// File: contracts/BrewlabsTreasury.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @author Brewlabs
 * This treasury contract has been developed by brewlabs.info
 */
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

import "./libs/IUniFactory.sol";
import "./libs/IUniRouter02.sol";

interface IStaking {
  function performanceFee() external view returns (uint256);

  function setServiceInfo(address _addr, uint256 _fee) external;
}

interface IFarm {
  function setBuyBackWallet(address _addr) external;
}

contract BrewlabsTreasury is Ownable {
  using SafeERC20 for IERC20;

  bool private isInitialized;
  uint256 private constant TIME_UNIT = 1 days;
  uint256 private constant PERCENT_PRECISION = 10000;

  IERC20 public token;
  address public dividendToken;
  address public pair;
  address private constant USDC = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;

  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;

  address public uniRouterAddress;
  address[] public ethToTokenPath;
  address[] public ethToDividendPath;
  address[] public dividendToTokenPath;
  uint256 public slippageFactor = 8300; // 17%
  uint256 public constant slippageFactorUL = 9950;

  event Initialized(
    address token,
    address dividendToken,
    address router,
    address[] ethToTokenPath,
    address[] ethToDividendPath,
    address[] dividendToTokenPath
  );

  event TokenBuyBack(uint256 amountETH, uint256 amountToken);
  event TokenBuyBackFromDividend(uint256 amount, uint256 amountToken);
  event LiquidityAdded(
    uint256 amountETH,
    uint256 amountToken,
    uint256 liquidity
  );
  event LiquidityWithdrawn(uint256 amount);
  event Withdrawn(uint256 amount);
  event Harvested(address account, uint256 amount);
  event Swapped(address token, uint256 amountETH, uint256 amountToken);

  event EthHarvested(address to, uint256 amount);
  event EmergencyWithdrawn();
  event AdminTokenRecovered(address tokenRecovered, uint256 amount);
  event UsdcHarvested(address to, uint256[] amounts);

  event SetSwapConfig(
    address router,
    uint256 slipPage,
    address[] ethToTokenPath,
    address[] ethToDividendPath,
    address[] dividendToTokenPath
  );
  event TransferBuyBackWallet(address staking, address wallet);
  event AddLiquidityRateUpdated(uint256 percent);
  event BuybackRateUpdated(uint256 percent);
  event PeriodUpdated(uint256 duration);
  event LiquidityWithdrawLimitUpdated(uint256 percent);
  event WithdrawLimitUpdated(uint256 percent);

  constructor() {}

  /**
   * @notice Initialize the contract
   * @param _token: token address
   * @param _dividendToken: reflection token address
   * @param _uniRouter: uniswap router address for swap tokens
   * @param _ethToTokenPath: swap path to buy Token
   * @param _ethToDividendPath: swap path to buy dividend token
   * @param _dividendToTokenPath: swap path to buy Token with dividend token
   */
  function initialize(
    IERC20 _token,
    address _dividendToken,
    address _uniRouter,
    address[] memory _ethToTokenPath,
    address[] memory _ethToDividendPath,
    address[] memory _dividendToTokenPath
  ) external onlyOwner {
    require(!isInitialized, "Already initialized");
    require(_uniRouter != address(0x0), "invalid address");
    require(address(_token) != address(0x0), "invalid token address");

    // Make this contract initialized
    isInitialized = true;

    token = _token;
    dividendToken = _dividendToken;
    pair = IUniV2Factory(IUniRouter02(_uniRouter).factory()).getPair(
      _ethToTokenPath[0],
      address(token)
    );

    uniRouterAddress = _uniRouter;
    ethToTokenPath = _ethToTokenPath;
    ethToDividendPath = _ethToDividendPath;
    dividendToTokenPath = _dividendToTokenPath;

    emit Initialized(
      address(_token),
      _dividendToken,
      _uniRouter,
      _ethToTokenPath,
      _ethToDividendPath,
      _dividendToTokenPath
    );
  }

  /**
   * @notice Buy token from ETH
   */
  function buyBack() external onlyOwner {
    uint256 ethAmt = address(this).balance;
    ethAmt = (ethAmt * buybackRate) / PERCENT_PRECISION;

    if (ethAmt > 0) {
      uint256 _tokenAmt = _safeSwapEth(ethAmt, ethToTokenPath, address(this));
      emit TokenBuyBack(ethAmt, _tokenAmt);
    }
  }

