// File: contracts/peripheral/PooledOptionsExerciser.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

import "@openzeppelin/contracts-0.8/utils/math/SafeMath.sol";
import "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts-0.8/utils/Address.sol";
import "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";

import { IBooster } from "../interfaces/IBooster.sol";
import { ILiqLocker } from "../interfaces/ILiqLocker.sol";
import { IBaseRewardPool } from "../interfaces/IBaseRewardPool.sol";
import { IRewardPool4626 } from "../interfaces/IRewardPool4626.sol";
import { ILitDepositorHelper } from "../interfaces/ILitDepositorHelper.sol";
import { IBalancerTwapOracle } from "../interfaces/balancer/BalancerV2.sol";

// Oracle 0x9d43ccb1aD7E0081cC8A8F1fd54D16E54A637E30
interface IOracle {
    /**
     * @notice The multiplier applied to the TWAP value. Encodes the discount of the options token.
     * @return multiplier The multiplier in 4 decimals precision
     */
    function multiplier() external view returns (uint16 multiplier);
}

/**
 * @title   PooledOptionsExerciser
 * @author  LiquisFinance
 * @notice  Allows for claiming oLIT from RewardPools, exercise it and lock LIT received.
 * @dev     Implements a pooled exercise model where oLIT are queued and exercised in two steps.
 */
contract PooledOptionsExerciser {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;

    address public owner;
    address public immutable operator;
    address public immutable liqLit;
    address public immutable litDepositorHelper;
    address public immutable lockerRewards;
    address public immutable liqLocker;

    address public immutable lit = 0xfd0205066521550D7d7AB19DA8F72bb004b4C341;
    address public immutable olit = 0x627fee87d0D9D2c55098A06ac805Db8F98B158Aa;
    address public immutable olitOracle = 0x9d43ccb1aD7E0081cC8A8F1fd54D16E54A637E30;

    uint256 public constant basisOne = 10000;
    bytes32 internal constant balancerPoolId = 0x9232a548dd9e81bac65500b5e0d918f8ba93675c000200000000000000000423;

    // Option execution queue
    mapping(address => mapping(uint256 => uint256)) public queued; // owner => epoch => balance
    mapping(uint256 => uint256) public totalQueued; // epoch => total queued
    mapping(address => mapping(uint256 => uint256)) public withdrawn; // owner => epoch => balance
    mapping(uint256 => uint256) public totalWithdrawable; // epoch => total withdrawable

    uint256 public epoch; // execution queue epoch
    uint256 public fee; // fee paid to option executor expressed in bps (100=1%, 50=0.5%)

    event OwnerUpdated(address newOwner);
    event FeeUpdated(uint256 fee);
    event Queued(address owner, uint256 epoch, uint256 amount);
    event Unqueued(address owner, uint256 epoch, uint256 amount);
    event Exercised(uint256 epoch, uint256 amountIn, uint256 amountOut);
    event Withdrawn(address owner, uint256 epoch, uint256 amount);

    /**
     * @param _liqLit ERC20 token minted when locking LIT to veLIT in VoterProxy through crvDepositor.
     * @param _operator Booster main deposit contract; keeps track of pool info & user deposits; distributes rewards.
     * @param _litDepositorHelper Converts LIT -> balBPT and then wraps to liqLIT via the crvDepositor.
     * @param _lockerRewards BaseRewardPool where staking token is liqLIT.
     */
    constructor(
        address _liqLit,
        address _operator,
        address _litDepositorHelper,
        address _lockerRewards,
        address _liqLocker
    ) {
        liqLit = _liqLit;
        operator = _operator;
        litDepositorHelper = _litDepositorHelper;
        lockerRewards = _lockerRewards;
        liqLocker = _liqLocker;

        owner = msg.sender;

        epoch = 0;
        fee = 100; // 1% expressed in bps

        IERC20(lit).safeApprove(litDepositorHelper, type(uint256).max);

