// File: @openzeppelin/contracts/drafts/IERC20Permit.sol



// 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);
}

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



// 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);
}

// File: @pancakeswap/v3-core/contracts/interfaces/callback/IPancakeV3SwapCallback.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;

/// @title Callback for IPancakeV3PoolActions#swap
/// @notice Any contract that calls IPancakeV3PoolActions#swap must implement this interface
interface IPancakeV3SwapCallback {
    /// @notice Called to `msg.sender` after executing a swap via IPancakeV3Pool#swap.
    /// @dev In the implementation you must pay the pool tokens owed for the swap.
    /// The caller of this method must be checked to be a PancakeV3Pool deployed by the canonical PancakeV3Factory.
    /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
    /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
    /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
    /// @param data Any data passed through by the caller via the IPancakeV3PoolActions#swap call
    function pancakeV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata data
    ) external;
}

// File: @pancakeswap/v3-core/contracts/interfaces/IPancakeV3Pool.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;

import './pool/IPancakeV3PoolImmutables.sol';
import './pool/IPancakeV3PoolState.sol';
import './pool/IPancakeV3PoolDerivedState.sol';
import './pool/IPancakeV3PoolActions.sol';
import './pool/IPancakeV3PoolOwnerActions.sol';
import './pool/IPancakeV3PoolEvents.sol';

/// @title The interface for a PancakeSwap V3 Pool
/// @notice A PancakeSwap 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 IPancakeV3Pool is
    IPancakeV3PoolImmutables,
    IPancakeV3PoolState,
    IPancakeV3PoolDerivedState,
    IPancakeV3PoolActions,
    IPancakeV3PoolOwnerActions,
    IPancakeV3PoolEvents
{

}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolActions.sol



// 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 IPancakeV3PoolActions {
    /// @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 IPancakeV3MintCallback#pancakeV3MintCallback
    /// 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 IPancakeV3SwapCallback#pancakeV3SwapCallback
    /// @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 IPancakeV3FlashCallback#pancakeV3FlashCallback
    /// @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;
}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolDerivedState.sol



// 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 IPancakeV3PoolDerivedState {
    /// @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
        );
}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolEvents.sol



// 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 IPancakeV3PoolEvents {
    /// @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
    /// @param protocolFeesToken0 The protocol fee of token0 in the swap
    /// @param protocolFeesToken1 The protocol fee of token1 in the swap
    event Swap(
        address indexed sender,
        address indexed recipient,
        int256 amount0,
        int256 amount1,
        uint160 sqrtPriceX96,
        uint128 liquidity,
        int24 tick,
        uint128 protocolFeesToken0,
        uint128 protocolFeesToken1
    );

    /// @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(
        uint32 feeProtocol0Old,
        uint32 feeProtocol1Old,
        uint32 feeProtocol0New,
        uint32 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);
}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolImmutables.sol



// 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 IPancakeV3PoolImmutables {
    /// @notice The contract that deployed the pool, which must adhere to the IPancakeV3Factory 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);
}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolOwnerActions.sol



// 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 IPancakeV3PoolOwnerActions {
    /// @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(uint32 feeProtocol0, uint32 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);

    /// @notice Set the LM pool to enable liquidity mining
    function setLmPool(address lmPool) external;
}

// File: @pancakeswap/v3-core/contracts/interfaces/pool/IPancakeV3PoolState.sol



// 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 IPancakeV3PoolState {
    /// @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,
            uint32 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
        );
}

// File: @pancakeswap/v3-core/contracts/libraries/LowGasSafeMath.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.0;

/// @title Optimized overflow and underflow safe math operations
/// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
library LowGasSafeMath {
    /// @notice Returns x + y, reverts if sum overflows uint256
    /// @param x The augend
    /// @param y The addend
    /// @return z The sum of x and y
    function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require((z = x + y) >= x);
    }

    /// @notice Returns x - y, reverts if underflows
    /// @param x The minuend
    /// @param y The subtrahend
    /// @return z The difference of x and y
    function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require((z = x - y) <= x);
    }

    /// @notice Returns x * y, reverts if overflows
    /// @param x The multiplicand
    /// @param y The multiplier
    /// @return z The product of x and y
    function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require(x == 0 || (z = x * y) / x == y);
    }

    /// @notice Returns x + y, reverts if overflows or underflows
    /// @param x The augend
    /// @param y The addend
    /// @return z The sum of x and y
    function add(int256 x, int256 y) internal pure returns (int256 z) {
        require((z = x + y) >= x == (y >= 0));
    }

