// File: contracts/UniAgent.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

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

import { TokenCollector } from "./abstracts/TokenCollector.sol";
import { Ownable } from "./abstracts/Ownable.sol";
import { IUniAgent } from "./interfaces/IUniAgent.sol";
import { Asset } from "./libraries/Asset.sol";

contract UniAgent is IUniAgent, Ownable, TokenCollector {
    using Asset for address;

    address private constant v2Router = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address private constant v3Router = 0xE592427A0AEce92De3Edee1F18E0157C05861564;
    address private constant swapRouter02 = 0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45;
    address payable private constant universalRouter = payable(0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD);

    constructor(
        address _owner,
        address _uniswapPermit2,
        address _allowanceTarget
    ) Ownable(_owner) TokenCollector(_uniswapPermit2, _allowanceTarget) {}

    receive() external payable {}

    function rescueTokens(address[] calldata tokens, address recipient) external onlyOwner {
        for (uint256 i = 0; i < tokens.length; ++i) {
            uint256 selfBalance = Asset.getBalance(tokens[i], address(this));
            if (selfBalance > 0) {
                Asset.transferTo(tokens[i], payable(recipient), selfBalance);
            }
        }
    }

    function approveTokensToRouters(address[] calldata tokens) external {
        for (uint256 i = 0; i < tokens.length; ++i) {
            // use low level call to avoid return size check
            // ignore return value and proceed anyway since three calls are independent
            tokens[i].call(abi.encodeCall(IERC20.approve, (v2Router, type(uint256).max)));
            tokens[i].call(abi.encodeCall(IERC20.approve, (v3Router, type(uint256).max)));
            tokens[i].call(abi.encodeCall(IERC20.approve, (swapRouter02, type(uint256).max)));
        }
    }

    /// @inheritdoc IUniAgent
    function approveAndSwap(
        RouterType routerType,
        address inputToken,
        uint256 inputAmount,
        bytes calldata payload,
        bytes calldata userPermit
    ) external payable override {
        _swap(routerType, true, inputToken, inputAmount, payload, userPermit);
    }

    /// @inheritdoc IUniAgent
    function swap(
        RouterType routerType,
        address inputToken,
        uint256 inputAmount,
        bytes calldata payload,
        bytes calldata userPermit
    ) external payable override {
        _swap(routerType, false, inputToken, inputAmount, payload, userPermit);
    }

    function _swap(
        RouterType routerType,
        bool needApprove,
        address inputToken,
        uint256 inputAmount,
        bytes calldata payload,
        bytes calldata userPermit
    ) private {
        address routerAddr = _getRouterAddress(routerType);
        if (needApprove) {
            // use low level call to avoid return size check
            (bool apvSuccess, bytes memory apvResult) = inputToken.call(abi.encodeCall(IERC20.approve, (routerAddr, type(uint256).max)));
            if (!apvSuccess) {
                assembly {
                    revert(add(apvResult, 32), mload(apvResult))
                }
            }
        }

        if (inputToken.isETH()) {
            if (msg.value != inputAmount) revert InvalidMsgValue();
        }
        if (!inputToken.isETH()) {
            if (msg.value != 0) revert InvalidMsgValue();

            if (routerType == RouterType.UniversalRouter) {
                // deposit directly into router if it's universal router
                _collect(inputToken, msg.sender, universalRouter, inputAmount, userPermit);
            } else {
                // v2, v3, swapRouter02 use transferFrom
                _collect(inputToken, msg.sender, address(this), inputAmount, userPermit);
            }
        }
        (bool success, bytes memory result) = routerAddr.call{ value: msg.value }(payload);
        if (!success) {
            assembly {
                revert(add(result, 32), mload(result))
            }
        }

        emit Swap({ user: msg.sender, router: routerAddr, inputToken: inputToken, inputAmount: inputAmount });
    }

    function _getRouterAddress(RouterType routerType) private pure returns (address) {
        if (routerType == RouterType.V2Router) {
            return v2Router;
        } else if (routerType == RouterType.V3Router) {
            return v3Router;
        } else if (routerType == RouterType.SwapRouter02) {
            return swapRouter02;
        } else if (routerType == RouterType.UniversalRouter) {
            return universalRouter;
        }

