// File: contracts/others/ShamanTreasury.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @author token
 * This treasury contract has been developed by token.info
 */
import '@openzeppelin/contracts/access/Ownable.sol';
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
import '@openzeppelin/contracts/utils/math/SafeMath.sol';

import "../libs/IUniFactory.sol";
import "../libs/IUniRouter02.sol";
import "../libs/IWETH.sol";

interface IStaking {
    function performanceFee() external view returns(uint256);
    function setServiceInfo(address _addr, uint256 _fee) external;
}

interface IFarm {
    function setBuyBackWallet(address _addr) external;
}

contract ShamanTreasury is Ownable, ReentrancyGuard {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // Whether it is initialized
    bool private isInitialized;
    uint256 private TIME_UNIT = 1 days;

    IERC20  public token;
    address public dividendToken;
    address public pair;

    uint256 public period = 30;                         // 30 days
    uint256 public withdrawalLimit = 500;               // 5% of total supply
    uint256 public liquidityWithdrawalLimit = 2000;     // 20% of LP supply
    uint256 public buybackRate = 9500;                  // 95%
    uint256 public addLiquidityRate = 9400;             // 94%

    uint256 private startTime;
    uint256 private sumWithdrawals = 0;
    uint256 private sumLiquidityWithdrawals = 0;

    uint256 public performanceFee = 100;     // 1%
    uint256 public performanceLpFee = 200;   // 2%
    address public feeWallet = 0xE1f1dd010BBC2860F81c8F90Ea4E38dB949BB16F;

    // swap router and path, slipPage
    address public uniRouterAddress;
    address[] public wNativeToTokenPath;
    uint256 public slippageFactor = 800;    // 20%
    uint256 public constant slippageFactorUL = 995;

    event TokenBuyBack(uint256 amountETH, uint256 amountToken);
    event LiquidityAdded(uint256 amountETH, uint256 amountToken, uint256 liquidity);
    event SetSwapConfig(address router, uint256 slipPage, address[] path);
    event TransferBuyBackWallet(address staking, address wallet);
    event LiquidityWithdrawn(uint256 amount);
    event Withdrawn(uint256 amount);

    event AddLiquidityRateUpdated(uint256 percent);
    event BuybackRateUpdated(uint256 percent);
    event PeriodUpdated(uint256 duration);
    event LiquidityWithdrawLimitUpdated(uint256 percent);
    event WithdrawLimitUpdated(uint256 percent);
    event ServiceInfoUpdated(address wallet, uint256 performanceFee, uint256 liquidityFee);

    constructor() {}
   
    /**
     * @notice Initialize the contract
     * @param _token: token address
     * @param _dividendToken: reflection token address
     * @param _uniRouter: uniswap router address for swap tokens
     * @param _wNativeToTokenPath: swap path to buy token
     */
    function initialize(
        IERC20 _token,
        address _dividendToken,
        address _uniRouter,
        address[] memory _wNativeToTokenPath
    ) external onlyOwner {
        require(!isInitialized, "Already initialized");

        // Make this contract initialized
        isInitialized = true;

        token = _token;
        dividendToken = _dividendToken;
        pair = IUniV2Factory(IUniRouter02(_uniRouter).factory()).getPair(_wNativeToTokenPath[0], address(token));

        uniRouterAddress = _uniRouter;
        wNativeToTokenPath = _wNativeToTokenPath;
    }

    /**
     * @notice Buy token from BNB
     */
    function buyBack() external onlyOwner nonReentrant{
        uint256 ethAmt = address(this).balance;
        uint256 _fee = ethAmt.mul(performanceFee).div(10000);
        if(_fee > 0) {
            payable(feeWallet).transfer(_fee);
            ethAmt = ethAmt.sub(_fee);
        }

        ethAmt = ethAmt.mul(buybackRate).div(10000);
        if(ethAmt > 0) {
            uint256[] memory amounts = _safeSwapEth(ethAmt, wNativeToTokenPath, address(this));
            emit TokenBuyBack(amounts[0], amounts[amounts.length - 1]);
        }
    }

    /**
     * @notice Add liquidity
     */
    function addLiquidity() external onlyOwner nonReentrant{
        uint256 ethAmt = address(this).balance;
        uint256 _fee = ethAmt.mul(performanceLpFee).div(10000);
        if(_fee > 0) {
            payable(feeWallet).transfer(_fee);
            ethAmt = ethAmt.sub(_fee);
        }

        ethAmt = ethAmt.mul(addLiquidityRate).div(10000).div(2);
        if(ethAmt > 0) {
            uint256[] memory amounts = _safeSwapEth(ethAmt, wNativeToTokenPath, address(this));
            uint256 _tokenAmt = amounts[amounts.length - 1];
            emit TokenBuyBack(amounts[0], _tokenAmt);
            