    /// @notice Returns x - y, reverts if overflows or underflows
    /// @param x The minuend
    /// @param y The subtrahend
    /// @return z The difference of x and y
    function sub(int256 x, int256 y) internal pure returns (int256 z) {
        require((z = x - y) <= x == (y >= 0));
    }
}

// File: @pancakeswap/v3-core/contracts/libraries/SafeCast.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;

/// @title Safe casting methods
/// @notice Contains methods for safely casting between types
library SafeCast {
    /// @notice Cast a uint256 to a uint160, revert on overflow
    /// @param y The uint256 to be downcasted
    /// @return z The downcasted integer, now type uint160
    function toUint160(uint256 y) internal pure returns (uint160 z) {
        require((z = uint160(y)) == y);
    }

    /// @notice Cast a int256 to a int128, revert on overflow or underflow
    /// @param y The int256 to be downcasted
    /// @return z The downcasted integer, now type int128
    function toInt128(int256 y) internal pure returns (int128 z) {
        require((z = int128(y)) == y);
    }

    /// @notice Cast a uint256 to a int256, revert on overflow
    /// @param y The uint256 to be casted
    /// @return z The casted integer, now type int256
    function toInt256(uint256 y) internal pure returns (int256 z) {
        require(y < 2**255);
        z = int256(y);
    }
}

// File: @pancakeswap/v3-core/contracts/libraries/TickMath.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0 <0.8.0;

/// @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;
    }
}

// File: contracts/base/BlockTimestamp.sol



// 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;
    }
}

// File: contracts/base/Multicall.sol



// 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) public 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;
        }
    }
}

// File: contracts/base/PeripheryImmutableState.sol



// 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 deployer;
    /// @inheritdoc IPeripheryImmutableState
    address public immutable override factory;
    /// @inheritdoc IPeripheryImmutableState
    address public immutable override WETH9;

    constructor(address _deployer, address _factory, address _WETH9) {
        deployer = _deployer;
        factory = _factory;
        WETH9 = _WETH9;
    }
}

// File: contracts/base/PeripheryPayments.sol



// 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) public 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
    ) public 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);
        }
    }
}

// File: contracts/base/PeripheryPaymentsWithFee.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;

import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@pancakeswap/v3-core/contracts/libraries/LowGasSafeMath.sol';

import './PeripheryPayments.sol';
import '../interfaces/IPeripheryPaymentsWithFee.sol';

import '../interfaces/external/IWETH9.sol';
import '../libraries/TransferHelper.sol';

abstract contract PeripheryPaymentsWithFee is PeripheryPayments, IPeripheryPaymentsWithFee {
    using LowGasSafeMath for uint256;

    /// @inheritdoc IPeripheryPaymentsWithFee
    function unwrapWETH9WithFee(
        uint256 amountMinimum,
        address recipient,
        uint256 feeBips,
        address feeRecipient
    ) public payable override {
        require(feeBips > 0 && feeBips <= 100);

        uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
        require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');

        if (balanceWETH9 > 0) {
            IWETH9(WETH9).withdraw(balanceWETH9);
            uint256 feeAmount = balanceWETH9.mul(feeBips) / 10_000;
            if (feeAmount > 0) TransferHelper.safeTransferETH(feeRecipient, feeAmount);
            TransferHelper.safeTransferETH(recipient, balanceWETH9 - feeAmount);
        }
    }

    /// @inheritdoc IPeripheryPaymentsWithFee
    function sweepTokenWithFee(
        address token,
        uint256 amountMinimum,
        address recipient,
        uint256 feeBips,
        address feeRecipient
    ) public payable override {
        require(feeBips > 0 && feeBips <= 100);

        uint256 balanceToken = IERC20(token).balanceOf(address(this));
        require(balanceToken >= amountMinimum, 'Insufficient token');

        if (balanceToken > 0) {
            uint256 feeAmount = balanceToken.mul(feeBips) / 10_000;
            if (feeAmount > 0) TransferHelper.safeTransfer(token, feeRecipient, feeAmount);
            TransferHelper.safeTransfer(token, recipient, balanceToken - feeAmount);
        }
    }
}