        // won't be reached
        revert();
    }
}

// File: lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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: contracts/abstracts/TokenCollector.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import { IERC20Permit } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

import { IUniswapPermit2 } from "../interfaces/IUniswapPermit2.sol";
import { IAllowanceTarget } from "../interfaces/IAllowanceTarget.sol";

abstract contract TokenCollector {
    using SafeERC20 for IERC20;

    error Permit2DataEmpty();

    enum Source {
        TokenlonAllowanceTarget,
        Token,
        TokenPermit,
        Permit2AllowanceTransfer,
        Permit2SignatureTransfer
    }

    address public immutable permit2;
    address public immutable allowanceTarget;

    constructor(address _permit2, address _allowanceTarget) {
        permit2 = _permit2;
        allowanceTarget = _allowanceTarget;
    }

    function _collect(
        address token,
        address from,
        address to,
        uint256 amount,
        bytes calldata data
    ) internal {
        Source src = Source(uint8(data[0]));

        if (src == Source.TokenlonAllowanceTarget) {
            return IAllowanceTarget(allowanceTarget).spendFromUserTo(from, token, to, amount);
        } else if (src == Source.Token) {
            return IERC20(token).safeTransferFrom(from, to, amount);
        } else if (src == Source.TokenPermit) {
            (bool success, bytes memory result) = token.call(abi.encodePacked(IERC20Permit.permit.selector, data[1:]));
            if (!success) {
                assembly {
                    revert(add(result, 32), returndatasize())
                }
            }
            return IERC20(token).safeTransferFrom(from, to, amount);
        } else if (src == Source.Permit2AllowanceTransfer) {
            bytes memory permit2Data = data[1:];
            if (permit2Data.length > 0) {
                (bool success, bytes memory result) = permit2.call(abi.encodePacked(IUniswapPermit2.permit.selector, permit2Data));
                if (!success) {
                    assembly {
                        revert(add(result, 32), returndatasize())
                    }
                }
            }
            return IUniswapPermit2(permit2).transferFrom(from, to, uint160(amount), token);
        } else if (src == Source.Permit2SignatureTransfer) {
            bytes memory permit2Data = data[1:];
            if (permit2Data.length == 0) revert Permit2DataEmpty();
            (uint256 nonce, uint256 deadline, bytes memory permitSig) = abi.decode(permit2Data, (uint256, uint256, bytes));
            IUniswapPermit2.PermitTransferFrom memory permit = IUniswapPermit2.PermitTransferFrom({
                permitted: IUniswapPermit2.TokenPermissions({ token: token, amount: amount }),
                nonce: nonce,
                deadline: deadline
            });
            IUniswapPermit2.SignatureTransferDetails memory detail = IUniswapPermit2.SignatureTransferDetails({ to: to, requestedAmount: amount });
            return IUniswapPermit2(permit2).permitTransferFrom(permit, detail, from, permitSig);
        }

        // won't be reached
        revert();
    }
}

// File: contracts/abstracts/Ownable.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Ownable Contract
/// @author imToken Labs
abstract contract Ownable {
    address public owner;
    address public nominatedOwner;

    error NotOwner();
    error NotNominated();
    error ZeroOwner();
    error NominationExists();

    event OwnerNominated(address indexed newOwner);
    event OwnerChanged(address indexed oldOwner, address indexed newOwner);

    constructor(address _owner) {
        if (_owner == address(0)) revert ZeroOwner();
        owner = _owner;
    }

    modifier onlyOwner() {
        if (msg.sender != owner) revert NotOwner();
        _;
    }

    /// @notice Activate new ownership
    /// @notice Only nominated owner can call
    function acceptOwnership() external {
        if (msg.sender != nominatedOwner) revert NotNominated();
        emit OwnerChanged(owner, nominatedOwner);

        owner = nominatedOwner;
        nominatedOwner = address(0);
    }

    /// @notice Give up the ownership
    /// @notice Only owner can call
    /// @notice Ownership cannot be recovered
    function renounceOwnership() external onlyOwner {
        if (nominatedOwner != address(0)) revert NominationExists();
        emit OwnerChanged(owner, address(0));
        owner = address(0);
    }

    /// @notice Nominate new owner
    /// @notice Only owner can call
    /// @param newOwner The address of the new owner
    function nominateNewOwner(address newOwner) external onlyOwner {
        nominatedOwner = newOwner;
        emit OwnerNominated(newOwner);
    }
}

// File: contracts/interfaces/IUniAgent.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