        emit OwnerUpdated(msg.sender);
        emit FeeUpdated(100);
    }

    /**
     * @notice Queue oLIT for execution
     * @param amount The amount of oLIT to be queued
     * @dev Adds queued oLIT to current epoch
     * @dev Reverts if insufficient balance
     */
    function queue(uint256 amount) external {
        IERC20(olit).safeTransferFrom(msg.sender, address(this), amount);

        queued[msg.sender][epoch] += amount;
        totalQueued[epoch] += amount;

        emit Queued(msg.sender, epoch, amount);
    }

    /**
     * @notice Claim oLIT rewards from liqLit staking and liqLocker
     * @param _pids Booster pools ids array to claim rewards from
     * @param _locker Boolean that indicates if the user is staking in lockerRewards (BaseRewardPool)
     * @param _liqLocker Boolean that indicates if the user is locking Liq in LiqLocker
     */
    function claimAndQueue(
        uint256[] memory _pids,
        bool _locker,
        bool _liqLocker
    ) external returns (uint256 amount) {
        for (uint256 i = 0; i < _pids.length; i++) {
            IBooster.PoolInfo memory pool = IBooster(operator).poolInfo(_pids[i]);
            // claim all the rewards, only oLIT is sent here, the rest directly to sender
            amount += IBaseRewardPool(pool.crvRewards).getRewardFor(msg.sender, true);
        }

        if (_locker) {
            amount += IBaseRewardPool(lockerRewards).getRewardFor(msg.sender, true);
        }

        if (_liqLocker) {
            amount += ILiqLocker(liqLocker).getRewardFor(msg.sender);
        }

        // queue claimed oLIT rewards
        queued[msg.sender][epoch] += amount;
        totalQueued[epoch] += amount;

        emit Queued(msg.sender, epoch, amount);
    }

    /**
     * @notice Withdraw Bunni LpTokens and claim oLIT rewards from liqLit staking and liqLocker
     * @param _pids Booster pools ids array to claim rewards from
     * @param _amounts Amounts of stakingToken (Liquis LpToken) array to withdraw per pool id
     * @param _locker Boolean that indicates if the user is staking in lockerRewards (BaseRewardPool)
     * @param _liqLocker Boolean that indicates if the user is locking Liq in LiqLocker
     * @dev owner needs to first approve this contract as spender on the rewards pool
     */
    function withdrawAndQueue(
        uint256[] memory _pids,
        uint256[] memory _amounts,
        bool _locker,
        bool _liqLocker
    ) external returns (uint256 amount) {
        require(_pids.length == _amounts.length, "array length missmatch");

        for (uint256 i = 0; i < _pids.length; i++) {
            IBooster.PoolInfo memory pool = IBooster(operator).poolInfo(_pids[i]);
            // sender will receive the Bunni LpTokens, already unwrapped
            IRewardPool4626(pool.crvRewards).withdraw(_amounts[i], msg.sender, msg.sender);
            // claim all the rewards, only oLIT is sent here, the rest directly to sender
            amount += IBaseRewardPool(pool.crvRewards).getRewardFor(msg.sender, true);
        }

        if (_locker) {
            amount += IBaseRewardPool(lockerRewards).getRewardFor(msg.sender, true);
        }

        if (_liqLocker) {
            amount += ILiqLocker(liqLocker).getRewardFor(msg.sender);
        }

        // queue claimed oLIT rewards
        queued[msg.sender][epoch] += amount;
        totalQueued[epoch] += amount;

        emit Queued(msg.sender, epoch, amount);
    }

    /**
     * @notice Unqueue oLIT from execution
     * @param amount The amount of oLIT to unqueue from execution
     * @dev Reverts if amount exceeds queued balance
     */
    function unqueue(uint256 amount) external {
        // queued balance
        uint256 _queued = queued[msg.sender][epoch];

        // revert if queued balance insufficient
        require(amount <= _queued, "insufficient balance");