// File: contracts/base/PeripheryValidation.sol



// 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');
        _;
    }
}

// File: contracts/base/SelfPermit.sol



// 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);
    }
}

// File: contracts/interfaces/external/IERC20PermitAllowed.sol



// 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;
}

// File: contracts/interfaces/external/IWETH9.sol



// 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;
}

// File: contracts/interfaces/IMulticall.sol



// 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);
}

// File: contracts/interfaces/IPeripheryImmutableState.sol



// 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 PancakeSwap V3 deployer
    function deployer() external view returns (address);

    /// @return Returns the address of the PancakeSwap V3 factory
    function factory() external view returns (address);

    /// @return Returns the address of WETH9
    function WETH9() external view returns (address);
}

// File: contracts/interfaces/IPeripheryPayments.sol



// 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. And in PancakeSwap Router, this would be called 
    /// at the very end of swap
    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;
}

// File: contracts/interfaces/IPeripheryPaymentsWithFee.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;

import './IPeripheryPayments.sol';

/// @title Periphery Payments
/// @notice Functions to ease deposits and withdrawals of ETH
interface IPeripheryPaymentsWithFee is IPeripheryPayments {
    /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH, with a percentage between
    /// 0 (exclusive), and 1 (inclusive) going to feeRecipient
    /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
    function unwrapWETH9WithFee(
        uint256 amountMinimum,
        address recipient,
        uint256 feeBips,
        address feeRecipient
    ) external payable;

    /// @notice Transfers the full amount of a token held by this contract to recipient, with a percentage between
    /// 0 (exclusive) and 1 (inclusive) going to feeRecipient
    /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
    function sweepTokenWithFee(
        address token,
        uint256 amountMinimum,
        address recipient,
        uint256 feeBips,
        address feeRecipient
    ) external payable;
}

// File: contracts/interfaces/ISelfPermit.sol



// 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;
}

// File: contracts/interfaces/ISwapRouter.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;

import '@pancakeswap/v3-core/contracts/interfaces/callback/IPancakeV3SwapCallback.sol';

/// @title Router token swapping functionality
/// @notice Functions for swapping tokens via PancakeSwap V3
interface ISwapRouter is IPancakeV3SwapCallback {
    struct ExactInputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);

    struct ExactInputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);

    struct ExactOutputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);

    struct ExactOutputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
}

// File: contracts/libraries/BytesLib.sol



// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * @title Solidity Bytes Arrays Utils
 * @author Gonçalo Sá <goncalo.sa@consensys.net>
 *
 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
 */
pragma solidity >=0.5.0 <0.8.0;

library BytesLib {
    function slice(
        bytes memory _bytes,
        uint256 _start,
        uint256 _length
    ) internal pure returns (bytes memory) {
        require(_length + 31 >= _length, 'slice_overflow');
        require(_start + _length >= _start, 'slice_overflow');
        require(_bytes.length >= _start + _length, 'slice_outOfBounds');

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
                case 0 {
                    // Get a location of some free memory and store it in tempBytes as
                    // Solidity does for memory variables.
                    tempBytes := mload(0x40)

                    // The first word of the slice result is potentially a partial
                    // word read from the original array. To read it, we calculate
                    // the length of that partial word and start copying that many
                    // bytes into the array. The first word we copy will start with
                    // data we don't care about, but the last `lengthmod` bytes will
                    // land at the beginning of the contents of the new array. When
                    // we're done copying, we overwrite the full first word with
                    // the actual length of the slice.
                    let lengthmod := and(_length, 31)

                    // The multiplication in the next line is necessary
                    // because when slicing multiples of 32 bytes (lengthmod == 0)
                    // the following copy loop was copying the origin's length
                    // and then ending prematurely not copying everything it should.
                    let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                    let end := add(mc, _length)

                    for {
                        // The multiplication in the next line has the same exact purpose
                        // as the one above.
                        let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                    } lt(mc, end) {
                        mc := add(mc, 0x20)
                        cc := add(cc, 0x20)
                    } {
                        mstore(mc, mload(cc))
                    }

                    mstore(tempBytes, _length)

