// File: contracts/PhunksAuctionHouse.sol



// SPDX-License-Identifier: GPL-3.0
/********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░██████████████████████░░░ *
 * ░░░██░░░░░░██░░░░░░████░░░░░ *
 * ░░░██░░░░░░██░░░░░░██░░░░░░░ *
 * ░░░██████████████████░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 ************************♥tt****/

// LICENSE
// PhunksAuctionHouse.sol is a modified version of Zora's AuctionHouse.sol:
// https://github.com/ourzora/auction-house/blob/54a12ec1a6cf562e49f0a4917990474b11350a2d/contracts/AuctionHouse.sol

// AuctionHouse.sol source code Copyright Zora licensed under the GPL-3.0 license.
// With modifications by Nounders DAO and ogkenobi.eth
// Not affiliated with Not Larva Labs

pragma solidity ^0.8.15;

import { Pausable } from '@openzeppelin/contracts/security/Pausable.sol';
import { ReentrancyGuard } from '@openzeppelin/contracts/security/ReentrancyGuard.sol';
import { Ownable } from '@openzeppelin/contracts/access/Ownable.sol';
import { IERC20 } from '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import { IPhunksAuctionHouse } from './interfaces/IPhunksAuctionHouse.sol';
import { IPhunksToken } from './interfaces/IPhunksToken.sol';
import { PunkDataInterface } from './interfaces/IPhunksToken.sol';
import { IWETH } from './interfaces/IWETH.sol';

contract PhunksAuctionHouse is IPhunksAuctionHouse, Pausable, ReentrancyGuard, Ownable {
    // The Phunks ERC721 token contract
    IPhunksToken public phunks;

    // The address of the WETH contract
    address public weth;

    // The minimum amount of time left in an auction after a new bid is created
    uint256 public timeBuffer;

    // The minimum price accepted in an auction
    uint256 public reservePrice;

    // The minimum percentage difference between the last bid amount and the current bid
    uint8 public minBidIncrementPercentage;

    // The duration of a single auction
    uint256 public duration;

    // The curren auction ID number
    uint256 public auctionId = 0;

    // The active auction
    IPhunksAuctionHouse.Auction public auction;

    // The Treasury wallet
    address public treasuryWallet;

    //CryptoPunks On-Chain Data contract address
    PunkDataInterface private punkDataContract;

    /**
     * @notice Initialize the auction house and base contracts,
     * populate configuration values, and pause the contract.
     * @dev This function can only be called once.
     */
    function initialize(
        IPhunksToken _phunks,
        address _weth,
        uint256 _timeBuffer,
        uint256 _reservePrice,
        uint8 _minBidIncrementPercentage,
        uint256 _duration,
        address _treasuryWallet,
        address _punksDataContractAddress
    ) public onlyOwner {

        _pause();

        phunks = _phunks;
        weth = _weth;
        timeBuffer = _timeBuffer;
        reservePrice = _reservePrice;
        minBidIncrementPercentage = _minBidIncrementPercentage;
        duration = _duration;
        treasuryWallet = _treasuryWallet;
        punkDataContract = PunkDataInterface(_punksDataContractAddress);
    }

    /**
     * @notice Settle the current auction, mint a new Phunk, and put it up for auction.
     */
    function settleCurrentAndCreateNewAuction() external override nonReentrant whenNotPaused {
        _settleAuction();
        _createAuction();
    }

    /**
     * @notice Settle the current auction.
     * @dev This function can only be called when the contract is paused.
     */
    function settleAuction() external override whenPaused nonReentrant {
        _settleAuction();
    }

    /**
     * @notice Create a bid for a Phunk, with a given amount.
     * @dev This contract only accepts payment in ETH.
     */
    function createBid(uint256 phunkId) external payable override nonReentrant {
        IPhunksAuctionHouse.Auction memory _auction = auction;

        require(_auction.phunkId == phunkId, 'Phunk not up for auction');
        require(block.timestamp < _auction.endTime, 'Auction expired');
        require(msg.value >= reservePrice, 'Must send at least reservePrice');
        require(
            msg.value >= _auction.amount + ((_auction.amount * minBidIncrementPercentage) / 100),
            'Must send more than last bid by minBidIncrementPercentage amount'
        );

        address payable lastBidder = _auction.bidder;

        // Refund the last bidder, if applicable
        if (lastBidder != address(0)) {
            _safeTransferETHWithFallback(lastBidder, _auction.amount);
        }

        auction.amount = msg.value;
        auction.bidder = payable(msg.sender);

        // Extend the auction if the bid was received within `timeBuffer` of the auction end time
        bool extended = _auction.endTime - block.timestamp < timeBuffer;
        if (extended) {
            auction.endTime = _auction.endTime = block.timestamp + timeBuffer;
        }

        emit AuctionBid(_auction.phunkId, auctionId, msg.sender, msg.value, extended);

        if (extended) {
            emit AuctionExtended(_auction.phunkId, auctionId, _auction.endTime);
        }
    }

