// File: contracts/accessless/OlympusChainlinkBasedSwapper.sol



pragma solidity ^0.8.7;

import "@chainlink/contracts/src/v0.8/interfaces/FeedRegistryInterface.sol";
import "@chainlink/contracts/src/v0.8/Denominations.sol";
import "@uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
import "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

struct V3Params {
    uint24[] fees;
    address[] path;
    address denomination;
    address recipient;
    uint256 deadline;
    uint256 amount;
    uint256 slippage;
}

struct V2Params {
    address router;
    address[] path;
    address denomination;
    address recipient;
    uint256 deadline;
    uint256 amount;
    uint256 slippage;
}

error OlympusChainlinkBasedSwapper_WrongV3PathLength();
error OlympusChainlinkBasedSwapper_ApproveFailed();
error OlympusChainlinkBasedSwapper_TransferFromFailed();
error OlympusChainlinkBasedSwapper_TransferFailed();

contract OlympusChainlinkBasedSwapper {
    FeedRegistryInterface public registry;
    ISwapRouter public v3SwapRouter;

    constructor(address _registry, address _v3SwapRouter) {
        registry = FeedRegistryInterface(_registry);
        v3SwapRouter = ISwapRouter(_v3SwapRouter);
    }

    function v3ExactInput(V3Params calldata params) external returns (uint256 amountOut) {
        amountOut = _exact(params, true);
    }

    function v3ExactOutput(V3Params calldata params) external returns (uint256 amountIn) {
        amountIn = _exact(params, false);
    }

    function v2Swap(V2Params calldata params) external {
        // reads
        address inputToken = params.path[0];
        address outputToken = params.path[params.path.length - 1];
        IUniswapV2Router02 router = IUniswapV2Router02(params.router);
        address denomination = (params.denomination == address(0)) ? Denominations.USD : params.denomination;

        // interactions + checks
        // didn't abstract to keep readable

        bool check = IERC20(inputToken).transferFrom(msg.sender, address(this), params.amount);

        if (!check) revert OlympusChainlinkBasedSwapper_TransferFromFailed();

        check = IERC20(inputToken).approve(params.router, params.amount);

        if (!check) revert OlympusChainlinkBasedSwapper_ApproveFailed();

        // big interaction
        router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
            params.amount,
            _calcAmountMin(inputToken, outputToken, denomination, params.slippage, params.amount),
            params.path,
            params.recipient,
            (params.deadline == 0) ? block.timestamp : params.deadline
        );

        // cleanup
        _clean(inputToken);
    }

    function _exact(V3Params calldata params, bool isIn) internal returns (uint256 amount) {
        // reads + calcs
        address inputToken = params.path[0];
        address outputToken = params.path[params.path.length - 1];
        address denomination = (params.denomination == address(0)) ? Denominations.USD : params.denomination;

        // checks
        if (params.path.length - 1 != params.fees.length) revert OlympusChainlinkBasedSwapper_WrongV3PathLength();

        // interactions + checks

        bool check = IERC20(inputToken).transferFrom(msg.sender, address(this), params.amount);

        if (!check) revert OlympusChainlinkBasedSwapper_TransferFromFailed();

        check = IERC20(inputToken).approve(address(v3SwapRouter), params.amount);

        if (!check) revert OlympusChainlinkBasedSwapper_ApproveFailed();

        // big interaction
        if (isIn) {
            amount = v3SwapRouter.exactInput(
                ISwapRouter.ExactInputParams({
                    path: _encode(params.fees.length, params.path, params.fees),
                    recipient: params.recipient,
                    deadline: (params.deadline == 0) ? block.timestamp : params.deadline,
                    amountIn: params.amount,
                    amountOutMinimum: _calcAmountMin(
                        inputToken,
                        outputToken,
                        denomination,
                        params.slippage,
                        params.amount
                    )
                })
            );
        } else {
            amount = v3SwapRouter.exactOutput(
                ISwapRouter.ExactOutputParams({
                    path: _encode(params.fees.length, params.path, params.fees),
                    recipient: params.recipient,
                    deadline: (params.deadline == 0) ? block.timestamp : params.deadline,
                    amountOut: _calcAmountMin(inputToken, outputToken, denomination, params.slippage, params.amount),
                    amountInMaximum: params.amount
                })
            );
        }

