pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "../Constants.sol";
contract CommonAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    /**
     * @dev Performs a swap
     * @param recipient The original msg.sender performing the swap
     * @param aggregator Address of the aggregator's contract
     * @param spender Address to which tokens will be approved
     * @param method Selector of the function to be called in the aggregator's contract
     * @param tokenFrom Token to be swapped
     * @param tokenTo Token to be received
     * @param amountFrom Amount of tokenFrom to swap
     * @param amountTo Minimum amount of tokenTo to receive
     * @param data Data used for the call made to the aggregator's contract
     */
    function swap(
        address payable recipient,
        address aggregator,
        address spender,
        bytes4 method,
        IERC20 tokenFrom,
        IERC20 tokenTo,
        uint256 amountFrom,
        uint256 amountTo,
        bytes calldata data
    ) external payable {
        require(tokenFrom != tokenTo, "TOKEN_PAIR_INVALID");
        if (address(tokenFrom) != Constants.ETH) {
            _approveSpender(tokenFrom, spender, amountFrom);
        }
        // We always forward msg.value as it may be necessary to pay fees
        bytes memory encodedData = abi.encodePacked(method, data);
        aggregator.functionCallWithValue(encodedData, msg.value);
        // Transfer remaining balance of tokenFrom to sender
        if (address(tokenFrom) != Constants.ETH) {
            uint256 balance = tokenFrom.balanceOf(address(this));
            _transfer(tokenFrom, balance, recipient);
        }
        uint256 weiBalance = address(this).balance;
        // Transfer remaining balance of tokenTo to sender
        if (address(tokenTo) != Constants.ETH) {
            uint256 balance = tokenTo.balanceOf(address(this));
            require(balance >= amountTo, "INSUFFICIENT_AMOUNT");
            _transfer(tokenTo, balance, recipient);
        } else {
            // If tokenTo == ETH, then check that the remaining ETH balance >= amountTo
            require(weiBalance >= amountTo, "INSUFFICIENT_AMOUNT");
        }
        // If there are unused fees or if tokenTo is ETH, transfer to sender
        if (weiBalance > 0) {
            recipient.sendValue(weiBalance);
        }
    }
    /**
     * @dev Transfers token to sender if amount > 0
     * @param token IERC20 token to transfer to sender
     * @param amount Amount of token to transfer
     * @param recipient Address that will receive the tokens
     */
    function _transfer(
        IERC20 token,
        uint256 amount,
        address recipient
    ) internal {
        if (amount > 0) {
            token.safeTransfer(recipient, amount);
        }
    }
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/SafeERC20.sol
    /**
     * @dev Approves max amount of token to the spender if the allowance is lower than amount
     * @param token The ERC20 token to approve
     * @param spender Address to which funds will be approved
     * @param amount Amount used to compare current allowance
     */
    function _approveSpender(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        // If allowance is not enough, approve max possible amount
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance < amount) {
            bytes memory returndata = address(token).functionCall(
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    type(uint256).max
                )
            );
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "APPROVAL_FAILED");
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "./IERC20.sol";
import "../../math/SafeMath.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 SafeMath for uint256;
    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'
        // solhint-disable-next-line max-line-length
        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).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _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
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;
        return c;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }
    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.2;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }
    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
library Constants {
    address internal constant ETH = 0x0000000000000000000000000000000000000000;
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "../Constants.sol";
contract FeeCommonAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    using SafeMath for uint256;
    // solhint-disable-next-line var-name-mixedcase
    address payable public immutable FEE_WALLET;
    constructor(address payable feeWallet) public {
        FEE_WALLET = feeWallet;
    }
    /**
     * @dev Performs a swap
     * @param recipient The original msg.sender performing the swap
     * @param aggregator Address of the aggregator's contract
     * @param spender Address to which tokens will be approved
     * @param method Selector of the function to be called in the aggregator's contract
     * @param tokenFrom Token to be swapped
     * @param tokenTo Token to be received
     * @param amountFrom Amount of tokenFrom to swap
     * @param amountTo Minimum amount of tokenTo to receive
     * @param data Data used for the call made to the aggregator's contract
     * @param fee Amount of tokenFrom sent to the fee wallet
     */
    function swap(
        address payable recipient,
        address aggregator,
        address spender,
        bytes4 method,
        IERC20 tokenFrom,
        IERC20 tokenTo,
        uint256 amountFrom,
        uint256 amountTo,
        bytes calldata data,
        uint256 fee
    ) external payable {
        require(tokenFrom != tokenTo, "TOKEN_PAIR_INVALID");
        if (address(tokenFrom) == Constants.ETH) {
            FEE_WALLET.sendValue(fee);
        } else {
            _transfer(tokenFrom, fee, FEE_WALLET);
            _approveSpender(tokenFrom, spender, amountFrom);
        }
        // We always forward msg.value as it may be necessary to pay fees
        aggregator.functionCallWithValue(
            abi.encodePacked(method, data),
            address(this).balance
        );
        // Transfer remaining balance of tokenFrom to sender
        if (address(tokenFrom) != Constants.ETH) {
            _transfer(tokenFrom, tokenFrom.balanceOf(address(this)), recipient);
        }
        uint256 weiBalance = address(this).balance;
        // Transfer remaining balance of tokenTo to sender
        if (address(tokenTo) != Constants.ETH) {
            uint256 balance = tokenTo.balanceOf(address(this));
            require(balance >= amountTo, "INSUFFICIENT_AMOUNT");
            _transfer(tokenTo, balance, recipient);
        } else {
            // If tokenTo == ETH, then check that the remaining ETH balance >= amountTo
            require(weiBalance >= amountTo, "INSUFFICIENT_AMOUNT");
        }
        // If there are unused fees or if tokenTo is ETH, transfer to sender
        if (weiBalance > 0) {
            recipient.sendValue(weiBalance);
        }
    }
    /**
     * @dev Transfers token to sender if amount > 0
     * @param token IERC20 token to transfer to sender
     * @param amount Amount of token to transfer
     * @param recipient Address that will receive the tokens
     */
    function _transfer(
        IERC20 token,
        uint256 amount,
        address recipient
    ) internal {
        if (amount > 0) {
            token.safeTransfer(recipient, amount);
        }
    }
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/SafeERC20.sol
    /**
     * @dev Approves max amount of token to the spender if the allowance is lower than amount
     * @param token The ERC20 token to approve
     * @param spender Address to which funds will be approved
     * @param amount Amount used to compare current allowance
     */
    function _approveSpender(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        // If allowance is not enough, approve max possible amount
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance < amount) {
            bytes memory returndata = address(token).functionCall(
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    type(uint256).max
                )
            );
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "APPROVAL_FAILED");
            }
        }
    }
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "../Constants.sol";
import "../IWETH.sol";
contract FeeWethAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    using SafeMath for uint256;
    IWETH public immutable weth;
    // solhint-disable-next-line var-name-mixedcase
    address payable public immutable FEE_WALLET;
    constructor(IWETH _weth, address payable feeWallet) public {
        weth = _weth;
        FEE_WALLET = feeWallet;
    }
    /**
     * @dev Performs a swap
     * @param recipient The original msg.sender performing the swap
     * @param aggregator Address of the aggregator's contract
     * @param spender Address to which tokens will be approved
     * @param method Selector of the function to be called in the aggregator's contract
     * @param tokenFrom Token to be swapped
     * @param tokenTo Token to be received
     * @param amountFrom Amount of tokenFrom to swap
     * @param amountTo Minimum amount of tokenTo to receive
     * @param data Data used for the call made to the aggregator's contract
     * @param fee Amount of tokenFrom sent to the fee wallet
     */
    function swap(
        address payable recipient,
        address aggregator,
        address spender,
        bytes4 method,
        IERC20 tokenFrom,
        IERC20 tokenTo,
        uint256 amountFrom,
        uint256 amountTo,
        bytes calldata data,
        uint256 fee
    ) external payable {
        require(tokenFrom != tokenTo, "TOKEN_PAIR_INVALID");
        if (address(tokenFrom) == Constants.ETH) {
            FEE_WALLET.sendValue(fee);
            // If tokenFrom is ETH, msg.value = fee + amountFrom (total fee could be 0)
            // Can't deal with ETH, convert to WETH, the remaining balance will be the fee
            weth.deposit{value: amountFrom}();
            _approveSpender(weth, spender, amountFrom);
        } else {
            _transfer(tokenFrom, fee, FEE_WALLET);
            // Otherwise capture tokens from sender
            _approveSpender(tokenFrom, spender, amountFrom);
        }
        // Perform the swap
        aggregator.functionCallWithValue(
            abi.encodePacked(method, data),
            address(this).balance
        );
        // Transfer remaining balance of tokenFrom to sender
        if (address(tokenFrom) != Constants.ETH) {
            _transfer(tokenFrom, tokenFrom.balanceOf(address(this)), recipient);
        } else {
            // If using ETH, just unwrap any remaining WETH
            // At the end of this function all ETH will be transferred to the sender
            _unwrapWETH();
        }
        uint256 weiBalance = address(this).balance;
        // Transfer remaining balance of tokenTo to sender
        if (address(tokenTo) != Constants.ETH) {
            uint256 balance = tokenTo.balanceOf(address(this));
            require(balance >= amountTo, "INSUFFICIENT_AMOUNT");
            _transfer(tokenTo, balance, recipient);
        } else {
            // If tokenTo == ETH, unwrap received WETH and add it to the wei balance,
            // then check that the remaining ETH balance >= amountTo
            // It is safe to not use safeMath as no one can have enough Ether to overflow
            weiBalance += _unwrapWETH();
            require(weiBalance >= amountTo, "INSUFFICIENT_AMOUNT");
        }
        // If there are unused fees or if tokenTo is ETH, transfer to sender
        if (weiBalance > 0) {
            recipient.sendValue(weiBalance);
        }
    }
    /**
     * @dev Unwraps all available WETH into ETH
     */
    function _unwrapWETH() internal returns (uint256) {
        uint256 balance = weth.balanceOf(address(this));
        weth.withdraw(balance);
        return balance;
    }
    /**
     * @dev Transfers token to sender if amount > 0
     * @param token IERC20 token to transfer to sender
     * @param amount Amount of token to transfer
     * @param recipient Address that will receive the tokens
     */
    function _transfer(
        IERC20 token,
        uint256 amount,
        address recipient
    ) internal {
        if (amount > 0) {
            token.safeTransfer(recipient, amount);
        }
    }
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/SafeERC20.sol
    /**
     * @dev Approves max amount of token to the spender if the allowance is lower than amount
     * @param token The ERC20 token to approve
     * @param spender Address to which funds will be approved
     * @param amount Amount used to compare current allowance
     */
    function _approveSpender(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        // If allowance is not enough, approve max possible amount
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance < amount) {
            bytes memory returndata = address(token).functionCall(
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    type(uint256).max
                )
            );
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "APPROVAL_FAILED");
            }
        }
    }
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
interface IWETH is IERC20 {
    function deposit() external payable;
    function withdraw(uint256) external;
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
import "../Constants.sol";
contract UniswapAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    using SafeMath for uint256;
    // solhint-disable-next-line var-name-mixedcase
    IUniswapV2Router02 public immutable UNISWAP;
    // solhint-disable-next-line var-name-mixedcase
    address payable public immutable FEE_WALLET;
    constructor(address payable feeWallet, IUniswapV2Router02 uniswap) public {
        FEE_WALLET = feeWallet;
        UNISWAP = uniswap;
    }
    /**
     * @dev Performs a swap
     * @param recipient The original msg.sender performing the swap
     * @param tokenFrom Token to be swapped
     * @param tokenTo Token to be received
     * @param amountFrom Amount of tokenFrom to swap
     * @param amountTo Minimum amount of tokenTo to receive
     * @param path Used by Uniswap
     * @param deadline Timestamp at which the swap becomes invalid. Used by Uniswap
     * @param feeOnTransfer Use `supportingFeeOnTransfer` Uniswap methods
     * @param fee Amount of tokenFrom sent to the fee wallet
     */
    function swap(
        address payable recipient,
        IERC20 tokenFrom,
        IERC20 tokenTo,
        uint256 amountFrom,
        uint256 amountTo,
        address[] calldata path,
        uint256 deadline,
        bool feeOnTransfer,
        uint256 fee
    ) external payable {
        require(tokenFrom != tokenTo, "TOKEN_PAIR_INVALID");
        if (address(tokenFrom) == Constants.ETH) {
            FEE_WALLET.sendValue(fee);
        } else {
            _transfer(tokenFrom, fee, FEE_WALLET);
        }
        if (address(tokenFrom) == Constants.ETH) {
            if (feeOnTransfer) {
                UNISWAP.swapExactETHForTokensSupportingFeeOnTransferTokens{
                    value: address(this).balance
                }(amountTo, path, address(this), deadline);
            } else {
                UNISWAP.swapExactETHForTokens{value: address(this).balance}(
                    amountTo,
                    path,
                    address(this),
                    deadline
                );
            }
        } else {
            _approveSpender(tokenFrom, address(UNISWAP), amountFrom);
            if (address(tokenTo) == Constants.ETH) {
                if (feeOnTransfer) {
                    UNISWAP.swapExactTokensForETHSupportingFeeOnTransferTokens(
                        amountFrom,
                        amountTo,
                        path,
                        address(this),
                        deadline
                    );
                } else {
                    UNISWAP.swapExactTokensForETH(
                        amountFrom,
                        amountTo,
                        path,
                        address(this),
                        deadline
                    );
                }
            } else {
                if (feeOnTransfer) {
                    UNISWAP
                        .swapExactTokensForTokensSupportingFeeOnTransferTokens(
                        amountFrom,
                        amountTo,
                        path,
                        address(this),
                        deadline
                    );
                } else {
                    UNISWAP.swapExactTokensForTokens(
                        amountFrom,
                        amountTo,
                        path,
                        address(this),
                        deadline
                    );
                }
            }
        }
        // Transfer remaining balance of tokenFrom to sender
        if (address(tokenFrom) != Constants.ETH) {
            _transfer(tokenFrom, tokenFrom.balanceOf(address(this)), recipient);
        }
        uint256 weiBalance = address(this).balance;
        // Transfer remaining balance of tokenTo to sender
        if (address(tokenTo) != Constants.ETH) {
            uint256 balance = tokenTo.balanceOf(address(this));
            require(balance >= amountTo, "INSUFFICIENT_AMOUNT");
            _transfer(tokenTo, balance, recipient);
        } else {
            // If tokenTo == ETH, then check that the remaining ETH balance >= amountTo
            require(weiBalance >= amountTo, "INSUFFICIENT_AMOUNT");
        }
        // If there are unused fees or if tokenTo is ETH, transfer to sender
        if (weiBalance > 0) {
            recipient.sendValue(weiBalance);
        }
    }
    /**
     * @dev Transfers token to sender if amount > 0
     * @param token IERC20 token to transfer to sender
     * @param amount Amount of token to transfer
     * @param recipient Address that will receive the tokens
     */
    function _transfer(
        IERC20 token,
        uint256 amount,
        address recipient
    ) internal {
        if (amount > 0) {
            token.safeTransfer(recipient, amount);
        }
    }
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/SafeERC20.sol
    /**
     * @dev Approves max amount of token to the spender if the allowance is lower than amount
     * @param token The ERC20 token to approve
     * @param spender Address to which funds will be approved
     * @param amount Amount used to compare current allowance
     */
    function _approveSpender(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        // If allowance is not enough, approve max possible amount
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance < amount) {
            bytes memory returndata = address(token).functionCall(
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    type(uint256).max
                )
            );
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "APPROVAL_FAILED");
            }
        }
    }
}
pragma solidity >=0.6.2;
import './IUniswapV2Router01.sol';
interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}
pragma solidity >=0.6.2;
interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "../Constants.sol";
import "../IWETH.sol";
contract WethAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    IWETH public immutable weth;
    constructor(IWETH _weth) public {
        weth = _weth;
    }
    /**
     * @dev Performs a swap
     * @param recipient The original msg.sender performing the swap
     * @param aggregator Address of the aggregator's contract
     * @param spender Address to which tokens will be approved
     * @param method Selector of the function to be called in the aggregator's contract
     * @param tokenFrom Token to be swapped
     * @param tokenTo Token to be received
     * @param amountFrom Amount of tokenFrom to swap
     * @param amountTo Minimum amount of tokenTo to receive
     * @param data Data used for the call made to the aggregator's contract
     */
    function swap(
        address payable recipient,
        address aggregator,
        address spender,
        bytes4 method,
        IERC20 tokenFrom,
        IERC20 tokenTo,
        uint256 amountFrom,
        uint256 amountTo,
        bytes calldata data
    ) external payable {
        require(tokenFrom != tokenTo, "TOKEN_PAIR_INVALID");
        if (address(tokenFrom) == Constants.ETH) {
            // If tokenFrom is ETH, msg.value = fee + amountFrom (total fee could be 0)
            // Can't deal with ETH, convert to WETH, the remaining balance will be the fee
            weth.deposit{value: amountFrom}();
            _approveSpender(weth, spender, amountFrom);
        } else {
            // Otherwise capture tokens from sender
            _approveSpender(tokenFrom, spender, amountFrom);
        }
        // Perform the swap
        aggregator.functionCallWithValue(
            abi.encodePacked(method, data),
            address(this).balance
        );
        // Transfer remaining balance of tokenFrom to sender
        if (address(tokenFrom) != Constants.ETH) {
            _transfer(tokenFrom, tokenFrom.balanceOf(address(this)), recipient);
        } else {
            // If using ETH, just unwrap any remaining WETH
            // At the end of this function all ETH will be transferred to the sender
            _unwrapWETH();
        }
        uint256 weiBalance = address(this).balance;
        // Transfer remaining balance of tokenTo to sender
        if (address(tokenTo) != Constants.ETH) {
            uint256 balance = tokenTo.balanceOf(address(this));
            require(balance >= amountTo, "INSUFFICIENT_AMOUNT");
            _transfer(tokenTo, balance, recipient);
        } else {
            // If tokenTo == ETH, unwrap received WETH and add it to the wei balance,
            // then check that the remaining ETH balance >= amountTo
            // It is safe to not use safeMath as no one can have enough Ether to overflow
            weiBalance += _unwrapWETH();
            require(weiBalance >= amountTo, "INSUFFICIENT_AMOUNT");
        }
        // If there are unused fees or if tokenTo is ETH, transfer to sender
        if (weiBalance > 0) {
            recipient.sendValue(weiBalance);
        }
    }
    /**
     * @dev Unwraps all available WETH into ETH
     */
    function _unwrapWETH() internal returns (uint256) {
        uint256 balance = weth.balanceOf(address(this));
        weth.withdraw(balance);
        return balance;
    }
    /**
     * @dev Transfers token to sender if amount > 0
     * @param token IERC20 token to transfer to sender
     * @param amount Amount of token to transfer
     * @param recipient Address that will receive the tokens
     */
    function _transfer(
        IERC20 token,
        uint256 amount,
        address recipient
    ) internal {
        if (amount > 0) {
            token.safeTransfer(recipient, amount);
        }
    }
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/SafeERC20.sol
    /**
     * @dev Approves max amount of token to the spender if the allowance is lower than amount
     * @param token The ERC20 token to approve
     * @param spender Address to which funds will be approved
     * @param amount Amount used to compare current allowance
     */
    function _approveSpender(
        IERC20 token,
        address spender,
        uint256 amount
    ) internal {
        // If allowance is not enough, approve max possible amount
        uint256 allowance = token.allowance(address(this), spender);
        if (allowance < amount) {
            bytes memory returndata = address(token).functionCall(
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    type(uint256).max
                )
            );
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "APPROVAL_FAILED");
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
interface ICHI is IERC20 {
    function freeUpTo(uint256 value) external returns (uint256);
    function freeFromUpTo(
        address from,
        uint256 value
    ) external returns (uint256);
    function mint(uint256 value) external;
}
  
