// File: contracts/Mortgage.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.4;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";

import "./interfaces/IFind.sol";
import "./interfaces/IFactory.sol";
import "./interfaces/IMath.sol";
import "./interfaces/IMortgageRender.sol";
import "./interfaces/external/IUniswapV3Pool.sol";
import "./interfaces/external/INonfungiblePositionManager.sol";
import "./interfaces/external/IWETH9.sol";
import "./interfaces/external/ISwapRouter02.sol";

import "./libraries/TransferHelper.sol";
import "./libraries/UniswapConstants.sol";
import "./libraries/SwapRouterHelper.sol";
import "./libraries/BytesLib.sol";

contract Mortgage is ERC721Enumerable, Ownable {
  using BytesLib for bytes;
  struct Position {
    uint256 tokenId;
    address ospAsset;
    uint256 ospAmount;
  }
  struct MultiplyEventParams {
    address sender;
    uint256 tokenId;
    address ospAsset;
    uint256 ospAmount;
    uint256 AllFindAmount;
    uint256 payFindAmount;
    uint256 feeFindAmount;
    uint256 amountNeedPay;
    address tokenPay;
  }

  // fee is 0.5%
  uint24 public constant MORTGAGE_FEE_DENOMINATOR = 1000000;
  uint24 public constant MORTGAGE_FEE_DEFAULT = 5000;

  uint24 public mortgageFee;
  address public immutable find;
  address public immutable factory;
  address public immutable earn;
  address public immutable math;

  address public mortgageRender;

  // tokenId -> Position
  mapping(uint256 => Position) public positions;

  uint256 private _nextId = 1;

  event SetMortgageFee(uint24 newMortgageFee);
  event SetMortgageRender(address newMortgageRender);
  event MortgageEvent(
    address sender,
    uint256 tokenId,
    address ospAsset,
    uint256 inOspAmount,
    uint256 outFindAmount,
    uint256 feeFindAmount,
    uint256 amountOut,
    address tokenOut
  );
  event Multiply(MultiplyEventParams params);

  event Redeem(
    address sender,
    uint256 tokenId,
    address ospAsset,
    uint256 outOspAmount,
    uint256 inFindAmount,
    uint256 amountIn,
    address tokenIn
  );
  event Cash(
    address sender,
    uint256 tokenId,
    address ospAsset,
    uint256 outOspPositionAmount,
    uint256 outFindAmount,
    uint256 amountOut,
    address tokenOut
  );
  event Split(
    address sender,
    uint256 tokenId,
    uint256 newTokenId,
    address ospAsset,
    uint256 newOspAmount,
    uint256 inFindAmount,
    uint256 amountIn,
    address tokenIn
  );
  event Merge(
    address sender,
    uint256 tokenId,
    uint256 otherTokenId,
    address ospAsset,
    uint256 outFindAmount,
    uint256 feeFindAmount,
    uint256 amountOut,
    address tokenOut
  );

  constructor(
    address _find,
    address _factory,
    address _earn,
    address _math,
    address _mortgageRender
  ) ERC721("HBG Position", "POSITION") {
    mortgageFee = MORTGAGE_FEE_DEFAULT;

    find = _find;
    factory = _factory;
    earn = _earn;
    math = _math;
    mortgageRender = _mortgageRender;
  }

  function setMortgageFee(uint24 newMortgageFee) external onlyOwner {
    require(newMortgageFee <= MORTGAGE_FEE_DEFAULT, "TB");
    mortgageFee = newMortgageFee;
    emit SetMortgageFee(newMortgageFee);
  }

  function setMortgageRender(address newMortgageRender) external onlyOwner {
    mortgageRender = newMortgageRender;
    emit SetMortgageRender(newMortgageRender);
  }

  function positionsOfOwner(address owner)
    public
    view
    returns (Position[] memory _positions)
  {
    uint256 count = balanceOf(owner);
    _positions = new Position[](count);
    for (uint256 index = 0; index < count; index++) {
      uint256 tokenId = tokenOfOwnerByIndex(owner, index);
      _positions[index] = positions[tokenId];
    }
  }

  function positionsOfOwnerByOsp(address owner, address ospAsset)
    external
    view
    returns (Position[] memory _positions)
  {
    uint256 count = 0;
    Position[] memory _positionsOfOwner = positionsOfOwner(owner);
    for (uint256 index = 0; index < _positionsOfOwner.length; index++) {
      if (_positionsOfOwner[index].ospAsset == ospAsset) {
        count += 1;
      }
    }
    _positions = new Position[](count);
    uint256 currentIndex = 0;
    for (uint256 index = 0; index < _positionsOfOwner.length; index++) {
      if (_positionsOfOwner[index].ospAsset == ospAsset) {
        _positions[currentIndex] = _positionsOfOwner[index];
        currentIndex += 1;
      }
    }
  }

  function tokenURI(uint256 tokenId)
    public
    view
    override
    returns (string memory output)
  {
    output = IMortgageRender(mortgageRender).tokenURI(tokenId);
  }