        // cleanup
        _clean(inputToken);
    }

    // @notice
    function _clean(address inputToken) internal {
        bool check = IERC20(inputToken).transfer(msg.sender, IERC20(inputToken).balanceOf(address(this)));
        if (!check) revert OlympusChainlinkBasedSwapper_TransferFailed();
    }

    function _calcAmountMin(
        address inputToken,
        address outputToken,
        address denom,
        uint256 slippage,
        uint256 amount
    ) internal view returns (uint256 amountMin) {
        uint256 inPrice = uint256(_latestPrice(inputToken, denom));
        uint256 outPrice = uint256(_latestPrice(outputToken, denom));

        // slippage must be normalized to 1e18
        amountMin = (amount * inPrice * slippage) / (1e18 * outPrice);
        amountMin = (amountMin * IERC20Metadata(outputToken).decimals()) / IERC20Metadata(inputToken).decimals();
    }

    function _latestPrice(address base, address quote) internal view returns (int256 price) {
        (, price, , , ) = registry.latestRoundData(base, quote);
    }

    function _encode(
        uint256 pairs,
        address[] memory tokens,
        uint24[] memory poolFees
    ) internal pure returns (bytes memory path) {
        if (pairs == 1) {
            path = abi.encodePacked(tokens[0], poolFees[0], tokens[1]);
        } else if (pairs == 2) {
            path = abi.encodePacked(tokens[0], poolFees[0], tokens[1], poolFees[1], tokens[2]);
        } else if (pairs == 3) {
            path = abi.encodePacked(tokens[0], poolFees[0], tokens[1], poolFees[1], tokens[2], poolFees[2], tokens[3]);
        } else if (pairs == 4) {
            path = abi.encodePacked(
                tokens[0],
                poolFees[0],
                tokens[1],
                poolFees[1],
                tokens[2],
                poolFees[2],
                tokens[3],
                poolFees[3],
                tokens[4]
            );
        } else if (pairs == 5) {
            path = abi.encodePacked(
                tokens[0],
                poolFees[0],
                tokens[1],
                poolFees[1],
                tokens[2],
                poolFees[2],
                tokens[3],
                poolFees[3],
                tokens[4],
                poolFees[4],
                tokens[5]
            );
        }
    }
}

// File: @chainlink/contracts/src/v0.8/interfaces/FeedRegistryInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
pragma abicoder v2;

import "./AggregatorV2V3Interface.sol";

interface FeedRegistryInterface {
  struct Phase {
    uint16 phaseId;
    uint80 startingAggregatorRoundId;
    uint80 endingAggregatorRoundId;
  }

  event FeedProposed(
    address indexed asset,
    address indexed denomination,
    address indexed proposedAggregator,
    address currentAggregator,
    address sender
  );
  event FeedConfirmed(
    address indexed asset,
    address indexed denomination,
    address indexed latestAggregator,
    address previousAggregator,
    uint16 nextPhaseId,
    address sender
  );

  // V3 AggregatorV3Interface

  function decimals(address base, address quote) external view returns (uint8);

  function description(address base, address quote) external view returns (string memory);

  function version(address base, address quote) external view returns (uint256);

  function latestRoundData(address base, address quote)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function getRoundData(
    address base,
    address quote,
    uint80 _roundId
  )
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  // V2 AggregatorInterface

  function latestAnswer(address base, address quote) external view returns (int256 answer);

  function latestTimestamp(address base, address quote) external view returns (uint256 timestamp);

  function latestRound(address base, address quote) external view returns (uint256 roundId);

  function getAnswer(
    address base,
    address quote,
    uint256 roundId
  ) external view returns (int256 answer);

  function getTimestamp(
    address base,
    address quote,
    uint256 roundId
  ) external view returns (uint256 timestamp);