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.6.0;
// We import the contract so truffle compiles it, and we have the ABI
// available when working from truffle console.
import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; //helpers// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../../GSN/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;
    using Address for address;
    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20};
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");
        _beforeTokenTransfer(sender, recipient, amount);
        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address(0), account, amount);
        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        _beforeTokenTransfer(account, address(0), amount);
        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }
    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }
    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Pausable.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "./ICHI.sol";
import "./Spender.sol";
/**
 * @title MetaSwap
 */
contract MetaSwap is Ownable, Pausable, ReentrancyGuard {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    struct Adapter {
        address addr; // adapter's address
        bytes4 selector;
        bytes data; // adapter's fixed data
    }
    ICHI public immutable chi;
    Spender public immutable spender;
    // Mapping of aggregatorId to aggregator
    mapping(string => Adapter) public adapters;
    mapping(string => bool) public adapterRemoved;
    event AdapterSet(
        string indexed aggregatorId,
        address indexed addr,
        bytes4 selector,
        bytes data
    );
    event AdapterRemoved(string indexed aggregatorId);
    event Swap(string indexed aggregatorId, address indexed sender);
    constructor(ICHI _chi) public {
        chi = _chi;
        spender = new Spender();
    }
    /**
     * @dev Sets the adapter for an aggregator. It can't be changed later.
     * @param aggregatorId Aggregator's identifier
     * @param addr Address of the contract that contains the logic for this aggregator
     * @param selector The function selector of the swap function in the adapter
     * @param data Fixed abi encoded data the will be passed in each delegatecall made to the adapter
     */
    function setAdapter(
        string calldata aggregatorId,
        address addr,
        bytes4 selector,
        bytes calldata data
    ) external onlyOwner {
        require(addr.isContract(), "ADAPTER_IS_NOT_A_CONTRACT");
        require(!adapterRemoved[aggregatorId], "ADAPTER_REMOVED");
        Adapter storage adapter = adapters[aggregatorId];
        require(adapter.addr == address(0), "ADAPTER_EXISTS");
        adapter.addr = addr;
        adapter.selector = selector;
        adapter.data = data;
        emit AdapterSet(aggregatorId, addr, selector, data);
    }
    /**
     * @dev Removes the adapter for an existing aggregator. This can't be undone.
     * @param aggregatorId Aggregator's identifier
     */
    function removeAdapter(string calldata aggregatorId) external onlyOwner {
        require(
            adapters[aggregatorId].addr != address(0),
            "ADAPTER_DOES_NOT_EXIST"
        );
        delete adapters[aggregatorId];
        adapterRemoved[aggregatorId] = true;
        emit AdapterRemoved(aggregatorId);
    }
    /**
     * @dev Performs a swap
     * @param aggregatorId Identifier of the aggregator to be used for the swap
     * @param data Dynamic data which is concatenated with the fixed aggregator's
     * data in the delecatecall made to the adapter
     */
    function swap(
        string calldata aggregatorId,
        IERC20 tokenFrom,
        uint256 amount,
        bytes calldata data
    ) external payable whenNotPaused nonReentrant {
        _swap(aggregatorId, tokenFrom, amount, data);
    }
    /**
     * @dev Performs a swap
     * @param aggregatorId Identifier of the aggregator to be used for the swap
     * @param data Dynamic data which is concatenated with the fixed aggregator's
     * data in the delecatecall made to the adapter
     */
    function swapUsingGasToken(
        string calldata aggregatorId,
        IERC20 tokenFrom,
        uint256 amount,
        bytes calldata data
    ) external payable whenNotPaused nonReentrant {
        uint256 gas = gasleft();
        _swap(aggregatorId, tokenFrom, amount, data);
        uint256 gasSpent = 21000 + gas - gasleft() + 16 * msg.data.length;
        chi.freeFromUpTo(msg.sender, (gasSpent + 14154) / 41947);
    }
    function pauseSwaps() external onlyOwner {
        _pause();
    }
    function unpauseSwaps() external onlyOwner {
        _unpause();
    }
    function _swap(
        string calldata aggregatorId,
        IERC20 tokenFrom,
        uint256 amount,
        bytes calldata data
    ) internal {
        Adapter storage adapter = adapters[aggregatorId];
        if (address(tokenFrom) != Constants.ETH) {
            tokenFrom.safeTransferFrom(msg.sender, address(spender), amount);
        }
        spender.swap{value: msg.value}(
            adapter.addr,
            abi.encodePacked(
                adapter.selector,
                abi.encode(msg.sender),
                adapter.data,
                data
            )
        );
        emit Swap(aggregatorId, msg.sender);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../GSN/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../GSN/Context.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor () internal {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!_paused, "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(_paused, "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    constructor () internal {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "./Constants.sol";
contract Spender {
    address public immutable metaswap;
    constructor() public {
        metaswap = msg.sender;
    }
    /// @dev Receives ether from swaps
    fallback() external payable {}
    function swap(address adapter, bytes calldata data) external payable {
        require(msg.sender == metaswap, "FORBIDDEN");
        require(adapter != address(0), "ADAPTER_NOT_PROVIDED");
        _delegate(adapter, data, "ADAPTER_DELEGATECALL_FAILED");
    }
    /**
     * @dev Performs a delegatecall and bubbles up the errors, adapted from
     * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol
     * @param target Address of the contract to delegatecall
     * @param data Data passed in the delegatecall
     * @param errorMessage Fallback revert reason
     */
    function _delegate(
        address target,
        bytes memory data,
        string memory errorMessage
    ) private returns (bytes memory) {
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
pragma solidity ^0.6.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
contract MockAdapter {
    using SafeERC20 for IERC20;
    using Address for address;
    using Address for address payable;
    event MockAdapterEvent(
        address sender,
        uint256 valueFixed,
        uint256 valueDynamic
    );
    function test(
        address sender,
        uint256 valueFixed,
        uint256 valueDynamic
    ) external payable {
        emit MockAdapterEvent(sender, valueFixed, valueDynamic);
    }
    function testRevert(
        address,
        uint256,
        uint256
    ) external payable {
        revert("SWAP_FAILED");
    }
    function testRevertNoReturnData(
        address,
        uint256,
        uint256
    ) external payable {
        revert();
    }
}
pragma solidity ^0.6.0;
// TAKEN FROM https://github.com/gnosis/mock-contract
// TODO: use their npm package once it is published for solidity 0.6
interface MockInterface {
    /**
     * @dev After calling this method, the mock will return `response` when it is called
     * with any calldata that is not mocked more specifically below
     * (e.g. using givenMethodReturn).
     * @param response ABI encoded response that will be returned if method is invoked
     */
    function givenAnyReturn(bytes calldata response) external;
    function givenAnyReturnBool(bool response) external;
    function givenAnyReturnUint(uint256 response) external;
    function givenAnyReturnAddress(address response) external;
    function givenAnyRevert() external;
    function givenAnyRevertWithMessage(string calldata message) external;
    function givenAnyRunOutOfGas() external;
    /**
     * @dev After calling this method, the mock will return `response` when the given
     * methodId is called regardless of arguments. If the methodId and arguments
     * are mocked more specifically (using `givenMethodAndArguments`) the latter
     * will take precedence.
     * @param method ABI encoded methodId. It is valid to pass full calldata (including arguments). The mock will extract the methodId from it
     * @param response ABI encoded response that will be returned if method is invoked
     */
    function givenMethodReturn(bytes calldata method, bytes calldata response)
        external;
    function givenMethodReturnBool(bytes calldata method, bool response)
        external;
    function givenMethodReturnUint(bytes calldata method, uint256 response)
        external;
    function givenMethodReturnAddress(bytes calldata method, address response)
        external;
    function givenMethodRevert(bytes calldata method) external;
    function givenMethodRevertWithMessage(
        bytes calldata method,
        string calldata message
    ) external;
    function givenMethodRunOutOfGas(bytes calldata method) external;
    /**
     * @dev After calling this method, the mock will return `response` when the given
     * methodId is called with matching arguments. These exact calldataMocks will take
     * precedence over all other calldataMocks.
     * @param call ABI encoded calldata (methodId and arguments)
     * @param response ABI encoded response that will be returned if contract is invoked with calldata
     */
    function givenCalldataReturn(bytes calldata call, bytes calldata response)
        external;
    function givenCalldataReturnBool(bytes calldata call, bool response)
        external;
    function givenCalldataReturnUint(bytes calldata call, uint256 response)
        external;
    function givenCalldataReturnAddress(bytes calldata call, address response)
        external;
    function givenCalldataRevert(bytes calldata call) external;
    function givenCalldataRevertWithMessage(
        bytes calldata call,
        string calldata message
    ) external;
    function givenCalldataRunOutOfGas(bytes calldata call) external;
    /**
     * @dev Returns the number of times anything has been called on this mock since last reset
     */
    function invocationCount() external returns (uint256);
    /**
     * @dev Returns the number of times the given method has been called on this mock since last reset
     * @param method ABI encoded methodId. It is valid to pass full calldata (including arguments). The mock will extract the methodId from it
     */
    function invocationCountForMethod(bytes calldata method)
        external
        returns (uint256);
    /**
     * @dev Returns the number of times this mock has been called with the exact calldata since last reset.
     * @param call ABI encoded calldata (methodId and arguments)
     */
    function invocationCountForCalldata(bytes calldata call)
        external
        returns (uint256);
    /**
     * @dev Resets all mocked methods and invocation counts.
     */
    function reset() external;
}
/**
 * Implementation of the MockInterface.
 */
contract MockContract is MockInterface {
    enum MockType {Return, Revert, OutOfGas}
    bytes32 public constant MOCKS_LIST_START = hex"01";
    bytes public constant MOCKS_LIST_END = "0xff";
    bytes32 public constant MOCKS_LIST_END_HASH = keccak256(MOCKS_LIST_END);
    bytes4 public constant SENTINEL_ANY_MOCKS = hex"01";
    bytes public constant DEFAULT_FALLBACK_VALUE = abi.encode(false);
    // A linked list allows easy iteration and inclusion checks
    mapping(bytes32 => bytes) calldataMocks;
    mapping(bytes => MockType) calldataMockTypes;
    mapping(bytes => bytes) calldataExpectations;
    mapping(bytes => string) calldataRevertMessage;
    mapping(bytes32 => uint256) calldataInvocations;
    mapping(bytes4 => bytes4) methodIdMocks;
    mapping(bytes4 => MockType) methodIdMockTypes;
    mapping(bytes4 => bytes) methodIdExpectations;
    mapping(bytes4 => string) methodIdRevertMessages;
    mapping(bytes32 => uint256) methodIdInvocations;
    MockType fallbackMockType;
    bytes fallbackExpectation = DEFAULT_FALLBACK_VALUE;
    string fallbackRevertMessage;
    uint256 invocations;
    uint256 resetCount;
    constructor() public {
        calldataMocks[MOCKS_LIST_START] = MOCKS_LIST_END;
        methodIdMocks[SENTINEL_ANY_MOCKS] = SENTINEL_ANY_MOCKS;
    }
    function trackCalldataMock(bytes memory call) private {
        bytes32 callHash = keccak256(call);
        if (calldataMocks[callHash].length == 0) {
            calldataMocks[callHash] = calldataMocks[MOCKS_LIST_START];
            calldataMocks[MOCKS_LIST_START] = call;
        }
    }
    function trackMethodIdMock(bytes4 methodId) private {
        if (methodIdMocks[methodId] == 0x0) {
            methodIdMocks[methodId] = methodIdMocks[SENTINEL_ANY_MOCKS];
            methodIdMocks[SENTINEL_ANY_MOCKS] = methodId;
        }
    }
    function _givenAnyReturn(bytes memory response) internal {
        fallbackMockType = MockType.Return;
        fallbackExpectation = response;
    }
    function givenAnyReturn(bytes calldata response) external override {
        _givenAnyReturn(response);
    }
    function givenAnyReturnBool(bool response) external override {
        uint256 flag = response ? 1 : 0;
        _givenAnyReturn(uintToBytes(flag));
    }
    function givenAnyReturnUint(uint256 response) external override {
        _givenAnyReturn(uintToBytes(response));
    }
    function givenAnyReturnAddress(address response) external override {
        _givenAnyReturn(uintToBytes(uint256(response)));
    }
    function givenAnyRevert() external override {
        fallbackMockType = MockType.Revert;
        fallbackRevertMessage = "";
    }
    function givenAnyRevertWithMessage(string calldata message)
        external
        override
    {
        fallbackMockType = MockType.Revert;
        fallbackRevertMessage = message;
    }
    function givenAnyRunOutOfGas() external override {
        fallbackMockType = MockType.OutOfGas;
    }
    function _givenCalldataReturn(bytes memory call, bytes memory response)
        private
    {
        calldataMockTypes[call] = MockType.Return;
        calldataExpectations[call] = response;
        trackCalldataMock(call);
    }
    function givenCalldataReturn(bytes calldata call, bytes calldata response)
        external
        override
    {
        _givenCalldataReturn(call, response);
    }
    function givenCalldataReturnBool(bytes calldata call, bool response)
        external
        override
    {
        uint256 flag = response ? 1 : 0;
        _givenCalldataReturn(call, uintToBytes(flag));
    }
    function givenCalldataReturnUint(bytes calldata call, uint256 response)
        external
        override
    {
        _givenCalldataReturn(call, uintToBytes(response));
    }
    function givenCalldataReturnAddress(bytes calldata call, address response)
        external
        override
    {
        _givenCalldataReturn(call, uintToBytes(uint256(response)));
    }
    function _givenMethodReturn(bytes memory call, bytes memory response)
        private
    {
        bytes4 method = bytesToBytes4(call);
        methodIdMockTypes[method] = MockType.Return;
        methodIdExpectations[method] = response;
        trackMethodIdMock(method);
    }
    function givenMethodReturn(bytes calldata call, bytes calldata response)
        external
        override
    {
        _givenMethodReturn(call, response);
    }
    function givenMethodReturnBool(bytes calldata call, bool response)
        external
        override
    {
        uint256 flag = response ? 1 : 0;
        _givenMethodReturn(call, uintToBytes(flag));
    }
    function givenMethodReturnUint(bytes calldata call, uint256 response)
        external
        override
    {
        _givenMethodReturn(call, uintToBytes(response));
    }
    function givenMethodReturnAddress(bytes calldata call, address response)
        external
        override
    {
        _givenMethodReturn(call, uintToBytes(uint256(response)));
    }
    function givenCalldataRevert(bytes calldata call) external override {
        calldataMockTypes[call] = MockType.Revert;
        calldataRevertMessage[call] = "";
        trackCalldataMock(call);
    }
    function givenMethodRevert(bytes calldata call) external override {
        bytes4 method = bytesToBytes4(call);
        methodIdMockTypes[method] = MockType.Revert;
        trackMethodIdMock(method);
    }
    function givenCalldataRevertWithMessage(
        bytes calldata call,
        string calldata message
    ) external override {
        calldataMockTypes[call] = MockType.Revert;
        calldataRevertMessage[call] = message;
        trackCalldataMock(call);
    }
    function givenMethodRevertWithMessage(
        bytes calldata call,
        string calldata message
    ) external override {
        bytes4 method = bytesToBytes4(call);
        methodIdMockTypes[method] = MockType.Revert;
        methodIdRevertMessages[method] = message;
        trackMethodIdMock(method);
    }
    function givenCalldataRunOutOfGas(bytes calldata call) external override {
        calldataMockTypes[call] = MockType.OutOfGas;
        trackCalldataMock(call);
    }
    function givenMethodRunOutOfGas(bytes calldata call) external override {
        bytes4 method = bytesToBytes4(call);
        methodIdMockTypes[method] = MockType.OutOfGas;
        trackMethodIdMock(method);
    }
    function invocationCount() external override returns (uint256) {
        return invocations;
    }
    function invocationCountForMethod(bytes calldata call)
        external
        override
        returns (uint256)
    {
        bytes4 method = bytesToBytes4(call);
        return
            methodIdInvocations[keccak256(
                abi.encodePacked(resetCount, method)
            )];
    }
    function invocationCountForCalldata(bytes calldata call)
        external
        override
        returns (uint256)
    {
        return
            calldataInvocations[keccak256(abi.encodePacked(resetCount, call))];
    }
    function reset() external override {
        // Reset all exact calldataMocks
        bytes memory nextMock = calldataMocks[MOCKS_LIST_START];
        bytes32 mockHash = keccak256(nextMock);
        // We cannot compary bytes
        while (mockHash != MOCKS_LIST_END_HASH) {
            // Reset all mock maps
            calldataMockTypes[nextMock] = MockType.Return;
            calldataExpectations[nextMock] = hex"";
            calldataRevertMessage[nextMock] = "";
            // Set next mock to remove
            nextMock = calldataMocks[mockHash];
            // Remove from linked list
            calldataMocks[mockHash] = "";
            // Update mock hash
            mockHash = keccak256(nextMock);
        }
        // Clear list
        calldataMocks[MOCKS_LIST_START] = MOCKS_LIST_END;
        // Reset all any calldataMocks
        bytes4 nextAnyMock = methodIdMocks[SENTINEL_ANY_MOCKS];
        while (nextAnyMock != SENTINEL_ANY_MOCKS) {
            bytes4 currentAnyMock = nextAnyMock;
            methodIdMockTypes[currentAnyMock] = MockType.Return;
            methodIdExpectations[currentAnyMock] = hex"";
            methodIdRevertMessages[currentAnyMock] = "";
            nextAnyMock = methodIdMocks[currentAnyMock];
            // Remove from linked list
            methodIdMocks[currentAnyMock] = 0x0;
        }
        // Clear list
        methodIdMocks[SENTINEL_ANY_MOCKS] = SENTINEL_ANY_MOCKS;
        fallbackExpectation = DEFAULT_FALLBACK_VALUE;
        fallbackMockType = MockType.Return;
        invocations = 0;
        resetCount += 1;
    }
    function useAllGas() private {
        while (true) {
            bool s;
            assembly {
                //expensive call to EC multiply contract
                s := call(sub(gas(), 2000), 6, 0, 0x0, 0xc0, 0x0, 0x60)
            }
        }
    }
    function bytesToBytes4(bytes memory b) private pure returns (bytes4) {
        bytes4 out;
        for (uint256 i = 0; i < 4; i++) {
            out |= bytes4(b[i] & 0xFF) >> (i * 8);
        }
        return out;
    }
    function uintToBytes(uint256 x) private pure returns (bytes memory b) {
        b = new bytes(32);
        assembly {
            mstore(add(b, 32), x)
        }
    }
    function updateInvocationCount(
        bytes4 methodId,
        bytes memory originalMsgData
    ) public {
        require(
            msg.sender == address(this),
            "Can only be called from the contract itself"
        );
        invocations += 1;
        methodIdInvocations[keccak256(
            abi.encodePacked(resetCount, methodId)
        )] += 1;
        calldataInvocations[keccak256(
            abi.encodePacked(resetCount, originalMsgData)
        )] += 1;
    }
    fallback() external payable {
        bytes4 methodId;
        assembly {
            methodId := calldataload(0)
        }
        // First, check exact matching overrides
        if (calldataMockTypes[msg.data] == MockType.Revert) {
            revert(calldataRevertMessage[msg.data]);
        }
        if (calldataMockTypes[msg.data] == MockType.OutOfGas) {
            useAllGas();
        }
        bytes memory result = calldataExpectations[msg.data];
        // Then check method Id overrides
        if (result.length == 0) {
            if (methodIdMockTypes[methodId] == MockType.Revert) {
                revert(methodIdRevertMessages[methodId]);
            }
            if (methodIdMockTypes[methodId] == MockType.OutOfGas) {
                useAllGas();
            }
            result = methodIdExpectations[methodId];
        }
        // Last, use the fallback override
        if (result.length == 0) {
            if (fallbackMockType == MockType.Revert) {
                revert(fallbackRevertMessage);
            }
            if (fallbackMockType == MockType.OutOfGas) {
                useAllGas();
            }
            result = fallbackExpectation;
        }
        // Record invocation as separate call so we don't rollback in case we are called with STATICCALL
        (, bytes memory r) = address(this).call{gas: 100000}(
            abi.encodeWithSignature(
                "updateInvocationCount(bytes4,bytes)",
                methodId,
                msg.data
            )
        );
        assert(r.length == 0);
        assembly {
            return(add(0x20, result), mload(result))
        }
    }
}
pragma solidity ^0.6.0;
contract MockSelfDestruct {
    constructor() public payable {}
    fallback() external payable {
        selfdestruct(msg.sender);
    }
    function kill(address payable target) external payable {
        selfdestruct(target);
    }
}