            (uint256 amountToken, uint256 amountETH, uint256 liquidity) = _addLiquidityEth(address(token), ethAmt, _tokenAmt, address(this));
            emit LiquidityAdded(amountETH, amountToken, liquidity);
        }
    }

    /**
     * @notice Withdraw brews as much as maximum 5% of total supply
     * @param _amount: amount to withdraw
     */
    function withdraw(uint256 _amount) external onlyOwner {
        uint256 tokenAmt = token.balanceOf(address(this));
        require(_amount > 0 && _amount <= tokenAmt, "Invalid Amount");

        if(block.timestamp.sub(startTime) > period.mul(TIME_UNIT)) {
            startTime = block.timestamp;
            sumWithdrawals = 0;
        }

        uint256 limit = withdrawalLimit.mul(token.totalSupply()).div(10000);
        require(sumWithdrawals.add(_amount) <= limit, "exceed maximum withdrawal limit for 30 days");

        token.safeTransfer(msg.sender, _amount);
        emit Withdrawn(_amount);
    }

    /**
     * @notice Withdraw brews as much as maximum 20% of lp supply
     * @param _amount: liquidity amount to withdraw
     */
    function withdrawLiquidity(uint256 _amount) external onlyOwner {
        uint256 tokenAmt = IERC20(pair).balanceOf(address(this));
        require(_amount > 0 && _amount <= tokenAmt, "Invalid Amount");

        if(block.timestamp.sub(startTime) > period.mul(TIME_UNIT)) {
            startTime = block.timestamp;
            sumLiquidityWithdrawals = 0;
        }

        uint256 limit = liquidityWithdrawalLimit.mul(IERC20(pair).totalSupply()).div(10000);
        require(sumLiquidityWithdrawals.add(_amount) <= limit, "exceed maximum LP withdrawal limit for 30 days");

        IERC20(pair).safeTransfer(msg.sender, _amount);
        emit LiquidityWithdrawn(_amount);
    }

    
    /**
     * @notice Withdraw tokens
     * @dev Needs to be for emergency.
     */
    function emergencyWithdraw() external onlyOwner {
        uint256 tokenAmt = token.balanceOf(address(this));
        if(tokenAmt > 0) {
            token.transfer(msg.sender, tokenAmt);
        }

        tokenAmt = IERC20(pair).balanceOf(address(this));
        if(tokenAmt > 0) {
            IERC20(pair).transfer(msg.sender, tokenAmt);
        }

        uint256 ethAmt = address(this).balance;
        if(ethAmt > 0) {
            payable(msg.sender).transfer(ethAmt);
        }
    }

    /**
     * @notice Harvest reflection for token
     */
    function harvest() external onlyOwner {
        if(dividendToken == address(0x0)) {
            uint256 ethAmt = address(dividendToken).balance;
            if(ethAmt > 0) {
                payable(msg.sender).transfer(ethAmt);
            }
        } else {
            uint256 tokenAmt = IERC20(dividendToken).balanceOf(address(this));
            if(tokenAmt > 0) {
                IERC20(dividendToken).transfer(msg.sender, tokenAmt);
            }
        }
    }

    /**
     * @notice Set duration for withdraw limit
     * @param _period: duration
     */
    function setWithdrawalLimitPeriod(uint256 _period) external onlyOwner {
        require(_period >= 10, "small period");
        period = _period;
        emit PeriodUpdated(_period);
    }

    /**
     * @notice Set liquidity withdraw limit
     * @param _percent: percentage of LP supply in point
     */
    function setLiquidityWithdrawalLimit(uint256 _percent) external onlyOwner {
        require(_percent < 10000, "Invalid percentage");
        
        liquidityWithdrawalLimit = _percent;
        emit LiquidityWithdrawLimitUpdated(_percent);
    }

    /**
     * @notice Set withdraw limit
     * @param _percent: percentage of total supply in point
     */
    function setWithdrawalLimit(uint256 _percent) external onlyOwner {
        require(_percent < 10000, "Invalid percentage");
        
        withdrawalLimit = _percent;
        emit WithdrawLimitUpdated(_percent);
    }
    
    /**
     * @notice Set buyback amount
     * @param _percent: percentage in point
     */
    function setBuybackRate(uint256 _percent) external onlyOwner {
        require(_percent < 10000, "Invalid percentage");

        buybackRate = _percent;
        emit BuybackRateUpdated(_percent);
    }

    /**
     * @notice Set addliquidy amount
     * @param _percent: percentage in point
     */
    function setAddLiquidityRate(uint256 _percent) external onlyOwner {
        require(_percent < 10000, "Invalid percentage");

        addLiquidityRate = _percent;
        emit AddLiquidityRateUpdated(_percent);
    }

    function setServiceInfo(address _wallet, uint256 _fee) external {
        require(msg.sender == feeWallet, "Invalid setter");
        require(_wallet != feeWallet && _wallet != address(0x0), "Invalid new wallet");
        require(_fee < 500, "invalid performance fee");
       