                    //update free-memory pointer
                    //allocating the array padded to 32 bytes like the compiler does now
                    mstore(0x40, and(add(mc, 31), not(31)))
                }
                //if we want a zero-length slice let's just return a zero-length array
                default {
                    tempBytes := mload(0x40)
                    //zero out the 32 bytes slice we are about to return
                    //we need to do it because Solidity does not garbage collect
                    mstore(tempBytes, 0)

                    mstore(0x40, add(tempBytes, 0x20))
                }
        }

        return tempBytes;
    }

    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
        require(_start + 20 >= _start, 'toAddress_overflow');
        require(_bytes.length >= _start + 20, 'toAddress_outOfBounds');
        address tempAddress;

        assembly {
            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
        }

        return tempAddress;
    }

    function toUint24(bytes memory _bytes, uint256 _start) internal pure returns (uint24) {
        require(_start + 3 >= _start, 'toUint24_overflow');
        require(_bytes.length >= _start + 3, 'toUint24_outOfBounds');
        uint24 tempUint;

        assembly {
            tempUint := mload(add(add(_bytes, 0x3), _start))
        }

        return tempUint;
    }
}

// File: contracts/libraries/CallbackValidation.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;

import '@pancakeswap/v3-core/contracts/interfaces/IPancakeV3Pool.sol';
import './PoolAddress.sol';

/// @notice Provides validation for callbacks from PancakeSwap V3 Pools
library CallbackValidation {
    /// @notice Returns the address of a valid PancakeSwap V3 Pool
    /// @param deployer The contract address of the PancakeSwap V3 Deployer
    /// @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 deployer,
        address tokenA,
        address tokenB,
        uint24 fee
    ) internal view returns (IPancakeV3Pool pool) {
        return verifyCallback(deployer, PoolAddress.getPoolKey(tokenA, tokenB, fee));
    }

    /// @notice Returns the address of a valid PancakeSwap V3 Pool
    /// @param deployer The contract address of the PancakeSwap V3 deployer
    /// @param poolKey The identifying key of the V3 pool
    /// @return pool The V3 pool contract address
    function verifyCallback(address deployer, PoolAddress.PoolKey memory poolKey)
        internal
        view
        returns (IPancakeV3Pool pool)
    {
        pool = IPancakeV3Pool(PoolAddress.computeAddress(deployer, poolKey));
        require(msg.sender == address(pool));
    }
}

// File: contracts/libraries/Path.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.0;

import './BytesLib.sol';

/// @title Functions for manipulating path data for multihop swaps
library Path {
    using BytesLib for bytes;

    /// @dev The length of the bytes encoded address
    uint256 private constant ADDR_SIZE = 20;
    /// @dev The length of the bytes encoded fee
    uint256 private constant FEE_SIZE = 3;

    /// @dev The offset of a single token address and pool fee
    uint256 private constant NEXT_OFFSET = ADDR_SIZE + FEE_SIZE;
    /// @dev The offset of an encoded pool key
    uint256 private constant POP_OFFSET = NEXT_OFFSET + ADDR_SIZE;
    /// @dev The minimum length of an encoding that contains 2 or more pools
    uint256 private constant MULTIPLE_POOLS_MIN_LENGTH = POP_OFFSET + NEXT_OFFSET;

    /// @notice Returns true iff the path contains two or more pools
    /// @param path The encoded swap path
    /// @return True if path contains two or more pools, otherwise false
    function hasMultiplePools(bytes memory path) internal pure returns (bool) {
        return path.length >= MULTIPLE_POOLS_MIN_LENGTH;
    }

    /// @notice Returns the number of pools in the path
    /// @param path The encoded swap path
    /// @return The number of pools in the path
    function numPools(bytes memory path) internal pure returns (uint256) {
        // Ignore the first token address. From then on every fee and token offset indicates a pool.
        return ((path.length - ADDR_SIZE) / NEXT_OFFSET);
    }

    /// @notice Decodes the first pool in path
    /// @param path The bytes encoded swap path
    /// @return tokenA The first token of the given pool
    /// @return tokenB The second token of the given pool
    /// @return fee The fee level of the pool
    function decodeFirstPool(bytes memory path)
        internal
        pure
        returns (
            address tokenA,
            address tokenB,
            uint24 fee
        )
    {
        tokenA = path.toAddress(0);
        fee = path.toUint24(ADDR_SIZE);
        tokenB = path.toAddress(NEXT_OFFSET);
    }

    /// @notice Gets the segment corresponding to the first pool in the path
    /// @param path The bytes encoded swap path
    /// @return The segment containing all data necessary to target the first pool in the path
    function getFirstPool(bytes memory path) internal pure returns (bytes memory) {
        return path.slice(0, POP_OFFSET);
    }

    /// @notice Skips a token + fee element from the buffer and returns the remainder
    /// @param path The swap path
    /// @return The remaining token + fee elements in the path
    function skipToken(bytes memory path) internal pure returns (bytes memory) {
        return path.slice(NEXT_OFFSET, path.length - NEXT_OFFSET);
    }
}