/** 
Website: http://HashAI.cc


https://t.me/HashAIEth


Twitter : https://twitter.com/hashai_eth
**/


// SPDX-License-Identifier: MIT

pragma solidity 0.8.15;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

interface IERC20 {

    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

interface IERC20Metadata is IERC20 {
    
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;
    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    function _createInitialSupply(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

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

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");
        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

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

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() external virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

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

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

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

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );
}

interface IDexFactory {
    function createPair(address tokenA, address tokenB)
        external
        returns (address pair);
}

contract token is ERC20, Ownable {

    uint256 public maxBuy;
    uint256 public maxSell;
    uint256 public maxWallet;

    IDexRouter public dexRouter;
    address public lpPair;

    bool private swapping;
    uint256 public swapTokensAtAmount;

    address operationsAddress;
    address devAddress;

    uint256 public tradingActiveBlock = 0; // 0 means trading is not active
    uint256 public blockForPenaltyEnd;
    mapping (address => bool) public boughtEarly;
    uint256 public botsCaught;

    bool public limitsInEffect = true;
    bool public tradingActive = false;
    bool public swapEnabled = false;

    // Anti-bot and anti-whale mappings and variables
    mapping(address => uint256) private _holderLastTransferTimestamp; // to hold last Transfers temporarily during launch
    bool public transferDelayEnabled = true;

    uint256 public buyTotalFees;
    uint256 public buyOperationsFee;
    uint256 public buyLiquidityFee;
    uint256 public buyDevFee;
    uint256 public buyBurnFee;

    uint256 public sellTotalFees;
    uint256 public sellOperationsFee;
    uint256 public sellLiquidityFee;
    uint256 public sellDevFee;
    uint256 public sellBurnFee;

    uint256 public tokensForOperations;
    uint256 public tokensForLiquidity;
    uint256 public tokensForDev;
    uint256 public tokensForBurn;

    /******************/

    // exlcude from fees and max transaction amount
    mapping (address => bool) private _isExcludedFromFees;
    mapping (address => bool) public _isExcludedMaxTransactionAmount;

    // store addresses that a automatic market maker pairs. Any transfer *to* these addresses
    // could be subject to a maximum transfer amount
    mapping (address => bool) public automatedMarketMakerPairs;

    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);

    event Launched();

    event RemovedLimits();

    event ExcludeFromFees(address indexed account, bool isExcluded);

    event UpdatedMaxBuyAmount(uint256 newAmount);

    event UpdatedMaxSellAmount(uint256 newAmount);

    event UpdatedMaxWalletAmount(uint256 newAmount);

    event UpdatedOperationsAddress(address indexed newWallet);

    event MaxTransactionExclusion(address _address, bool excluded);

    event BuyBackTriggered(uint256 amount);

    event OwnerForcedSwapBack(uint256 timestamp);

    event CaughtEarlyBuyer(address sniper);

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );

    event TransferForeignToken(address token, uint256 amount);

    constructor() ERC20("HashAI", "HashAI") {

        address newOwner = msg.sender;
        IDexRouter _dexRouter = IDexRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        dexRouter = _dexRouter;

        // create pair
        lpPair = IDexFactory(_dexRouter.factory()).createPair(address(this), _dexRouter.WETH());
        _excludeFromMaxTransaction(address(lpPair), true);
        _setAutomatedMarketMakerPair(address(lpPair), true);

        uint256 totalSupply = 1 * 1e11 * 1e18;

        maxBuy = totalSupply * 1 / 100;
        maxSell = totalSupply * 1 / 100;
        maxWallet = totalSupply * 1 / 100;
        swapTokensAtAmount = totalSupply * 5 / 10000;

        buyOperationsFee = 10;
        buyLiquidityFee = 0;
        buyDevFee = 0;
        buyBurnFee = 0;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;

        sellOperationsFee = 25;
        sellLiquidityFee = 0;
        sellDevFee = 0;
        sellBurnFee = 0;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;