/// @title IUniAgent Interface
/// @author imToken Labs
interface IUniAgent {
    error InvalidMsgValue();

    /// @notice Emitted when a swap is executed
    /// @param user The user address of the swap.
    /// @param router The uniswap router address of the swap.
    /// @param inputToken The input token address of the swap.
    /// @param inputAmount The input amount of the swap.
    event Swap(address indexed user, address indexed router, address indexed inputToken, uint256 inputAmount);

    /// @notice The enum of which uniswap router should be called.
    enum RouterType {
        V2Router,
        V3Router,
        SwapRouter02,
        UniversalRouter
    }

    /// @notice Approve token to router and execute a swap
    /// @param routerType The type of uniswap router should be used.
    /// @param inputToken The input token address of the swap.
    /// @param inputAmount The input amount of the swap.
    /// @param payload The execution payload for uniswap router.
    /// @param userPermit The permit of user for token transfering.
    function approveAndSwap(
        RouterType routerType,
        address inputToken,
        uint256 inputAmount,
        bytes calldata payload,
        bytes calldata userPermit
    ) external payable;

    /// @notice Execute a swap
    /// @param routerType The type of uniswap router should be used.
    /// @param inputToken The input token address of the swap.
    /// @param inputAmount The input amount of the swap.
    /// @param payload The execution payload for uniswap router.
    /// @param userPermit The permit of user for token transfering.
    function swap(
        RouterType routerType,
        address inputToken,
        uint256 inputAmount,
        bytes calldata payload,
        bytes calldata userPermit
    ) external payable;
}

// File: contracts/libraries/Asset.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

import { Constant } from "./Constant.sol";

library Asset {
    using SafeERC20 for IERC20;

    error InsufficientBalance();

    function isETH(address addr) internal pure returns (bool) {
        return (addr == Constant.ETH_ADDRESS || addr == Constant.ZERO_ADDRESS);
    }

    function getBalance(address asset, address owner) internal view returns (uint256) {
        if (isETH(asset)) {
            return owner.balance;
        } else {
            return IERC20(asset).balanceOf(owner);
        }
    }

    function transferTo(
        address asset,
        address payable to,
        uint256 amount
    ) internal {
        if (to == address(this) || amount == 0) {
            return;
        }
        if (isETH(asset)) {
            // @dev forward all available gas and may cause reentrancy
            if (address(this).balance < amount) revert InsufficientBalance();
            (bool success, bytes memory result) = to.call{ value: amount }("");
            if (!success) {
                assembly {
                    revert(add(result, 32), mload(result))
                }
            }
        } else {
            IERC20(asset).safeTransfer(to, amount);
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/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: lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";

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

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    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));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    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");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    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");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation 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).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // 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 cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
}

// File: contracts/interfaces/IUniswapPermit2.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

interface IUniswapPermit2 {
    /// @notice Thrown when an allowance on a token has expired.
    /// @param deadline The timestamp at which the allowed amount is no longer valid
    error AllowanceExpired(uint256 deadline);

    /// @notice Thrown when an allowance on a token has been depleted.
    /// @param amount The maximum amount allowed
    error InsufficientAllowance(uint256 amount);

    /// @notice Thrown when the requested amount for a transfer is larger than the permissioned amount
    /// @param maxAmount The maximum amount a spender can request to transfer
    error InvalidAmount(uint256 maxAmount);

    /// @notice Thrown when validating that the inputted nonce has not been used
    error InvalidNonce();

    /// @notice Thrown when the recovered signer does not equal the claimedSigner
    error InvalidSigner();

    /// @notice Thrown when validating an inputted signature that is stale
    /// @param signatureDeadline The timestamp at which a signature is no longer valid
    error SignatureExpired(uint256 signatureDeadline);

    /*
     * Allowance Transfer
     */

    /// @notice The permit data for a token
    struct PermitDetails {
        // ERC20 token address
        address token;
        // the maximum amount allowed to spend
        uint160 amount;
        // timestamp at which a spender's token allowances become invalid
        uint48 expiration;
        // an incrementing value indexed per owner,token,and spender for each signature
        uint48 nonce;
    }

    /// @notice The permit message signed for a single token allownce
    struct PermitSingle {
        // the permit data for a single token alownce
        PermitDetails details;
        // address permissioned on the allowed tokens
        address spender;
        // deadline on the permit signature
        uint256 sigDeadline;
    }