  // create a new position
  function mortgage(
    address ospAsset,
    uint256 inOspAmount,
    bytes memory findToOtherInPath
  )
    external
    returns (
      uint256 outFindAmount,
      uint256 amountOut,
      address tokenOut,
      uint256 tokenId
    )
  {
    tokenId = _mintEmpty(ospAsset);
    (outFindAmount, amountOut, tokenOut) = _mortgageAdd(
      tokenId,
      inOspAmount,
      findToOtherInPath
    );
  }

  // update a position
  function mortgageAdd(
    uint256 tokenId,
    uint256 inOspAmount,
    bytes memory findToOtherInPath
  )
    external
    returns (
      uint256 outFindAmount,
      uint256 amountOut,
      address tokenOut
    )
  {
    (outFindAmount, amountOut, tokenOut) = _mortgageAdd(
      tokenId,
      inOspAmount,
      findToOtherInPath
    );
  }

  function multiply(
    address ospAsset,
    uint256 AllFindAmount,
    uint256 amountPayMax,
    bytes memory otherToFindOutPath
  )
    external
    payable
    returns (
      uint256 positionOspAmountDelta,
      uint256 payFindAmount,
      uint256 amountNeedPay,
      address tokenPay,
      uint256 tokenId
    )
  {
    tokenId = _mintEmpty(ospAsset);
    (
      positionOspAmountDelta,
      payFindAmount,
      amountNeedPay,
      tokenPay
    ) = _multiplyAdd(tokenId, AllFindAmount, amountPayMax, otherToFindOutPath);
  }

  function multiplyAdd(
    uint256 tokenId,
    uint256 AllFindAmount,
    uint256 amountPayMax,
    bytes memory otherToFindOutPath
  )
    external
    payable
    returns (
      uint256 positionOspAmountDelta,
      uint256 payFindAmount,
      uint256 amountNeedPay,
      address tokenPay
    )
  {
    (
      positionOspAmountDelta,
      payFindAmount,
      amountNeedPay,
      tokenPay
    ) = _multiplyAdd(tokenId, AllFindAmount, amountPayMax, otherToFindOutPath);
  }

  function redeem(
    uint256 tokenId,
    uint256 outOspAmount,
    uint256 amountInMax,
    bytes memory otherToFindOutPath
  )
    external
    payable
    returns (
      uint256 inFindAmount,
      uint256 amountIn,
      address tokenIn
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );
    address ospAsset = positions[tokenId].ospAsset;

    inFindAmount = _mathAndRemovePosition(tokenId, outOspAmount);

    (amountIn, tokenIn) = _transferFindOrPathTokenFromUser(
      otherToFindOutPath,
      inFindAmount,
      amountInMax,
      _msgSender()
    );
    IFind(find).burn(inFindAmount);
    TransferHelper.safeTransfer(ospAsset, _msgSender(), outOspAmount);

    emit Redeem(
      _msgSender(),
      tokenId,
      ospAsset,
      outOspAmount,
      inFindAmount,
      amountIn,
      tokenIn
    );
  }

  function cash(
    uint256 tokenId,
    uint256 outOspPositionAmount,
    bytes memory findToOtherInPath
  )
    external
    returns (
      uint256 outFindAmount,
      uint256 amountOut,
      address tokenOut
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );

    address ospAsset = positions[tokenId].ospAsset;

    uint256 needFindAmount = _mathAndRemovePosition(
      tokenId,
      outOspPositionAmount
    );

    if (
      IERC20(ospAsset).allowance(
        address(this),
        UniswapConstants.UNISWAP_ROUTER
      ) < outOspPositionAmount
    ) {
      IERC20(ospAsset).approve(
        UniswapConstants.UNISWAP_ROUTER,
        type(uint256).max
      );
    }

    (uint256 poolConfigIndex, , , , , ) = IFactory(factory).token2OspInfo(
      ospAsset
    );
    (uint24 fee, , , , ) = IFactory(factory).getOspPoolConfigs(poolConfigIndex);

    uint256 swapFindAmount = SwapRouterHelper.exactInputSingle(
      ISwapRouter02.ExactInputSingleParams({
        tokenIn: ospAsset,
        tokenOut: find,
        fee: fee,
        recipient: address(this),
        amountIn: outOspPositionAmount,
        amountOutMinimum: 0,
        sqrtPriceLimitX96: 0
      })
    );

    require(swapFindAmount >= needFindAmount, "FE");
    outFindAmount = swapFindAmount - needFindAmount;