        _excludeFromMaxTransaction(newOwner, true);
        _excludeFromMaxTransaction(address(this), true);
        _excludeFromMaxTransaction(address(0xdead), true);

        excludeFromFees(newOwner, true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);

        operationsAddress = address(newOwner);
        devAddress = address(newOwner);

        _createInitialSupply(newOwner, totalSupply);
        transferOwnership(newOwner);
    }

    receive() external payable {}

    // only enable if no plan to airdrop

    function golive(uint256 _deadblocks) external onlyOwner {
        require(!tradingActive, "Cannot reenable trading");
        tradingActive = true;
        swapEnabled = true;
        tradingActiveBlock = block.number;
        blockForPenaltyEnd = tradingActiveBlock + _deadblocks;
        emit Launched();
    }

    // remove limits after token is stable
    function removeLimits() external onlyOwner {
        limitsInEffect = false;
        transferDelayEnabled = false;
        emit RemovedLimits();
    }

    function manageEarly(address wallet, bool flag) external onlyOwner {
        boughtEarly[wallet] = flag;
    }


    function disableTransferDelay() external onlyOwner {
        transferDelayEnabled = false;
    }

    function updateMaxBuy(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 2 / 1000)/1e18, "Cannot set max buy amount lower than 0.2%");
        maxBuy = newNum * (10**18);
        emit UpdatedMaxBuyAmount(maxBuy);
    }

    function updateMaxSell(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 2 / 1000)/1e18, "Cannot set max sell amount lower than 0.2%");
        maxSell = newNum * (10**18);
        emit UpdatedMaxSellAmount(maxSell);
    }

    function updateMaxWallet(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 3 / 1000)/1e18, "Cannot set max wallet amount lower than 0.3%");
        maxWallet = newNum * (10**18);
        emit UpdatedMaxWalletAmount(maxWallet);
    }

    function updateSwapTokens(uint256 newAmount) external onlyOwner {
        require(newAmount >= totalSupply() * 1 / 100000, "Swap amount cannot be lower than 0.001% total supply.");
        require(newAmount <= totalSupply() * 1 / 1000, "Swap amount cannot be higher than 0.1% total supply.");
        swapTokensAtAmount = newAmount;
    }

    function _excludeFromMaxTransaction(address updAds, bool isExcluded) private {
        _isExcludedMaxTransactionAmount[updAds] = isExcluded;
        emit MaxTransactionExclusion(updAds, isExcluded);
    }

    function excludeFromMax(address updAds, bool isEx) external onlyOwner {
        if(!isEx){
            require(updAds != lpPair, "Cannot remove uniswap pair from max txn");
        }
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }

    function setAMM(address pair, bool value) external onlyOwner {
        require(pair != lpPair, "The pair cannot be removed");

        _setAutomatedMarketMakerPair(pair, value);
        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;
        _excludeFromMaxTransaction(pair, value);
        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function updateBuyFees(uint256 _operationsFee, uint256 _liquidityFee, uint256 _DevFee, uint256 _burnFee) external onlyOwner {
        buyOperationsFee = _operationsFee;
        buyLiquidityFee = _liquidityFee;
        buyDevFee = _DevFee;
        buyBurnFee = _burnFee;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;
        require(buyTotalFees <= 20, "Must keep fees at 20% or less");
    }

    function updateSellFees(uint256 _operationsFee, uint256 _liquidityFee, uint256 _DevFee, uint256 _burnFee) external onlyOwner {
        sellOperationsFee = _operationsFee;
        sellLiquidityFee = _liquidityFee;
        sellDevFee = _DevFee;
        sellBurnFee = _burnFee;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;
        require(sellTotalFees <= 25, "Must keep fees at 25% or less");
    }

    function returnToStandardTax() external onlyOwner {
        sellOperationsFee = 20;
        sellLiquidityFee = 0;
        sellDevFee = 0;
        sellBurnFee = 0;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;
        require(sellTotalFees <= 20, "Must keep fees at 20% or less");
        buyOperationsFee = 25;
        buyLiquidityFee = 0;
        buyDevFee = 0;
        buyBurnFee = 0;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;
        require(buyTotalFees <= 20, "Must keep fees at 20% or less");
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
        emit ExcludeFromFees(account, excluded);
    }

    function _transfer(address from, address to, uint256 amount) internal override {

        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "amount must be greater than 0");

        if(!tradingActive){
            require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
        }

        if(blockForPenaltyEnd > 0){
            require(!boughtEarly[from] || to == owner() || to == address(0xdead), "Bots cannot transfer tokens in or out except to owner or dead address.");
        }

        if(limitsInEffect){
            if (from != owner() && to != owner() && to != address(0) && to != address(0xdead) && !_isExcludedFromFees[from] && !_isExcludedFromFees[to]){

                // at launch if the transfer delay is enabled, ensure the block timestamps for purchasers is set -- during launch.
                if (transferDelayEnabled){
                    if (to != address(dexRouter) && to != address(lpPair)){
                        require(_holderLastTransferTimestamp[tx.origin] < block.number - 3 && _holderLastTransferTimestamp[to] < block.number - 3, "_transfer:: Transfer Delay enabled.  Try again later.");
                        _holderLastTransferTimestamp[tx.origin] = block.number;
                        _holderLastTransferTimestamp[to] = block.number;
                    }
                }

                //when buy
                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) {
                        require(amount <= maxBuy, "Buy transfer amount exceeds the max buy.");
                        require(amount + balanceOf(to) <= maxWallet, "Cannot Exceed max wallet");
                }
                //when sell
                else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
                        require(amount <= maxSell, "Sell transfer amount exceeds the max sell.");
                }
                else if (!_isExcludedMaxTransactionAmount[to]){
                    require(amount + balanceOf(to) <= maxWallet, "Cannot Exceed max wallet");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));

        bool canSwap = contractTokenBalance >= swapTokensAtAmount;

        if(canSwap && swapEnabled && !swapping && !automatedMarketMakerPairs[from] && !_isExcludedFromFees[from] && !_isExcludedFromFees[to]) {
            swapping = true;

            swapBack();

            swapping = false;
        }

        bool takeFee = true;
        // if any account belongs to _isExcludedFromFee account then remove the fee
        if(_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }

        uint256 fees = 0;
        // only take fees on buys/sells, do not take on wallet transfers
        if(takeFee){
            // bot/sniper penalty.
            if(earlyBuyPenaltyInEffect() && automatedMarketMakerPairs[from] && !automatedMarketMakerPairs[to] && buyTotalFees > 0){

                if(!boughtEarly[to]){
                    boughtEarly[to] = true;
                    botsCaught += 1;
                    emit CaughtEarlyBuyer(to);
                }

                fees = amount * 99 / 100;
                tokensForLiquidity += fees * buyLiquidityFee / buyTotalFees;
                tokensForOperations += fees * buyOperationsFee / buyTotalFees;
                tokensForDev += fees * buyDevFee / buyTotalFees;
                tokensForBurn += fees * buyBurnFee / buyTotalFees;
            }

            // on sell
            else if (automatedMarketMakerPairs[to] && sellTotalFees > 0){
                fees = amount * sellTotalFees / 100;
                tokensForLiquidity += fees * sellLiquidityFee / sellTotalFees;
                tokensForOperations += fees * sellOperationsFee / sellTotalFees;
                tokensForDev += fees * sellDevFee / sellTotalFees;
                tokensForBurn += fees * sellBurnFee / sellTotalFees;
            }

            // on buy
            else if(automatedMarketMakerPairs[from] && buyTotalFees > 0) {
                fees = amount * buyTotalFees / 100;
                tokensForLiquidity += fees * buyLiquidityFee / buyTotalFees;
                tokensForOperations += fees * buyOperationsFee / buyTotalFees;
                tokensForDev += fees * buyDevFee / buyTotalFees;
                tokensForBurn += fees * buyBurnFee / buyTotalFees;
            }

            if(fees > 0){
                super._transfer(from, address(this), fees);
            }

            amount -= fees;
        }

        super._transfer(from, to, amount);
    }

    function earlyBuyPenaltyInEffect() public view returns (bool){
        return block.number < blockForPenaltyEnd;
    }

    function swapTokensForEth(uint256 tokenAmount) private {

        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = dexRouter.WETH();

        _approve(address(this), address(dexRouter), tokenAmount);

        // make the swap
        dexRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(dexRouter), tokenAmount);

        // add the liquidity
        dexRouter.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            address(0xdead),
            block.timestamp
        );
    }

    function swapBack() private {

        if(tokensForBurn > 0 && balanceOf(address(this)) >= tokensForBurn) {
            _burn(address(this), tokensForBurn);
        }
        tokensForBurn = 0;

        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForLiquidity + tokensForOperations + tokensForDev;

        if(contractBalance == 0 || totalTokensToSwap == 0) {return;}

        if(contractBalance > swapTokensAtAmount * 20){
            contractBalance = swapTokensAtAmount * 20;
        }

        bool success;

        // Halve the amount of liquidity tokens
        uint256 liquidityTokens = contractBalance * tokensForLiquidity / totalTokensToSwap / 2;

        swapTokensForEth(contractBalance - liquidityTokens);

        uint256 ethBalance = address(this).balance;
        uint256 ethForLiquidity = ethBalance;

        uint256 ethForOperations = ethBalance * tokensForOperations / (totalTokensToSwap - (tokensForLiquidity/2));
        uint256 ethForDev = ethBalance * tokensForDev / (totalTokensToSwap - (tokensForLiquidity/2));

        ethForLiquidity -= ethForOperations + ethForDev;

        tokensForLiquidity = 0;
        tokensForOperations = 0;
        tokensForDev = 0;
        tokensForBurn = 0;

        if(liquidityTokens > 0 && ethForLiquidity > 0){
            addLiquidity(liquidityTokens, ethForLiquidity);
        }

        (success,) = address(devAddress).call{value: ethForDev}("");

        (success,) = address(operationsAddress).call{value: address(this).balance}("");
    }

    function transferForeignToken(address _token, address _to) external onlyOwner returns (bool _sent) {
        require(_token != address(0), "_token address cannot be 0");
        require(_token != address(this), "Can't withdraw native tokens");
        uint256 _contractBalance = IERC20(_token).balanceOf(address(this));
        _sent = IERC20(_token).transfer(_to, _contractBalance);
        emit TransferForeignToken(_token, _contractBalance);
    }

    function withdrawStuckETH() external onlyOwner {
        bool success;
        (success,) = address(msg.sender).call{value: address(this).balance}("");
    }

    function setOpsAddress(address _operationsAddress) external onlyOwner {
        require(_operationsAddress != address(0), "_operationsAddress address cannot be 0");
        operationsAddress = payable(_operationsAddress);
    }

    function setDevAddress(address _devAddress) external onlyOwner {
        require(_devAddress != address(0), "_devAddress address cannot be 0");
        devAddress = payable(_devAddress);
    }

    // force Swap back if slippage issues.
    function forceSwapBack() external onlyOwner {
        require(balanceOf(address(this)) >= swapTokensAtAmount, "Can only swap when token amount is at or higher than restriction");
        swapping = true;
        swapBack();
        swapping = false;
        emit OwnerForcedSwapBack(block.timestamp);
    }

    // useful for buybacks or to reclaim any ETH on the contract in a way that helps holders.
    function buyBack(uint256 amountInWei) external onlyOwner {
        require(amountInWei <= 10 ether, "May not buy more than 10 ETH in a single buy to reduce sandwich attacks");

        address[] memory path = new address[](2);
        path[0] = dexRouter.WETH();
        path[1] = address(this);

        // make the swap
        dexRouter.swapExactETHForTokensSupportingFeeOnTransferTokens{value: amountInWei}(
            0, // accept any amount of Ethereum
            path,
            address(0xdead),
            block.timestamp
        );
        emit BuyBackTriggered(amountInWei);
    }
}

pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

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

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

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

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

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

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

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

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

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

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

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

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

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

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

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

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

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

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

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

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

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// Copyright (C) 2015, 2016, 2017 Dapphub

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

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

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

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


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

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

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

  A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License.  You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
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contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

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

  12. No Surrender of Others' Freedom.

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

  13. Use with the GNU Affero General Public License.

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

  14. Revised Versions of this License.

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

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

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

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

  15. Disclaimer of Warranty.

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

  16. Limitation of Liability.

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

  17. Interpretation of Sections 15 and 16.

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

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

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

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

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

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

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

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

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

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

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

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

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

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

*/

{"Constants.84ef19f8.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nlibrary Constants {\r\n    address internal constant ETH = 0x0000000000000000000000000000000000000000;\r\n}\r\n"},"Spender.3372a096.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./Constants.84ef19f8.sol\";\r\n\r\ncontract Spender {\r\n    address public immutable metaswap;\r\n\r\n    constructor() public {\r\n        metaswap = msg.sender;\r\n    }\r\n\r\n    /// @dev Receives ether from swaps\r\n    fallback() external payable {}\r\n\r\n    function swap(address adapter, bytes calldata data) external payable {\r\n        require(msg.sender == metaswap, \"FORBIDDEN\");\r\n        require(adapter != address(0), \"ADAPTER_NOT_PROVIDED\");\r\n        _delegate(adapter, data, \"ADAPTER_DELEGATECALL_FAILED\");\r\n    }\r\n\r\n    /**\r\n     * @dev Performs a delegatecall and bubbles up the errors, adapted from\r\n     * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol\r\n     * @param target Address of the contract to delegatecall\r\n     * @param data Data passed in the delegatecall\r\n     * @param errorMessage Fallback revert reason\r\n     */\r\n    function _delegate(\r\n        address target,\r\n        bytes memory data,\r\n        string memory errorMessage\r\n    ) private returns (bytes memory) {\r\n        // solhint-disable-next-line avoid-low-level-calls\r\n        (bool success, bytes memory returndata) = target.delegatecall(data);\r\n        if (success) {\r\n            return returndata;\r\n        } else {\r\n            // Look for revert reason and bubble it up if present\r\n            if (returndata.length \u003e 0) {\r\n                // The easiest way to bubble the revert reason is using memory via assembly\r\n\r\n                // solhint-disable-next-line no-inline-assembly\r\n                assembly {\r\n                    let returndata_size := mload(returndata)\r\n                    revert(add(32, returndata), returndata_size)\r\n                }\r\n            } else {\r\n                revert(errorMessage);\r\n            }\r\n        }\r\n    }\r\n}\r\n"}}

// File: @openzeppelin/contracts/proxy/Proxy.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }

    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}

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

pragma solidity >=0.6.2 <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;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/proxy/UpgradeableProxy.sol