    /// @notice Returns the domain separator for the current chain.
    /// @dev Uses cached version if chainid and address are unchanged from construction.
    function DOMAIN_SEPARATOR() external view returns (bytes32);

    /// @notice A mapping from owner address to token address to spender address to PackedAllowance struct, which contains details and conditions of the approval.
    /// @notice The mapping is indexed in the above order see: allowance[ownerAddress][tokenAddress][spenderAddress]
    /// @dev The packed slot holds the allowed amount, expiration at which the allowed amount is no longer valid, and current nonce thats updated on any signature based approvals.
    function allowance(
        address user,
        address token,
        address spender
    )
        external
        view
        returns (
            uint160 amount,
            uint48 expiration,
            uint48 nonce
        );

    /// @notice Permit a spender to a given amount of the owners token via the owner's EIP-712 signature
    /// @dev May fail if the owner's nonce was invalidated in-flight by invalidateNonce
    /// @param owner The owner of the tokens being approved
    /// @param permitSingle Data signed over by the owner specifying the terms of approval
    /// @param signature The owner's signature over the permit data
    function permit(
        address owner,
        PermitSingle memory permitSingle,
        bytes calldata signature
    ) external;

    /// @notice Transfer approved tokens from one address to another
    /// @param from The address to transfer from
    /// @param to The address of the recipient
    /// @param amount The amount of the token to transfer
    /// @param token The token address to transfer
    /// @dev Requires the from address to have approved at least the desired amount
    /// of tokens to msg.sender.
    function transferFrom(
        address from,
        address to,
        uint160 amount,
        address token
    ) external;

    /// @notice Approves the spender to use up to amount of the specified token up until the expiration
    /// @param token The token to approve
    /// @param spender The spender address to approve
    /// @param amount The approved amount of the token
    /// @param expiration The timestamp at which the approval is no longer valid
    /// @dev The packed allowance also holds a nonce, which will stay unchanged in approve
    /// @dev Setting amount to type(uint160).max sets an unlimited approval
    function approve(
        address token,
        address spender,
        uint160 amount,
        uint48 expiration
    ) external;

    /*
     * Signature Transfer
     */

    /// @notice The token and amount details for a transfer signed in the permit transfer signature
    struct TokenPermissions {
        // ERC20 token address
        address token;
        // the maximum amount that can be spent
        uint256 amount;
    }

    /// @notice The signed permit message for a single token transfer
    struct PermitTransferFrom {
        TokenPermissions permitted;
        // a unique value for every token owner's signature to prevent signature replays
        uint256 nonce;
        // deadline on the permit signature
        uint256 deadline;
    }

    /// @notice Specifies the recipient address and amount for batched transfers.
    /// @dev Recipients and amounts correspond to the index of the signed token permissions array.
    /// @dev Reverts if the requested amount is greater than the permitted signed amount.
    struct SignatureTransferDetails {
        // recipient address
        address to;
        // spender requested amount
        uint256 requestedAmount;
    }

    /// @notice Transfers a token using a signed permit message
    /// @dev Reverts if the requested amount is greater than the permitted signed amount
    /// @param permit The permit data signed over by the owner
    /// @param owner The owner of the tokens to transfer
    /// @param transferDetails The spender's requested transfer details for the permitted token
    /// @param signature The signature to verify
    function permitTransferFrom(
        PermitTransferFrom memory permit,
        SignatureTransferDetails calldata transferDetails,
        address owner,
        bytes calldata signature
    ) external;
}

// File: contracts/interfaces/IAllowanceTarget.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

/// @title IAllowanceTarget Interface
/// @author imToken Labs
interface IAllowanceTarget {
    error NotAuthorized();

    /// @dev Spend tokens on user's behalf. Only an authority can call this.
    /// @param  from The user to spend token from.
    /// @param  token The address of the token.
    /// @param  to The recipient of the trasnfer.
    /// @param  amount Amount to spend.
    function spendFromUserTo(
        address from,
        address token,
        address to,
        uint256 amount
    ) external;
}

// File: contracts/libraries/Constant.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library Constant {
    uint16 internal constant BPS_MAX = 10000;
    address internal constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    address internal constant ZERO_ADDRESS = address(0);
}

// File: lib/openzeppelin-contracts/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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);
        }
    }
}