        // unqueue
        queued[msg.sender][epoch] -= amount;
        totalQueued[epoch] -= amount;
        IERC20(olit).safeTransfer(msg.sender, amount);

        emit Unqueued(msg.sender, epoch, amount);
    }

    // compute oLIT amountIn and LIT amountOut for exercising the oLIT queued for execution in current epoch
    function _exerciseAmounts() internal view returns (uint256 amountIn, uint256 amountOut) {
        // oLIT amount available for exercise
        amountIn = totalQueued[epoch];

        if (amountIn == 0) return (0, 0);

        // oLIT execution price denominated in LIT and expressed in bps
        uint256 price = uint256(IOracle(olitOracle).multiplier()).mul(basisOne.add(fee)).div(basisOne);

        // amount of LIT available for claiming is exercised LIT minus execution price
        amountOut = amountIn.sub(amountIn.mul(price).div(basisOne));
    }

    /**
     * @notice Compute oLIT in and LIT out for option exercise
     * @return amountIn The amount of oLIT options exercised
     * @return amountOut The amount of LIT received
     */
    function exerciseAmounts() external view returns (uint256 amountIn, uint256 amountOut) {
        return _exerciseAmounts();
    }

    /**
     * @notice Exercise queued oLIT options
     * @dev Increments epoch
     */
    function exercise() external {
        // compute oLIT exercise amounts
        (uint256 amountIn, uint256 amountOut) = _exerciseAmounts();

        if (amountOut == 0) return;

        // Update withdrawable amount for epoch
        // note, can only exercise once for every epoch
        totalWithdrawable[epoch] += amountOut;
        epoch += 1;

        // Transfer oLIT to caller and LIT to exerciser contract
        IERC20(lit).safeTransferFrom(msg.sender, address(this), amountOut);
        IERC20(olit).safeTransfer(msg.sender, amountIn);

        emit Exercised(epoch - 1, amountIn, amountOut);
    }

    /**
     * @notice Withdraw exercised LIT
     * @param _epoch The epoch for which to withdraw LIT
     * @return withdrawn_ The LIT withdrawn
     * @dev Returns zero if nothing withdrawable
     */
    function withdraw(uint256 _epoch) external returns (uint256 withdrawn_) {
        // only withdraw past epochs
        require(_epoch < epoch, "epoch not withdrawable");

        // compute withdrawable LIT rewards for caller and _epoch
        withdrawn_ = _withdrawable(msg.sender, _epoch);

        // return if nothing claimable
        if (withdrawn_ == 0) return 0;

        // update withdrawn amount for user and epoch
        withdrawn[msg.sender][_epoch] += withdrawn_;

        // transfer withdrawable LIT
        IERC20(lit).safeTransfer(msg.sender, withdrawn_);

        emit Withdrawn(msg.sender, _epoch, withdrawn_);
    }

    /**
     * @notice Withdraw exercised LIT and lock as liqLIT
     * @param _epoch Epoch for which to withdraw and lock LIT
     * @param _stake Stake liqLit into the liqLit staking rewards pool
     * @param _minOut Units of BPT to expect as output
     * @return withdrawn_ The amount of LIT rewards withdrawn and locked
     */
    function withdrawAndLock(
        uint256 _epoch,
        bool _stake,
        uint256 _minOut
    ) external returns (uint256 withdrawn_) {
        // only withdraw past epochs
        require(_epoch < epoch, "epoch not withdrawable");

        // compute withdrawable LIT rewards for caller and _epoch
        withdrawn_ = _withdrawable(msg.sender, _epoch);

        // return if nothing claimable
        if (withdrawn_ == 0) return 0;

        // update withdrawn amount for user and epoch
        withdrawn[msg.sender][_epoch] += withdrawn_;

        // convert lit to liqLit, send it to sender or stake it in liqLit staking
        // note, convert _maxSlippage to _outputBps param used in BalInvestor
        _convertLitToLiqLit(withdrawn_, _minOut, _stake);

        emit Withdrawn(msg.sender, _epoch, withdrawn_);
    }

    function _convertLitToLiqLit(
        uint256 amount,
        uint256 _minOut,
        bool _stake
    ) internal {
        _stake == true
            ? ILitDepositorHelper(litDepositorHelper).depositFor(msg.sender, amount, _minOut, true, lockerRewards, lit)
            : ILitDepositorHelper(litDepositorHelper).depositFor(msg.sender, amount, _minOut, true, address(0), lit);
    }

