// File: /home/marbach/Projects/Vera/Rental-ERC721/contracts/vRent.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.6;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol";
import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Receiver.sol";
import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";

import "./IResolver.sol"; 
import "./IvRent.sol"; 

contract vRent is IvRent, ERC721Holder, ERC1155Receiver, ERC1155Holder {
    using SafeERC20 for ERC20; 

    IResolver private resolver;
    address private admin;
    address payable private beneficiary;
    uint256 private lendingId = 1;
    bool public paused = false;

    // in bps. so 1000 => 1%
    uint256 public rentFee = 0;

    uint256 private constant SECONDS_IN_DAY = 86400;

    // single storage slot: address - 160 bits, 168, 200, 232, 240, 248
    struct Lending {
        address payable lenderAddress;
        uint8 maxRentDuration;
        bytes4 dailyRentPrice;
        bytes4 nftPrice;
        uint8 lentAmount;
        IResolver.PaymentToken paymentToken;
    }

    // single storage slot: 160 bits, 168, 200
    struct Renting {
        address payable renterAddress;
        uint8 rentDuration;
        uint32 rentedAt;
    }

    struct LendingRenting {
        Lending lending;
        Renting renting;
    }

    mapping(bytes32 => LendingRenting) private lendingRenting;

    struct CallData {
        uint256 left;
        uint256 right;
        address[] nfts;
        uint256[] tokenIds;
        uint256[] lentAmounts;
        uint8[] maxRentDurations;
        bytes4[] dailyRentPrices;
        bytes4[] nftPrices;
        uint256[] lendingIds;
        uint8[] rentDurations;
        IResolver.PaymentToken[] paymentTokens;
    }

    modifier onlyAdmin {
        require(msg.sender == admin, "vRent::not admin");
        _;
    }

    modifier notPaused {
        require(!paused, "vRent::paused");
        _;
    }

    constructor(
        address _resolver,
        address payable _beneficiary,
        address _admin
    ) {
        ensureIsNotZeroAddr(_resolver);
        ensureIsNotZeroAddr(_beneficiary);
        ensureIsNotZeroAddr(_admin);
        resolver = IResolver(_resolver);
        beneficiary = _beneficiary;
        admin = _admin;
    }

    function bundleCall(function(CallData memory) _handler, CallData memory _cd)
        private
    {
        require(_cd.nfts.length > 0, "vRent::no nfts");
        while (_cd.right != _cd.nfts.length) {
            if (
                (_cd.nfts[_cd.left] == _cd.nfts[_cd.right]) &&
                (is1155(_cd.nfts[_cd.right]))
            ) {
                _cd.right++;
            } else {
                _handler(_cd);
                _cd.left = _cd.right;
                _cd.right++;
            }
        }
        _handler(_cd);
    }

    // lend, rent, return, stop, claim

    function lend(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendAmounts,
        uint8[] memory _maxRentDurations,
        bytes4[] memory _dailyRentPrices,
        bytes4[] memory _nftPrices,
        IResolver.PaymentToken[] memory _paymentTokens
    ) external override notPaused {
        bundleCall(
            handleLend,
            createLendCallData(
                _nfts,
                _tokenIds,
                _lendAmounts,
                _maxRentDurations,
                _dailyRentPrices,
                _nftPrices,
                _paymentTokens
            )
        );
    }

    function rent(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds,
        uint8[] memory _rentDurations
    ) external override notPaused {
        bundleCall(
            handleRent,
            createRentCallData(_nfts, _tokenIds, _lendingIds, _rentDurations)
        );
    }

    function returnIt(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds
    ) external override notPaused {
        bundleCall(
            handleReturn,
            createActionCallData(_nfts, _tokenIds, _lendingIds)
        );
    }

    function stopLending(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds
    ) external override notPaused {
        bundleCall(
            handleStopLending,
            createActionCallData(_nfts, _tokenIds, _lendingIds)
        );
    }

    function claimCollateral(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds
    ) external override notPaused {
        bundleCall(
            handleClaimCollateral,
            createActionCallData(_nfts, _tokenIds, _lendingIds)
        );
    }