  /**
   * @notice Buy token from reflections
   */
  function buyBackFromDividend() external onlyOwner {
    if (dividendToken == address(0x0) || dividendToken == address(token)) return;

    uint256 reflections = IERC20(dividendToken).balanceOf(address(this));
    if (reflections > 0) {
      uint256 _tokenAmt = _safeSwap(
        reflections,
        dividendToTokenPath,
        address(this)
      );
      emit TokenBuyBackFromDividend(reflections, _tokenAmt);
    }
  }

  /**
   * @notice Add liquidity
   */
  function addLiquidity() external onlyOwner {
    uint256 ethAmt = address(this).balance;
    ethAmt = (ethAmt * addLiquidityRate) / PERCENT_PRECISION / 2;

    if (ethAmt > 0) {
      uint256 _tokenAmt = _safeSwapEth(ethAmt, ethToTokenPath, address(this));
      emit TokenBuyBack(ethAmt, _tokenAmt);

      (
        uint256 amountToken,
        uint256 amountETH,
        uint256 liquidity
      ) = _addLiquidityEth(address(token), ethAmt, _tokenAmt, address(this));
      emit LiquidityAdded(amountETH, amountToken, liquidity);
    }
  }

  /**
   * @notice Swap and harvest reflection for token
   * @param _to: receiver address
   */
  function harvest(address _to) external onlyOwner {
    uint256 ethAmt = address(this).balance;
    ethAmt = (ethAmt * buybackRate) / PERCENT_PRECISION;

    if (dividendToken == address(0x0)) {
      if (ethAmt > 0) {
        payable(_to).transfer(ethAmt);
        emit Harvested(_to, ethAmt);
      }
    } else {
      if (ethAmt > 0) {
        uint256 _tokenAmt = _safeSwapEth(
          ethAmt,
          ethToDividendPath,
          address(this)
        );
        emit Swapped(dividendToken, ethAmt, _tokenAmt);
      }

      uint256 tokenAmt = IERC20(dividendToken).balanceOf(address(this));
      if (tokenAmt > 0) {
        IERC20(dividendToken).transfer(_to, tokenAmt);
        emit Harvested(_to, tokenAmt);
      }
    }
  }

  function harvestETH(address _to) external onlyOwner {
    require(_to != address(0x0), "invalid address");
    uint256 ethAmt = address(this).balance;
    payable(_to).transfer(ethAmt);
    emit EthHarvested(_to, ethAmt);
  }

  function harvestUSDC(address _to) external onlyOwner {
    require(_to != address(0x0), "invalid address");
    uint256 ethAmt = address(this).balance;
    ethAmt = (ethAmt * buybackRate) / PERCENT_PRECISION;

    if (ethAmt == 0) return;

    address[] memory path = new address[](2);
    path[0] = IUniRouter02(uniRouterAddress).WETH();
    path[1] = USDC;

    uint256[] memory amounts = IUniRouter02(uniRouterAddress)
      .swapExactETHForTokens{ value: ethAmt }(
      0,
      path,
      _to,
      block.timestamp + 600
    );
    emit UsdcHarvested(_to, amounts);
  }

  /**
   * @notice Withdraw token 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 - startTime > period * TIME_UNIT) {
      startTime = block.timestamp;
      sumWithdrawals = 0;
    }

    uint256 limit = (withdrawalLimit * (token.totalSupply())) /
      PERCENT_PRECISION;
    require(
      sumWithdrawals + _amount <= limit,
      "exceed maximum withdrawal limit for 30 days"
    );

    token.safeTransfer(msg.sender, _amount);
    emit Withdrawn(_amount);
  }

  /**
   * @notice Withdraw liquidity
   * @param _amount: 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 - startTime > period * TIME_UNIT) {
      startTime = block.timestamp;
      sumLiquidityWithdrawals = 0;
    }

    uint256 limit = (liquidityWithdrawalLimit * (IERC20(pair).totalSupply())) /
      PERCENT_PRECISION;
    require(
      sumLiquidityWithdrawals + _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);
    }
    emit EmergencyWithdrawn();
  }