    /**
     * @notice User claims their olit from pool, converts into liqLit and sends it back to the user
     * @param account The account for which to query withdrawable LIT
     * @param _epoch Epoch for which to query withdrawable LIT
     * @return withdrawable_ The amount of withdrawable LIT rewards
     */
    function withdrawable(address account, uint256 _epoch) external view returns (uint256 withdrawable_) {
        withdrawable_ = _withdrawable(account, _epoch);
    }

    // internal function to view withdrawable LIT rewards by account and epoch
    function _withdrawable(address account, uint256 _epoch) internal view returns (uint256 withdrawable_) {
        // note, totalQueued > 0 for all past epochs
        uint256 share = queued[account][_epoch].mul(1e18).div(totalQueued[_epoch]);
        withdrawable_ = share.mul(totalWithdrawable[_epoch]).div(1e18).sub(withdrawn[account][_epoch]);
    }

    /**
     * @notice Owner is responsible for setting initial config and updating operational params
     */
    function setOwner(address _owner) external {
        require(msg.sender == owner, "!auth");
        owner = _owner;

        emit OwnerUpdated(_owner);
    }

    /**
     * @notice Updates the fee parameter within a restricted range
     * @param _fee The fee in bps for compensating the option exerciser
     */
    function setFee(uint256 _fee) external {
        require(msg.sender == owner, "!auth");
        require(_fee <= basisOne, "unsupported value");
        fee = _fee;
        emit FeeUpdated(_fee);
    }
}

// File: @openzeppelin/contracts-0.8/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
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) {
        unchecked {
            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) {
        unchecked {
            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) {
        unchecked {
            // 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) {
        unchecked {
            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) {
        unchecked {
            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) {
        return a + b;
    }

    /**
     * @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 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) {
        return a * b;
    }

    /**
     * @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.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        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) {
        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) {
        unchecked {
            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.
     *
     * 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) {
        unchecked {
            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) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: @openzeppelin/contracts-0.8/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts-0.8/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.0;

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

        uint256 size;
        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");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

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

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

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

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

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

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

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

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

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

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

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

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

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

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

// File: contracts/interfaces/IBooster.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IBooster {
    struct FeeDistro {
        address distro;
        address rewards;
        bool active;
    }

    function feeTokens(address _token) external returns (FeeDistro memory);

    function earmarkFees(address _feeToken) external returns (bool);

    struct PoolInfo {
        address lptoken;
        address token;
        address gauge;
        address crvRewards;
        address stash;
        bool shutdown;
    }

    function earmarkRewards(uint256 _pid) external returns (bool);

    function poolInfo(uint256 _pid) external view returns (PoolInfo memory poolInfo);

    function poolLength() external view returns (uint256);

    function lockRewards() external view returns (address);
}

// File: contracts/interfaces/ILiqLocker.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface ILiqLocker {
    function lock(address _account, uint256 _amount) external;

    function checkpointEpoch() external;

    function epochCount() external view returns (uint256);

    function balanceAtEpochOf(uint256 _epoch, address _user) external view returns (uint256 amount);

    function totalSupplyAtEpoch(uint256 _epoch) external view returns (uint256 supply);

    function queueNewRewards(address _rewardsToken, uint256 reward) external;

    function getReward(address _account, bool _stake) external;

    function getReward(address _account) external;

    function getRewardFor(address _account) external returns (uint256 rewardAmount);

    function earned(address _account, address token) external view returns (uint256 userRewards);
}