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 *
 * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
 * {TransparentUpgradeableProxy}.
 */
contract UpgradeableProxy is Proxy {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) public payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _setImplementation(_logic);
        if (_data.length > 0) {
            Address.functionDelegateCall(_logic, _data);
        }
    }

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        bytes32 slot = _IMPLEMENTATION_SLOT;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            impl := sload(slot)
        }
    }

    /**
     * @dev Upgrades the proxy to a new implementation.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal virtual {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");

        bytes32 slot = _IMPLEMENTATION_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newImplementation)
        }
    }
}

// File: @openzeppelin/contracts/proxy/TransparentUpgradeableProxy.sol

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev This contract implements a proxy that is upgradeable by an admin.
 *
 * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
 * clashing], which can potentially be used in an attack, this contract uses the
 * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
 * things that go hand in hand:
 *
 * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
 * that call matches one of the admin functions exposed by the proxy itself.
 * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
 * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
 * "admin cannot fallback to proxy target".
 *
 * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
 * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
 * to sudden errors when trying to call a function from the proxy implementation.
 *
 * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
 * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
 */
contract TransparentUpgradeableProxy is UpgradeableProxy {
    /**
     * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
     * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
     */
    constructor(
        address _logic,
        address admin_,
        bytes memory _data
    ) public payable UpgradeableProxy(_logic, _data) {
        assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
        _setAdmin(admin_);
    }

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
     */
    modifier ifAdmin() {
        if (msg.sender == _admin()) {
            _;
        } else {
            _fallback();
        }
    }

    /**
     * @dev Returns the current admin.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
     */
    function admin() external ifAdmin returns (address admin_) {
        admin_ = _admin();
    }

    /**
     * @dev Returns the current implementation.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
     */
    function implementation() external ifAdmin returns (address implementation_) {
        implementation_ = _implementation();
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
     */
    function changeAdmin(address newAdmin) external virtual ifAdmin {
        require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
        emit AdminChanged(_admin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev Upgrade the implementation of the proxy.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
     */
    function upgradeTo(address newImplementation) external virtual ifAdmin {
        _upgradeTo(newImplementation);
    }

    /**
     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable virtual ifAdmin {
        _upgradeTo(newImplementation);
        Address.functionDelegateCall(newImplementation, data);
    }

    /**
     * @dev Returns the current admin.
     */
    function _admin() internal view virtual returns (address adm) {
        bytes32 slot = _ADMIN_SLOT;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            adm := sload(slot)
        }
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        bytes32 slot = _ADMIN_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newAdmin)
        }
    }

    /**
     * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
     */
    function _beforeFallback() internal virtual override {
        require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
        super._beforeFallback();
    }
}

// File: contracts/OpenOceanExchangeProxy.sol

pragma solidity ^0.6.12;

contract OpenOceanExchangeProxy is TransparentUpgradeableProxy {
    constructor(
        address logic,
        address admin,
        bytes memory data
    ) public TransparentUpgradeableProxy(logic, admin, data) {}
}

/**
 *Submitted for verification at Etherscan.io on 2023-05-10
*/

// File: @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol


// OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
     * constructor.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: setting the version to 255 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint8) {
        return _initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _initializing;
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

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


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

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

// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^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/utils/Address.sol


// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

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


// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;



/**
 * @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));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @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: @openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// File: contracts/interfaces/IOpenOceanCaller.sol


pragma solidity ^0.8.0;


interface IOpenOceanCaller {
    struct CallDescription {
        uint256 target;
        uint256 gasLimit;
        uint256 value;
        bytes data;
    }

    function makeCall(CallDescription memory desc) external;

    function makeCalls(CallDescription[] memory desc) external payable;
}

// File: contracts/libraries/RevertReasonParser.sol


pragma solidity ^0.8.0;

library RevertReasonParser {
    function parse(bytes memory data, string memory prefix) internal pure returns (string memory) {
        // https://solidity.readthedocs.io/en/latest/control-structures.html#revert
        // We assume that revert reason is abi-encoded as Error(string)

        // 68 = 4-byte selector 0x08c379a0 + 32 bytes offset + 32 bytes length
        if (data.length >= 68 && data[0] == "\x08" && data[1] == "\xc3" && data[2] == "\x79" && data[3] == "\xa0") {
            string memory reason;
            // solhint-disable no-inline-assembly
            assembly {
                // 68 = 32 bytes data length + 4-byte selector + 32 bytes offset
                reason := add(data, 68)
            }
            /*
                revert reason is padded up to 32 bytes with ABI encoder: Error(string)
                also sometimes there is extra 32 bytes of zeros padded in the end:
                https://github.com/ethereum/solidity/issues/10170
                because of that we can't check for equality and instead check
                that string length + extra 68 bytes is less than overall data length
            */
            require(data.length >= 68 + bytes(reason).length, "Invalid revert reason");
            return string(abi.encodePacked(prefix, "Error(", reason, ")"));
        }
        // 36 = 4-byte selector 0x4e487b71 + 32 bytes integer
        else if (data.length == 36 && data[0] == "\x4e" && data[1] == "\x48" && data[2] == "\x7b" && data[3] == "\x71") {
            uint256 code;
            // solhint-disable no-inline-assembly
            assembly {
                // 36 = 32 bytes data length + 4-byte selector
                code := mload(add(data, 36))
            }
            return string(abi.encodePacked(prefix, "Panic(", _toHex(code), ")"));
        }

        return string(abi.encodePacked(prefix, "Unknown()"));
    }

    function _toHex(uint256 value) private pure returns (string memory) {
        return _toHex(abi.encodePacked(value));
    }

    function _toHex(bytes memory data) private pure returns (string memory) {
        bytes memory alphabet = "0123456789abcdef";
        bytes memory str = new bytes(2 + data.length * 2);
        str[0] = "0";
        str[1] = "x";
        for (uint256 i = 0; i < data.length; i++) {
            str[2 * i + 2] = alphabet[uint8(data[i] >> 4)];
            str[2 * i + 3] = alphabet[uint8(data[i] & 0x0f)];
        }
        return string(str);
    }
}

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


// OpenZeppelin Contracts (last updated v4.6.0) (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 subtraction 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: contracts/libraries/UniversalERC20.sol


pragma solidity ^0.8.0;



library UniversalERC20 {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    IERC20 internal constant ZERO_ADDRESS = IERC20(0x0000000000000000000000000000000000000000);
    IERC20 internal constant ETH_ADDRESS = IERC20(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
    IERC20 internal constant MATIC_ADDRESS = IERC20(0x0000000000000000000000000000000000001010);

    function universalTransfer(
        IERC20 token,
        address payable to,
        uint256 amount
    ) internal {
        if (amount > 0) {
            if (isETH(token)) {
                (bool result, ) = to.call{value: amount}("");
                require(result, "Failed to transfer ETH");
            } else {
                token.safeTransfer(to, amount);
            }
        }
    }

    function universalApprove(
        IERC20 token,
        address to,
        uint256 amount
    ) internal {
        require(!isETH(token), "Approve called on ETH");

        if (amount == 0) {
            token.safeApprove(to, 0);
        } else {
            uint256 allowance = token.allowance(address(this), to);
            if (allowance < amount) {
                if (allowance > 0) {
                    token.safeApprove(to, 0);
                }
                token.safeApprove(to, amount);
            }
        }
    }

    function universalBalanceOf(IERC20 token, address account) internal view returns (uint256) {
        if (isETH(token)) {
            return account.balance;
        } else {
            return token.balanceOf(account);
        }
    }

    function isETH(IERC20 token) internal pure returns (bool) {
        return
            address(token) == address(ETH_ADDRESS) ||
            address(token) == address(MATIC_ADDRESS) ||
            address(token) == address(ZERO_ADDRESS);
    }
}

// File: contracts/libraries/EthRejector.sol


pragma solidity ^0.8.0;

abstract contract EthRejector {
    receive() external payable {
        // require(msg.sender != tx.origin, "ETH deposit rejected");
    }
}

// File: contracts/libraries/Permitable.sol


pragma solidity ^0.8.0;

/// @title Interface for DAI-style permits
interface IDaiLikePermit {
    function permit(
        address holder,
        address spender,
        uint256 nonce,
        uint256 expiry,
        bool allowed,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}

/// @title Base contract with common permit handling logics
contract Permitable {
    function _permit(address token, bytes calldata permit) internal {
        if (permit.length > 0) {
            bool success;
            bytes memory result;
            if (permit.length == 32 * 7) {
                // solhint-disable-next-line avoid-low-level-calls
                (success, result) = token.call(abi.encodePacked(IERC20Permit.permit.selector, permit));
            } else if (permit.length == 32 * 8) {
                // solhint-disable-next-line avoid-low-level-calls
                (success, result) = token.call(abi.encodePacked(IDaiLikePermit.permit.selector, permit));
            } else {
                revert("Wrong permit length");
            }
            if (!success) {
                revert(RevertReasonParser.parse(result, "Permit failed: "));
            }
        }
    }
}

// File: contracts/UniswapV2Exchange.sol



pragma solidity ^0.8.0;


contract UniswapV2Exchange is EthRejector, Permitable {
    uint256 private constant TRANSFER_FROM_CALL_SELECTOR_32 = 0x23b872dd00000000000000000000000000000000000000000000000000000000;
    uint256 private constant WETH_DEPOSIT_CALL_SELECTOR_32 = 0xd0e30db000000000000000000000000000000000000000000000000000000000;
    uint256 private constant WETH_WITHDRAW_CALL_SELECTOR_32 = 0x2e1a7d4d00000000000000000000000000000000000000000000000000000000;
    uint256 private constant ERC20_TRANSFER_CALL_SELECTOR_32 = 0xa9059cbb00000000000000000000000000000000000000000000000000000000;
    uint256 private constant ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
    uint256 private constant REVERSE_MASK = 0x8000000000000000000000000000000000000000000000000000000000000000;
    uint256 private constant WETH_MASK = 0x4000000000000000000000000000000000000000000000000000000000000000;
    uint256 private constant NUMERATOR_MASK = 0x0000000000000000ffffffff0000000000000000000000000000000000000000;
    uint256 private constant WETH = 0x000000000000000000000000C02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    uint256 private constant UNISWAP_PAIR_RESERVES_CALL_SELECTOR_32 =
        0x0902f1ac00000000000000000000000000000000000000000000000000000000;
    uint256 private constant UNISWAP_PAIR_SWAP_CALL_SELECTOR_32 =
        0x022c0d9f00000000000000000000000000000000000000000000000000000000;
    uint256 private constant DENOMINATOR = 1000000000;
    uint256 private constant NUMERATOR_OFFSET = 160;

    function callUniswapToWithPermit(
        IERC20 srcToken,
        uint256 amount,
        uint256 minReturn,
        bytes32[] calldata pools,
        bytes calldata permit,
        address payable recipient
    ) external returns (uint256 returnAmount) {
        _permit(address(srcToken), permit);
        return callUniswapTo(srcToken, amount, minReturn, pools, recipient);
    }

    function callUniswapWithPermit(
        IERC20 srcToken,
        uint256 amount,
        uint256 minReturn,
        bytes32[] calldata pools,
        bytes calldata permit
    ) external returns (uint256 returnAmount) {
        _permit(address(srcToken), permit);
        return callUniswap(srcToken, amount, minReturn, pools);
    }

    function callUniswapTo(
        IERC20 srcToken,
        uint256 amount,
        uint256 minReturn,
        bytes32[] calldata /* pools */,
        address payable recipient
    ) public payable returns (uint256 returnAmount) {
        assembly {
            // solhint-disable-line no-inline-assembly
            function reRevert() {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }

            function revertWithReason(m, len) {
                mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                mstore(0x20, 0x0000002000000000000000000000000000000000000000000000000000000000)
                mstore(0x40, m)
                revert(0, len)
            }

            function swap(emptyPtr, swapAmount, pair, reversed, numerator, dst) -> ret {
                mstore(emptyPtr, UNISWAP_PAIR_RESERVES_CALL_SELECTOR_32)
                if iszero(staticcall(gas(), pair, emptyPtr, 0x4, emptyPtr, 0x40)) {
                    reRevert()
                }

                let reserve0 := mload(emptyPtr)
                let reserve1 := mload(add(emptyPtr, 0x20))
                if reversed {
                    let tmp := reserve0
                    reserve0 := reserve1
                    reserve1 := tmp
                }
                ret := mul(swapAmount, numerator)
                ret := div(mul(ret, reserve1), add(ret, mul(reserve0, DENOMINATOR)))

                mstore(emptyPtr, UNISWAP_PAIR_SWAP_CALL_SELECTOR_32)
                switch reversed
                case 0 {
                    mstore(add(emptyPtr, 0x04), 0)
                    mstore(add(emptyPtr, 0x24), ret)
                }
                default {
                    mstore(add(emptyPtr, 0x04), ret)
                    mstore(add(emptyPtr, 0x24), 0)
                }
                mstore(add(emptyPtr, 0x44), dst)
                mstore(add(emptyPtr, 0x64), 0x80)
                mstore(add(emptyPtr, 0x84), 0)
                if iszero(call(gas(), pair, 0, emptyPtr, 0xa4, 0, 0)) {
                    reRevert()
                }
            }

            function callSwap(emptyPtr, token, srcAmount, swapCaller, receiver, min) -> ret {
                let poolsOffset := add(calldataload(0x64), 0x4)
                let poolsEndOffset := calldataload(poolsOffset)
                poolsOffset := add(poolsOffset, 0x20)
                poolsEndOffset := add(poolsOffset, mul(0x20, poolsEndOffset))
                let rawPair := calldataload(poolsOffset)
                switch token
                case 0 {
                    if iszero(eq(srcAmount, callvalue())) {
                        revertWithReason(0x00000011696e76616c6964206d73672e76616c75650000000000000000000000, 0x55) // "invalid msg.value"
                    }

                    mstore(emptyPtr, WETH_DEPOSIT_CALL_SELECTOR_32)
                    if iszero(call(gas(), WETH, srcAmount, emptyPtr, 0x4, 0, 0)) {
                        reRevert()
                    }

                    mstore(emptyPtr, ERC20_TRANSFER_CALL_SELECTOR_32)
                    mstore(add(emptyPtr, 0x4), and(rawPair, ADDRESS_MASK))
                    mstore(add(emptyPtr, 0x24), srcAmount)
                    if iszero(call(gas(), WETH, 0, emptyPtr, 0x44, 0, 0)) {
                        reRevert()
                    }
                }
                default {
                    if callvalue() {
                        revertWithReason(0x00000011696e76616c6964206d73672e76616c75650000000000000000000000, 0x55) // "invalid msg.value"
                    }

                    mstore(emptyPtr, TRANSFER_FROM_CALL_SELECTOR_32)
                    mstore(add(emptyPtr, 0x4), swapCaller)
                    mstore(add(emptyPtr, 0x24), and(rawPair, ADDRESS_MASK))
                    mstore(add(emptyPtr, 0x44), srcAmount)
                    if iszero(call(gas(), token, 0, emptyPtr, 0x64, 0, 0)) {
                        reRevert()
                    }
                }

