// File: contracts/peripheral/LitDepositorHelper.sol



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

import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
import { IBalancerVault } from "../interfaces/balancer/IBalancerCore.sol";
import { ILitDepositorHelper } from "../interfaces/ILitDepositorHelper.sol";
import { ICrvDepositor } from "../interfaces/ICrvDepositor.sol";
import { BalInvestor } from "./BalInvestor.sol";

/**
 * @title   LitDepositorHelper
 * @notice  Converts LIT -> balBPT and then wraps to liqLIT via the crvDepositor
 */
contract LitDepositorHelper is ILitDepositorHelper, BalInvestor {
    using SafeERC20 for IERC20;

    address public immutable crvDeposit;

    constructor(
        address _crvDeposit,
        IBalancerVault _balancerVault,
        address _lit,
        address _weth,
        bytes32 _balETHPoolId
    ) BalInvestor(_balancerVault, _lit, _weth, _balETHPoolId) {
        crvDeposit = _crvDeposit;
    }

    function setApprovals() external {
        _setApprovals();
        require(IERC20(BALANCER_POOL_TOKEN).approve(crvDeposit, type(uint256).max), "!approval");
    }

    /**
     * @dev Gets minimum output based on BPT oracle price
     * @param _amount Units of LIT to deposit
     * @param _outputBps Multiplier where 100% == 10000, 99.5% == 9950 and 98% == 9800
     * @return minOut Units of BPT to expect as output
     */
    function getMinOut(uint256 _amount, uint256 _outputBps) external view returns (uint256) {
        return _getMinOut(_amount, _outputBps);
    }

    function deposit(
        uint256 _amount,
        uint256 _minOut,
        bool _lock,
        address _stakeAddress
    ) external returns (uint256 bptOut) {
        bptOut = _depositFor(msg.sender, _amount, _minOut, _lock, _stakeAddress);
    }

    function depositFor(
        address _for,
        uint256 _amount,
        uint256 _minOut,
        bool _lock,
        address _stakeAddress
    ) external returns (uint256 bptOut) {
        bptOut = _depositFor(_for, _amount, _minOut, _lock, _stakeAddress);
    }

    function _depositFor(
        address _for,
        uint256 _amount,
        uint256 _minOut,
        bool _lock,
        address _stakeAddress
    ) internal returns (uint256 bptOut) {
        _investBalToPool(_amount, _minOut);
        bptOut = IERC20(BALANCER_POOL_TOKEN).balanceOf(address(this));
        ICrvDepositor(crvDeposit).depositFor(_for, bptOut, _lock, _stakeAddress);
    }

    /**
     * @dev Converts LIT to LIT/WETH and sends BPT to user
     * @param _amount Units of LIT to deposit
     * @param _minOut Units of BPT to expect as output
     */
    function convertLitToBpt(uint256 _amount, uint256 _minOut) external returns (uint256 bptOut) {
        _investBalToPool(_amount, _minOut);

        bptOut = IERC20(BALANCER_POOL_TOKEN).balanceOf(address(this));
        if (bptOut > 0) {
            IERC20(BALANCER_POOL_TOKEN).safeTransfer(msg.sender, bptOut);
        }
    }
}

// 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/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/balancer/IBalancerCore.sol



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

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

interface IPriceOracle {
    struct OracleAverageQuery {
        Variable variable;
        uint256 secs;
        uint256 ago;
    }
    enum Variable {
        PAIR_PRICE,
        BPT_PRICE,
        INVARIANT
    }

    function getTimeWeightedAverage(OracleAverageQuery[] memory queries)
        external
        view
        returns (uint256[] memory results);
}