// File: contracts/interfaces/IBaseRewardPool.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IBaseRewardPool {
    function pid() external view returns (uint256);

    function earned(address account) external view returns (uint256);

    function stake(uint256 _amount) external returns (bool);

    function stakeAll() external returns (bool);

    function stakeFor(address _for, uint256 _amount) external returns (bool);

    function withdraw(uint256 amount, bool claim) external returns (bool);

    function withdrawAll(bool claim) external;

    function withdrawAndUnwrap(uint256 amount, bool claim) external returns (bool);

    function withdrawAllAndUnwrap(bool claim) external;

    function getReward(address _account, bool _claimExtras) external returns (bool);

    function getReward() external returns (bool);

    function getRewardFor(address _account, bool _claimExtras) external returns (uint256 rewardAmount);

    function processIdleRewards() external;

    function queueNewRewards(uint256 _rewards) external returns (bool);

    function extraRewardsLength() external view returns (uint256);

    function stakingToken() external view returns (address);

    function rewardToken() external view returns (address);
}

// File: contracts/interfaces/IRewardPool4626.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IRewardPool4626 {
    function withdraw(
        uint256 assets,
        address receiver,
        address owner
    ) external returns (uint256 shares);

    function deposit(uint256 assets, address receiver) external returns (uint256 shares);

    function asset() external view returns (address);

    function balanceOf(address account) external view returns (uint256);

    function processIdleRewards() external;
}

// File: contracts/interfaces/ILitDepositorHelper.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface ILitDepositorHelper {
    function deposit(
        uint256 _amount,
        uint256 _minOut,
        bool _lock,
        address _stakeAddress,
        address _asset
    ) external payable returns (uint256 bptOut);

    function depositFor(
        address _for,
        uint256 _amount,
        uint256 _minOut,
        bool _lock,
        address _stakeAddress,
        address _asset
    ) external payable returns (uint256 bptOut);

    function convertLitToBpt(uint256 _amount, uint256 _minOut) external returns (uint256 bptOut);

    function convertWethToBpt(uint256 _amount, uint256 _minOut) external returns (uint256 bptOut);

    function convertEthToBpt(uint256 _minOut) external payable returns (uint256 bptOut);
}

// File: contracts/interfaces/balancer/BalancerV2.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

import "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";

interface IBalancerPool is IERC20 {
    enum SwapKind {
        GIVEN_IN,
        GIVEN_OUT
    }

    struct SwapRequest {
        SwapKind kind;
        IERC20 tokenIn;
        IERC20 tokenOut;
        uint256 amount;
        // Misc data
        bytes32 poolId;
        uint256 lastChangeBlock;
        address from;
        address to;
        bytes userData;
    }

    function getPoolId() external view returns (bytes32 poolId);

    function symbol() external view returns (string memory s);

    /**
     * @dev This function returns the appreciation of one BPT relative to the
     * underlying tokens. This starts at 1 when the pool is created and grows over time.
     * Because of pre minted BPT, it uses `getVirtualSupply` instead of `totalSupply`.
     */

    function getRate() external view returns (uint256);

    /**
     * @dev Returns the token rate for token. All token rates are fixed-point values with 18 decimals.
     * In case there is no rate provider for the provided token it returns 1e18.
     */
    function getTokenRate(IERC20 token) external view returns (uint256);

    function getScalingFactor(IERC20 token) external view returns (uint256);

    function onSwap(
        SwapRequest memory swapRequest,
        uint256[] memory balances,
        uint256 indexIn,
        uint256 indexOut
    ) external view returns (uint256 amount);

    function getNormalizedWeights() external view returns (uint256[] memory);

    function getSwapEnabled() external view returns (bool);

    function getOwner() external view returns (address);
}

interface IBalancerVault {
    enum PoolSpecialization {
        GENERAL,
        MINIMAL_SWAP_INFO,
        TWO_TOKEN
    }
    enum JoinKind {
        INIT,
        EXACT_TOKENS_IN_FOR_BPT_OUT,
        TOKEN_IN_FOR_EXACT_BPT_OUT,
        ALL_TOKENS_IN_FOR_EXACT_BPT_OUT
    }
    enum ExitKind {
        EXACT_BPT_IN_FOR_ONE_TOKEN_OUT,
        EXACT_BPT_IN_FOR_TOKENS_OUT,
        BPT_IN_FOR_EXACT_TOKENS_OUT
    }
    enum SwapKind {
        GIVEN_IN,
        GIVEN_OUT
    }