    // -------------------------------------------------------------------------

    function takeFee(uint256 _rent, IResolver.PaymentToken _paymentToken)
        private
        returns (uint256 fee)
    {
        fee = _rent * rentFee;
        fee /= 10000;
        uint8 paymentTokenIx = uint8(_paymentToken);
        ensureTokenNotSentinel(paymentTokenIx);
        ERC20 paymentToken = ERC20(resolver.getPaymentToken(paymentTokenIx));
        paymentToken.safeTransfer(beneficiary, fee);
    }

    function distributePayments(
        LendingRenting storage _lendingRenting,
        uint256 _secondsSinceRentStart
    ) private {
        uint8 paymentTokenIx = uint8(_lendingRenting.lending.paymentToken);
        ensureTokenNotSentinel(paymentTokenIx);
        address paymentToken = resolver.getPaymentToken(paymentTokenIx);
        uint256 decimals = ERC20(paymentToken).decimals();

        uint256 scale = 10**decimals;
        uint256 nftPrice =
            _lendingRenting.lending.lentAmount *
                unpackPrice(_lendingRenting.lending.nftPrice, scale);
        uint256 rentPrice =
            unpackPrice(_lendingRenting.lending.dailyRentPrice, scale);
        uint256 totalRenterPmtWoCollateral =
            rentPrice * _lendingRenting.renting.rentDuration;
        uint256 sendLenderAmt =
            (_secondsSinceRentStart * rentPrice) / SECONDS_IN_DAY;
        require(
            totalRenterPmtWoCollateral > 0,
            "vRent::total payment wo collateral is zero"
        );
        require(sendLenderAmt > 0, "vRent::lender payment is zero");
        uint256 sendRenterAmt = totalRenterPmtWoCollateral - sendLenderAmt;

        uint256 takenFee =
            takeFee(sendLenderAmt, _lendingRenting.lending.paymentToken);

        sendLenderAmt -= takenFee;
        sendRenterAmt += nftPrice;

        ERC20(paymentToken).safeTransfer(
            _lendingRenting.lending.lenderAddress,
            sendLenderAmt
        );
        ERC20(paymentToken).safeTransfer(
            _lendingRenting.renting.renterAddress,
            sendRenterAmt
        );
    }

    function distributeClaimPayment(LendingRenting memory _lendingRenting)
        private
    {
        uint8 paymentTokenIx = uint8(_lendingRenting.lending.paymentToken);
        ensureTokenNotSentinel(paymentTokenIx);
        ERC20 paymentToken = ERC20(resolver.getPaymentToken(paymentTokenIx));

        uint256 decimals = ERC20(paymentToken).decimals();
        uint256 scale = 10**decimals;
        uint256 nftPrice =
            _lendingRenting.lending.lentAmount *
                unpackPrice(_lendingRenting.lending.nftPrice, scale);
        uint256 rentPrice =
            unpackPrice(_lendingRenting.lending.dailyRentPrice, scale);
        uint256 maxRentPayment =
            rentPrice * _lendingRenting.renting.rentDuration;
        uint256 takenFee =
            takeFee(maxRentPayment, IResolver.PaymentToken(paymentTokenIx));
        uint256 finalAmt = maxRentPayment + nftPrice;

        require(maxRentPayment > 0, "vRent::collateral plus rent is zero");

        paymentToken.safeTransfer(
            _lendingRenting.lending.lenderAddress,
            finalAmt - takenFee
        );
    }

    function safeTransfer(
        CallData memory _cd,
        address _from,
        address _to,
        uint256[] memory _tokenIds,
        uint256[] memory _lentAmounts
    ) private {
        if (is721(_cd.nfts[_cd.left])) {
            IERC721(_cd.nfts[_cd.left]).transferFrom(
                _from,
                _to,
                _cd.tokenIds[_cd.left]
            );
        } else if (is1155(_cd.nfts[_cd.left])) {
            IERC1155(_cd.nfts[_cd.left]).safeBatchTransferFrom(
                _from,
                _to,
                _tokenIds,
                _lentAmounts,
                ""
            );
        } else {
            revert("vRent::unsupported token type");
        }
    }