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 SwapKind {
        GIVEN_IN,
        GIVEN_OUT
    }

    struct BatchSwapStep {
        bytes32 poolId;
        uint256 assetInIndex;
        uint256 assetOutIndex;
        uint256 amount;
        bytes userData;
    }

    function batchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IAsset[] memory assets,
        FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline
    ) external payable returns (int256[] memory);

    struct SingleSwap {
        bytes32 poolId;
        SwapKind kind;
        IAsset assetIn;
        IAsset assetOut;
        uint256 amount;
        bytes userData;
    }

    struct FundManagement {
        address sender;
        bool fromInternalBalance;
        address payable recipient;
        bool toInternalBalance;
    }

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

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

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

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

    function swap(
        SingleSwap memory singleSwap,
        FundManagement memory funds,
        uint256 limit,
        uint256 deadline
    ) external returns (uint256 amountCalculated);

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

    function getInternalBalance(address user, address[] memory tokens) external view returns (uint256[] memory);

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

    struct ExitPoolRequest {
        IAsset[] assets;
        uint256[] minAmountsOut;
        bytes userData;
        bool toInternalBalance;
    }
    enum ExitKind {
        EXACT_BPT_IN_FOR_ONE_TOKEN_OUT,
        EXACT_BPT_IN_FOR_TOKENS_OUT,
        BPT_IN_FOR_EXACT_TOKENS_OUT,
        MANAGEMENT_FEE_TOKENS_OUT // for ManagedPool
    }
}

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

interface IBalancerPool {
    function getPoolId() external view returns (bytes32);

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

    function getSwapEnabled() external view returns (bool);

    function getOwner() external view returns (address);

    function totalSupply() external view returns (uint256);

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

interface ILBPFactory {
    function create(
        string memory name,
        string memory symbol,
        IERC20[] memory tokens,
        uint256[] memory weights,
        uint256 swapFeePercentage,
        address owner,
        bool swapEnabledOnStart
    ) external returns (address);
}

interface ILBP {
    function setSwapEnabled(bool swapEnabled) external;

    function updateWeightsGradually(
        uint256 startTime,
        uint256 endTime,
        uint256[] memory endWeights
    ) external;

    function getGradualWeightUpdateParams()
        external
        view
        returns (
            uint256 startTime,
            uint256 endTime,
            uint256[] memory endWeights
        );
}

interface IStablePoolFactory {
    function create(
        string memory name,
        string memory symbol,
        IERC20[] memory tokens,
        uint256 amplificationParameter,
        uint256 swapFeePercentage,
        address owner
    ) external returns (address);
}

interface IWeightedPool2TokensFactory {
    function create(
        string memory name,
        string memory symbol,
        IERC20[] memory tokens,
        uint256[] memory weights,
        uint256 swapFeePercentage,
        bool oracleEnabled,
        address owner
    ) external returns (address);
}

interface IRateProvider {
    function getRate() external view returns (uint256);
}

interface IWeightedPoolFactory {
    /**
     * @dev Deploys a new `WeightedPool`.
     */
    function create(
        string memory name,
        string memory symbol,
        IERC20[] memory tokens,
        uint256[] memory normalizedWeights,
        IRateProvider[] memory rateProviders,
        uint256 swapFeePercentage,
        address owner
    ) external returns (address);
}

// 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
    ) external returns (uint256 bptOut);

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

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

// File: contracts/interfaces/ICrvDepositor.sol



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

interface ICrvDepositor {
    function depositFor(
        address to,
        uint256 _amount,
        bool _lock,
        address _stakeAddress
    ) external;
}

// File: contracts/peripheral/BalInvestor.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;
pragma abicoder v2;

import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
import { IBalancerVault, IPriceOracle, IAsset } from "../interfaces/balancer/IBalancerCore.sol";

/**
 * @title   BalInvestor
 * @notice  Deposits $LIT into a LIT/WETH BPT. Hooks into TWAP to determine minOut.
 * @dev     Abstract contract for depositing LIT -> balBPT -> auraBAL via crvDepositor
 */
abstract contract BalInvestor {
    using SafeERC20 for IERC20;