    IFind(find).burn(needFindAmount);
    if (outFindAmount > 0) {
      (amountOut, tokenOut) = _transferFindOrPathTokenToUser(
        findToOtherInPath,
        outFindAmount,
        _msgSender()
      );
    }
    emit Cash(
      _msgSender(),
      tokenId,
      ospAsset,
      outOspPositionAmount,
      outFindAmount,
      amountOut,
      tokenOut
    );
  }

  function split(
    uint256 tokenId,
    uint256 splitOspAmount,
    uint256 amountInMax,
    bytes memory otherToFindOutPath
  )
    external
    payable
    returns (
      uint256 needFind,
      uint256 amountIn,
      address tokenIn,
      uint256 newTokenId
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );
    require(splitOspAmount < positions[tokenId].ospAmount, "AE");

    address ospAsset = positions[tokenId].ospAsset;
    {
      uint256 inFindAmount = _mathAndRemovePosition(tokenId, splitOspAmount);
      newTokenId = _mintEmpty(ospAsset);

      (
        uint256 outFindAmountSplit,
        uint256 feeFindAmountSplit
      ) = _mathAndAddPosition(newTokenId, splitOspAmount);
      uint256 baseFind = outFindAmountSplit + feeFindAmountSplit;
      needFind = inFindAmount - baseFind;
    }

    (amountIn, tokenIn) = _transferFindOrPathTokenFromUser(
      otherToFindOutPath,
      needFind,
      amountInMax,
      _msgSender()
    );

    IFind(find).burn(needFind);

    emit Split(
      _msgSender(),
      tokenId,
      newTokenId,
      ospAsset,
      splitOspAmount,
      needFind,
      amountIn,
      tokenIn
    );
  }

  function merge(
    uint256 tokenId,
    uint256 otherTokenId,
    bytes memory findToOtherInPath
  )
    external
    returns (
      uint256 outFind,
      uint256 amountOut,
      address tokenOut
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );
    require(
      _isApprovedOrOwner(_msgSender(), otherTokenId),
      "ERC721: caller is not token owner nor approved"
    );
    require(
      positions[tokenId].ospAsset == positions[otherTokenId].ospAsset,
      "OE"
    );
    require(positions[tokenId].ospAmount > 0, "AE1");
    require(positions[otherTokenId].ospAmount > 0, "AE2");

    address ospAsset = positions[tokenId].ospAsset;

    uint256 feeFind;
    {
      uint256 otherOspAmount = positions[otherTokenId].ospAmount;

      uint256 baseFind = _mathAndRemovePosition(otherTokenId, otherOspAmount);
      (
        uint256 outFindAmountMerge,
        uint256 feeFindAmountMerge
      ) = _mathAndAddPosition(tokenId, otherOspAmount);
      uint256 outFindAmountMergeWithFee = outFindAmountMerge +
        feeFindAmountMerge;
      uint256 outFindWithFee = outFindAmountMergeWithFee - baseFind;
      (outFind, feeFind) = _mathFee(outFindWithFee);

      IFind(find).mint(outFindWithFee);
    }

    if (feeFind > 0) {
      TransferHelper.safeTransfer(find, earn, feeFind);
    }

    if (outFind > 0) {
      (amountOut, tokenOut) = _transferFindOrPathTokenToUser(
        findToOtherInPath,
        outFind,
        _msgSender()
      );
    }

    emit Merge(
      _msgSender(),
      tokenId,
      otherTokenId,
      ospAsset,
      outFind,
      feeFind,
      amountOut,
      tokenOut
    );
  }

  function _multiplyAdd(
    uint256 tokenId,
    uint256 AllFindAmount,
    uint256 amountPayMax,
    bytes memory otherToFindOutPath
  )
    private
    returns (
      uint256 positionOspAmountDelta,
      uint256 payFindAmount,
      uint256 amountNeedPay,
      address tokenPay
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );
    address ospAsset = positions[tokenId].ospAsset;

    IFind(find).mint(AllFindAmount);

    if (
      IERC20(find).allowance(address(this), UniswapConstants.UNISWAP_ROUTER) <
      AllFindAmount
    ) {
      IERC20(find).approve(UniswapConstants.UNISWAP_ROUTER, type(uint256).max);
    }

    {
      (uint256 poolConfigIndex, , , , , ) = IFactory(factory).token2OspInfo(
        ospAsset
      );
      (uint24 fee, , , , ) = IFactory(factory).getOspPoolConfigs(
        poolConfigIndex
      );

      positionOspAmountDelta = SwapRouterHelper.exactInputSingle(
        ISwapRouter02.ExactInputSingleParams({
          tokenIn: find,
          tokenOut: ospAsset,
          fee: fee,
          recipient: address(this),
          amountIn: AllFindAmount,
          amountOutMinimum: 0,
          sqrtPriceLimitX96: 0
        })
      );
    }

    uint256 feeFindAmount;
    {
      uint256 outFindAmount;
      (outFindAmount, feeFindAmount) = _mathAndAddPosition(
        tokenId,
        positionOspAmountDelta
      );

      payFindAmount = AllFindAmount - outFindAmount;

