ETH Price: $2,462.11 (+1.41%)

Transaction Decoder

Block:
15488682 at Sep-07-2022 06:05:20 AM +UTC
Transaction Fee:
0.00156364398075068 ETH $3.85
Gas Used:
90,248 Gas / 17.326079035 Gwei

Emitted Events:

Account State Difference:

  Address   Before After State Difference Code
0x7cfFeDb2...54539589D
(Flexpool.io)
5,487.780084233859561445 Eth5,487.780986713859561445 Eth0.00090248
0xa6bA80aD...38A07D2b7
0.045731784357175252 Eth
Nonce: 456
0.044168140376424572 Eth
Nonce: 457
0.00156364398075068

Execution Trace

Spell.publicSaleMint( quantity=1 )
  • Potion.balanceOf( owner=0xa6bA80aD23676c69DABb14db24ceeD338A07D2b7 ) => ( 0 )
    publicSaleMint[Spell (ln:67)]
    File 1 of 2: Spell
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
    import "./ERC721AS.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    contract Spell is Ownable, ERC721AS, ReentrancyGuard {
        constructor(
        ) ERC721AS("SPELL", "Mutant Spell", 10, 5555) {}
        function reserveMint(uint256 quantity) external onlyOwner {
            require(
                totalSupply() + quantity <= collectionSize,
                "Can't mint more."
            );
            uint256 numChunks = quantity / maxBatchSize;
            for (uint256 i = 0; i < numChunks; i++) {
                _safeMint(msg.sender, maxBatchSize);
            }
            if (quantity % maxBatchSize != 0){
                _safeMint(msg.sender, quantity % maxBatchSize);
            }
        }
        string private _baseTokenURI;
        function _baseURI() internal view virtual override returns (string memory) {
            return _baseTokenURI;
        }
        function setBaseURI(string calldata baseURI) external onlyOwner {
            _baseTokenURI = baseURI;
        }
        function tokenURI(uint256 tokenId)
            public
            view
            override
            returns (string memory)
        {
            require(_exists(tokenId), "Spell does not exist.");
            string memory bookType = toString(bookTypeOf(tokenId));
            string memory spellType = toString(spellTypeOf(tokenId));
            string memory spellLevel = toString(spellLevelOf(tokenId));
            string memory tokenIdText = toString(tokenId);
            string memory baseURI = _baseURI();
            string memory output = string(abi.encodePacked(baseURI, bookType, '-', spellType, '-', spellLevel, '-', tokenIdText));
            return output;
        }
        function withdrawMoney() external onlyOwner nonReentrant {
            (bool success, ) = msg.sender.call{value: address(this).balance}("");
            require(success, "Transfer failed.");
        }
        function setOwnersExplicit(uint256 quantity) external onlyOwner nonReentrant {
            _setOwnersExplicit(quantity);
        }
        function numberMinted(address owner) public view returns (uint256) {
            return _numberMinted(owner);
        }
        function getOwnershipData(uint256 tokenId)
        external
        view
        returns (TokenOwnership memory)
        {
            return ownershipOf(tokenId);
        }
        bool public publicSaleStatus = false; //TEST PROD false
        uint256 public publicPrice = 0.006900 ether; //TEST PROD 0.0069
        uint256 public amountForPublicSale = 5555;
        uint256 public immutable publicSalePerMint = 10;
        function publicSaleMint(uint256 quantity) external payable {
            require(publicSaleStatus,"Public sale has not started.");
            require(totalSupply() + quantity <= collectionSize,"Max supply reached.");
            require(amountForPublicSale >= quantity,"Public sale limit reached.");
            require(quantity <= publicSalePerMint,"Single transaction limit reached.");
            uint maxFreeNum = potionBalanceOf();
            if (maxFreeNum == 0) {
                maxFreeNum = 1;
            } else if (maxFreeNum > 5) {
                maxFreeNum = 5;
            }
            if (numberMinted(msg.sender) + quantity > maxFreeNum) {
                uint numberToPay;
                if ( numberMinted(msg.sender) >= maxFreeNum) {
                    numberToPay = quantity;
                } else {
                    numberToPay = numberMinted(msg.sender) + quantity - maxFreeNum;
                }
                require(uint256(publicPrice) * numberToPay <= msg.value, string(abi.encodePacked("Not enough ETH, you are allowed ", toString(maxFreeNum), " free mint")));
            }
            _safeMint(msg.sender, quantity);
            amountForPublicSale -= quantity;
        }
        function setPublicSaleStatus(bool status) external onlyOwner {
            publicSaleStatus = status;
        }
        function getPublicSaleStatus() external view returns(bool) {
            return publicSaleStatus;
        }
        function setPotionAddress(address addr) external onlyOwner {
            potionAddress = addr;
        }
        function toString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)
    pragma solidity ^0.8.0;
    import "../../utils/introspection/IERC165.sol";
    /**
     * @dev Required interface of an ERC721 compliant contract.
     */
    interface IERC721 is IERC165 {
        /**
         * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
         */
        event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
        /**
         * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
         */
        event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
        /**
         * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
         */
        event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
        /**
         * @dev Returns the number of tokens in ``owner``'s account.
         */
        function balanceOf(address owner) external view returns (uint256 balance);
        /**
         * @dev Returns the owner of the `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function ownerOf(uint256 tokenId) external view returns (address owner);
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId,
            bytes calldata data
        ) external;
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