  /**
   * @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 < PERCENT_PRECISION, "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 < PERCENT_PRECISION, "Invalid percentage");

    withdrawalLimit = _percent;
    emit WithdrawLimitUpdated(_percent);
  }

  /**
   * @notice Set buyback rate
   * @param _percent: percentage in point
   */
  function setBuybackRate(uint256 _percent) external onlyOwner {
    require(_percent < PERCENT_PRECISION, "Invalid percentage");

    buybackRate = _percent;
    emit BuybackRateUpdated(_percent);
  }

  /**
   * @notice Set addliquidy rate
   * @param _percent: percentage in point
   */
  function setAddLiquidityRate(uint256 _percent) external onlyOwner {
    require(_percent < PERCENT_PRECISION, "Invalid percentage");

    addLiquidityRate = _percent;
    emit AddLiquidityRateUpdated(_percent);
  }

  /**
   * @notice Set buyback wallet of farm contract
   * @param _uniRouter: dex router address
   * @param _slipPage: slip page for swap
   * @param _ethToTokenPath: eth-token swap path
   * @param _ethToDividendPath: eth-token swap path
   * @param _dividendToTokenPath: eth-token swap path
   */
  function setSwapSettings(
    address _uniRouter,
    uint256 _slipPage,
    address[] memory _ethToTokenPath,
    address[] memory _ethToDividendPath,
    address[] memory _dividendToTokenPath
  ) external onlyOwner {
    require(_uniRouter != address(0x0), "invalid address");
    require(_slipPage <= slippageFactorUL, "_slippage too high");

    uniRouterAddress = _uniRouter;
    slippageFactor = _slipPage;
    ethToTokenPath = _ethToTokenPath;
    ethToDividendPath = _ethToDividendPath;
    dividendToTokenPath = _dividendToTokenPath;

    emit SetSwapConfig(
      _uniRouter,
      _slipPage,
      _ethToTokenPath,
      _ethToDividendPath,
      _dividendToTokenPath
    );
  }

  /**
   * @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 rescueTokens(address _token) external onlyOwner {
    require(
      _token != address(token) && _token != dividendToken && _token != pair,
      "Cannot be token & dividend token, pair"
    );

    uint256 _tokenAmount;
    if (_token == address(0x0)) {
      _tokenAmount = address(this).balance;
      payable(msg.sender).transfer(_tokenAmount);
    } else {
      _tokenAmount = IERC20(_token).balanceOf(address(this));
      IERC20(_token).safeTransfer(msg.sender, _tokenAmount);
    }
    emit AdminTokenRecovered(_token, _tokenAmount);
  }

  /************************
   ** Internal Methods
   *************************/

  /**
   * @notice get token from ETH via swap.
   * @param _amountIn: eth amount to swap
   * @param _path: swap path
   * @param _to: receiver address
   */
  function _safeSwapEth(
    uint256 _amountIn,
    address[] memory _path,
    address _to
  ) internal returns (uint256) {
    uint256[] memory amounts = IUniRouter02(uniRouterAddress).getAmountsOut(
      _amountIn,
      _path
    );
    uint256 amountOut = amounts[amounts.length - 1];

    address _token = _path[_path.length - 1];
    uint256 beforeAmt = IERC20(_token).balanceOf(address(this));
    IUniRouter02(uniRouterAddress)
      .swapExactETHForTokensSupportingFeeOnTransferTokens{ value: _amountIn }(
      (amountOut * slippageFactor) / PERCENT_PRECISION,
      _path,
      _to,
      block.timestamp + 600
    );
    uint256 afterAmt = IERC20(_token).balanceOf(address(this));

    return afterAmt - beforeAmt;
  }

  /**
   * @notice swap token based on path.
   * @param _amountIn: token amount to swap
   * @param _path: swap path
   * @param _to: receiver address
   */
  function _safeSwap(
    uint256 _amountIn,
    address[] memory _path,
    address _to
  ) internal returns (uint256) {
    uint256[] memory amounts = IUniRouter02(uniRouterAddress).getAmountsOut(
      _amountIn,
      _path
    );
    uint256 amountOut = amounts[amounts.length - 1];

    IERC20(_path[0]).safeApprove(uniRouterAddress, _amountIn);

    address _token = _path[_path.length - 1];
    uint256 beforeAmt = IERC20(_token).balanceOf(address(this));
    IUniRouter02(uniRouterAddress)
      .swapExactTokensForTokensSupportingFeeOnTransferTokens(
        _amountIn,
        (amountOut * slippageFactor) / PERCENT_PRECISION,
        _path,
        _to,
        block.timestamp + 600
      );
    uint256 afterAmt = IERC20(_token).balanceOf(address(this));

    return afterAmt - beforeAmt;
  }

  /**
   * @notice add token-ETH liquidity.
   * @param _token: token address
   * @param _ethAmt: eth amount to add liquidity
   * @param _tokenAmt: token amount to add liquidity
   * @param _to: receiver address
   */
  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 + 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/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: @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);
}