    // -------------------------------------------------------------------------
    function handleLend(CallData memory _cd) private {
        for (uint256 i = _cd.left; i < _cd.right; i++) {
            ensureIsLendable(_cd, i);

            LendingRenting storage item =
                lendingRenting[
                    keccak256(
                        abi.encodePacked(
                            _cd.nfts[_cd.left],
                            _cd.tokenIds[i],
                            lendingId
                        )
                    )
                ];

            ensureIsNull(item.lending);
            ensureIsNull(item.renting);

            bool nftIs721 = is721(_cd.nfts[i]);
            item.lending = Lending({
                lenderAddress: payable(msg.sender),
                lentAmount: nftIs721 ? 1 : uint8(_cd.lentAmounts[i]),
                maxRentDuration: _cd.maxRentDurations[i],
                dailyRentPrice: _cd.dailyRentPrices[i],
                nftPrice: _cd.nftPrices[i],
                paymentToken: _cd.paymentTokens[i]
            });

            emit Lent(
                _cd.nfts[_cd.left],
                _cd.tokenIds[i],
                nftIs721 ? 1 : uint8(_cd.lentAmounts[i]),
                lendingId,
                msg.sender,
                _cd.maxRentDurations[i],
                _cd.dailyRentPrices[i],
                _cd.nftPrices[i],
                nftIs721,
                _cd.paymentTokens[i]
            );

            lendingId++;
        }

        safeTransfer(
            _cd,
            msg.sender,
            address(this),
            sliceArr(_cd.tokenIds, _cd.left, _cd.right, 0),
            sliceArr(_cd.lentAmounts, _cd.left, _cd.right, 0)
        );
    }

    function handleRent(CallData memory _cd) private {
        uint256[] memory lentAmounts = new uint256[](_cd.right - _cd.left);

        for (uint256 i = _cd.left; i < _cd.right; i++) {
            LendingRenting storage item =
                lendingRenting[
                    keccak256(
                        abi.encodePacked(
                            _cd.nfts[_cd.left],
                            _cd.tokenIds[i],
                            _cd.lendingIds[i]
                        )
                    )
                ];

            ensureIsNotNull(item.lending);
            ensureIsNull(item.renting);
            ensureIsRentable(item.lending, _cd, i, msg.sender);

            uint8 paymentTokenIx = uint8(item.lending.paymentToken);
            ensureTokenNotSentinel(paymentTokenIx);
            address paymentToken = resolver.getPaymentToken(paymentTokenIx);
            uint256 decimals = ERC20(paymentToken).decimals();

            {
                uint256 scale = 10**decimals;
                uint256 rentPrice =
                    _cd.rentDurations[i] *
                        unpackPrice(item.lending.dailyRentPrice, scale);
                uint256 nftPrice =
                    item.lending.lentAmount *
                        unpackPrice(item.lending.nftPrice, scale);

                require(rentPrice > 0, "vRent::rent price is zero");
                require(nftPrice > 0, "vRent::nft price is zero");

                ERC20(paymentToken).safeTransferFrom(
                    msg.sender,
                    address(this),
                    rentPrice + nftPrice
                );
            }

            lentAmounts[i - _cd.left] = item.lending.lentAmount;

            item.renting.renterAddress = payable(msg.sender);
            item.renting.rentDuration = _cd.rentDurations[i];
            item.renting.rentedAt = uint32(block.timestamp);

            emit Rented(
                _cd.lendingIds[i],
                msg.sender,
                _cd.rentDurations[i],
                item.renting.rentedAt
            );
        }

        safeTransfer(
            _cd,
            address(this),
            msg.sender,
            sliceArr(_cd.tokenIds, _cd.left, _cd.right, 0),
            sliceArr(lentAmounts, _cd.left, _cd.right, _cd.left)
        );
    }

    function handleReturn(CallData memory _cd) private {
        uint256[] memory lentAmounts = new uint256[](_cd.right - _cd.left);