      (amountNeedPay, tokenPay) = _transferFindOrPathTokenFromUser(
        otherToFindOutPath,
        payFindAmount,
        amountPayMax,
        _msgSender()
      );

      require(amountNeedPay <= amountPayMax, "E");
      IFind(find).burn(payFindAmount - feeFindAmount);

      TransferHelper.safeTransfer(find, earn, feeFindAmount);
    }

    emit Multiply(
      MultiplyEventParams({
        sender: _msgSender(),
        tokenId: tokenId,
        ospAsset: ospAsset,
        ospAmount: positionOspAmountDelta,
        AllFindAmount: AllFindAmount,
        payFindAmount: payFindAmount,
        feeFindAmount: feeFindAmount,
        amountNeedPay: amountNeedPay,
        tokenPay: tokenPay
      })
    );
  }

  function _mortgageAdd(
    uint256 tokenId,
    uint256 inOspAmount,
    bytes memory findToOtherInPath
  )
    private
    returns (
      uint256 outFindAmount,
      uint256 amountOut,
      address tokenOut
    )
  {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      "ERC721: caller is not token owner nor approved"
    );

    address ospAsset = positions[tokenId].ospAsset;

    uint256 feeFindAmount;
    (outFindAmount, feeFindAmount) = _mathAndAddPosition(tokenId, inOspAmount);

    TransferHelper.safeTransferFrom(
      ospAsset,
      _msgSender(),
      address(this),
      inOspAmount
    );

    IFind(find).mint(outFindAmount + feeFindAmount);
    TransferHelper.safeTransfer(find, earn, feeFindAmount);
    (amountOut, tokenOut) = _transferFindOrPathTokenToUser(
      findToOtherInPath,
      outFindAmount,
      _msgSender()
    );

    emit MortgageEvent(
      _msgSender(),
      tokenId,
      ospAsset,
      inOspAmount,
      outFindAmount,
      feeFindAmount,
      amountOut,
      tokenOut
    );
  }

  function _transferFindOrPathTokenFromUser(
    bytes memory otherToFindOutPath,
    uint256 needInFindAmount,
    uint256 amountInMax,
    address user
  ) private returns (uint256 amountIn, address tokenIn) {
    if (otherToFindOutPath.length == 20) {
      tokenIn = otherToFindOutPath.toAddress(0);
      require(tokenIn == find, "PE1");
      amountIn = needInFindAmount;
      TransferHelper.safeTransferFrom(
        find,
        user,
        address(this),
        needInFindAmount
      );
    } else {
      (amountIn, tokenIn) = _transferFromAndSwapOtherToFindByOut(
        otherToFindOutPath,
        needInFindAmount,
        amountInMax,
        user
      );
    }
  }

  function _transferFindOrPathTokenToUser(
    bytes memory swapInPath,
    uint256 outFindAmount,
    address user
  ) private returns (uint256 amountOut, address tokenOut) {
    if (swapInPath.length == 20) {
      require(swapInPath.toAddress(0) == find);
      tokenOut = find;
      amountOut = outFindAmount;
    } else {
      (amountOut, tokenOut) = _swapFindToOtherByIn(swapInPath, outFindAmount);
    }

    if (tokenOut != _weth9()) {
      TransferHelper.safeTransfer(tokenOut, user, amountOut);
    } else {
      IWETH9(_weth9()).withdraw(amountOut);
      TransferHelper.safeTransferETH(user, amountOut);
    }
  }

  function _swapFindToOtherByIn(
    bytes memory findToOtherInPath,
    uint256 inFindAmount
  ) private returns (uint256 amountOut, address tokenOut) {
    require(findToOtherInPath.toAddress(0) == find);
    tokenOut = findToOtherInPath.toAddress(findToOtherInPath.length - 20);
    require(tokenOut != find);

    if (
      IERC20(find).allowance(address(this), UniswapConstants.UNISWAP_ROUTER) <
      type(uint256).max
    ) {
      IERC20(find).approve(UniswapConstants.UNISWAP_ROUTER, type(uint256).max);
    }

    amountOut = SwapRouterHelper.exactInput(
      ISwapRouter02.ExactInputParams({
        path: findToOtherInPath,
        recipient: address(this),
        amountIn: inFindAmount,
        amountOutMinimum: 0
      })
    );
  }

  function _transferFromAndSwapOtherToFindByOut(
    bytes memory otherToFindOutPath,
    uint256 needFindAmount,
    uint256 amountInMax,
    address user
  ) private returns (uint256 amountIn, address tokenIn) {
    tokenIn = otherToFindOutPath.toAddress(otherToFindOutPath.length - 20);
    address tokenOut = otherToFindOutPath.toAddress(0);
    require(tokenIn != find, "PE2");
    require(tokenOut == find, "PE3");

