAutoStake
        );

        _emitStakeStart(newStakeId, newStakedHearts, newStakeShares, newStakedDays, newAutoStake);

        /* Stake is added to total in the next round, not the current round */
        g._nextStakeSharesTotal += newStakeShares;

        /* Track total staked Hearts for inflation calculations */
        g._lockedHeartsTotal += newStakedHearts;
    }

    /**
     * @dev Calculates total stake payout including rewards for a multi-day range
     * @param g Cache of stored globals
     * @param stakeSharesParam Param from stake to calculate bonuses for
     * @param beginDay First day to calculate bonuses for
     * @param endDay Last day (non-inclusive) of range to calculate bonuses for
     * @return Payout in Hearts
     */
    function _calcPayoutRewards(
        GlobalsCache memory g,
        uint256 stakeSharesParam,
        uint256 beginDay,
        uint256 endDay
    )
        private
        view
        returns (uint256 payout)
    {
        for (uint256 day = beginDay; day < endDay; day++) {
            payout += dailyData[day].dayPayoutTotal * stakeSharesParam
                / dailyData[day].dayStakeSharesTotal;
        }

        /* Less expensive to re-read storage than to have the condition inside the loop */
        if (beginDay <= BIG_PAY_DAY && endDay > BIG_PAY_DAY) {
            uint256 bigPaySlice = g._unclaimedSatoshisTotal * HEARTS_PER_SATOSHI * stakeSharesParam
                / dailyData[BIG_PAY_DAY].dayStakeSharesTotal;

            payout += bigPaySlice + _calcAdoptionBonus(g, bigPaySlice);
        }
        return payout;
    }

    /**
     * @dev Calculate bonus Hearts for a new stake, if any
     * @param newStakedHearts Number of Hearts to stake
     * @param newStakedDays Number of days to stake
     */
    function _stakeStartBonusHearts(uint256 newStakedHearts, uint256 newStakedDays)
        private
        pure
        returns (uint256 bonusHearts)
    {
        /*
            LONGER PAYS BETTER:

            If longer than 1 day stake is committed to, each extra day
            gives bonus shares of approximately 0.0548%, which is approximately 20%
            extra per year of increased stake length committed to, but capped to a
            maximum of 200% extra.

            extraDays       =  stakedDays - 1

            longerBonus%    = (extraDays / 364) * 20%
                            = (extraDays / 364) / 5
                            =  extraDays / 1820
                            =  extraDays / LPB

            extraDays       =  longerBonus% * 1820
            extraDaysMax    =  longerBonusMax% * 1820
                            =  200% * 1820
                            =  3640
                            =  LPB_MAX_DAYS

            BIGGER PAYS BETTER:

            Bonus percentage scaled 0% to 10% for the first 150M HEX of stake.

            biggerBonus%    = (cappedHearts /  BPB_MAX_HEARTS) * 10%
                            = (cappedHearts /  BPB_MAX_HEARTS) / 10
                            =  cappedHearts / (BPB_MAX_HEARTS * 10)
                            =  cappedHearts /  BPB

            COMBINED:

            combinedBonus%  =            longerBonus%  +  biggerBonus%

                                      cappedExtraDays     cappedHearts
                            =         ---------------  +  ------------
                                            LPB               BPB

                                cappedExtraDays * BPB     cappedHearts * LPB
                            =   ---------------------  +  ------------------
                                      LPB * BPB               LPB * BPB

                                cappedExtraDays * BPB  +  cappedHearts * LPB
                            =   --------------------------------------------
                                                  LPB  *  BPB

            bonusHearts     = hearts * combinedBonus%
                            = hearts * (cappedExtraDays * BPB  +  cappedHearts * LPB) / (LPB * BPB)
        */
        uint256 cappedExtraDays = 0;

        /* Must be more than 1 day for Longer-Pays-Better */
        if (newStakedDays > 1) {
            cappedExtraDays = newStakedDays <= LPB_MAX_DAYS ? newStakedDays - 1 : LPB_MAX_DAYS;
        }

        uint256 cappedStakedHearts = newStakedHearts <= BPB_MAX_HEARTS
            ? newStakedHearts
            : BPB_MAX_HEARTS;

        bonusHearts = cappedExtraDays * BPB + cappedStakedHearts * LPB;
        bonusHearts = newStakedHearts * bonusHearts / (LPB * BPB);

        return bonusHearts;
    }

    function _stakeUnlock(GlobalsCache memory g, StakeCache memory st)
        private
        pure
    {
        g._stakeSharesTotal -= st._stakeShares;
        st._unlockedDay = g._currentDay;
    }

    function _stakePerformance(GlobalsCache memory g, StakeCache memory st, uint256 servedDays)
        private
        view
        returns (uint256 stakeReturn, uint256 payout, uint256 penalty, uint256 cappedPenalty)
    {
        if (servedDays < st._stakedDays) {
            (payout, penalty) = _calcPayoutAndEarlyPenalty(
                g,
                st._lockedDay,
                st._stakedDays,
                servedDays,
                st._stakeShares
            );
            stakeReturn = st._stakedHearts + payout;
        } else {
            // servedDays must == stakedDays here
            payout = _calcPayoutRewards(
                g,
                st._stakeShares,
                st._lockedDay,
                st._lockedDay + servedDays
            );
            stakeReturn = st._stakedHearts + payout;

            penalty = _calcLatePenalty(st._lockedDay, st._stakedDays, st._unlockedDay, stakeReturn);
        }
        if (penalty != 0) {
            if (penalty > stakeReturn) {
                /* Cannot have a negative stake return */
                cappedPenalty = stakeReturn;
                stakeReturn = 0;
            } else {
                /* Remove penalty from the stake return */
                cappedPenalty = penalty;
                stakeReturn -= cappedPenalty;
            }
        }
        return (stakeReturn, payout, penalty, cappedPenalty);
    }

    function _calcPayoutAndEarlyPenalty(
        GlobalsCache memory g,
        uint256 lockedDayParam,
        uint256 stakedDaysParam,
        uint256 servedDays,
        uint256 stakeSharesParam
    )
        private
        view
        returns (uint256 payout, uint256 penalty)
    {
        uint256 servedEndDay = lockedDayParam + servedDays;