    IBalancerVault public immutable BALANCER_VAULT;
    address public immutable LIT;
    address public immutable WETH;
    address public immutable BALANCER_POOL_TOKEN;
    bytes32 public immutable BAL_ETH_POOL_ID;

    constructor(
        IBalancerVault _balancerVault,
        address _lit,
        address _weth,
        bytes32 _balETHPoolId
    ) {
        (
            address poolAddress, /* */

        ) = _balancerVault.getPool(_balETHPoolId);
        require(poolAddress != address(0), "!poolAddress");

        BALANCER_VAULT = _balancerVault;
        LIT = _lit;
        WETH = _weth;
        BALANCER_POOL_TOKEN = poolAddress;
        BAL_ETH_POOL_ID = _balETHPoolId;
    }

    function _setApprovals() internal {
        IERC20(WETH).safeApprove(address(BALANCER_VAULT), type(uint256).max);
        IERC20(LIT).safeApprove(address(BALANCER_VAULT), type(uint256).max);
    }

    function _getBptPrice() internal view returns (uint256) {
        IPriceOracle.OracleAverageQuery[] memory queries = new IPriceOracle.OracleAverageQuery[](1);

        queries[0].variable = IPriceOracle.Variable.BPT_PRICE;
        queries[0].secs = 3600; // last hour
        queries[0].ago = 0; // now

        // Gets the balancer time weighted average price denominated in LIT
        return IPriceOracle(BALANCER_POOL_TOKEN).getTimeWeightedAverage(queries)[0];
    }

    function _getPairPrice() internal view returns (uint256) {
        IPriceOracle.OracleAverageQuery[] memory queries = new IPriceOracle.OracleAverageQuery[](1);

        queries[0].variable = IPriceOracle.Variable.PAIR_PRICE;
        queries[0].secs = 3600; // last hour
        queries[0].ago = 0; // now

        // Gets the balancer time weighted average price for LIT in ETH
        // e.g LIT price is 0.10$ and ETH price is 1800$ -> return 0.56e14
        return IPriceOracle(BALANCER_POOL_TOKEN).getTimeWeightedAverage(queries)[0];
    }

    function _getMinOut(uint256 amount, uint256 minOutBps) internal view returns (uint256) {
        // Gets the balancer time weighted average price denominated in WETH
        // e.g.  if 1 WETH == 0.4 BPT, bptOraclePrice == 2.5
        uint256 bptOraclePrice = _getBptPrice(); // e.g bptOraclePrice = 3.52e14
        uint256 pairOraclePrice = _getPairPrice(); // e.g pairOraclePrice = 0.56e14
        uint256 bptOraclePriceInLit = (bptOraclePrice * 1e18) / pairOraclePrice; // e.g bptOraclePriceInLit = 6.28e18
        // e.g. minOut = (((100e18 * 1e18) / 2.5e18) * 9980) / 10000;
        // e.g. minout = 39.92e18
        uint256 minOut = (((amount * 1e18) / bptOraclePriceInLit) * minOutBps) / 10000;
        return minOut;
    }

    function _investBalToPool(uint256 amount, uint256 minOut) internal {
        IERC20(LIT).safeTransferFrom(msg.sender, address(this), amount);
        IAsset[] memory assets = new IAsset[](2);
        assets[0] = IAsset(WETH);
        assets[1] = IAsset(LIT);
        uint256[] memory maxAmountsIn = new uint256[](2);
        maxAmountsIn[0] = 0;
        maxAmountsIn[1] = amount;

        BALANCER_VAULT.joinPool(
            BAL_ETH_POOL_ID,
            address(this),
            address(this),
            IBalancerVault.JoinPoolRequest(
                assets,
                maxAmountsIn,
                abi.encode(IBalancerVault.JoinKind.EXACT_TOKENS_IN_FOR_BPT_OUT, maxAmountsIn, minOut),
                false // Don't use internal balances
            )
        );
    }
}

// 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);
            }
        }
    }
}