        for (uint256 i = _cd.left; i < _cd.right; i++) {
            LendingRenting storage item =
                lendingRenting[
                    keccak256(
                        abi.encodePacked(
                            _cd.nfts[_cd.left],
                            _cd.tokenIds[i],
                            _cd.lendingIds[i]
                        )
                    )
                ];

            ensureIsNotNull(item.lending);
            ensureIsReturnable(item.renting, msg.sender, block.timestamp);

            uint256 secondsSinceRentStart =
                block.timestamp - item.renting.rentedAt;
            distributePayments(item, secondsSinceRentStart);

            lentAmounts[i - _cd.left] = item.lending.lentAmount;

            emit Returned(_cd.lendingIds[i], uint32(block.timestamp));

            delete item.renting;
        }

        safeTransfer(
            _cd,
            msg.sender,
            address(this),
            sliceArr(_cd.tokenIds, _cd.left, _cd.right, 0),
            sliceArr(lentAmounts, _cd.left, _cd.right, _cd.left)
        );
    }

    function handleStopLending(CallData memory _cd) private {
        uint256[] memory lentAmounts = new uint256[](_cd.right - _cd.left);

        for (uint256 i = _cd.left; i < _cd.right; i++) {
            LendingRenting storage item =
                lendingRenting[
                    keccak256(
                        abi.encodePacked(
                            _cd.nfts[_cd.left],
                            _cd.tokenIds[i],
                            _cd.lendingIds[i]
                        )
                    )
                ];

            ensureIsNotNull(item.lending);
            ensureIsNull(item.renting);
            ensureIsStoppable(item.lending, msg.sender);

            lentAmounts[i - _cd.left] = item.lending.lentAmount;

            emit LendingStopped(_cd.lendingIds[i], uint32(block.timestamp));

            delete item.lending;
        }

        safeTransfer(
            _cd,
            address(this),
            msg.sender,
            sliceArr(_cd.tokenIds, _cd.left, _cd.right, 0),
            sliceArr(lentAmounts, _cd.left, _cd.right, _cd.left)
        );
    }

    function handleClaimCollateral(CallData memory _cd) private {
        for (uint256 i = _cd.left; i < _cd.right; i++) {
            LendingRenting storage item =
                lendingRenting[
                    keccak256(
                        abi.encodePacked(
                            _cd.nfts[_cd.left],
                            _cd.tokenIds[i],
                            _cd.lendingIds[i]
                        )
                    )
                ];

            ensureIsNotNull(item.lending);
            ensureIsNotNull(item.renting);
            ensureIsClaimable(item.renting, block.timestamp);

            distributeClaimPayment(item);

            emit CollateralClaimed(_cd.lendingIds[i], uint32(block.timestamp));

            delete item.lending;
            delete item.renting;
        }
    }

   // -------------------------------------------------------------------------

    function is721(address _nft) private view returns (bool) {
        return IERC165(_nft).supportsInterface(type(IERC721).interfaceId);
    }

    function is1155(address _nft) private view returns (bool) {
        return IERC165(_nft).supportsInterface(type(IERC1155).interfaceId);
    }

    // -------------------------------------------------------------------------

    function createLendCallData(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendAmounts,
        uint8[] memory _maxRentDurations,
        bytes4[] memory _dailyRentPrices,
        bytes4[] memory _nftPrices,
        IResolver.PaymentToken[] memory _paymentTokens
    ) private pure returns (CallData memory cd) {
        cd = CallData({
            left: 0,
            right: 1,
            nfts: _nfts,
            tokenIds: _tokenIds,
            lentAmounts: _lendAmounts,
            lendingIds: new uint256[](0),
            rentDurations: new uint8[](0),
            maxRentDurations: _maxRentDurations,
            dailyRentPrices: _dailyRentPrices,
            nftPrices: _nftPrices,
            paymentTokens: _paymentTokens
        });
    }