        /* 50% of stakedDays (rounded up) with a minimum applied */
        uint256 penaltyDays = (stakedDaysParam + 1) / 2;
        if (penaltyDays < EARLY_PENALTY_MIN_DAYS) {
            penaltyDays = EARLY_PENALTY_MIN_DAYS;
        }

        if (servedDays == 0) {
            /* Fill penalty days with the estimated average payout */
            uint256 expected = _estimatePayoutRewardsDay(g, stakeSharesParam, lockedDayParam);
            penalty = expected * penaltyDays;
            return (payout, penalty); // Actual payout was 0
        }

        if (penaltyDays < servedDays) {
            /*
                Simplified explanation of intervals where end-day is non-inclusive:

                penalty:    [lockedDay  ...  penaltyEndDay)
                delta:                      [penaltyEndDay  ...  servedEndDay)
                payout:     [lockedDay  .......................  servedEndDay)
            */
            uint256 penaltyEndDay = lockedDayParam + penaltyDays;
            penalty = _calcPayoutRewards(g, stakeSharesParam, lockedDayParam, penaltyEndDay);

            uint256 delta = _calcPayoutRewards(g, stakeSharesParam, penaltyEndDay, servedEndDay);
            payout = penalty + delta;
            return (payout, penalty);
        }

        /* penaltyDays >= servedDays  */
        payout = _calcPayoutRewards(g, stakeSharesParam, lockedDayParam, servedEndDay);

        if (penaltyDays == servedDays) {
            penalty = payout;
        } else {
            /*
                (penaltyDays > servedDays) means not enough days served, so fill the
                penalty days with the average payout from only the days that were served.
            */
            penalty = payout * penaltyDays / servedDays;
        }
        return (payout, penalty);
    }

    function _calcLatePenalty(
        uint256 lockedDayParam,
        uint256 stakedDaysParam,
        uint256 unlockedDayParam,
        uint256 rawStakeReturn
    )
        private
        pure
        returns (uint256)
    {
        /* Allow grace time before penalties accrue */
        uint256 maxUnlockedDay = lockedDayParam + stakedDaysParam + LATE_PENALTY_GRACE_DAYS;
        if (unlockedDayParam <= maxUnlockedDay) {
            return 0;
        }

        /* Calculate penalty as a percentage of stake return based on time */
        return rawStakeReturn * (unlockedDayParam - maxUnlockedDay) / LATE_PENALTY_SCALE_DAYS;
    }

    function _splitPenaltyProceeds(GlobalsCache memory g, uint256 penalty)
        private
    {
        /* Split a penalty 50:50 between Origin and stakePenaltyTotal */
        uint256 splitPenalty = penalty / 2;

        if (splitPenalty != 0) {
            _mint(ORIGIN_ADDR, splitPenalty);
        }

        /* Use the other half of the penalty to account for an odd-numbered penalty */
        splitPenalty = penalty - splitPenalty;
        g._stakePenaltyTotal += splitPenalty;
    }

    function _shareRateUpdate(GlobalsCache memory g, StakeCache memory st, uint256 stakeReturn)
        private
    {
        if (stakeReturn > st._stakedHearts) {
            /*
                Calculate the new shareRate that would yield the same number of shares if
                the user re-staked this stakeReturn, factoring in any bonuses they would
                receive in stakeStart().
            */
            uint256 bonusHearts = _stakeStartBonusHearts(stakeReturn, st._stakedDays);
            uint256 newShareRate = (stakeReturn + bonusHearts) * SHARE_RATE_SCALE / st._stakeShares;

            if (newShareRate > SHARE_RATE_MAX) {
                /*
                    Realistically this can't happen, but there are contrived theoretical
                    scenarios that can lead to extreme values of newShareRate, so it is
                    capped to prevent them anyway.
                */
                newShareRate = SHARE_RATE_MAX;
            }

            if (newShareRate > g._shareRate) {
                g._shareRate = newShareRate;

                _emitShareRateChange(newShareRate, st._stakeId);
            }
        }
    }

    function _emitStakeStart(
        uint40 stakeId,
        uint256 stakedHearts,
        uint256 stakeShares,
        uint256 stakedDays,
        bool isAutoStake
    )
        private
    {
        emit StakeStart( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint72(stakedHearts)) << 40)
                | (uint256(uint72(stakeShares)) << 112)
                | (uint256(uint16(stakedDays)) << 184)
                | (isAutoStake ? (1 << 200) : 0),
            msg.sender,
            stakeId
        );
    }

    function _emitStakeGoodAccounting(
        address stakerAddr,
        uint40 stakeId,
        uint256 stakedHearts,
        uint256 stakeShares,
        uint256 payout,
        uint256 penalty
    )
        private
    {
        emit StakeGoodAccounting( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint72(stakedHearts)) << 40)
                | (uint256(uint72(stakeShares)) << 112)
                | (uint256(uint72(payout)) << 184),
            uint256(uint72(penalty)),
            stakerAddr,
            stakeId,
            msg.sender
        );
    }

    function _emitStakeEnd(
        uint40 stakeId,
        uint256 stakedHearts,
        uint256 stakeShares,
        uint256 payout,
        uint256 penalty,
        uint256 servedDays,
        bool prevUnlocked
    )
        private
    {
        emit StakeEnd( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint72(stakedHearts)) << 40)
                | (uint256(uint72(stakeShares)) << 112)
                | (uint256(uint72(payout)) << 184),
            uint256(uint72(penalty))
                | (uint256(uint16(servedDays)) << 72)
                | (prevUnlocked ? (1 << 88) : 0),
            msg.sender,
            stakeId
        );
    }

    function _emitShareRateChange(uint256 shareRate, uint40 stakeId)
        private
    {
        emit ShareRateChange( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint40(shareRate)) << 40),
            stakeId
        );
    }
}