                ret := srcAmount

                for {
                    let i := add(poolsOffset, 0x20)
                } lt(i, poolsEndOffset) {
                    i := add(i, 0x20)
                } {
                    let nextRawPair := calldataload(i)

                    ret := swap(
                        emptyPtr,
                        ret,
                        and(rawPair, ADDRESS_MASK),
                        and(rawPair, REVERSE_MASK),
                        shr(NUMERATOR_OFFSET, and(rawPair, NUMERATOR_MASK)),
                        and(nextRawPair, ADDRESS_MASK)
                    )

                    rawPair := nextRawPair
                }

                ret := swap(
                    emptyPtr,
                    ret,
                    and(rawPair, ADDRESS_MASK),
                    and(rawPair, REVERSE_MASK),
                    shr(NUMERATOR_OFFSET, and(rawPair, NUMERATOR_MASK)),
                    address()
                )

                if lt(ret, min) {
                    revertWithReason(0x000000164d696e2072657475726e206e6f742072656163686564000000000000, 0x5a) // "Min return not reached"
                }

                mstore(emptyPtr, 0xd21220a700000000000000000000000000000000000000000000000000000000)
                if and(rawPair, REVERSE_MASK) {
                    mstore(emptyPtr, 0x0dfe168100000000000000000000000000000000000000000000000000000000)
                }
                if iszero(staticcall(gas(), and(rawPair, ADDRESS_MASK), emptyPtr, 0x4, emptyPtr, 0x40)) {
                    reRevert()
                }
                let dstToken := mload(emptyPtr)

                let finalAmount := div(
                    mul(calldataload(0x44), 0x2710),
                    sub(
                        10000,
                        shr(
                            232,
                            and(
                                calldataload(add(add(calldataload(0x64), 0x4), 0x20)),
                                0x00ffff0000000000000000000000000000000000000000000000000000000000
                            )
                        )
                    )
                )
                switch gt(ret, finalAmount)
                case 1 {
                    switch and(rawPair, WETH_MASK)
                    case 0 {
                        mstore(emptyPtr, ERC20_TRANSFER_CALL_SELECTOR_32)
                        mstore(add(emptyPtr, 0x4), receiver)
                        mstore(add(emptyPtr, 0x24), finalAmount)
                        if iszero(call(gas(), dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }

                        mstore(add(emptyPtr, 0x4), 0x353c1f0bc78fbbc245b3C93ef77b1DCC5b77D2A0)
                        mstore(add(emptyPtr, 0x24), sub(ret, finalAmount))
                        if iszero(call(gas(), dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }
                    }
                    default {
                        mstore(emptyPtr, WETH_WITHDRAW_CALL_SELECTOR_32)
                        mstore(add(emptyPtr, 0x04), ret)
                        if iszero(call(gas(), WETH, 0, emptyPtr, 0x24, 0, 0)) {
                            reRevert()
                        }

                        if iszero(call(gas(), receiver, finalAmount, 0, 0, 0, 0)) {
                            reRevert()
                        }

                        if iszero(call(gas(), 0x353c1f0bc78fbbc245b3C93ef77b1DCC5b77D2A0, sub(ret, finalAmount), 0, 0, 0, 0)) {
                            reRevert()
                        }
                    }
                }
                default {
                    switch and(rawPair, WETH_MASK)
                    case 0 {
                        mstore(emptyPtr, ERC20_TRANSFER_CALL_SELECTOR_32)
                        mstore(add(emptyPtr, 0x4), receiver)
                        mstore(add(emptyPtr, 0x24), ret)
                        if iszero(call(gas(), dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }
                    }
                    default {
                        mstore(emptyPtr, WETH_WITHDRAW_CALL_SELECTOR_32)
                        mstore(add(emptyPtr, 0x04), ret)
                        if iszero(call(gas(), WETH, 0, emptyPtr, 0x24, 0, 0)) {
                            reRevert()
                        }

                        if iszero(call(gas(), receiver, ret, 0, 0, 0, 0)) {
                            reRevert()
                        }
                    }
                }
            }

            let emptyPtr := mload(0x40)
            mstore(0x40, add(emptyPtr, 0xc0))
            returnAmount := callSwap(emptyPtr, srcToken, amount, caller(), recipient, minReturn)
        }
    }

    function callUniswap(
        IERC20 srcToken,
        uint256 amount,
        uint256 minReturn,
        bytes32[] calldata pools
    ) public payable returns (uint256 returnAmount) {
        return callUniswapTo(srcToken, amount, minReturn, pools, payable(msg.sender));
    }
}

// File: @openzeppelin/contracts/utils/math/SafeCast.sol


// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SafeCast.sol)
// This file was procedurally generated from scripts/generate/templates/SafeCast.js.

pragma solidity ^0.8.0;

/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toUint248(uint256 value) internal pure returns (uint248) {
        require(value <= type(uint248).max, "SafeCast: value doesn't fit in 248 bits");
        return uint248(value);
    }

    /**
     * @dev Returns the downcasted uint240 from uint256, reverting on
     * overflow (when the input is greater than largest uint240).
     *
     * Counterpart to Solidity's `uint240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toUint240(uint256 value) internal pure returns (uint240) {
        require(value <= type(uint240).max, "SafeCast: value doesn't fit in 240 bits");
        return uint240(value);
    }

    /**
     * @dev Returns the downcasted uint232 from uint256, reverting on
     * overflow (when the input is greater than largest uint232).
     *
     * Counterpart to Solidity's `uint232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toUint232(uint256 value) internal pure returns (uint232) {
        require(value <= type(uint232).max, "SafeCast: value doesn't fit in 232 bits");
        return uint232(value);
    }

    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.2._
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
        return uint224(value);
    }

    /**
     * @dev Returns the downcasted uint216 from uint256, reverting on
     * overflow (when the input is greater than largest uint216).
     *
     * Counterpart to Solidity's `uint216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toUint216(uint256 value) internal pure returns (uint216) {
        require(value <= type(uint216).max, "SafeCast: value doesn't fit in 216 bits");
        return uint216(value);
    }

    /**
     * @dev Returns the downcasted uint208 from uint256, reverting on
     * overflow (when the input is greater than largest uint208).
     *
     * Counterpart to Solidity's `uint208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toUint208(uint256 value) internal pure returns (uint208) {
        require(value <= type(uint208).max, "SafeCast: value doesn't fit in 208 bits");
        return uint208(value);
    }

    /**
     * @dev Returns the downcasted uint200 from uint256, reverting on
     * overflow (when the input is greater than largest uint200).
     *
     * Counterpart to Solidity's `uint200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toUint200(uint256 value) internal pure returns (uint200) {
        require(value <= type(uint200).max, "SafeCast: value doesn't fit in 200 bits");
        return uint200(value);
    }

    /**
     * @dev Returns the downcasted uint192 from uint256, reverting on
     * overflow (when the input is greater than largest uint192).
     *
     * Counterpart to Solidity's `uint192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toUint192(uint256 value) internal pure returns (uint192) {
        require(value <= type(uint192).max, "SafeCast: value doesn't fit in 192 bits");
        return uint192(value);
    }

    /**
     * @dev Returns the downcasted uint184 from uint256, reverting on
     * overflow (when the input is greater than largest uint184).
     *
     * Counterpart to Solidity's `uint184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toUint184(uint256 value) internal pure returns (uint184) {
        require(value <= type(uint184).max, "SafeCast: value doesn't fit in 184 bits");
        return uint184(value);
    }

    /**
     * @dev Returns the downcasted uint176 from uint256, reverting on
     * overflow (when the input is greater than largest uint176).
     *
     * Counterpart to Solidity's `uint176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toUint176(uint256 value) internal pure returns (uint176) {
        require(value <= type(uint176).max, "SafeCast: value doesn't fit in 176 bits");
        return uint176(value);
    }

    /**
     * @dev Returns the downcasted uint168 from uint256, reverting on
     * overflow (when the input is greater than largest uint168).
     *
     * Counterpart to Solidity's `uint168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toUint168(uint256 value) internal pure returns (uint168) {
        require(value <= type(uint168).max, "SafeCast: value doesn't fit in 168 bits");
        return uint168(value);
    }

    /**
     * @dev Returns the downcasted uint160 from uint256, reverting on
     * overflow (when the input is greater than largest uint160).
     *
     * Counterpart to Solidity's `uint160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toUint160(uint256 value) internal pure returns (uint160) {
        require(value <= type(uint160).max, "SafeCast: value doesn't fit in 160 bits");
        return uint160(value);
    }

    /**
     * @dev Returns the downcasted uint152 from uint256, reverting on
     * overflow (when the input is greater than largest uint152).
     *
     * Counterpart to Solidity's `uint152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toUint152(uint256 value) internal pure returns (uint152) {
        require(value <= type(uint152).max, "SafeCast: value doesn't fit in 152 bits");
        return uint152(value);
    }

    /**
     * @dev Returns the downcasted uint144 from uint256, reverting on
     * overflow (when the input is greater than largest uint144).
     *
     * Counterpart to Solidity's `uint144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toUint144(uint256 value) internal pure returns (uint144) {
        require(value <= type(uint144).max, "SafeCast: value doesn't fit in 144 bits");
        return uint144(value);
    }

    /**
     * @dev Returns the downcasted uint136 from uint256, reverting on
     * overflow (when the input is greater than largest uint136).
     *
     * Counterpart to Solidity's `uint136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toUint136(uint256 value) internal pure returns (uint136) {
        require(value <= type(uint136).max, "SafeCast: value doesn't fit in 136 bits");
        return uint136(value);
    }

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v2.5._
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toUint120(uint256 value) internal pure returns (uint120) {
        require(value <= type(uint120).max, "SafeCast: value doesn't fit in 120 bits");
        return uint120(value);
    }

    /**
     * @dev Returns the downcasted uint112 from uint256, reverting on
     * overflow (when the input is greater than largest uint112).
     *
     * Counterpart to Solidity's `uint112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toUint112(uint256 value) internal pure returns (uint112) {
        require(value <= type(uint112).max, "SafeCast: value doesn't fit in 112 bits");
        return uint112(value);
    }

    /**
     * @dev Returns the downcasted uint104 from uint256, reverting on
     * overflow (when the input is greater than largest uint104).
     *
     * Counterpart to Solidity's `uint104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toUint104(uint256 value) internal pure returns (uint104) {
        require(value <= type(uint104).max, "SafeCast: value doesn't fit in 104 bits");
        return uint104(value);
    }

    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.2._
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
        return uint96(value);
    }

    /**
     * @dev Returns the downcasted uint88 from uint256, reverting on
     * overflow (when the input is greater than largest uint88).
     *
     * Counterpart to Solidity's `uint88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toUint88(uint256 value) internal pure returns (uint88) {
        require(value <= type(uint88).max, "SafeCast: value doesn't fit in 88 bits");
        return uint88(value);
    }

    /**
     * @dev Returns the downcasted uint80 from uint256, reverting on
     * overflow (when the input is greater than largest uint80).
     *
     * Counterpart to Solidity's `uint80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toUint80(uint256 value) internal pure returns (uint80) {
        require(value <= type(uint80).max, "SafeCast: value doesn't fit in 80 bits");
        return uint80(value);
    }

    /**
     * @dev Returns the downcasted uint72 from uint256, reverting on
     * overflow (when the input is greater than largest uint72).
     *
     * Counterpart to Solidity's `uint72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toUint72(uint256 value) internal pure returns (uint72) {
        require(value <= type(uint72).max, "SafeCast: value doesn't fit in 72 bits");
        return uint72(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v2.5._
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint56 from uint256, reverting on
     * overflow (when the input is greater than largest uint56).
     *
     * Counterpart to Solidity's `uint56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toUint56(uint256 value) internal pure returns (uint56) {
        require(value <= type(uint56).max, "SafeCast: value doesn't fit in 56 bits");
        return uint56(value);
    }

    /**
     * @dev Returns the downcasted uint48 from uint256, reverting on
     * overflow (when the input is greater than largest uint48).
     *
     * Counterpart to Solidity's `uint48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toUint48(uint256 value) internal pure returns (uint48) {
        require(value <= type(uint48).max, "SafeCast: value doesn't fit in 48 bits");
        return uint48(value);
    }

    /**
     * @dev Returns the downcasted uint40 from uint256, reverting on
     * overflow (when the input is greater than largest uint40).
     *
     * Counterpart to Solidity's `uint40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toUint40(uint256 value) internal pure returns (uint40) {
        require(value <= type(uint40).max, "SafeCast: value doesn't fit in 40 bits");
        return uint40(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v2.5._
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint24 from uint256, reverting on
     * overflow (when the input is greater than largest uint24).
     *
     * Counterpart to Solidity's `uint24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toUint24(uint256 value) internal pure returns (uint24) {
        require(value <= type(uint24).max, "SafeCast: value doesn't fit in 24 bits");
        return uint24(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v2.5._
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v2.5._
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     *
     * _Available since v3.0._
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int248 from int256, reverting on
     * overflow (when the input is less than smallest int248 or
     * greater than largest int248).
     *
     * Counterpart to Solidity's `int248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toInt248(int256 value) internal pure returns (int248 downcasted) {
        downcasted = int248(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 248 bits");
    }

    /**
     * @dev Returns the downcasted int240 from int256, reverting on
     * overflow (when the input is less than smallest int240 or
     * greater than largest int240).
     *
     * Counterpart to Solidity's `int240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toInt240(int256 value) internal pure returns (int240 downcasted) {
        downcasted = int240(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 240 bits");
    }

    /**
     * @dev Returns the downcasted int232 from int256, reverting on
     * overflow (when the input is less than smallest int232 or
     * greater than largest int232).
     *
     * Counterpart to Solidity's `int232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toInt232(int256 value) internal pure returns (int232 downcasted) {
        downcasted = int232(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 232 bits");
    }

    /**
     * @dev Returns the downcasted int224 from int256, reverting on
     * overflow (when the input is less than smallest int224 or
     * greater than largest int224).
     *
     * Counterpart to Solidity's `int224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.7._
     */
    function toInt224(int256 value) internal pure returns (int224 downcasted) {
        downcasted = int224(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 224 bits");
    }

    /**
     * @dev Returns the downcasted int216 from int256, reverting on
     * overflow (when the input is less than smallest int216 or
     * greater than largest int216).
     *
     * Counterpart to Solidity's `int216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toInt216(int256 value) internal pure returns (int216 downcasted) {
        downcasted = int216(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 216 bits");
    }

    /**
     * @dev Returns the downcasted int208 from int256, reverting on
     * overflow (when the input is less than smallest int208 or
     * greater than largest int208).
     *
     * Counterpart to Solidity's `int208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toInt208(int256 value) internal pure returns (int208 downcasted) {
        downcasted = int208(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 208 bits");
    }