    // prepare for swap
    if (tokenIn != _weth9()) {
      require(msg.value == 0, "VE1");
      TransferHelper.safeTransferFrom(
        tokenIn,
        user,
        address(this),
        amountInMax
      );

      if (
        IERC20(tokenIn).allowance(
          address(this),
          UniswapConstants.UNISWAP_ROUTER
        ) < type(uint256).max
      ) {
        IERC20(tokenIn).approve(
          UniswapConstants.UNISWAP_ROUTER,
          type(uint256).max
        );
      }
    } else {
      require(msg.value == amountInMax, "VE2");
    }

    // swap
    amountIn = ISwapRouter02(UniswapConstants.UNISWAP_ROUTER).exactOutput{
      value: msg.value
    }(
      ISwapRouter02.ExactOutputParams({
        path: otherToFindOutPath,
        recipient: address(this),
        amountOut: needFindAmount,
        amountInMaximum: amountInMax
      })
    );
    // refund
    if (tokenIn == _weth9()) {
      ISwapRouter02(UniswapConstants.UNISWAP_ROUTER).refundETH();
    }

    uint256 refund = amountInMax - amountIn;

    if (refund > 0) {
      if (tokenIn != _weth9()) {
        TransferHelper.safeTransfer(tokenIn, user, refund);
      } else {
        TransferHelper.safeTransferETH(user, refund);
      }
    }
  }

  function _mathAndAddPosition(uint256 tokenId, uint256 inOspAmount)
    private
    returns (uint256 outFindAmount, uint256 feeFindAmount)
  {
    uint256 newPositionOspAmount = 0;
    (outFindAmount, feeFindAmount, newPositionOspAmount) = _mathForMortgage(
      tokenId,
      inOspAmount
    );
    positions[tokenId].ospAmount = newPositionOspAmount;
  }

  function _mathAndRemovePosition(uint256 tokenId, uint256 outOspAmount)
    private
    returns (uint256 inFindAmount)
  {
    uint256 positionOspAmount = positions[tokenId].ospAmount;

    require(positionOspAmount > 0, "E1");
    require(outOspAmount <= positionOspAmount, "E2");
    require(outOspAmount > 0, "E3");

    uint256 newPositionOspAmount = 0;
    (inFindAmount, newPositionOspAmount) = _mathForRedeem(
      tokenId,
      outOspAmount
    );

    if (newPositionOspAmount == 0) {
      _burn(tokenId);
      delete positions[tokenId];
    } else {
      positions[tokenId].ospAmount = newPositionOspAmount;
    }
  }

  function _mathForMortgage(uint256 tokenId, uint256 inOspAmount)
    private
    returns (
      uint256 outFindAmount,
      uint256 feeFindAmount,
      uint256 newPositionOspAmount
    )
  {
    uint256 positionOspAmount = positions[tokenId].ospAmount;
    address ospAsset = positions[tokenId].ospAsset;

    newPositionOspAmount = positionOspAmount + inOspAmount;

    uint256 oldFind = 0;
    if (positionOspAmount != 0) {
      oldFind = _mortgage(ospAsset, positionOspAmount);
    }
    uint256 newFind = _mortgage(ospAsset, newPositionOspAmount);
    uint256 outFindAmountWithFee = newFind - oldFind;

    (outFindAmount, feeFindAmount) = _mathFee(outFindAmountWithFee);
  }

  function _mathForRedeem(uint256 tokenId, uint256 outOspAmount)
    private
    returns (uint256 inFindAmount, uint256 newPositionOspAmount)
  {
    uint256 positionOspAmount = positions[tokenId].ospAmount;
    address ospAsset = positions[tokenId].ospAsset;

    newPositionOspAmount = positionOspAmount - outOspAmount;

    uint256 oldFind = _mortgage(ospAsset, positionOspAmount);
    uint256 newFind = 0;
    if (newPositionOspAmount != 0) {
      newFind = _mortgage(ospAsset, newPositionOspAmount);
    }

    inFindAmount = oldFind - newFind;
  }

  function _mathFee(uint256 findAmountWithFee)
    private
    view
    returns (uint256 outFindAmout, uint256 feeFindAmount)
  {
    feeFindAmount =
      (findAmountWithFee * mortgageFee) /
      MORTGAGE_FEE_DENOMINATOR;
    outFindAmout = findAmountWithFee - feeFindAmount;
  }

  function _mortgage(address ospAsset, uint256 ospAmount)
    private
    returns (uint256 findAmount)
  {
    findAmount = IMath(math).mortgage(ospAsset, ospAmount);
  }

  function _weth9() private view returns (address) {
    return
      INonfungiblePositionManager(UniswapConstants.UNISWAP_V3_POSITIONS)
        .WETH9();
  }

  function _mintEmpty(address ospAsset) private returns (uint256 tokenId) {
    (, , address pool, , , ) = IFactory(factory).token2OspInfo(ospAsset);

    require(pool != address(0), "NE");

    tokenId = _nextId;
    _nextId += 1;
    _mint(msg.sender, tokenId);
    positions[tokenId] = Position({
      tokenId: tokenId,
      ospAsset: ospAsset,
      ospAmount: 0
    });
  }

  receive() external payable {}
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../ERC721.sol";
import "./IERC721Enumerable.sol";