/**
 * @dev These functions deal with verification of Merkle trees (hash trees),
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
        bytes32 computedHash = leaf;

        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];

            if (computedHash < proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
            }
        }

        // Check if the computed hash (root) is equal to the provided root
        return computedHash == root;
    }
}

contract UTXOClaimValidation is StakeableToken {
    /**
     * @dev PUBLIC FACING: Verify a BTC address and balance are unclaimed and part of the Merkle tree
     * @param btcAddr Bitcoin address (binary; no base58-check encoding)
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @param proof Merkle tree proof
     * @return True if can be claimed
     */
    function btcAddressIsClaimable(bytes20 btcAddr, uint256 rawSatoshis, bytes32[] calldata proof)
        external
        view
        returns (bool)
    {
        uint256 day = _currentDay();

        require(day >= CLAIM_PHASE_START_DAY, "HEX: Claim phase has not yet started");
        require(day < CLAIM_PHASE_END_DAY, "HEX: Claim phase has ended");

        /* Don't need to check Merkle proof if UTXO BTC address has already been claimed    */
        if (btcAddressClaims[btcAddr]) {
            return false;
        }

        /* Verify the Merkle tree proof */
        return _btcAddressIsValid(btcAddr, rawSatoshis, proof);
    }

    /**
     * @dev PUBLIC FACING: Verify a BTC address and balance are part of the Merkle tree
     * @param btcAddr Bitcoin address (binary; no base58-check encoding)
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @param proof Merkle tree proof
     * @return True if valid
     */
    function btcAddressIsValid(bytes20 btcAddr, uint256 rawSatoshis, bytes32[] calldata proof)
        external
        pure
        returns (bool)
    {
        return _btcAddressIsValid(btcAddr, rawSatoshis, proof);
    }

    /**
     * @dev PUBLIC FACING: Verify a Merkle proof using the UTXO Merkle tree
     * @param merkleLeaf Leaf asserted to be present in the Merkle tree
     * @param proof Generated Merkle tree proof
     * @return True if valid
     */
    function merkleProofIsValid(bytes32 merkleLeaf, bytes32[] calldata proof)
        external
        pure
        returns (bool)
    {
        return _merkleProofIsValid(merkleLeaf, proof);
    }

    /**
     * @dev PUBLIC FACING: Verify that a Bitcoin signature matches the claim message containing
     * the Ethereum address and claim param hash
     * @param claimToAddr Eth address within the signed claim message
     * @param claimParamHash Param hash within the signed claim message
     * @param pubKeyX First  half of uncompressed ECDSA public key
     * @param pubKeyY Second half of uncompressed ECDSA public key
     * @param claimFlags Claim flags specifying address and message formats
     * @param v v parameter of ECDSA signature
     * @param r r parameter of ECDSA signature
     * @param s s parameter of ECDSA signature
     * @return True if matching
     */
    function claimMessageMatchesSignature(
        address claimToAddr,
        bytes32 claimParamHash,
        bytes32 pubKeyX,
        bytes32 pubKeyY,
        uint8 claimFlags,
        uint8 v,
        bytes32 r,
        bytes32 s
    )
        public
        pure
        returns (bool)
    {
        require(v >= 27 && v <= 30, "HEX: v invalid");

        /*
            ecrecover() returns an Eth address rather than a public key, so
            we must do the same to compare.
        */
        address pubKeyEthAddr = pubKeyToEthAddress(pubKeyX, pubKeyY);

        /* Create and hash the claim message text */
        bytes32 messageHash = _hash256(
            _claimMessageCreate(claimToAddr, claimParamHash, claimFlags)
        );

        /* Verify the public key */
        return ecrecover(messageHash, v, r, s) == pubKeyEthAddr;
    }

    /**
     * @dev PUBLIC FACING: Derive an Ethereum address from an ECDSA public key
     * @param pubKeyX First  half of uncompressed ECDSA public key
     * @param pubKeyY Second half of uncompressed ECDSA public key
     * @return Derived Eth address
     */
    function pubKeyToEthAddress(bytes32 pubKeyX, bytes32 pubKeyY)
        public
        pure
        returns (address)
    {
        return address(uint160(uint256(keccak256(abi.encodePacked(pubKeyX, pubKeyY)))));
    }

    /**
     * @dev PUBLIC FACING: Derive a Bitcoin address from an ECDSA public key
     * @param pubKeyX First  half of uncompressed ECDSA public key
     * @param pubKeyY Second half of uncompressed ECDSA public key
     * @param claimFlags Claim flags specifying address and message formats
     * @return Derived Bitcoin address (binary; no base58-check encoding)
     */
    function pubKeyToBtcAddress(bytes32 pubKeyX, bytes32 pubKeyY, uint8 claimFlags)
        public
        pure
        returns (bytes20)
    {
        /*
            Helpful references:
             - https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses
             - https://github.com/cryptocoinjs/ecurve/blob/master/lib/point.js
        */
        uint8 startingByte;
        bytes memory pubKey;
        bool compressed = (claimFlags & CLAIM_FLAG_BTC_ADDR_COMPRESSED) != 0;
        bool nested = (claimFlags & CLAIM_FLAG_BTC_ADDR_P2WPKH_IN_P2SH) != 0;
        bool bech32 = (claimFlags & CLAIM_FLAG_BTC_ADDR_BECH32) != 0;

        if (compressed) {
            /* Compressed public key format */
            require(!(nested && bech32), "HEX: claimFlags invalid");

            startingByte = (pubKeyY[31] & 0x01) == 0 ? 0x02 : 0x03;
            pubKey = abi.encodePacked(startingByte, pubKeyX);
        } else {
            /* Uncompressed public key format */
            require(!nested && !bech32, "HEX: claimFlags invalid");

            startingByte = 0x04;
            pubKey = abi.encodePacked(startingByte, pubKeyX, pubKeyY);
        }

        bytes20 pubKeyHash = _hash160(pubKey);
        if (nested) {
            return _hash160(abi.encodePacked(hex"0014", pubKeyHash));
        }
        return pubKeyHash;
    }

    /**
     * @dev Verify a BTC address and balance are part of the Merkle tree
     * @param btcAddr Bitcoin address (binary; no base58-check encoding)
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @param proof Merkle tree proof
     * @return True if valid
     */
    function _btcAddressIsValid(bytes20 btcAddr, uint256 rawSatoshis, bytes32[] memory proof)
        internal
        pure
        returns (bool)
    {
        /*
            Ensure the proof does not attempt to treat a Merkle leaf as if it were an
            internal Merkle tree node. A leaf will always have the zero-fill. An
            internal node will never have the zero-fill, as guaranteed by HEX's Merkle
            tree construction.