    /**
     * @notice Pause the Phunks auction house.
     * @dev This function can only be called by the owner when the
     * contract is unpaused. While no new auctions can be started when paused,
     * anyone can settle an ongoing auction.
     */
    function pause() external override onlyOwner {
        _pause();
    }

    /**
     * @notice Unpause the Phunks auction house.
     * @dev This function can only be called by the owner when the
     * contract is paused. If required, this function will start a new auction.
     */
    function unpause() external override onlyOwner {
        _unpause();

        if (auction.startTime == 0 || auction.settled) {
            _createAuction();
        }
    }

    /**
     * @notice Set the treausury wallet address.
     * @dev Only callable by the owner.
     */
     function setTreasuryWallet(address _treasuryWallet) public onlyOwner {
        treasuryWallet = _treasuryWallet;
    }

    /**
     * @notice Set the duration of an auction
     * @dev Only callable by the owner.
     */
    function setDuration(uint256 _duration) external override onlyOwner {
        duration = _duration;

        emit AuctionDurationUpdated(_duration);
    }

    /**
     * @notice Set the auction time buffer.
     * @dev Only callable by the owner.
     */
    function setTimeBuffer(uint256 _timeBuffer) external override onlyOwner {
        timeBuffer = _timeBuffer;

        emit AuctionTimeBufferUpdated(_timeBuffer);
    }

    /**
     * @notice Set the auction reserve price.
     * @dev Only callable by the owner.
     */
    function setReservePrice(uint256 _reservePrice) external override onlyOwner {
        reservePrice = _reservePrice;

        emit AuctionReservePriceUpdated(_reservePrice);
    }

    /**
     * @notice Set the auction minimum bid increment percentage.
     * @dev Only callable by the owner.
     */
    function setMinBidIncrementPercentage(uint8 _minBidIncrementPercentage) external override onlyOwner {
        minBidIncrementPercentage = _minBidIncrementPercentage;

        emit AuctionMinBidIncrementPercentageUpdated(_minBidIncrementPercentage);
    }

    /**
     * @notice Generates a big random number on the cheap.
     * 
     */
    function _getRand() internal view returns(uint256) {
        uint256 randNum = uint256(keccak256(abi.encodePacked(block.timestamp + block.difficulty +  
        ((uint256(keccak256(abi.encodePacked(msg.sender)))) / (block.timestamp)) + block.number)));
        
        return randNum;
    }

    /**
     * @notice Create an auction.
     * @dev Store the auction details in the `auction` state variable and emit an AuctionCreated event.
     * If the mint reverts, the minter was updated without pausing this contract first. To remedy this,
     * catch the revert and pause this contract.
     */
    function _createAuction() internal {
            try phunks.getPhunksBelongingToOwner(treasuryWallet) returns (uint256[] memory phunkArray) {
            uint256 phunkId = phunkArray[(_getRand() % phunkArray.length)];
            uint i = 0;
            //reserves 6 phunk IDs: 1 ape, 4 zombies, and 7-trait
            while (phunkId == 2711 || phunkId == 1478 || phunkId == 5066 || phunkId == 5312 || phunkId == 5742 || phunkId == 8348)
            {
                phunkId = phunkArray[i];
                ++i;
            }
            bytes memory phunkImage = punkDataContract.punkImage(uint16(phunkId));
            string memory attributes = punkDataContract.punkAttributes(uint16(phunkId));
            uint256 startTime = block.timestamp;
            uint256 endTime = startTime + duration;
            auctionId++;

            auction = Auction({
                phunkId: phunkId,
                amount: 0,
                startTime: startTime,
                endTime: endTime,
                bidder: payable(0),
                settled: false,
                auctionId: auctionId
            });

            emit AuctionCreated(phunkId, auctionId, startTime, endTime, attributes, phunkImage);

        } catch Error(string memory) {
            _pause();
        }
    }
    /**
     * @notice Create an speacial auction for specific phunkID
     * @dev Store the auction details in the `auction` state variable and emit an AuctionCreated event.
     * If the mint reverts, the minter was updated without pausing this contract first. To remedy this,
     * catch the revert and pause this contract.
     */
    function createSpecialAuction(uint256 _phunkId, uint256 _endTime) public onlyOwner {
        uint256 phunkId = _phunkId;
        uint256 startTime = block.timestamp;
        uint256 endTime = _endTime;
        bytes memory phunkImage = punkDataContract.punkImage(uint16(phunkId));
        string memory attributes = punkDataContract.punkAttributes(uint16(phunkId));
        auctionId++;

        auction = Auction({
            phunkId: phunkId,
            amount: 0,
            startTime: startTime,
            endTime: endTime,
            bidder: payable(0),
            settled: false,
            auctionId: auctionId
        });

        emit AuctionCreated(phunkId, auctionId, startTime, endTime, attributes, phunkImage);
    