  // Registry getters

  function getFeed(address base, address quote) external view returns (AggregatorV2V3Interface aggregator);

  function getPhaseFeed(
    address base,
    address quote,
    uint16 phaseId
  ) external view returns (AggregatorV2V3Interface aggregator);

  function isFeedEnabled(address aggregator) external view returns (bool);

  function getPhase(
    address base,
    address quote,
    uint16 phaseId
  ) external view returns (Phase memory phase);

  // Round helpers

  function getRoundFeed(
    address base,
    address quote,
    uint80 roundId
  ) external view returns (AggregatorV2V3Interface aggregator);

  function getPhaseRange(
    address base,
    address quote,
    uint16 phaseId
  ) external view returns (uint80 startingRoundId, uint80 endingRoundId);

  function getPreviousRoundId(
    address base,
    address quote,
    uint80 roundId
  ) external view returns (uint80 previousRoundId);

  function getNextRoundId(
    address base,
    address quote,
    uint80 roundId
  ) external view returns (uint80 nextRoundId);

  // Feed management

  function proposeFeed(
    address base,
    address quote,
    address aggregator
  ) external;

  function confirmFeed(
    address base,
    address quote,
    address aggregator
  ) external;

  // Proposed aggregator

  function getProposedFeed(address base, address quote)
    external
    view
    returns (AggregatorV2V3Interface proposedAggregator);

  function proposedGetRoundData(
    address base,
    address quote,
    uint80 roundId
  )
    external
    view
    returns (
      uint80 id,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function proposedLatestRoundData(address base, address quote)
    external
    view
    returns (
      uint80 id,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  // Phases
  function getCurrentPhaseId(address base, address quote) external view returns (uint16 currentPhaseId);
}

// File: @chainlink/contracts/src/v0.8/Denominations.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library Denominations {
  address public constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
  address public constant BTC = 0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB;

  // Fiat currencies follow https://en.wikipedia.org/wiki/ISO_4217
  address public constant USD = address(840);
  address public constant GBP = address(826);
  address public constant EUR = address(978);
  address public constant JPY = address(392);
  address public constant KRW = address(410);
  address public constant CNY = address(156);
  address public constant AUD = address(36);
  address public constant CAD = address(124);
  address public constant CHF = address(756);
  address public constant ARS = address(32);
  address public constant PHP = address(608);
  address public constant NZD = address(554);
  address public constant SGD = address(702);
  address public constant NGN = address(566);
  address public constant ZAR = address(710);
  address public constant RUB = address(643);
  address public constant INR = address(356);
  address public constant BRL = address(986);
}

// File: @uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;

import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol';

/// @title Router token swapping functionality
/// @notice Functions for swapping tokens via Uniswap V3
interface ISwapRouter is IUniswapV3SwapCallback {
    struct ExactInputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);

    struct ExactInputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);

    struct ExactOutputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);

    struct ExactOutputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol



pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

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

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

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



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

pragma solidity ^0.8.0;

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

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

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

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

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

    function _isConstructor() private view returns (bool) {
        return !Address.isContract(address(this));
    }
}

// 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/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV2V3Interface.sol



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

import "./AggregatorInterface.sol";
import "./AggregatorV3Interface.sol";

interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface {}

// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorInterface.sol



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

interface AggregatorInterface {
  function latestAnswer() external view returns (int256);

  function latestTimestamp() external view returns (uint256);

  function latestRound() external view returns (uint256);

  function getAnswer(uint256 roundId) external view returns (int256);

  function getTimestamp(uint256 roundId) external view returns (uint256);

  event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);

  event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
}

// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol



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

interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

  // getRoundData and latestRoundData should both raise "No data present"
  // if they do not have data to report, instead of returning unset values
  // which could be misinterpreted as actual reported values.
  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
}

// File: @uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;

/// @title Callback for IUniswapV3PoolActions#swap
/// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
interface IUniswapV3SwapCallback {
    /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
    /// @dev In the implementation you must pay the pool tokens owed for the swap.
    /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
    /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
    /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
    /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
    /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
    function uniswapV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata data
    ) external;
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router01.sol



pragma solidity >=0.6.2;

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

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

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

// 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);
            }
        }
    }
}