            The first element, proof[0], will always be a leaf because it is the pair
            of the leaf being validated. The rest of the elements, proof[1..length-1],
            must be internal nodes.

            The number of leaves (CLAIMABLE_BTC_ADDR_COUNT) is even, as guaranteed by
            HEX's Merkle tree construction, which eliminates the only edge-case where
            this validation would not apply.
        */
        require((uint256(proof[0]) & MERKLE_LEAF_FILL_MASK) == 0, "HEX: proof invalid");
        for (uint256 i = 1; i < proof.length; i++) {
            require((uint256(proof[i]) & MERKLE_LEAF_FILL_MASK) != 0, "HEX: proof invalid");
        }

        /*
            Calculate the 32 byte Merkle leaf associated with this BTC address and balance
                160 bits: BTC address
                 52 bits: Zero-fill
                 45 bits: Satoshis (limited by MAX_BTC_ADDR_BALANCE_SATOSHIS)
        */
        bytes32 merkleLeaf = bytes32(btcAddr) | bytes32(rawSatoshis);

        /* Verify the Merkle tree proof */
        return _merkleProofIsValid(merkleLeaf, proof);
    }

    /**
     * @dev Verify a Merkle proof using the UTXO Merkle tree
     * @param merkleLeaf Leaf asserted to be present in the Merkle tree
     * @param proof Generated Merkle tree proof
     * @return True if valid
     */
    function _merkleProofIsValid(bytes32 merkleLeaf, bytes32[] memory proof)
        private
        pure
        returns (bool)
    {
        return MerkleProof.verify(proof, MERKLE_TREE_ROOT, merkleLeaf);
    }

    function _claimMessageCreate(address claimToAddr, bytes32 claimParamHash, uint8 claimFlags)
        private
        pure
        returns (bytes memory)
    {
        bytes memory prefixStr = (claimFlags & CLAIM_FLAG_MSG_PREFIX_OLD) != 0
            ? OLD_CLAIM_PREFIX_STR
            : STD_CLAIM_PREFIX_STR;

        bool includeAddrChecksum = (claimFlags & CLAIM_FLAG_ETH_ADDR_LOWERCASE) == 0;

        bytes memory addrStr = _addressStringCreate(claimToAddr, includeAddrChecksum);

        if (claimParamHash == 0) {
            return abi.encodePacked(
                BITCOIN_SIG_PREFIX_LEN,
                BITCOIN_SIG_PREFIX_STR,
                uint8(prefixStr.length) + ETH_ADDRESS_HEX_LEN,
                prefixStr,
                addrStr
            );
        }

        bytes memory claimParamHashStr = new bytes(CLAIM_PARAM_HASH_HEX_LEN);

        _hexStringFromData(claimParamHashStr, claimParamHash, CLAIM_PARAM_HASH_BYTE_LEN);

        return abi.encodePacked(
            BITCOIN_SIG_PREFIX_LEN,
            BITCOIN_SIG_PREFIX_STR,
            uint8(prefixStr.length) + ETH_ADDRESS_HEX_LEN + 1 + CLAIM_PARAM_HASH_HEX_LEN,
            prefixStr,
            addrStr,
            "_",
            claimParamHashStr
        );
    }

    function _addressStringCreate(address addr, bool includeAddrChecksum)
        private
        pure
        returns (bytes memory addrStr)
    {
        addrStr = new bytes(ETH_ADDRESS_HEX_LEN);
        _hexStringFromData(addrStr, bytes32(bytes20(addr)), ETH_ADDRESS_BYTE_LEN);

        if (includeAddrChecksum) {
            bytes32 addrStrHash = keccak256(addrStr);

            uint256 offset = 0;

            for (uint256 i = 0; i < ETH_ADDRESS_BYTE_LEN; i++) {
                uint8 b = uint8(addrStrHash[i]);

                _addressStringChecksumChar(addrStr, offset++, b >> 4);
                _addressStringChecksumChar(addrStr, offset++, b & 0x0f);
            }
        }

        return addrStr;
    }

    function _addressStringChecksumChar(bytes memory addrStr, uint256 offset, uint8 hashNybble)
        private
        pure
    {
        bytes1 ch = addrStr[offset];

        if (ch >= "a" && hashNybble >= 8) {
            addrStr[offset] = ch ^ 0x20;
        }
    }

    function _hexStringFromData(bytes memory hexStr, bytes32 data, uint256 dataLen)
        private
        pure
    {
        uint256 offset = 0;

        for (uint256 i = 0; i < dataLen; i++) {
            uint8 b = uint8(data[i]);

            hexStr[offset++] = HEX_DIGITS[b >> 4];
            hexStr[offset++] = HEX_DIGITS[b & 0x0f];
        }
    }

    /**
     * @dev sha256(sha256(data))
     * @param data Data to be hashed
     * @return 32-byte hash
     */
    function _hash256(bytes memory data)
        private
        pure
        returns (bytes32)
    {
        return sha256(abi.encodePacked(sha256(data)));
    }