/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;

    // Array with all token ids, used for enumeration
    uint256[] private _allTokens;

    // Mapping from token id to position in the allTokens array
    mapping(uint256 => uint256) private _allTokensIndex;

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
        return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
        return _ownedTokens[owner][index];
    }

    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
        return _allTokens[index];
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual override {
        super._beforeTokenTransfer(from, to, tokenId);

        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }

    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Private function to add a token to this extension's token tracking data structures.
     * @param tokenId uint256 ID of the token to be added to the tokens list
     */
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }

        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }

    /**
     * @dev Private function to remove a token from this extension's token tracking data structures.
     * This has O(1) time complexity, but alters the order of the _allTokens array.
     * @param tokenId uint256 ID of the token to be removed from the tokens list
     */
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
        uint256 lastTokenId = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index

        // This also deletes the contents at the last position of the array
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}

// File: contracts/interfaces/IFind.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface IFind {
    function mint(uint256 amount) external;

    function burn(uint256 amount) external;

    function transfer(address to, uint256 amount) external returns (bool);
}

// File: contracts/interfaces/IFactory.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6;
pragma abicoder v2;

import "../libraries/UniswapStruct.sol";

interface IFactory {
  function getOspPoolConfigs(uint256 index)
    external
    view
    returns (
      uint24 fee,
      uint160 findOspPoolInitSqrtPriceX96,
      UniswapStruct.Position[] memory findOspPoolPositions,
      uint160 ospFindPoolInitSqrtPriceX96,
      UniswapStruct.Position[] memory ospFindPoolPositions
    );

  function findInfo()
    external
    view
    returns (
      address token,
      address pool,
      uint256 cnftTokenId,
      uint256 onftTokenId,
      uint24 fee
    );

  function findLpTokenIdList()
    external
    view
    returns (uint256[] memory lpTokenIdList);

  function token2OspInfo(address _token)
    external
    view
    returns (
      uint256 poolConfigIndex,
      uint256 stars,
      address pool,
      uint256 cnftTokenId,
      uint256 onftTokenId,
      string memory projectId
    );

  function ospLpTokenIdList(address osp)
    external
    view
    returns (uint256[] memory lpTokenIdList);
}

// File: contracts/interfaces/IMath.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface IMath {
  function createPoolInfo(
    uint256 poolConfigIndex,
    address pool,
    uint256[] memory tokenIdList,
    bool isFindOspPool
  ) external;

  function mortgage(address osp, uint256 ospAmount)
    external
    returns (uint256 findAmount);
}

// File: contracts/interfaces/IMortgageRender.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface IMortgageRender {
  function tokenURI(uint256 tokenId)
    external
    view
    returns (string memory output);
}

// File: contracts/interfaces/external/IUniswapV3Pool.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6;

interface IUniswapV3Pool {
  function token0() external view returns (address);

  function token1() external view returns (address);

  function fee() external view returns (uint24);

  function slot0()
    external
    view
    returns (
      uint160 sqrtPriceX96,
      int24 tick,
      uint16 observationIndex,
      uint16 observationCardinality,
      uint16 observationCardinalityNext,
      uint8 feeProtocol,
      bool unlocked
    );

  function tickSpacing() external view returns (int24);

  function maxLiquidityPerTick() external view returns (uint128);

  function liquidity() external view returns (uint128);

  function ticks(int24 tick)
    external
    view
    returns (
      uint128 liquidityGross,
      int128 liquidityNet,
      uint256 feeGrowthOutside0X128,
      uint256 feeGrowthOutside1X128,
      int56 tickCumulativeOutside,
      uint160 secondsPerLiquidityOutsideX128,
      uint32 secondsOutside,
      bool initialized
    );
}