        feeWallet = _wallet;
        performanceFee = _fee;
        performanceLpFee = _fee.mul(2);

        emit ServiceInfoUpdated(_wallet, performanceFee, performanceLpFee);
    }
    
    /**
     * @notice Set buyback wallet of farm contract
     * @param _uniRouter: dex router address
     * @param _slipPage: slip page for swap
     * @param _path: bnb-brews path
     */
    function setSwapSettings(address _uniRouter, uint256 _slipPage, address[] memory _path) external onlyOwner {
        require(_slipPage < 1000, "Invalid percentage");

        uniRouterAddress = _uniRouter;
        slippageFactor = _slipPage;
        wNativeToTokenPath = _path;

        emit SetSwapConfig(_uniRouter, _slipPage, _path);
    }

    /**
     * @notice set buyback wallet of farm contract
     * @param _farm: farm contract address
     * @param _addr: buyback wallet address
     */
    function setFarmServiceInfo(address _farm, address _addr) external onlyOwner {
        require(_farm != address(0x0) && _addr != address(0x0), "Invalid Address");
        IFarm(_farm).setBuyBackWallet(_addr);

        emit TransferBuyBackWallet(_farm, _addr);
    }

    /**
     * @notice set buyback wallet of staking contract 
     * @param _staking: staking contract address
     * @param _addr: buyback wallet address
     */
    function setStakingServiceInfo(address _staking, address _addr) external onlyOwner {
        require(_staking != address(0x0) && _addr != address(0x0), "Invalid Address");
        uint256 _fee = IStaking(_staking).performanceFee();
        IStaking(_staking).setServiceInfo(_addr, _fee);

        emit TransferBuyBackWallet(_staking, _addr);
    }

    /**
     * @notice It allows the admin to recover wrong tokens sent to the contract
     * @param _token: the address of the token to withdraw
     * @dev This function is only callable by admin.
     */
    function recoverWrongTokens(address _token) external onlyOwner {
        require(_token != address(token) && _token != dividendToken && _token != pair, "Cannot be token & dividend token, pair");

        if(_token == address(0x0)) {
            uint256 _tokenAmount = address(this).balance;
            payable(msg.sender).transfer(_tokenAmount);
        } else {
            uint256 _tokenAmount = IERC20(_token).balanceOf(address(this));
            IERC20(_token).safeTransfer(msg.sender, _tokenAmount);
        }
    }


    /************************
    ** Internal Methods
    *************************/
    /*
     * @notice  get token from ETH via swap.
     */
    function _safeSwapEth(
        uint256 _amountIn,
        address[] memory _path,
        address _to
    ) internal returns (uint256[] memory amounts) {
        amounts = IUniRouter02(uniRouterAddress).getAmountsOut(_amountIn, _path);
        uint256 amountOut = amounts[amounts.length.sub(1)];

        IUniRouter02(uniRouterAddress).swapExactETHForTokensSupportingFeeOnTransferTokens{value: _amountIn}(
            amountOut.mul(slippageFactor).div(1000),
            _path,
            _to,
            block.timestamp.add(600)
        );
    }

    /*
     * @notice Add liquidity for token-BNB pair.
     */
    function _addLiquidityEth(
        address _token,
        uint256 _ethAmt,
        uint256 _tokenAmt,
        address _to
    ) internal returns(uint256 amountToken, uint256 amountETH, uint256 liquidity) {
        IERC20(_token).safeIncreaseAllowance(uniRouterAddress, _tokenAmt);

        (amountToken, amountETH, liquidity) = IUniRouter02(uniRouterAddress).addLiquidityETH{value: _ethAmt}(
            address(_token),
            _tokenAmt,
            0,
            0,
            _to,
            block.timestamp.add(600)
        );

        IERC20(_token).safeApprove(uniRouterAddress, uint256(0));
    }

    receive() external payable {}
}
// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/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.
 */
abstract 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() {
        _transferOwnership(_msgSender());
    }

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

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @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].
 */
abstract 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() {
        _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 making 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;
    }
}

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



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: contracts/libs/IUniFactory.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IUniV2Factory {
    function getPair(address tokenA, address tokenB)
        external
        view
        returns (address);
}
// File: contracts/libs/IUniRouter02.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IUniRouter01.sol";

interface IUniRouter02 is IUniRouter01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountETH);

    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}
// File: contracts/libs/IWETH.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}
// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// 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 Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

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



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: contracts/libs/IUniRouter01.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

interface IUniRouter01 {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    )
        external
        returns (
            uint256 amountA,
            uint256 amountB,
            uint256 liquidity
        );

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );

    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETH(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountToken, uint256 amountETH);

    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETHWithPermit(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountToken, uint256 amountETH);

    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);

    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);

    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);

    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);
}