    /**
     * @dev ripemd160(sha256(data))
     * @param data Data to be hashed
     * @return 20-byte hash
     */
    function _hash160(bytes memory data)
        private
        pure
        returns (bytes20)
    {
        return ripemd160(abi.encodePacked(sha256(data)));
    }
}

contract UTXORedeemableToken is UTXOClaimValidation {
    /**
     * @dev PUBLIC FACING: Claim a BTC address and its Satoshi balance in Hearts
     * crediting the appropriate amount to a specified Eth address. Bitcoin ECDSA
     * signature must be from that BTC address and must match the claim message
     * for the Eth address.
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @param proof Merkle tree proof
     * @param claimToAddr Destination Eth address to credit Hearts to
     * @param pubKeyX First  half of uncompressed ECDSA public key for the BTC address
     * @param pubKeyY Second half of uncompressed ECDSA public key for the BTC address
     * @param claimFlags Claim flags specifying address and message formats
     * @param v v parameter of ECDSA signature
     * @param r r parameter of ECDSA signature
     * @param s s parameter of ECDSA signature
     * @param autoStakeDays Number of days to auto-stake, subject to minimum auto-stake days
     * @param referrerAddr Eth address of referring user (optional; 0x0 for no referrer)
     * @return Total number of Hearts credited, if successful
     */
    function btcAddressClaim(
        uint256 rawSatoshis,
        bytes32[] calldata proof,
        address claimToAddr,
        bytes32 pubKeyX,
        bytes32 pubKeyY,
        uint8 claimFlags,
        uint8 v,
        bytes32 r,
        bytes32 s,
        uint256 autoStakeDays,
        address referrerAddr
    )
        external
        returns (uint256)
    {
        /* Sanity check */
        require(rawSatoshis <= MAX_BTC_ADDR_BALANCE_SATOSHIS, "HEX: CHK: rawSatoshis");

        /* Enforce the minimum stake time for the auto-stake from this claim */
        require(autoStakeDays >= MIN_AUTO_STAKE_DAYS, "HEX: autoStakeDays lower than minimum");

        /* Ensure signature matches the claim message containing the Eth address and claimParamHash */
        {
            bytes32 claimParamHash = 0;

            if (claimToAddr != msg.sender) {
                /* Claimer did not send this, so claim params must be signed */
                claimParamHash = keccak256(
                    abi.encodePacked(MERKLE_TREE_ROOT, autoStakeDays, referrerAddr)
                );
            }

            require(
                claimMessageMatchesSignature(
                    claimToAddr,
                    claimParamHash,
                    pubKeyX,
                    pubKeyY,
                    claimFlags,
                    v,
                    r,
                    s
                ),
                "HEX: Signature mismatch"
            );
        }

        /* Derive BTC address from public key */
        bytes20 btcAddr = pubKeyToBtcAddress(pubKeyX, pubKeyY, claimFlags);

        /* Ensure BTC address has not yet been claimed */
        require(!btcAddressClaims[btcAddr], "HEX: BTC address balance already claimed");

        /* Ensure BTC address is part of the Merkle tree */
        require(
            _btcAddressIsValid(btcAddr, rawSatoshis, proof),
            "HEX: BTC address or balance unknown"
        );

        /* Mark BTC address as claimed */
        btcAddressClaims[btcAddr] = true;

        return _satoshisClaimSync(
            rawSatoshis,
            claimToAddr,
            btcAddr,
            claimFlags,
            autoStakeDays,
            referrerAddr
        );
    }

    function _satoshisClaimSync(
        uint256 rawSatoshis,
        address claimToAddr,
        bytes20 btcAddr,
        uint8 claimFlags,
        uint256 autoStakeDays,
        address referrerAddr
    )
        private
        returns (uint256 totalClaimedHearts)
    {
        GlobalsCache memory g;
        GlobalsCache memory gSnapshot;
        _globalsLoad(g, gSnapshot);

        totalClaimedHearts = _satoshisClaim(
            g,
            rawSatoshis,
            claimToAddr,
            btcAddr,
            claimFlags,
            autoStakeDays,
            referrerAddr
        );

        _globalsSync(g, gSnapshot);

        return totalClaimedHearts;
    }

    /**
     * @dev Credit an Eth address with the Hearts value of a raw Satoshis balance
     * @param g Cache of stored globals
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @param claimToAddr Destination Eth address for the claimed Hearts to be sent
     * @param btcAddr Bitcoin address (binary; no base58-check encoding)
     * @param autoStakeDays Number of days to auto-stake, subject to minimum auto-stake days
     * @param referrerAddr Eth address of referring user (optional; 0x0 for no referrer)
     * @return Total number of Hearts credited, if successful
     */
    function _satoshisClaim(
        GlobalsCache memory g,
        uint256 rawSatoshis,
        address claimToAddr,
        bytes20 btcAddr,
        uint8 claimFlags,
        uint256 autoStakeDays,
        address referrerAddr
    )
        private
        returns (uint256 totalClaimedHearts)
    {
        /* Allowed only during the claim phase */
        require(g._currentDay >= CLAIM_PHASE_START_DAY, "HEX: Claim phase has not yet started");
        require(g._currentDay < CLAIM_PHASE_END_DAY, "HEX: Claim phase has ended");

        /* Check if log data needs to be updated */
        _dailyDataUpdateAuto(g);

        /* Sanity check */
        require(
            g._claimedBtcAddrCount < CLAIMABLE_BTC_ADDR_COUNT,
            "HEX: CHK: _claimedBtcAddrCount"
        );

        (uint256 adjSatoshis, uint256 claimedHearts, uint256 claimBonusHearts) = _calcClaimValues(
            g,
            rawSatoshis
        );

        /* Increment claim count to track viral rewards */
        g._claimedBtcAddrCount++;

        totalClaimedHearts = _remitBonuses(
            claimToAddr,
            btcAddr,
            claimFlags,
            rawSatoshis,
            adjSatoshis,
            claimedHearts,
            claimBonusHearts,
            referrerAddr
        );

        /* Auto-stake a percentage of the successful claim */
        uint256 autoStakeHearts = totalClaimedHearts * AUTO_STAKE_CLAIM_PERCENT / 100;
        _stakeStart(g, autoStakeHearts, autoStakeDays, true);