// File: contracts/interfaces/external/INonfungiblePositionManager.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6;
pragma abicoder v2;

interface INonfungiblePositionManager {
  function tokenOfOwnerByIndex(address owner, uint256 index)
    external
    view
    returns (uint256 tokenId);

  function refundETH() external payable;

  function factory() external view returns (address);

  function WETH9() external view returns (address);

  function balanceOf(address owner) external view returns (uint256 balance);

  function ownerOf(uint256 tokenId) external view returns (address owner);

  function positions(uint256 tokenId)
    external
    view
    returns (
      uint96 nonce,
      address operator,
      address token0,
      address token1,
      uint24 fee,
      int24 tickLower,
      int24 tickUpper,
      uint128 liquidity,
      uint256 feeGrowthInside0LastX128,
      uint256 feeGrowthInside1LastX128,
      uint128 tokensOwed0,
      uint128 tokensOwed1
    );

  struct MintParams {
    address token0;
    address token1;
    uint24 fee;
    int24 tickLower;
    int24 tickUpper;
    uint256 amount0Desired;
    uint256 amount1Desired;
    uint256 amount0Min;
    uint256 amount1Min;
    address recipient;
    uint256 deadline;
  }

  function createAndInitializePoolIfNecessary(
    address token0,
    address token1,
    uint24 fee,
    uint160 sqrtPriceX96
  ) external payable returns (address pool);

  function mint(MintParams calldata params)
    external
    payable
    returns (
      uint256 tokenId,
      uint128 liquidity,
      uint256 amount0,
      uint256 amount1
    );

  struct CollectParams {
    uint256 tokenId;
    address recipient;
    uint128 amount0Max;
    uint128 amount1Max;
  }

  function collect(CollectParams calldata params)
    external
    payable
    returns (uint256 amount0, uint256 amount1);
}

// File: contracts/interfaces/external/IWETH9.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

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

interface IWETH9 is IERC20 {
  function deposit() external payable;

  function withdraw(uint256) external;
}

// File: contracts/interfaces/external/ISwapRouter02.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface ISwapRouter02 {
  struct ExactInputSingleParams {
    address tokenIn;
    address tokenOut;
    uint24 fee;
    address recipient;
    uint256 amountIn;
    uint256 amountOutMinimum;
    uint160 sqrtPriceLimitX96;
  }

  function exactInputSingle(ExactInputSingleParams calldata params)
    external
    payable
    returns (uint256 amountOut);

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

  function exactInput(ExactInputParams calldata params)
    external
    payable
    returns (uint256 amountOut);

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

  function exactOutputSingle(ExactOutputSingleParams calldata params)
    external
    payable
    returns (uint256 amountIn);

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

  function exactOutput(ExactOutputParams calldata params)
    external
    payable
    returns (uint256 amountIn);

  function refundETH() external payable;
}

// File: contracts/libraries/TransferHelper.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

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

library TransferHelper {
  function safeTransfer(
    address token,
    address to,
    uint256 value
  ) internal {
    (bool success, bytes memory data) = token.call(
      abi.encodeWithSelector(IERC20.transfer.selector, to, value)
    );
    require(success && (data.length == 0 || abi.decode(data, (bool))), "ST");
  }

  function safeTransferFrom(
    address token,
    address from,
    address to,
    uint256 value
  ) internal {
    (bool success, bytes memory data) = token.call(
      abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value)
    );
    require(success && (data.length == 0 || abi.decode(data, (bool))), "STF");
  }

  function safeTransferETH(address to, uint256 value) internal {
    (bool success, ) = to.call{ value: value }(new bytes(0));
    require(success, "STE");
  }
}

// File: contracts/libraries/UniswapConstants.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6;

library UniswapConstants {
  address public constant UNISWAP_V3_POSITIONS =
    0xC36442b4a4522E871399CD717aBDD847Ab11FE88;
  address public constant UNISWAP_ROUTER =
    0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45;
}

// File: contracts/libraries/SwapRouterHelper.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

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

import "../interfaces/external/ISwapRouter02.sol";

import "./UniswapConstants.sol";
import "./Path.sol";

library SwapRouterHelper {
  function exactInputSingle(ISwapRouter02.ExactInputSingleParams memory params)
    internal
    returns (uint256 amountOut)
  {
    uint256 balanceOfBefore = IERC20(params.tokenIn).balanceOf(address(this));

    amountOut = ISwapRouter02(UniswapConstants.UNISWAP_ROUTER).exactInputSingle(
        params
      );

    uint256 balanceOfAfter = IERC20(params.tokenIn).balanceOf(address(this));
    require(balanceOfBefore - balanceOfAfter == params.amountIn, "IE");
  }

  function exactInput(ISwapRouter02.ExactInputParams memory params)
    internal
    returns (uint256 amountOut)
  {
    uint256[] memory balanceOfsBefore = _getPathTokenBalanceOf(params.path);

    amountOut = ISwapRouter02(UniswapConstants.UNISWAP_ROUTER).exactInput(
      params
    );
    uint256[] memory balanceOfsAfter = _getPathTokenBalanceOf(params.path);
    _assertBalanceOf(balanceOfsBefore, balanceOfsAfter, params.amountIn);
  }