    function createRentCallData(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds,
        uint8[] memory _rentDurations
    ) private pure returns (CallData memory cd) {
        cd = CallData({
            left: 0,
            right: 1,
            nfts: _nfts,
            tokenIds: _tokenIds,
            lentAmounts: new uint256[](0),
            lendingIds: _lendingIds,
            rentDurations: _rentDurations,
            maxRentDurations: new uint8[](0),
            dailyRentPrices: new bytes4[](0),
            nftPrices: new bytes4[](0),
            paymentTokens: new IResolver.PaymentToken[](0)
        });
    }

    function createActionCallData(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds
    ) private pure returns (CallData memory cd) {
        cd = CallData({
            left: 0,
            right: 1,
            nfts: _nfts,
            tokenIds: _tokenIds,
            lentAmounts: new uint256[](0),
            lendingIds: _lendingIds,
            rentDurations: new uint8[](0),
            maxRentDurations: new uint8[](0),
            dailyRentPrices: new bytes4[](0),
            nftPrices: new bytes4[](0),
            paymentTokens: new IResolver.PaymentToken[](0)
        });
    }

    function unpackPrice(bytes4 _price, uint256 _scale)
        private
        pure
        returns (uint256)
    {
        ensureIsUnpackablePrice(_price, _scale);

        uint16 whole = uint16(bytes2(_price));
        uint16 decimal = uint16(bytes2(_price << 16));
        uint256 decimalScale = _scale / 10000;

        if (whole > 9999) {
            whole = 9999;
        }
        if (decimal > 9999) {
            decimal = 9999;
        }

        uint256 w = whole * _scale;
        uint256 d = decimal * decimalScale;
        uint256 price = w + d;

        return price;
    }

    function sliceArr(
        uint256[] memory _arr,
        uint256 _fromIx,
        uint256 _toIx,
        uint256 _arrOffset
    ) private pure returns (uint256[] memory r) {
        r = new uint256[](_toIx - _fromIx);
        for (uint256 i = _fromIx; i < _toIx; i++) {
            r[i - _fromIx] = _arr[i - _arrOffset];
        }
    }

    // -------------------------------------------------------------------------

    function ensureIsNotZeroAddr(address _addr) private pure {
        require(_addr != address(0), "vRent::zero address");
    }

    function ensureIsZeroAddr(address _addr) private pure {
        require(_addr == address(0), "vRent::not a zero address");
    }

    function ensureIsNull(Lending memory _lending) private pure {
        ensureIsZeroAddr(_lending.lenderAddress);
        require(_lending.maxRentDuration == 0, "vRent::duration not zero");
        require(_lending.dailyRentPrice == 0, "vRent::rent price not zero");
        require(_lending.nftPrice == 0, "vRent::nft price not zero");
    }

    function ensureIsNotNull(Lending memory _lending) private pure {
        ensureIsNotZeroAddr(_lending.lenderAddress);
        require(_lending.maxRentDuration != 0, "vRent::duration zero");
        require(_lending.dailyRentPrice != 0, "vRent::rent price is zero");
        require(_lending.nftPrice != 0, "vRent::nft price is zero");
    }

    function ensureIsNull(Renting memory _renting) private pure {
        ensureIsZeroAddr(_renting.renterAddress);
        require(_renting.rentDuration == 0, "vRent::duration not zero");
        require(_renting.rentedAt == 0, "vRent::rented at not zero");
    }

    function ensureIsNotNull(Renting memory _renting) private pure {
        ensureIsNotZeroAddr(_renting.renterAddress);
        require(_renting.rentDuration != 0, "vRent::duration is zero");
        require(_renting.rentedAt != 0, "vRent::rented at is zero");
    }

    function ensureIsLendable(CallData memory _cd, uint256 _i) private pure {
        require(_cd.lentAmounts[_i] > 0, "vRent::lend amount is zero");
        require(_cd.lentAmounts[_i] <= type(uint8).max, "vRent::not uint8");
        require(_cd.maxRentDurations[_i] > 0, "vRent::duration is zero");
        require(
            _cd.maxRentDurations[_i] <= type(uint8).max,
            "vRent::not uint8"
        );
        require(
            uint32(_cd.dailyRentPrices[_i]) > 0,
            "vRent::rent price is zero"
        );
        require(uint32(_cd.nftPrices[_i]) > 0, "vRent::nft price is zero");
    }