        /* Mint remaining claimed Hearts to claim address */
        _mint(claimToAddr, totalClaimedHearts - autoStakeHearts);

        return totalClaimedHearts;
    }

    function _remitBonuses(
        address claimToAddr,
        bytes20 btcAddr,
        uint8 claimFlags,
        uint256 rawSatoshis,
        uint256 adjSatoshis,
        uint256 claimedHearts,
        uint256 claimBonusHearts,
        address referrerAddr
    )
        private
        returns (uint256 totalClaimedHearts)
    {
        totalClaimedHearts = claimedHearts + claimBonusHearts;

        uint256 originBonusHearts = claimBonusHearts;

        if (referrerAddr == address(0)) {
            /* No referrer */
            _emitClaim(
                claimToAddr,
                btcAddr,
                claimFlags,
                rawSatoshis,
                adjSatoshis,
                totalClaimedHearts,
                referrerAddr
            );
        } else {
            /* Referral bonus of 10% of total claimed Hearts to claimer */
            uint256 referralBonusHearts = totalClaimedHearts / 10;

            totalClaimedHearts += referralBonusHearts;

            /* Then a cumulative referrer bonus of 20% to referrer */
            uint256 referrerBonusHearts = totalClaimedHearts / 5;

            originBonusHearts += referralBonusHearts + referrerBonusHearts;

            if (referrerAddr == claimToAddr) {
                /* Self-referred */
                totalClaimedHearts += referrerBonusHearts;
                _emitClaim(
                    claimToAddr,
                    btcAddr,
                    claimFlags,
                    rawSatoshis,
                    adjSatoshis,
                    totalClaimedHearts,
                    referrerAddr
                );
            } else {
                /* Referred by different address */
                _emitClaim(
                    claimToAddr,
                    btcAddr,
                    claimFlags,
                    rawSatoshis,
                    adjSatoshis,
                    totalClaimedHearts,
                    referrerAddr
                );
                _mint(referrerAddr, referrerBonusHearts);
            }
        }

        _mint(ORIGIN_ADDR, originBonusHearts);

        return totalClaimedHearts;
    }

    function _emitClaim(
        address claimToAddr,
        bytes20 btcAddr,
        uint8 claimFlags,
        uint256 rawSatoshis,
        uint256 adjSatoshis,
        uint256 claimedHearts,
        address referrerAddr
    )
        private
    {
        emit Claim( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint56(rawSatoshis)) << 40)
                | (uint256(uint56(adjSatoshis)) << 96)
                | (uint256(claimFlags) << 152)
                | (uint256(uint72(claimedHearts)) << 160),
            uint256(uint160(msg.sender)),
            btcAddr,
            claimToAddr,
            referrerAddr
        );

        if (claimToAddr == msg.sender) {
            return;
        }

        emit ClaimAssist( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint160(btcAddr)) << 40)
                | (uint256(uint56(rawSatoshis)) << 200),
            uint256(uint56(adjSatoshis))
                | (uint256(uint160(claimToAddr)) << 56)
                | (uint256(claimFlags) << 216),
            uint256(uint72(claimedHearts))
                | (uint256(uint160(referrerAddr)) << 72),
            msg.sender
        );
    }

    function _calcClaimValues(GlobalsCache memory g, uint256 rawSatoshis)
        private
        pure
        returns (uint256 adjSatoshis, uint256 claimedHearts, uint256 claimBonusHearts)
    {
        /* Apply Silly Whale reduction */
        adjSatoshis = _adjustSillyWhale(rawSatoshis);
        require(
            g._claimedSatoshisTotal + adjSatoshis <= CLAIMABLE_SATOSHIS_TOTAL,
            "HEX: CHK: _claimedSatoshisTotal"
        );
        g._claimedSatoshisTotal += adjSatoshis;

        uint256 daysRemaining = CLAIM_PHASE_END_DAY - g._currentDay;

        /* Apply late-claim reduction */
        adjSatoshis = _adjustLateClaim(adjSatoshis, daysRemaining);
        g._unclaimedSatoshisTotal -= adjSatoshis;

        /* Convert to Hearts and calculate speed bonus */
        claimedHearts = adjSatoshis * HEARTS_PER_SATOSHI;
        claimBonusHearts = _calcSpeedBonus(claimedHearts, daysRemaining);

        return (adjSatoshis, claimedHearts, claimBonusHearts);
    }

    /**
     * @dev Apply Silly Whale adjustment
     * @param rawSatoshis Raw BTC address balance in Satoshis
     * @return Adjusted BTC address balance in Satoshis
     */
    function _adjustSillyWhale(uint256 rawSatoshis)
        private
        pure
        returns (uint256)
    {
        if (rawSatoshis < 1000e8) {
            /* For < 1,000 BTC: no penalty */
            return rawSatoshis;
        }
        if (rawSatoshis >= 10000e8) {
            /* For >= 10,000 BTC: penalty is 75%, leaving 25% */
            return rawSatoshis / 4;
        }
        /*
            For 1,000 <= BTC < 10,000: penalty scales linearly from 50% to 75%

            penaltyPercent  = (btc - 1000) / (10000 - 1000) * (75 - 50) + 50
                            = (btc - 1000) / 9000 * 25 + 50
                            = (btc - 1000) / 360 + 50

            appliedPercent  = 100 - penaltyPercent
                            = 100 - ((btc - 1000) / 360 + 50)
                            = 100 - (btc - 1000) / 360 - 50
                            = 50 - (btc - 1000) / 360
                            = (18000 - (btc - 1000)) / 360
                            = (18000 - btc + 1000) / 360
                            = (19000 - btc) / 360

            adjustedBtc     = btc * appliedPercent / 100
                            = btc * ((19000 - btc) / 360) / 100
                            = btc * (19000 - btc) / 36000

            adjustedSat     = 1e8 * adjustedBtc
                            = 1e8 * (btc * (19000 - btc) / 36000)
                            = 1e8 * ((sat / 1e8) * (19000 - (sat / 1e8)) / 36000)
                            = 1e8 * (sat / 1e8) * (19000 - (sat / 1e8)) / 36000
                            = (sat / 1e8) * 1e8 * (19000 - (sat / 1e8)) / 36000
                            = (sat / 1e8) * (19000e8 - sat) / 36000
                            = sat * (19000e8 - sat) / 36000e8
        */
        return rawSatoshis * (19000e8 - rawSatoshis) / 36000e8;
    }