    /**
     * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
     * `assets` array passed to that function, and ETH assets are converted to WETH.
     *
     * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
     * from the previous swap, depending on the swap kind.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct BatchSwapStep {
        bytes32 poolId;
        uint256 assetInIndex;
        uint256 assetOutIndex;
        uint256 amount;
        bytes userData;
    }
    /**
     * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
     * `recipient` account.
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
     * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
     * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
     * `joinPool`.
     *
     * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
     * transferred. This matches the behavior of `exitPool`.
     *
     * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
     * revert.
     */
    struct FundManagement {
        address sender;
        bool fromInternalBalance;
        address payable recipient;
        bool toInternalBalance;
    }

    /**
     * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
     * the `kind` value.
     *
     * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
     * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct SingleSwap {
        bytes32 poolId;
        SwapKind kind;
        IAsset assetIn;
        IAsset assetOut;
        uint256 amount;
        bytes userData;
    }

    // encoding formats https://github.com/balancer-labs/balancer-v2-monorepo/blob/master/pkg/balancer-js/src/pool-weighted/encoder.ts
    struct JoinPoolRequest {
        IAsset[] assets;
        uint256[] maxAmountsIn;
        bytes userData;
        bool fromInternalBalance;
    }

    struct ExitPoolRequest {
        IAsset[] assets;
        uint256[] minAmountsOut;
        bytes userData;
        bool toInternalBalance;
    }

    function joinPool(
        bytes32 poolId,
        address sender,
        address recipient,
        JoinPoolRequest memory request
    ) external payable;

    function exitPool(
        bytes32 poolId,
        address sender,
        address payable recipient,
        ExitPoolRequest calldata request
    ) external;

    function getPool(bytes32 poolId) external view returns (address poolAddress, PoolSpecialization);

    function getPoolTokenInfo(bytes32 poolId, IERC20 token)
        external
        view
        returns (
            uint256 cash,
            uint256 managed,
            uint256 lastChangeBlock,
            address assetManager
        );

    function getPoolTokens(bytes32 poolId)
        external
        view
        returns (
            IERC20[] calldata tokens,
            uint256[] calldata balances,
            uint256 lastChangeBlock
        );

    /**
     * @dev Performs a swap with a single Pool.
     *
     * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
     * taken from the Pool, which must be greater than or equal to `limit`.
     *
     * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
     * sent to the Pool, which must be less than or equal to `limit`.
     *
     * Internal Balance usage and the recipient are determined by the `funds` struct.
     *
     * Emits a `Swap` event.
     */
    function swap(
        SingleSwap memory singleSwap,
        FundManagement memory funds,
        uint256 limit,
        uint256 deadline
    ) external returns (uint256 amountCalculated);

    /**
     * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
     * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
     *
     * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
     * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
     * the same index in the `assets` array.
     *
     * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
     * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
     * `amountOut` depending on the swap kind.
     *
     * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
     * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
     * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
     *
     * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
     * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
     * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
     * or unwrapped from WETH by the Vault.
     *
     * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
     * the minimum or maximum amount of each token the vault is allowed to transfer.
     *
     * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
     * equivalent `swap` call.
     *
     * Emits `Swap` events.
     */
    function batchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IAsset[] memory assets,
        FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline
    ) external payable returns (int256[] memory);

    function flashLoan(
        IFlashLoanRecipient recipient,
        IERC20[] memory tokens,
        uint256[] memory amounts,
        bytes memory userData
    ) external;

    function queryBatchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IAsset[] memory assets,
        FundManagement memory funds
    ) external returns (int256[] memory assetDeltas);
}

interface IAsset {
    // solhint-disable-previous-line no-empty-blocks
}

interface IBalancerVaultHelper {
    struct JoinPoolRequest {
        IAsset[] assets;
        uint256[] maxAmountsIn;
        bytes userData;
        bool fromInternalBalance;
    }

    struct ExitPoolRequest {
        IAsset[] assets;
        uint256[] minAmountsOut;
        bytes userData;
        bool toInternalBalance;
    }

    function queryJoin(
        bytes32 poolId,
        address sender,
        address recipient,
        IBalancerVault.JoinPoolRequest memory request
    ) external view returns (uint256 bptOut, uint256[] memory amountsIn);

    function queryExit(
        bytes32 poolId,
        address sender,
        address recipient,
        IBalancerVault.ExitPoolRequest memory request
    ) external view returns (uint256 bptIn, uint256[] memory amountsOut);
}