// File: contracts/libraries/PoolAddress.sol



// 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 = 0x6ce8eb472fa82df5469c6ab6d485f17c3ad13c8cd7af59b3d4a8026c5ce0f7e2;

    /// @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 deployer The PancakeSwap V3 deployer contract address
    /// @param key The PoolKey
    /// @return pool The contract address of the V3 pool
    function computeAddress(address deployer, PoolKey memory key) internal pure returns (address pool) {
        require(key.token0 < key.token1);
        pool = address(
            uint256(
                keccak256(
                    abi.encodePacked(
                        hex'ff',
                        deployer,
                        keccak256(abi.encode(key.token0, key.token1, key.fee)),
                        POOL_INIT_CODE_HASH
                    )
                )
            )
        );
    }
}

// File: contracts/libraries/TransferHelper.sol



// 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');
    }
}

// File: contracts/SwapRouter.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.7.6;
pragma abicoder v2;

import '@pancakeswap/v3-core/contracts/libraries/SafeCast.sol';
import '@pancakeswap/v3-core/contracts/libraries/TickMath.sol';
import '@pancakeswap/v3-core/contracts/interfaces/IPancakeV3Pool.sol';

import './interfaces/ISwapRouter.sol';
import './base/PeripheryImmutableState.sol';
import './base/PeripheryValidation.sol';
import './base/PeripheryPaymentsWithFee.sol';
import './base/Multicall.sol';
import './base/SelfPermit.sol';
import './libraries/Path.sol';
import './libraries/PoolAddress.sol';
import './libraries/CallbackValidation.sol';
import './interfaces/external/IWETH9.sol';

/// @title Pancake V3 Swap Router
/// @notice Router for stateless execution of swaps against Pancake V3
contract SwapRouter is
    ISwapRouter,
    PeripheryImmutableState,
    PeripheryValidation,
    PeripheryPaymentsWithFee,
    Multicall,
    SelfPermit
{
    using Path for bytes;
    using SafeCast for uint256;

    /// @dev Used as the placeholder value for amountInCached, because the computed amount in for an exact output swap
    /// can never actually be this value
    uint256 private constant DEFAULT_AMOUNT_IN_CACHED = type(uint256).max;

    /// @dev Transient storage variable used for returning the computed amount in for an exact output swap.
    uint256 private amountInCached = DEFAULT_AMOUNT_IN_CACHED;

    constructor(address _deployer, address _factory, address _WETH9) PeripheryImmutableState(_deployer, _factory, _WETH9) {}

    /// @dev Returns the pool for the given token pair and fee. The pool contract may or may not exist.
    function getPool(
        address tokenA,
        address tokenB,
        uint24 fee
    ) private view returns (IPancakeV3Pool) {
        return IPancakeV3Pool(PoolAddress.computeAddress(deployer, PoolAddress.getPoolKey(tokenA, tokenB, fee)));
    }

    struct SwapCallbackData {
        bytes path;
        address payer;
    }

    /// @inheritdoc IPancakeV3SwapCallback
    function pancakeV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata _data
    ) external override {
        require(amount0Delta > 0 || amount1Delta > 0); // swaps entirely within 0-liquidity regions are not supported
        SwapCallbackData memory data = abi.decode(_data, (SwapCallbackData));
        (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();
        CallbackValidation.verifyCallback(deployer, tokenIn, tokenOut, fee);

        (bool isExactInput, uint256 amountToPay) =
            amount0Delta > 0
                ? (tokenIn < tokenOut, uint256(amount0Delta))
                : (tokenOut < tokenIn, uint256(amount1Delta));
        if (isExactInput) {
            pay(tokenIn, data.payer, msg.sender, amountToPay);
        } else {
            // either initiate the next swap or pay
            if (data.path.hasMultiplePools()) {
                data.path = data.path.skipToken();
                exactOutputInternal(amountToPay, msg.sender, 0, data);
            } else {
                amountInCached = amountToPay;
                tokenIn = tokenOut; // swap in/out because exact output swaps are reversed
                pay(tokenIn, data.payer, msg.sender, amountToPay);
            }
        }
    }

    /// @dev Performs a single exact input swap
    function exactInputInternal(
        uint256 amountIn,
        address recipient,
        uint160 sqrtPriceLimitX96,
        SwapCallbackData memory data
    ) private returns (uint256 amountOut) {
        // allow swapping to the router address with address 0
        if (recipient == address(0)) recipient = address(this);

        (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();

        bool zeroForOne = tokenIn < tokenOut;