    /**
     * @dev Apply late-claim adjustment to scale claim to zero by end of claim phase
     * @param adjSatoshis Adjusted BTC address balance in Satoshis (after Silly Whale)
     * @param daysRemaining Number of reward days remaining in claim phase
     * @return Adjusted BTC address balance in Satoshis (after Silly Whale and Late-Claim)
     */
    function _adjustLateClaim(uint256 adjSatoshis, uint256 daysRemaining)
        private
        pure
        returns (uint256)
    {
        /*
            Only valid from CLAIM_PHASE_DAYS to 1, and only used during that time.

            adjustedSat = sat * (daysRemaining / CLAIM_PHASE_DAYS) * 100%
                        = sat *  daysRemaining / CLAIM_PHASE_DAYS
        */
        return adjSatoshis * daysRemaining / CLAIM_PHASE_DAYS;
    }

    /**
     * @dev Calculates speed bonus for claiming earlier in the claim phase
     * @param claimedHearts Hearts claimed from adjusted BTC address balance Satoshis
     * @param daysRemaining Number of claim days remaining in claim phase
     * @return Speed bonus in Hearts
     */
    function _calcSpeedBonus(uint256 claimedHearts, uint256 daysRemaining)
        private
        pure
        returns (uint256)
    {
        /*
            Only valid from CLAIM_PHASE_DAYS to 1, and only used during that time.
            Speed bonus is 20% ... 0% inclusive.

            bonusHearts = claimedHearts  * ((daysRemaining - 1)  /  (CLAIM_PHASE_DAYS - 1)) * 20%
                        = claimedHearts  * ((daysRemaining - 1)  /  (CLAIM_PHASE_DAYS - 1)) * 20/100
                        = claimedHearts  * ((daysRemaining - 1)  /  (CLAIM_PHASE_DAYS - 1)) / 5
                        = claimedHearts  *  (daysRemaining - 1)  / ((CLAIM_PHASE_DAYS - 1)  * 5)
        */
        return claimedHearts * (daysRemaining - 1) / ((CLAIM_PHASE_DAYS - 1) * 5);
    }
}

contract TransformableToken is UTXORedeemableToken {
    /**
     * @dev PUBLIC FACING: Enter the tranform lobby for the current round
     * @param referrerAddr Eth address of referring user (optional; 0x0 for no referrer)
     */
    function xfLobbyEnter(address referrerAddr)
        external
        payable
    {
        uint256 enterDay = _currentDay();
        require(enterDay < CLAIM_PHASE_END_DAY, "HEX: Lobbies have ended");

        uint256 rawAmount = msg.value;
        require(rawAmount != 0, "HEX: Amount required");

        XfLobbyQueueStore storage qRef = xfLobbyMembers[enterDay][msg.sender];

        uint256 entryIndex = qRef.tailIndex++;

        qRef.entries[entryIndex] = XfLobbyEntryStore(uint96(rawAmount), referrerAddr);

        xfLobby[enterDay] += rawAmount;

        _emitXfLobbyEnter(enterDay, entryIndex, rawAmount, referrerAddr);
    }

    /**
     * @dev PUBLIC FACING: Leave the transform lobby after the round is complete
     * @param enterDay Day number when the member entered
     * @param count Number of queued-enters to exit (optional; 0 for all)
     */
    function xfLobbyExit(uint256 enterDay, uint256 count)
        external
    {
        require(enterDay < _currentDay(), "HEX: Round is not complete");

        XfLobbyQueueStore storage qRef = xfLobbyMembers[enterDay][msg.sender];

        uint256 headIndex = qRef.headIndex;
        uint256 endIndex;

        if (count != 0) {
            require(count <= qRef.tailIndex - headIndex, "HEX: count invalid");
            endIndex = headIndex + count;
        } else {
            endIndex = qRef.tailIndex;
            require(headIndex < endIndex, "HEX: count invalid");
        }

        uint256 waasLobby = _waasLobby(enterDay);
        uint256 _xfLobby = xfLobby[enterDay];
        uint256 totalXfAmount = 0;
        uint256 originBonusHearts = 0;

        do {
            uint256 rawAmount = qRef.entries[headIndex].rawAmount;
            address referrerAddr = qRef.entries[headIndex].referrerAddr;

            delete qRef.entries[headIndex];

            uint256 xfAmount = waasLobby * rawAmount / _xfLobby;

            if (referrerAddr == address(0)) {
                /* No referrer */
                _emitXfLobbyExit(enterDay, headIndex, xfAmount, referrerAddr);
            } else {
                /* Referral bonus of 10% of xfAmount to member */
                uint256 referralBonusHearts = xfAmount / 10;

                xfAmount += referralBonusHearts;

                /* Then a cumulative referrer bonus of 20% to referrer */
                uint256 referrerBonusHearts = xfAmount / 5;

                if (referrerAddr == msg.sender) {
                    /* Self-referred */
                    xfAmount += referrerBonusHearts;
                    _emitXfLobbyExit(enterDay, headIndex, xfAmount, referrerAddr);
                } else {
                    /* Referred by different address */
                    _emitXfLobbyExit(enterDay, headIndex, xfAmount, referrerAddr);
                    _mint(referrerAddr, referrerBonusHearts);
                }
                originBonusHearts += referralBonusHearts + referrerBonusHearts;
            }

            totalXfAmount += xfAmount;
        } while (++headIndex < endIndex);

        qRef.headIndex = uint40(headIndex);

        if (originBonusHearts != 0) {
            _mint(ORIGIN_ADDR, originBonusHearts);
        }
        if (totalXfAmount != 0) {
            _mint(msg.sender, totalXfAmount);
        }
    }