/**
 * @dev Interface for querying historical data from a Pool that can be used as a Price Oracle.
 *
 * This lets third parties retrieve average prices of tokens held by a Pool over a given period of time, as well as the
 * price of the Pool share token (BPT) and invariant. Since the invariant is a sensible measure of Pool liquidity, it
 * can be used to compare two different price sources, and choose the most liquid one.
 *
 * Once the oracle is fully initialized, all queries are guaranteed to succeed as long as they require no data that
 * is not older than the largest safe query window.
 */
interface IBalancerTwapOracle {
    // The three values that can be queried:
    //
    // - PAIR_PRICE: the price of the tokens in the Pool, expressed as the price of the second token in units of the
    //   first token. For example, if token A is worth $2, and token B is worth $4, the pair price will be 2.0.
    //   Note that the price is computed *including* the tokens decimals. This means that the pair price of a Pool with
    //   DAI and USDC will be close to 1.0, despite DAI having 18 decimals and USDC 6.
    //
    // - BPT_PRICE: the price of the Pool share token (BPT), in units of the first token.
    //   Note that the price is computed *including* the tokens decimals. This means that the BPT price of a Pool with
    //   USDC in which BPT is worth $5 will be 5.0, despite the BPT having 18 decimals and USDC 6.
    //
    // - INVARIANT: the value of the Pool's invariant, which serves as a measure of its liquidity.
    enum Variable {
        PAIR_PRICE,
        BPT_PRICE,
        INVARIANT
    }

    /**
     * @dev Returns the time average weighted price corresponding to each of `queries`. Prices are represented as 18
     * decimal fixed point values.
     */
    function getTimeWeightedAverage(OracleAverageQuery[] memory queries)
        external
        view
        returns (uint256[] memory results);

    /**
     * @dev Returns latest sample of `variable`. Prices are represented as 18 decimal fixed point values.
     */
    function getLatest(Variable variable) external view returns (uint256);

    /**
     * @dev Information for a Time Weighted Average query.
     *
     * Each query computes the average over a window of duration `secs` seconds that ended `ago` seconds ago. For
     * example, the average over the past 30 minutes is computed by settings secs to 1800 and ago to 0. If secs is 1800
     * and ago is 1800 as well, the average between 60 and 30 minutes ago is computed instead.
     */
    struct OracleAverageQuery {
        Variable variable;
        uint256 secs;
        uint256 ago;
    }

    /**
     * @dev Returns largest time window that can be safely queried, where 'safely' means the Oracle is guaranteed to be
     * able to produce a result and not revert.
     *
     * If a query has a non-zero `ago` value, then `secs + ago` (the oldest point in time) must be smaller than this
     * value for 'safe' queries.
     */
    function getLargestSafeQueryWindow() external view returns (uint256);

    /**
     * @dev Returns the accumulators corresponding to each of `queries`.
     */
    function getPastAccumulators(OracleAccumulatorQuery[] memory queries)
        external
        view
        returns (int256[] memory results);

    /**
     * @dev Information for an Accumulator query.
     *
     * Each query estimates the accumulator at a time `ago` seconds ago.
     */
    struct OracleAccumulatorQuery {
        Variable variable;
        uint256 ago;
    }
}

interface IFlashLoanRecipient {
    /**
     * @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
     *
     * At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
     * call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
     * Vault, or else the entire flash loan will revert.
     *
     * `userData` is the same value passed in the `IVault.flashLoan` call.
     */
    function receiveFlashLoan(
        IERC20[] memory tokens,
        uint256[] memory amounts,
        uint256[] memory feeAmounts,
        bytes memory userData
    ) external;
}