        (int256 amount0, int256 amount1) =
            getPool(tokenIn, tokenOut, fee).swap(
                recipient,
                zeroForOne,
                amountIn.toInt256(),
                sqrtPriceLimitX96 == 0
                    ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                    : sqrtPriceLimitX96,
                abi.encode(data)
            );

        return uint256(-(zeroForOne ? amount1 : amount0));
    }

    /// @inheritdoc ISwapRouter
    function exactInputSingle(ExactInputSingleParams calldata params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (uint256 amountOut)
    {
        amountOut = exactInputInternal(
            params.amountIn,
            params.recipient,
            params.sqrtPriceLimitX96,
            SwapCallbackData({path: abi.encodePacked(params.tokenIn, params.fee, params.tokenOut), payer: msg.sender})
        );
        require(amountOut >= params.amountOutMinimum, 'Too little received');
    }

    /// @inheritdoc ISwapRouter
    function exactInput(ExactInputParams memory params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (uint256 amountOut)
    {
        address payer = msg.sender; // msg.sender pays for the first hop

        while (true) {
            bool hasMultiplePools = params.path.hasMultiplePools();

            // the outputs of prior swaps become the inputs to subsequent ones
            params.amountIn = exactInputInternal(
                params.amountIn,
                hasMultiplePools ? address(this) : params.recipient, // for intermediate swaps, this contract custodies
                0,
                SwapCallbackData({
                    path: params.path.getFirstPool(), // only the first pool in the path is necessary
                    payer: payer
                })
            );

            // decide whether to continue or terminate
            if (hasMultiplePools) {
                payer = address(this); // at this point, the caller has paid
                params.path = params.path.skipToken();
            } else {
                amountOut = params.amountIn;
                break;
            }
        }

        require(amountOut >= params.amountOutMinimum, 'Too little received');
    }

    /// @dev Performs a single exact output swap
    function exactOutputInternal(
        uint256 amountOut,
        address recipient,
        uint160 sqrtPriceLimitX96,
        SwapCallbackData memory data
    ) private returns (uint256 amountIn) {
        // allow swapping to the router address with address 0
        if (recipient == address(0)) recipient = address(this);

        (address tokenOut, address tokenIn, uint24 fee) = data.path.decodeFirstPool();

        bool zeroForOne = tokenIn < tokenOut;

        (int256 amount0Delta, int256 amount1Delta) =
            getPool(tokenIn, tokenOut, fee).swap(
                recipient,
                zeroForOne,
                -amountOut.toInt256(),
                sqrtPriceLimitX96 == 0
                    ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                    : sqrtPriceLimitX96,
                abi.encode(data)
            );

        uint256 amountOutReceived;
        (amountIn, amountOutReceived) = zeroForOne
            ? (uint256(amount0Delta), uint256(-amount1Delta))
            : (uint256(amount1Delta), uint256(-amount0Delta));
        // it's technically possible to not receive the full output amount,
        // so if no price limit has been specified, require this possibility away
        if (sqrtPriceLimitX96 == 0) require(amountOutReceived == amountOut);
    }

    /// @inheritdoc ISwapRouter
    function exactOutputSingle(ExactOutputSingleParams calldata params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (uint256 amountIn)
    {
        // avoid an SLOAD by using the swap return data
        amountIn = exactOutputInternal(
            params.amountOut,
            params.recipient,
            params.sqrtPriceLimitX96,
            SwapCallbackData({path: abi.encodePacked(params.tokenOut, params.fee, params.tokenIn), payer: msg.sender})
        );

        require(amountIn <= params.amountInMaximum, 'Too much requested');
        // has to be reset even though we don't use it in the single hop case
        amountInCached = DEFAULT_AMOUNT_IN_CACHED;
    }

    /// @inheritdoc ISwapRouter
    function exactOutput(ExactOutputParams calldata params)
        external
        payable
        override
        checkDeadline(params.deadline)
        returns (uint256 amountIn)
    {
        // it's okay that the payer is fixed to msg.sender here, as they're only paying for the "final" exact output
        // swap, which happens first, and subsequent swaps are paid for within nested callback frames
        exactOutputInternal(
            params.amountOut,
            params.recipient,
            0,
            SwapCallbackData({path: params.path, payer: msg.sender})
        );

        amountIn = amountInCached;
        require(amountIn <= params.amountInMaximum, 'Too much requested');
        amountInCached = DEFAULT_AMOUNT_IN_CACHED;
    }
}