    /**
     * @dev PUBLIC FACING: Release any value that has been sent to the contract
     */
    function xfLobbyFlush()
        external
    {
        require(address(this).balance != 0, "HEX: No value");

        FLUSH_ADDR.transfer(address(this).balance);
    }

    /**
     * @dev PUBLIC FACING: External helper to return multiple values of xfLobby[] with
     * a single call
     * @param beginDay First day of data range
     * @param endDay Last day (non-inclusive) of data range
     * @return Fixed array of values
     */
    function xfLobbyRange(uint256 beginDay, uint256 endDay)
        external
        view
        returns (uint256[] memory list)
    {
        require(
            beginDay < endDay && endDay <= CLAIM_PHASE_END_DAY && endDay <= _currentDay(),
            "HEX: invalid range"
        );

        list = new uint256[](endDay - beginDay);

        uint256 src = beginDay;
        uint256 dst = 0;
        do {
            list[dst++] = uint256(xfLobby[src++]);
        } while (src < endDay);

        return list;
    }

    /**
     * @dev PUBLIC FACING: Return a current lobby member queue entry.
     * Only needed due to limitations of the standard ABI encoder.
     * @param memberAddr Eth address of the lobby member
     * @param entryId 49 bit compound value. Top 9 bits: enterDay, Bottom 40 bits: entryIndex
     * @return 1: Raw amount that was entered with; 2: Referring Eth addr (optional; 0x0 for no referrer)
     */
    function xfLobbyEntry(address memberAddr, uint256 entryId)
        external
        view
        returns (uint256 rawAmount, address referrerAddr)
    {
        uint256 enterDay = entryId >> XF_LOBBY_ENTRY_INDEX_SIZE;
        uint256 entryIndex = entryId & XF_LOBBY_ENTRY_INDEX_MASK;

        XfLobbyEntryStore storage entry = xfLobbyMembers[enterDay][memberAddr].entries[entryIndex];

        require(entry.rawAmount != 0, "HEX: Param invalid");

        return (entry.rawAmount, entry.referrerAddr);
    }

    /**
     * @dev PUBLIC FACING: Return the lobby days that a user is in with a single call
     * @param memberAddr Eth address of the user
     * @return Bit vector of lobby day numbers
     */
    function xfLobbyPendingDays(address memberAddr)
        external
        view
        returns (uint256[XF_LOBBY_DAY_WORDS] memory words)
    {
        uint256 day = _currentDay() + 1;

        if (day > CLAIM_PHASE_END_DAY) {
            day = CLAIM_PHASE_END_DAY;
        }

        while (day-- != 0) {
            if (xfLobbyMembers[day][memberAddr].tailIndex > xfLobbyMembers[day][memberAddr].headIndex) {
                words[day >> 8] |= 1 << (day & 255);
            }
        }

        return words;
    }

    function _waasLobby(uint256 enterDay)
        private
        returns (uint256 waasLobby)
    {
        if (enterDay >= CLAIM_PHASE_START_DAY) {
            GlobalsCache memory g;
            GlobalsCache memory gSnapshot;
            _globalsLoad(g, gSnapshot);

            _dailyDataUpdateAuto(g);

            uint256 unclaimed = dailyData[enterDay].dayUnclaimedSatoshisTotal;
            waasLobby = unclaimed * HEARTS_PER_SATOSHI / CLAIM_PHASE_DAYS;

            _globalsSync(g, gSnapshot);
        } else {
            waasLobby = WAAS_LOBBY_SEED_HEARTS;
        }
        return waasLobby;
    }

    function _emitXfLobbyEnter(
        uint256 enterDay,
        uint256 entryIndex,
        uint256 rawAmount,
        address referrerAddr
    )
        private
    {
        emit XfLobbyEnter( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint96(rawAmount)) << 40),
            msg.sender,
            (enterDay << XF_LOBBY_ENTRY_INDEX_SIZE) | entryIndex,
            referrerAddr
        );
    }

    function _emitXfLobbyExit(
        uint256 enterDay,
        uint256 entryIndex,
        uint256 xfAmount,
        address referrerAddr
    )
        private
    {
        emit XfLobbyExit( // (auto-generated event)
            uint256(uint40(block.timestamp))
                | (uint256(uint72(xfAmount)) << 40),
            msg.sender,
            (enterDay << XF_LOBBY_ENTRY_INDEX_SIZE) | entryIndex,
            referrerAddr
        );
    }
}

contract HEX is TransformableToken {
    constructor()
        public
    {
        /* Initialize global shareRate to 1 */
        globals.shareRate = uint40(1 * SHARE_RATE_SCALE);

        /* Initialize dailyDataCount to skip pre-claim period */
        globals.dailyDataCount = uint16(PRE_CLAIM_DAYS);

        /* Add all Satoshis from UTXO snapshot to contract */
        globals.claimStats = _claimStatsEncode(
            0, // _claimedBtcAddrCount
            0, // _claimedSatoshisTotal
            FULL_SATOSHIS_TOTAL // _unclaimedSatoshisTotal
        );
    }

    function() external payable {}
}

// 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

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covered work, you indicate your acceptance of this License to do so.

  10. Automatic Licensing of Downstream Recipients.

  Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License.  You are not responsible
for enforcing compliance by third parties with this License.

  An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations.  If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.

  You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License.  For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

  11. Patents.

  A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based.  The
work thus licensed is called the contributor's "contributor version".

  A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version.  For
purposes of this definition, "control" includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.

  Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.

  In the following three paragraphs, a "patent license" is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement).  To "grant" such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.

  If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients.  "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

  If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.

  A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License.  You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

  Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

  12. No Surrender of Others' Freedom.

  If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all.  For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Use with the GNU Affero General Public License.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

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

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

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

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

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

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

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

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

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

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

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

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

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

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

*/