  function _assertBalanceOf(
    uint256[] memory balanceOfsBefore,
    uint256[] memory balanceOfsAfter,
    uint256 amountIn
  ) private pure {
    require(balanceOfsBefore.length == balanceOfsAfter.length, "LE");

    for (uint256 i = 0; i < balanceOfsBefore.length; i++) {
      if (i == 0) {
        require(balanceOfsBefore[i] - balanceOfsAfter[i] == amountIn, "LEF0");
      } else {
        require(balanceOfsBefore[i] == balanceOfsAfter[i], "LEF1");
      }
    }
  }

  function _getPathTokenBalanceOf(bytes memory path)
    private
    view
    returns (uint256[] memory balanceOfs)
  {
    balanceOfs = new uint256[](Path.numPools(path));
    for (uint256 i = 0; i < balanceOfs.length; i++) {
      if (i == 0) {
        (address tokenIn, , ) = Path.decodeFirstPool(path);
        balanceOfs[i] = IERC20(tokenIn).balanceOf(address(this));
      } else {
        path = Path.skipToken(path);
        (address tokenIn, , ) = Path.decodeFirstPool(path);
        balanceOfs[i] = IERC20(tokenIn).balanceOf(
          UniswapConstants.UNISWAP_ROUTER
        );
      }
    }
  }
}

// File: contracts/libraries/BytesLib.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

library BytesLib {
  function slice(
    bytes memory _bytes,
    uint256 _start,
    uint256 _length
  ) internal pure returns (bytes memory) {
    require(_length + 31 >= _length, "slice_overflow");
    require(_start + _length >= _start, "slice_overflow");
    require(_bytes.length >= _start + _length, "slice_outOfBounds");

    bytes memory tempBytes;

    assembly {
      switch iszero(_length)
      case 0 {
        tempBytes := mload(0x40)

        let lengthmod := and(_length, 31)

        let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
        let end := add(mc, _length)

        for {
          let cc := add(
            add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))),
            _start
          )
        } lt(mc, end) {
          mc := add(mc, 0x20)
          cc := add(cc, 0x20)
        } {
          mstore(mc, mload(cc))
        }

        mstore(tempBytes, _length)

        mstore(0x40, and(add(mc, 31), not(31)))
      }
      default {
        tempBytes := mload(0x40)

        mstore(tempBytes, 0)

        mstore(0x40, add(tempBytes, 0x20))
      }
    }

    return tempBytes;
  }

  function toAddress(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (address)
  {
    require(_start + 20 >= _start, "toAddress_overflow");
    require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
    address tempAddress;

    assembly {
      tempAddress := div(
        mload(add(add(_bytes, 0x20), _start)),
        0x1000000000000000000000000
      )
    }

    return tempAddress;
  }

  function toUint24(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint24)
  {
    require(_start + 3 >= _start, "toUint24_overflow");
    require(_bytes.length >= _start + 3, "toUint24_outOfBounds");
    uint24 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x3), _start))
    }

    return tempUint;
  }
}

// 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/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: address zero is not a valid owner");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: invalid token ID");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        _requireMinted(tokenId);

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not token owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner nor approved");
        _safeTransfer(from, to, tokenId, data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits an {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

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

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

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

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return 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
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: contracts/libraries/UniswapStruct.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6;

library UniswapStruct {
  struct Position {
    int24 tickLower;
    int24 tickUpper;
    uint256 amount;
  }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

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

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

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

// File: contracts/libraries/Path.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

import "./BytesLib.sol";

library Path {
  using BytesLib for bytes;

  uint256 private constant ADDR_SIZE = 20;

  uint256 private constant FEE_SIZE = 3;

  uint256 private constant NEXT_OFFSET = ADDR_SIZE + FEE_SIZE;

  uint256 private constant POP_OFFSET = NEXT_OFFSET + ADDR_SIZE;

  uint256 private constant MULTIPLE_POOLS_MIN_LENGTH = POP_OFFSET + NEXT_OFFSET;

  function hasMultiplePools(bytes memory path) internal pure returns (bool) {
    return path.length >= MULTIPLE_POOLS_MIN_LENGTH;
  }

  function numPools(bytes memory path) internal pure returns (uint256) {
    return ((path.length - ADDR_SIZE) / NEXT_OFFSET);
  }

  function decodeFirstPool(bytes memory path)
    internal
    pure
    returns (
      address tokenA,
      address tokenB,
      uint24 fee
    )
  {
    tokenA = path.toAddress(0);
    fee = path.toUint24(ADDR_SIZE);
    tokenB = path.toAddress(NEXT_OFFSET);
  }

  function getFirstPool(bytes memory path)
    internal
    pure
    returns (bytes memory)
  {
    return path.slice(0, POP_OFFSET);
  }

  function skipToken(bytes memory path) internal pure returns (bytes memory) {
    return path.slice(NEXT_OFFSET, path.length - NEXT_OFFSET);
  }
}