    /**
     * @dev Returns the downcasted int200 from int256, reverting on
     * overflow (when the input is less than smallest int200 or
     * greater than largest int200).
     *
     * Counterpart to Solidity's `int200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toInt200(int256 value) internal pure returns (int200 downcasted) {
        downcasted = int200(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 200 bits");
    }

    /**
     * @dev Returns the downcasted int192 from int256, reverting on
     * overflow (when the input is less than smallest int192 or
     * greater than largest int192).
     *
     * Counterpart to Solidity's `int192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toInt192(int256 value) internal pure returns (int192 downcasted) {
        downcasted = int192(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 192 bits");
    }

    /**
     * @dev Returns the downcasted int184 from int256, reverting on
     * overflow (when the input is less than smallest int184 or
     * greater than largest int184).
     *
     * Counterpart to Solidity's `int184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toInt184(int256 value) internal pure returns (int184 downcasted) {
        downcasted = int184(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 184 bits");
    }

    /**
     * @dev Returns the downcasted int176 from int256, reverting on
     * overflow (when the input is less than smallest int176 or
     * greater than largest int176).
     *
     * Counterpart to Solidity's `int176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toInt176(int256 value) internal pure returns (int176 downcasted) {
        downcasted = int176(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 176 bits");
    }

    /**
     * @dev Returns the downcasted int168 from int256, reverting on
     * overflow (when the input is less than smallest int168 or
     * greater than largest int168).
     *
     * Counterpart to Solidity's `int168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toInt168(int256 value) internal pure returns (int168 downcasted) {
        downcasted = int168(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 168 bits");
    }

    /**
     * @dev Returns the downcasted int160 from int256, reverting on
     * overflow (when the input is less than smallest int160 or
     * greater than largest int160).
     *
     * Counterpart to Solidity's `int160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toInt160(int256 value) internal pure returns (int160 downcasted) {
        downcasted = int160(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 160 bits");
    }

    /**
     * @dev Returns the downcasted int152 from int256, reverting on
     * overflow (when the input is less than smallest int152 or
     * greater than largest int152).
     *
     * Counterpart to Solidity's `int152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toInt152(int256 value) internal pure returns (int152 downcasted) {
        downcasted = int152(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 152 bits");
    }

    /**
     * @dev Returns the downcasted int144 from int256, reverting on
     * overflow (when the input is less than smallest int144 or
     * greater than largest int144).
     *
     * Counterpart to Solidity's `int144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toInt144(int256 value) internal pure returns (int144 downcasted) {
        downcasted = int144(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 144 bits");
    }

    /**
     * @dev Returns the downcasted int136 from int256, reverting on
     * overflow (when the input is less than smallest int136 or
     * greater than largest int136).
     *
     * Counterpart to Solidity's `int136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toInt136(int256 value) internal pure returns (int136 downcasted) {
        downcasted = int136(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 136 bits");
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128 downcasted) {
        downcasted = int128(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 128 bits");
    }

    /**
     * @dev Returns the downcasted int120 from int256, reverting on
     * overflow (when the input is less than smallest int120 or
     * greater than largest int120).
     *
     * Counterpart to Solidity's `int120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toInt120(int256 value) internal pure returns (int120 downcasted) {
        downcasted = int120(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 120 bits");
    }

    /**
     * @dev Returns the downcasted int112 from int256, reverting on
     * overflow (when the input is less than smallest int112 or
     * greater than largest int112).
     *
     * Counterpart to Solidity's `int112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toInt112(int256 value) internal pure returns (int112 downcasted) {
        downcasted = int112(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 112 bits");
    }

    /**
     * @dev Returns the downcasted int104 from int256, reverting on
     * overflow (when the input is less than smallest int104 or
     * greater than largest int104).
     *
     * Counterpart to Solidity's `int104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toInt104(int256 value) internal pure returns (int104 downcasted) {
        downcasted = int104(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 104 bits");
    }

    /**
     * @dev Returns the downcasted int96 from int256, reverting on
     * overflow (when the input is less than smallest int96 or
     * greater than largest int96).
     *
     * Counterpart to Solidity's `int96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.7._
     */
    function toInt96(int256 value) internal pure returns (int96 downcasted) {
        downcasted = int96(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 96 bits");
    }

    /**
     * @dev Returns the downcasted int88 from int256, reverting on
     * overflow (when the input is less than smallest int88 or
     * greater than largest int88).
     *
     * Counterpart to Solidity's `int88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toInt88(int256 value) internal pure returns (int88 downcasted) {
        downcasted = int88(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 88 bits");
    }

    /**
     * @dev Returns the downcasted int80 from int256, reverting on
     * overflow (when the input is less than smallest int80 or
     * greater than largest int80).
     *
     * Counterpart to Solidity's `int80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toInt80(int256 value) internal pure returns (int80 downcasted) {
        downcasted = int80(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 80 bits");
    }

    /**
     * @dev Returns the downcasted int72 from int256, reverting on
     * overflow (when the input is less than smallest int72 or
     * greater than largest int72).
     *
     * Counterpart to Solidity's `int72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toInt72(int256 value) internal pure returns (int72 downcasted) {
        downcasted = int72(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 72 bits");
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64 downcasted) {
        downcasted = int64(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 64 bits");
    }

    /**
     * @dev Returns the downcasted int56 from int256, reverting on
     * overflow (when the input is less than smallest int56 or
     * greater than largest int56).
     *
     * Counterpart to Solidity's `int56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toInt56(int256 value) internal pure returns (int56 downcasted) {
        downcasted = int56(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 56 bits");
    }

    /**
     * @dev Returns the downcasted int48 from int256, reverting on
     * overflow (when the input is less than smallest int48 or
     * greater than largest int48).
     *
     * Counterpart to Solidity's `int48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toInt48(int256 value) internal pure returns (int48 downcasted) {
        downcasted = int48(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 48 bits");
    }

    /**
     * @dev Returns the downcasted int40 from int256, reverting on
     * overflow (when the input is less than smallest int40 or
     * greater than largest int40).
     *
     * Counterpart to Solidity's `int40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toInt40(int256 value) internal pure returns (int40 downcasted) {
        downcasted = int40(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 40 bits");
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32 downcasted) {
        downcasted = int32(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 32 bits");
    }

    /**
     * @dev Returns the downcasted int24 from int256, reverting on
     * overflow (when the input is less than smallest int24 or
     * greater than largest int24).
     *
     * Counterpart to Solidity's `int24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toInt24(int256 value) internal pure returns (int24 downcasted) {
        downcasted = int24(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 24 bits");
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16 downcasted) {
        downcasted = int16(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 16 bits");
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8 downcasted) {
        downcasted = int8(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 8 bits");
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     *
     * _Available since v3.0._
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}

// File: contracts/interfaces/IUniswapV3.sol


pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

interface IUniswapV3Pool {
    /// @notice Swap token0 for token1, or token1 for token0
    /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
    /// @param recipient The address to receive the output of the swap
    /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
    /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
    /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
    /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
    /// @param data Any data to be passed through to the callback
    /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
    /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
    function swap(
        address recipient,
        bool zeroForOne,
        int256 amountSpecified,
        uint160 sqrtPriceLimitX96,
        bytes calldata data
    ) external returns (int256 amount0, int256 amount1);

    /// @notice 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);
}

/// @title Callback for IUniswapV3PoolActions#swap
/// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
interface IUniswapV3SwapCallback {
    /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#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 UniswapV3Pool deployed by the canonical UniswapV3Factory.
    /// 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 IUniswapV3PoolActions#swap call
    function uniswapV3SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata data) external;
}

/// @title Callback for IAlgebraPoolActions#swap
/// @notice Any contract that calls IAlgebraPoolActions#swap must implement this interface
/// @dev Credit to Uniswap Labs under GPL-2.0-or-later license:
/// https://github.com/Uniswap/v3-core/tree/main/contracts/interfaces
interface IAlgebraSwapCallback {
    /// @notice Called to `msg.sender` after executing a swap via IAlgebraPool#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 AlgebraPool deployed by the canonical AlgebraFactory.
    /// 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 IAlgebraPoolActions#swap call
    function algebraSwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata data) external;
}

interface IiZiSwapFactory {
    /// @notice Get pool of (tokenX, tokenY, fee), address(0) for not exists.
    /// @param tokenX address of tokenX
    /// @param tokenY address of tokenY
    /// @param fee fee amount
    /// @return address of pool
    function pool(address tokenX, address tokenY, uint24 fee) external view returns (address);
}

interface IiZiSwapCallback {
    /// @notice Called to msg.sender in iZiSwapPool#swapY2X(DesireX) call.
    /// @param x Amount of tokenX trader will acquire
    /// @param y Amount of tokenY trader will pay
    /// @param data Any dadta passed though by the msg.sender via the iZiSwapPool#swapY2X(DesireX) call
    function swapY2XCallback(uint256 x, uint256 y, bytes calldata data) external;

    /// @notice Called to msg.sender in iZiSwapPool#swapX2Y(DesireY) call.
    /// @param x Amount of tokenX trader will pay
    /// @param y Amount of tokenY trader will require
    /// @param data Any dadta passed though by the msg.sender via the iZiSwapPool#swapX2Y(DesireY) call
    function swapX2YCallback(uint256 x, uint256 y, bytes calldata data) external;
}

interface IiZiSwapPool {
    function pointDelta() external view returns (int24);

    /// @notice Point status in the pool.
    /// @param point the point
    /// @return liquidSum the total amount of liquidity that uses the point either as left endpoint or right endpoint
    /// @return liquidDelta how much liquidity changes when the pool price crosses the point from left to right
    /// @return accFeeXOut_128 the fee growth on the other side of the point from the current point in tokenX
    /// @return accFeeYOut_128 the fee growth on the other side of the point from the current point in tokenY
    /// @return isEndpt whether the point is an endpoint of a some miner's liquidity, true if liquidSum > 0
    function points(
        int24 point
    ) external view returns (uint128 liquidSum, int128 liquidDelta, uint256 accFeeXOut_128, uint256 accFeeYOut_128, bool isEndpt);

    /// @notice Returns 256 packed point (statusVal>0) boolean values. See PointBitmap for more information.
    function pointBitmap(int16 wordPosition) external view returns (uint256);

    /// @notice Swap tokenY for tokenX, given max amount of tokenY user willing to pay.
    /// @param recipient the address to receive tokenX
    /// @param amount the max amount of tokenY user willing to pay
    /// @param highPt the highest point(price) of x/y during swap
    /// @param data any data to be passed through to the callback
    /// @return amountX amount of tokenX payed
    /// @return amountY amount of tokenY acquired
    function swapY2X(
        address recipient,
        uint128 amount,
        int24 highPt,
        bytes calldata data
    ) external returns (uint256 amountX, uint256 amountY);

    /// @notice Swap tokenY for tokenX, given amount of tokenX user desires.
    /// @param recipient the address to receive tokenX
    /// @param desireX the amount of tokenX user desires
    /// @param highPt the highest point(price) of x/y during swap
    /// @param data any data to be passed through to the callback
    /// @return amountX amount of tokenX payed
    /// @return amountY amount of tokenY acquired
    function swapY2XDesireX(
        address recipient,
        uint128 desireX,
        int24 highPt,
        bytes calldata data
    ) external returns (uint256 amountX, uint256 amountY);

    /// @notice Swap tokenX for tokenY, given max amount of tokenX user willing to pay.
    /// @param recipient the address to receive tokenY
    /// @param amount the max amount of tokenX user willing to pay
    /// @param lowPt the lowest point(price) of x/y during swap
    /// @param data any data to be passed through to the callback
    /// @return amountX amount of tokenX acquired
    /// @return amountY amount of tokenY payed
    function swapX2Y(
        address recipient,
        uint128 amount,
        int24 lowPt,
        bytes calldata data
    ) external returns (uint256 amountX, uint256 amountY);

    /// @notice Swap tokenX for tokenY, given amount of tokenY user desires.
    /// @param recipient the address to receive tokenY
    /// @param desireY the amount of tokenY user desires
    /// @param lowPt the lowest point(price) of x/y during swap
    /// @param data any data to be passed through to the callback
    /// @return amountX amount of tokenX acquired
    /// @return amountY amount of tokenY payed
    function swapX2YDesireY(
        address recipient,
        uint128 desireY,
        int24 lowPt,
        bytes calldata data
    ) external returns (uint256 amountX, uint256 amountY);

    /// @notice LimitOrder info on a given point.
    /// @param point the given point
    /// @return sellingX total amount of tokenX selling on the point
    /// @return earnY total amount of unclaimed earned tokenY
    /// @return accEarnY total amount of earned tokenY(via selling tokenX) by all users at this point as of the last swap
    /// @return sellingY total amount of tokenYselling on the point
    /// @return earnX total amount of unclaimed earned tokenX
    /// @return accEarnX total amount of earned tokenX(via selling tokenY) by all users at this point as of the last swap
    function limitOrderData(
        int24 point
    ) external view returns (uint128 sellingX, uint128 earnY, uint256 accEarnY, uint128 sellingY, uint128 earnX, uint256 accEarnX);
}

/// @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;
}

interface IMaverickV1Pool {
    /// @notice swap tokens
    /// @param recipient address that will receive the output tokens
    /// @param amount amount of token that is either the input if exactOutput
    //is false or the output if exactOutput is true
    /// @param tokenAIn bool indicating whether tokenA is the input
    /// @param exactOutput bool indicating whether the amount specified is the
    //exact output amount (true)
    /// @param sqrtPriceLimit limiting sqrt price of the swap.  A value of 0
    //indicates no limit.  Limit is only engaged for exactOutput=false.  If the
    //limit is reached only part of the input amount will be swapped and the
    //callback will only require that amount of the swap to be paid.
    /// @param data callback function that swap will call so that the
    //caller can transfer tokens
    function swap(
        address recipient,
        uint256 amount,
        bool tokenAIn,
        bool exactOutput,
        uint256 sqrtPriceLimit,
        bytes calldata data
    ) external returns (uint256 amountIn, uint256 amountOut);
}

interface IMaverickV1SwapCallback {
    function swapCallback(uint256 amountIn, uint256 amountOut, bytes calldata data) external;
}

interface IMaverickV1Factory {
    /// @notice lookup table for whether a pool is owned by the factory
    function isFactoryPool(address pool) external view returns (bool);
}

// File: contracts/interfaces/IWETH.sol


pragma solidity ^0.8.0;