    function ensureIsRentable(
        Lending memory _lending,
        CallData memory _cd,
        uint256 _i,
        address _msgSender
    ) private pure {
        require(
            _msgSender != _lending.lenderAddress,
            "vRent::cant rent own nft"
        );
        require(_cd.rentDurations[_i] <= type(uint8).max, "vRent::not uint8");
        require(_cd.rentDurations[_i] > 0, "vRent::duration is zero");
        require(
            _cd.rentDurations[_i] <= _lending.maxRentDuration,
            "vRent::rent duration exceeds allowed max"
        );
    }

    function ensureIsReturnable(
        Renting memory _renting,
        address _msgSender,
        uint256 _blockTimestamp
    ) private pure {
        require(_renting.renterAddress == _msgSender, "vRent::not renter");
        require(
            !isPastReturnDate(_renting, _blockTimestamp),
            "vRent::past return date"
        );
    }

    function ensureIsStoppable(Lending memory _lending, address _msgSender)
        private
        pure
    {
        require(_lending.lenderAddress == _msgSender, "vRent::not lender");
    }

    function ensureIsClaimable(Renting memory _renting, uint256 _blockTimestamp)
        private
        pure
    {
        require(
            isPastReturnDate(_renting, _blockTimestamp),
            "vRent::return date not passed"
        );
    }

    function ensureIsUnpackablePrice(bytes4 _price, uint256 _scale)
        private
        pure
    {
        require(uint32(_price) > 0, "vRent::invalid price");
        require(_scale >= 10000, "vRent::invalid scale");
    }

    function ensureTokenNotSentinel(uint8 _paymentIx) private pure {
        require(_paymentIx > 0, "vRent::token is sentinel");
    }

    function isPastReturnDate(Renting memory _renting, uint256 _now)
        private
        pure
        returns (bool)
    {
        require(_now > _renting.rentedAt, "vRent::now before rented");
        return
            _now - _renting.rentedAt > _renting.rentDuration * SECONDS_IN_DAY;
    }

    // -------------------------------------------------------------------------

    function setRentFee(uint256 _rentFee) external onlyAdmin {
        require(_rentFee < 10000, "vRent::fee exceeds 100pct");
        rentFee = _rentFee;
    }

    function setBeneficiary(address payable _newBeneficiary)
        external
        onlyAdmin
    {
        beneficiary = _newBeneficiary;
    }

    function setPaused(bool _paused) external onlyAdmin {
        paused = _paused;
    }
}
// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT

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



// SPDX-License-Identifier: MIT

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/Context.sol



// SPDX-License-Identifier: MIT

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/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC721Receiver.sol";

/**
 * @dev Implementation of the {IERC721Receiver} interface.
 *
 * Accepts all token transfers.
 * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.
 */
contract ERC721Holder is IERC721Receiver {
    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     *
     * Always returns `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
}

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



// SPDX-License-Identifier: MIT

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 `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

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



// SPDX-License-Identifier: MIT

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

    /**
     * @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 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);

    /**
     * @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;
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT

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



// SPDX-License-Identifier: MIT

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/ERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens 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 amount
    ) 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, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been 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 _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Receiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC1155Receiver.sol";
import "../../../utils/introspection/ERC165.sol";

/**
 * @dev _Available since v3.1._
 */
abstract contract ERC1155Receiver is ERC165, IERC1155Receiver {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC1155Receiver).interfaceId || super.supportsInterface(interfaceId);
    }
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./ERC1155Receiver.sol";

/**
 * @dev _Available since v3.1._
 */
contract ERC1155Holder is ERC1155Receiver {
    function onERC1155Received(
        address,
        address,
        uint256,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    function onERC1155BatchReceived(
        address,
        address,
        uint256[] memory,
        uint256[] memory,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