    }

    /**
     * @notice Settle an auction, finalizing the bid and paying out to the owner.
     * @dev If there are no bids, the Phunk is burned.
     */
    function _settleAuction() internal {
        IPhunksAuctionHouse.Auction memory _auction = auction;

        require(_auction.startTime != 0, "Auction hasn't begun");
        require(!_auction.settled, 'Auction has already been settled');
        require(block.timestamp >= _auction.endTime, "Auction hasn't completed");

        auction.settled = true;

        if (_auction.bidder != address(0)) {
            phunks.transferFrom(address(treasuryWallet), _auction.bidder, _auction.phunkId);
        }

        if (_auction.amount > 0) {
            _safeTransferETHWithFallback(treasuryWallet, _auction.amount);
        }

        emit AuctionSettled(_auction.phunkId, auctionId, _auction.bidder, _auction.amount);
    }

    /**
     * @notice Transfer ETH. If the ETH transfer fails, wrap the ETH and try send it as WETH.
     */
    function _safeTransferETHWithFallback(address to, uint256 amount) internal {
        if (!_safeTransferETH(to, amount)) {
            IWETH(weth).deposit{ value: amount }();
            IERC20(weth).transfer(to, amount);
        }
    }

    /**
     * @notice Transfer ETH and return the success status.
     * @dev This function only forwards 30,000 gas to the callee.
     */
    function _safeTransferETH(address to, uint256 value) internal returns (bool) {
        (bool success, ) = to.call{ value: value, gas: 30_000 }(new bytes(0));
        return success;
    }
}
// File: @openzeppelin/contracts/security/Pausable.sol



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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

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



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

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

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



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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

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

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

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

// File: @openzeppelin/contracts/token/ERC20/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/interfaces/IPhunksAuctionHouse.sol



// SPDX-License-Identifier: GPL-3.0
/********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░██████████████████████░░░ *
 * ░░░██░░░░░░██░░░░░░████░░░░░ *
 * ░░░██░░░░░░██░░░░░░██░░░░░░░ *
 * ░░░██████████████████░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 ************************♥tt****/
pragma solidity ^0.8.15;

interface IPhunksAuctionHouse {
    struct Auction {
        // ID for the Phunk (ERC721 token ID)
        uint256 phunkId;
        // The current highest bid amount
        uint256 amount;
        // The time that the auction started
        uint256 startTime;
        // The time that the auction is scheduled to end
        uint256 endTime;
        // The address of the current highest bid
        address payable bidder;
        // Whether or not the auction has been settled
        bool settled;
        // Auction ID number
        uint256 auctionId;
    }

    event AuctionCreated(uint256 indexed phunkId, uint256 auctionId, uint256 startTime, uint256 endTime, string attributes, bytes image);

    event AuctionBid(uint256 indexed phunkId, uint256 auctionId, address sender, uint256 value, bool extended);

    event AuctionExtended(uint256 indexed phunkId, uint256 auctionId, uint256 endTime);

    event AuctionSettled(uint256 indexed phunkId, uint256 auctionId, address winner, uint256 amount);

    event AuctionTimeBufferUpdated(uint256 timeBuffer);

    event AuctionDurationUpdated(uint256 duration);

    event AuctionReservePriceUpdated(uint256 reservePrice);

    event AuctionMinBidIncrementPercentageUpdated(uint256 minBidIncrementPercentage);

    function settleAuction() external;

    function settleCurrentAndCreateNewAuction() external;

    function createBid(uint256 phunkId) external payable;

    function pause() external;

    function unpause() external;

    function setTimeBuffer(uint256 timeBuffer) external;

    function setDuration(uint256 duration) external;

    function setReservePrice(uint256 reservePrice) external;

    function setMinBidIncrementPercentage(uint8 minBidIncrementPercentage) external;
}
// File: contracts/interfaces/IPhunksToken.sol



// SPDX-License-Identifier: GPL-3.0
/********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░██████████████████████░░░ *
 * ░░░██░░░░░░██░░░░░░████░░░░░ *
 * ░░░██░░░░░░██░░░░░░██░░░░░░░ *
 * ░░░██████████████████░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 ************************♥tt****/
pragma solidity ^0.8.15;

import { IERC721 } from '@openzeppelin/contracts/token/ERC721/IERC721.sol';

interface IPhunksToken is IERC721 {

    function getPhunksBelongingToOwner(address _owner) external view returns (uint256[] memory);

}

interface PunkDataInterface {

    function punkImage(uint16 index) external view returns (bytes memory);
    function punkAttributes(uint16 index) external view returns (string memory);

}
// File: contracts/interfaces/IWETH.sol



// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.15;

interface IWETH {
    function deposit() external payable;

    function withdraw(uint256 wad) external;

    function transfer(address to, uint256 value) external returns (bool);
}
// 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/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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 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 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/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);
}