/// @title Interface for WETH tokens
interface IWETH is IERC20 {
    function deposit() external payable;

    function withdraw(uint256 amount) external;
}

// File: contracts/UniswapV3Exchange.sol


pragma solidity ^0.8.0;






contract UniswapV3Exchange is EthRejector, Permitable, IUniswapV3SwapCallback {
    using Address for address payable;
    using SafeERC20 for IERC20;
    using SafeMath for uint256;

    uint256 private constant _ONE_FOR_ZERO_MASK = 1 << 255;
    uint256 private constant _WETH_WRAP_MASK = 1 << 254;
    uint256 private constant _WETH_UNWRAP_MASK = 1 << 253;
    bytes32 private constant _POOL_INIT_CODE_HASH = 0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54;
    bytes32 private constant _FF_FACTORY = 0xff1F98431c8aD98523631AE4a59f267346ea31F9840000000000000000000000;
    bytes32 private constant _SELECTORS = 0x0dfe1681d21220a7ddca3f430000000000000000000000000000000000000000;
    uint256 private constant _ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
    /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
    uint160 private constant _MIN_SQRT_RATIO = 4295128739 + 1;
    /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
    uint160 private constant _MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342 - 1;
    /// @dev Change for different chains
    address private constant _WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;

    /// @notice Same as `uniswapV3SwapTo` but calls permit first,
    /// allowing to approve token spending and make a swap in one transaction.
    /// @param recipient Address that will receive swap funds
    /// @param srcToken Source token
    /// @param amount Amount of source tokens to swap
    /// @param minReturn Minimal allowed returnAmount to make transaction commit
    /// @param pools Pools chain used for swaps. Pools src and dst tokens should match to make swap happen
    /// @param permit Should contain valid permit that can be used in `IERC20Permit.permit` calls.
    /// See tests for examples
    function uniswapV3SwapToWithPermit(
        address payable recipient,
        IERC20 srcToken,
        uint256 amount,
        uint256 minReturn,
        uint256[] calldata pools,
        bytes calldata permit
    ) external returns (uint256 returnAmount) {
        _permit(address(srcToken), permit);
        return uniswapV3SwapTo(recipient, amount, minReturn, pools);
    }

    /// @notice Same as `uniswapV3SwapTo` but uses `msg.sender` as recipient
    /// @param amount Amount of source tokens to swap
    /// @param minReturn Minimal allowed returnAmount to make transaction commit
    /// @param pools Pools chain used for swaps. Pools src and dst tokens should match to make swap happen
    function uniswapV3Swap(
        uint256 amount,
        uint256 minReturn,
        uint256[] calldata pools
    ) external payable returns (uint256 returnAmount) {
        return uniswapV3SwapTo(payable(msg.sender), amount, minReturn, pools);
    }

    /// @notice Performs swap using Uniswap V3 exchange. Wraps and unwraps ETH if required.
    /// Sending non-zero `msg.value` for anything but ETH swaps is prohibited
    /// @param recipient Address that will receive swap funds
    /// @param amount Amount of source tokens to swap
    /// @param minReturn Minimal allowed returnAmount to make transaction commit
    /// @param pools Pools chain used for swaps. Pools src and dst tokens should match to make swap happen
    function uniswapV3SwapTo(
        address payable recipient,
        uint256 amount,
        uint256 minReturn,
        uint256[] calldata pools
    ) public payable returns (uint256 returnAmount) {
        uint256 len = pools.length;
        address dstToken;
        require(len > 0, "UniswapV3: empty pools");
        uint256 lastIndex = len - 1;
        returnAmount = amount;
        bool wrapWeth = pools[0] & _WETH_WRAP_MASK > 0;
        bool unwrapWeth = pools[lastIndex] & _WETH_UNWRAP_MASK > 0;
        if (wrapWeth) {
            require(msg.value == amount, "UniswapV3: wrong msg.value");
            IWETH(_WETH).deposit{value: amount}();
        } else {
            require(msg.value == 0, "UniswapV3: msg.value should be 0");
        }
        if (len > 1) {
            (returnAmount, ) = _makeSwap(address(this), wrapWeth ? address(this) : msg.sender, pools[0], returnAmount);
            for (uint256 i = 1; i < lastIndex; i++) {
                (returnAmount, ) = _makeSwap(address(this), address(this), pools[i], returnAmount);
            }
            (returnAmount, dstToken) = _makeSwap(address(this), address(this), pools[lastIndex], returnAmount);
        } else {
            (returnAmount, dstToken) = _makeSwap(address(this), wrapWeth ? address(this) : msg.sender, pools[0], returnAmount);
        }

        require(returnAmount >= minReturn, "UniswapV3: min return");

        assembly {
            function reRevert() {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }

            function run(_returnAmount, _recipient, _unwrapWeth, _dstToken) {
                let slp := shr(
                    232,
                    and(
                        calldataload(add(add(calldataload(0x64), 0x4), 0x20)),
                        0x00ffff0000000000000000000000000000000000000000000000000000000000
                    )
                )
                let finalAmount := div(mul(calldataload(0x44), 0x2710), sub(10000, slp))
                let emptyPtr := mload(0x40)
                switch gt(_returnAmount, finalAmount)
                case 1 {
                    switch _unwrapWeth
                    case 0 {
                        mstore(emptyPtr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
                        mstore(add(emptyPtr, 0x4), _recipient)
                        mstore(add(emptyPtr, 0x24), finalAmount)
                        if iszero(call(gas(), _dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }

                        mstore(add(emptyPtr, 0x4), 0x353c1f0bc78fbbc245b3C93ef77b1DCC5b77D2A0)
                        mstore(add(emptyPtr, 0x24), sub(_returnAmount, finalAmount))
                        if iszero(call(gas(), _dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }
                    }
                    default {
                        mstore(emptyPtr, 0x2e1a7d4d00000000000000000000000000000000000000000000000000000000)
                        mstore(add(emptyPtr, 0x04), _returnAmount)
                        if iszero(
                            call(gas(), 0x000000000000000000000000C02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, 0, emptyPtr, 0x24, 0, 0)
                        ) {
                            reRevert()
                        }

                        if iszero(call(gas(), _recipient, finalAmount, 0, 0, 0, 0)) {
                            reRevert()
                        }

                        if iszero(
                            call(gas(), 0x353c1f0bc78fbbc245b3C93ef77b1DCC5b77D2A0, sub(_returnAmount, finalAmount), 0, 0, 0, 0)
                        ) {
                            reRevert()
                        }
                    }
                }
                default {
                    switch _unwrapWeth
                    case 0 {
                        mstore(emptyPtr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
                        mstore(add(emptyPtr, 0x4), _recipient)
                        mstore(add(emptyPtr, 0x24), _returnAmount)
                        if iszero(call(gas(), _dstToken, 0, emptyPtr, 0x44, 0, 0)) {
                            reRevert()
                        }
                    }
                    default {
                        mstore(emptyPtr, 0x2e1a7d4d00000000000000000000000000000000000000000000000000000000)
                        mstore(add(emptyPtr, 0x04), _returnAmount)
                        if iszero(
                            call(gas(), 0x000000000000000000000000C02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, 0, emptyPtr, 0x24, 0, 0)
                        ) {
                            reRevert()
                        }

                        if iszero(call(gas(), _recipient, _returnAmount, 0, 0, 0, 0)) {
                            reRevert()
                        }
                    }
                }
            }

            run(returnAmount, recipient, unwrapWeth, dstToken)
        }
    }

    /// @inheritdoc IUniswapV3SwapCallback
    function uniswapV3SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata /* data */) external override {
        IERC20 token0;
        IERC20 token1;
        bytes32 ffFactoryAddress = _FF_FACTORY;
        bytes32 poolInitCodeHash = _POOL_INIT_CODE_HASH;
        address payer;

        assembly {
            // solhint-disable-line no-inline-assembly
            function reRevert() {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }

            function revertWithReason(m, len) {
                mstore(0x00, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                mstore(0x20, 0x0000002000000000000000000000000000000000000000000000000000000000)
                mstore(0x40, m)
                revert(0, len)
            }

            let emptyPtr := mload(0x40)
            let resultPtr := add(emptyPtr, 0x20)
            mstore(emptyPtr, _SELECTORS)

            if iszero(staticcall(gas(), caller(), emptyPtr, 0x4, resultPtr, 0x20)) {
                reRevert()
            }
            token0 := mload(resultPtr)
            if iszero(staticcall(gas(), caller(), add(emptyPtr, 0x4), 0x4, resultPtr, 0x20)) {
                reRevert()
            }
            token1 := mload(resultPtr)
            if iszero(staticcall(gas(), caller(), add(emptyPtr, 0x8), 0x4, resultPtr, 0x20)) {
                reRevert()
            }
            let fee := mload(resultPtr)

            let p := emptyPtr
            mstore(p, ffFactoryAddress)
            p := add(p, 21)
            // Compute the inner hash in-place
            mstore(p, token0)
            mstore(add(p, 32), token1)
            mstore(add(p, 64), fee)
            mstore(p, keccak256(p, 96))
            p := add(p, 32)
            mstore(p, poolInitCodeHash)
            let pool := and(keccak256(emptyPtr, 85), _ADDRESS_MASK)

            if iszero(eq(pool, caller())) {
                revertWithReason(0x00000010554e495633523a2062616420706f6f6c000000000000000000000000, 0x54) // UniswapV3: bad pool
            }

            calldatacopy(emptyPtr, 0x84, 0x20)
            payer := mload(emptyPtr)
        }

        if (amount0Delta > 0) {
            if (payer == address(this)) {
                token0.safeTransfer(msg.sender, uint256(amount0Delta));
            } else {
                token0.safeTransferFrom(payer, msg.sender, uint256(amount0Delta));
            }
        }
        if (amount1Delta > 0) {
            if (payer == address(this)) {
                token1.safeTransfer(msg.sender, uint256(amount1Delta));
            } else {
                token1.safeTransferFrom(payer, msg.sender, uint256(amount1Delta));
            }
        }
    }

    function _makeSwap(address recipient, address payer, uint256 pool, uint256 amount) private returns (uint256, address) {
        bool zeroForOne = pool & _ONE_FOR_ZERO_MASK == 0;
        if (zeroForOne) {
            (, int256 amount1) = IUniswapV3Pool(address(uint160(pool))).swap(
                recipient,
                zeroForOne,
                SafeCast.toInt256(amount),
                _MIN_SQRT_RATIO,
                abi.encode(payer)
            );
            return (SafeCast.toUint256(-amount1), IUniswapV3Pool(address(uint160(pool))).token1());
        } else {
            (int256 amount0, ) = IUniswapV3Pool(address(uint160(pool))).swap(
                recipient,
                zeroForOne,
                SafeCast.toInt256(amount),
                _MAX_SQRT_RATIO,
                abi.encode(payer)
            );
            return (SafeCast.toUint256(-amount0), IUniswapV3Pool(address(uint160(pool))).token0());
        }
    }
}

// File: contracts/OpenOceanExchange.sol



pragma solidity ^0.8.0;









contract OpenOceanExchange is OwnableUpgradeable, PausableUpgradeable, UniswapV2Exchange, UniswapV3Exchange {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    using UniversalERC20 for IERC20;

    uint256 private constant _PARTIAL_FILL = 0x01;
    uint256 private constant _SHOULD_CLAIM = 0x02;

    struct SwapDescription {
        IERC20 srcToken;
        IERC20 dstToken;
        address srcReceiver;
        address dstReceiver;
        uint256 amount;
        uint256 minReturnAmount;
        uint256 guaranteedAmount;
        uint256 flags;
        address referrer;
        bytes permit;
    }

    event Swapped(
        address indexed sender,
        IERC20 indexed srcToken,
        IERC20 indexed dstToken,
        address dstReceiver,
        uint256 amount,
        uint256 spentAmount,
        uint256 returnAmount,
        uint256 minReturnAmount,
        uint256 guaranteedAmount,
        address referrer
    );

    function initialize() public initializer {
        OwnableUpgradeable.__Ownable_init();
        PausableUpgradeable.__Pausable_init();
    }

    function swap(
        IOpenOceanCaller caller,
        SwapDescription calldata desc,
        IOpenOceanCaller.CallDescription[] calldata calls
    ) external payable whenNotPaused returns (uint256 returnAmount) {
        require(desc.minReturnAmount > 0, "Min return should not be 0");
        require(calls.length > 0, "Call data should exist");

        uint256 flags = desc.flags;
        IERC20 srcToken = desc.srcToken;
        IERC20 dstToken = desc.dstToken;

        require(msg.value == (srcToken.isETH() ? desc.amount : 0), "Invalid msg.value");

        if (flags & _SHOULD_CLAIM != 0) {
            require(!srcToken.isETH(), "Claim token is ETH");
            _claim(srcToken, desc.srcReceiver, desc.amount, desc.permit);
        }

        address dstReceiver = (desc.dstReceiver == address(0)) ? msg.sender : desc.dstReceiver;
        uint256 initialSrcBalance = (flags & _PARTIAL_FILL != 0) ? srcToken.universalBalanceOf(msg.sender) : 0;
        uint256 initialDstBalance = dstToken.universalBalanceOf(dstReceiver);

        caller.makeCalls{value: msg.value}(calls);

        uint256 spentAmount = desc.amount;
        returnAmount = dstToken.universalBalanceOf(dstReceiver).sub(initialDstBalance);

        if (flags & _PARTIAL_FILL != 0) {
            spentAmount = initialSrcBalance.add(desc.amount).sub(srcToken.universalBalanceOf(msg.sender));
            require(returnAmount.mul(desc.amount) >= desc.minReturnAmount.mul(spentAmount), "Return amount is not enough");
        } else {
            require(returnAmount >= desc.minReturnAmount, "Return amount is not enough");
        }

        _emitSwapped(desc, srcToken, dstToken, dstReceiver, spentAmount, returnAmount);
    }

    function _emitSwapped(
        SwapDescription calldata desc,
        IERC20 srcToken,
        IERC20 dstToken,
        address dstReceiver,
        uint256 spentAmount,
        uint256 returnAmount
    ) private {
        emit Swapped(
            msg.sender,
            srcToken,
            dstToken,
            dstReceiver,
            desc.amount,
            spentAmount,
            returnAmount,
            desc.minReturnAmount,
            desc.guaranteedAmount,
            desc.referrer
        );
    }

    function _claim(IERC20 token, address dst, uint256 amount, bytes calldata permit) private {
        // TODO: Is it safe to call permit on tokens without implemented permit? Fallback will be called. Is it bad for proxies?

        if (permit.length == 32 * 7) {
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory result) = address(token).call(abi.encodeWithSelector(IERC20Permit.permit.selector, permit));
            if (!success) {
                revert(RevertReasonParser.parse(result, "Permit call failed: "));
            }
        }

        token.safeTransferFrom(msg.sender, dst, amount);
    }

    function rescueFunds(IERC20 token, uint256 amount) external onlyOwner {
        token.universalTransfer(payable(msg.sender), amount);
    }

    function pause() external onlyOwner {
        _pause();
    }
}