/**
 * @dev _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {
    /**
        @dev Handles the receipt of a single ERC1155 token type. This function is
        called at the end of a `safeTransferFrom` after the balance has been updated.
        To accept the transfer, this must return
        `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
        (i.e. 0xf23a6e61, or its own function selector).
        @param operator The address which initiated the transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param id The ID of the token being transferred
        @param value The amount of tokens being transferred
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
    */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    ) external returns (bytes4);

    /**
        @dev Handles the receipt of a multiple ERC1155 token types. This function
        is called at the end of a `safeBatchTransferFrom` after the balances have
        been updated. To accept the transfer(s), this must return
        `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
        (i.e. 0xbc197c81, or its own function selector).
        @param operator The address which initiated the batch transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param ids An array containing ids of each token being transferred (order and length must match values array)
        @param values An array containing amounts of each token being transferred (order and length must match ids array)
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
    */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(
        address indexed operator,
        address indexed from,
        address indexed to,
        uint256[] ids,
        uint256[] values
    );

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
        external
        view
        returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes calldata data
    ) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] calldata ids,
        uint256[] calldata amounts,
        bytes calldata data
    ) external;
}

// File: /home/marbach/Projects/Vera/Rental-ERC721/contracts/IvRent.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.6;

import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

import "./IResolver.sol";

interface IvRent is IERC721Receiver, IERC1155Receiver {
    event Lent(
        address indexed nftAddress,
        uint256 indexed tokenId,
        uint8 lentAmount,
        uint256 lendingId,
        address indexed lenderAddress,
        uint8 maxRentDuration,
        bytes4 dailyRentPrice,
        bytes4 nftPrice,
        bool isERC721,
        IResolver.PaymentToken paymentToken
    );

    event Rented(
        uint256 lendingId,
        address indexed renterAddress,
        uint8 rentDuration,
        uint32 rentedAt
    );

    event Returned(uint256 indexed lendingId, uint32 returnedAt);

    event CollateralClaimed(uint256 indexed lendingId, uint32 claimedAt);

    event LendingStopped(uint256 indexed lendingId, uint32 stoppedAt);

    /**
     * @dev sends your NFT to ReNFT contract, which acts as an escrow
     * between the lender and the renter
     */
    function lend(
        address[] memory _nft,
        uint256[] memory _tokenId,
        uint256[] memory _lendAmounts,
        uint8[] memory _maxRentDuration,
        bytes4[] memory _dailyRentPrice,
        bytes4[] memory _nftPrice,
        IResolver.PaymentToken[] memory _paymentToken
    ) external;

    /**
     * @dev renter sends rentDuration * dailyRentPrice
     * to cover for the potentially full cost of renting. They also
     * must send the collateral (nft price set by the lender in lend)
     */
    function rent(
        address[] memory _nft,
        uint256[] memory _tokenId,
        uint256[] memory _lendingIds,
        uint8[] memory _rentDurations
    ) external;

    /**
     * @dev renters call this to return the rented NFT before the
     * deadline. If they fail to do so, they will lose the posted
     * collateral
     */
    function returnIt(
        address[] memory _nft,
        uint256[] memory _tokenId,
        uint256[] memory _lendingIds
    ) external;

    /**
     * @dev claim collateral on rentals that are past their due date
     */
    function claimCollateral(
        address[] memory _nfts,
        uint256[] memory _tokenIds,
        uint256[] memory _lendingIds
    ) external;

    /**
     * @dev stop lending releases the NFT from escrow and sends it back
     * to the lender
     */
    function stopLending(
        address[] memory _nft,
        uint256[] memory _tokenId,
        uint256[] memory _lendingIds
    ) external;
}
// File: /home/marbach/Projects/Vera/Rental-ERC721/contracts/IResolver.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.6;

interface IResolver {
    enum PaymentToken {
        SENTINEL,
        WETH,
        DAI,
        USDC,
        USDT,
        TUSD,
        RENT
    }

    function getPaymentToken(uint8 _pt) external view returns (address);

    function setPaymentToken(uint8 _pt, address _v) external;
}