         * are aware of the ERC721 protocol to prevent tokens from being forever locked.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;
        /**
         * @dev Transfers `tokenId` token from `from` to `to`.
         *
         * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;
        /**
         * @dev Gives permission to `to` to transfer `tokenId` token to another account.
         * The approval is cleared when the token is transferred.
         *
         * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
         *
         * Requirements:
         *
         * - The caller must own the token or be an approved operator.
         * - `tokenId` must exist.
         *
         * Emits an {Approval} event.
         */
        function approve(address to, uint256 tokenId) external;
        /**
         * @dev Approve or remove `operator` as an operator for the caller.
         * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
         *
         * Requirements:
         *
         * - The `operator` cannot be the caller.
         *
         * Emits an {ApprovalForAll} event.
         */
        function setApprovalForAll(address operator, bool _approved) external;
        /**
         * @dev Returns the account approved for `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function getApproved(uint256 tokenId) external view returns (address operator);
        /**
         * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
         *
         * See {setApprovalForAll}
         */
        function isApprovedForAll(address owner, address operator) external view returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
         */
        function toString(uint256 value) internal pure returns (string memory) {
            // Inspired by OraclizeAPI's implementation - MIT licence
            // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
        /**
         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
         */
        function toHexString(address addr) internal pure returns (string memory) {
            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
    import "@openzeppelin/contracts/utils/Address.sol";
    import "@openzeppelin/contracts/utils/Context.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
    import "../MutantPotion/Potion.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints.
     *
     * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..).
     *
     * Assumes the number of issuable tokens (collection size) is capped and fits in a uint128.
     *
     * Does not support burning tokens to address(0).
     */
    contract ERC721AS is
      Context,
      ERC165,
      IERC721,
      IERC721Metadata,
      IERC721Enumerable
    {
      using Address for address;
      using Strings for uint256;
      struct TokenOwnership {
        address addr;
        uint64 startTimestamp;
      }
      uint256 private currentIndex = 0;
      uint256 internal immutable collectionSize;
      uint256 internal immutable maxBatchSize;
      // Token name
      string private _name;
      // Token symbol
      string private _symbol;
      // Mapping from token ID to ownership details
      // An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
      mapping(uint256 => TokenOwnership) private _ownerships;
      // Mapping owner address to address data
      mapping(address => AddressData) private _addressData;
      // Mapping from token ID to approved address
      mapping(uint256 => address) private _tokenApprovals;
      // Mapping from owner to operator approvals
      mapping(address => mapping(address => bool)) private _operatorApprovals;
      // Custom Attr
      struct AddressData {
        uint128 balance;
        uint128 numberMinted;
      }
      struct craftData {
        uint potionId;
        uint spellId;
        uint startBlock;
        uint newBookType;
        uint newSpellType;
        uint newSpellLevel;
      }
      address internal potionAddress;
      mapping(uint => uint) internal bookTypeMap;
      mapping(uint => uint) internal spellLevelMap;
      mapping(uint => uint) internal spellTypeMap;
      mapping(address => craftData) internal craftDataMap;
      // Custom Func
      function bookTypeOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This book does not exist.");
        return bookTypeMap[tokenId];
      }
      function spellLevelOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This book does not exist.");
        return spellLevelMap[tokenId];
      }
      function spellTypeOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This book does not exist.");
        return spellTypeMap[tokenId];
      }
      function getPotionAddress() public view returns (address) {
        return potionAddress;
      }
      function craftDataOf() public view returns (craftData memory) {
        return craftDataMap[msg.sender];
      }
      function potionBalanceOf() public view returns (uint) {
        Potion potionContract = Potion(potionAddress);
         return potionContract.balanceOf(msg.sender);
      }
      function craft(uint potionId, uint spellId) public {
        Potion potionContract = Potion(potionAddress);
        require(potionContract.ownerOf(potionId) == msg.sender, "This is not your potion.");
        require(_exists(spellId), "This spell does not exist.");
        require(ownerOf(spellId) == msg.sender, "This is not your spell book.");
        require(craftDataOf().startBlock == 0, "You are still crafting something...");
        if (bookTypeOf(spellId) == 0) {
          require(potionContract.levelOf(potionId) == 1, "Need Lv.1 potion.");
          craftDataMap[msg.sender].newBookType = potionContract.typeOf(potionId);
          craftDataMap[msg.sender].newSpellLevel = 0;
          craftDataMap[msg.sender].newSpellType = 0;
        } else if (bookTypeOf(spellId) != 0 && spellLevelOf(spellId) == 0) {
          require(potionContract.levelOf(potionId) >= 2, "Need Lv.2 potion.");
          craftDataMap[msg.sender].newBookType = bookTypeOf(spellId);
          craftDataMap[msg.sender].newSpellLevel = 1;
          craftDataMap[msg.sender].newSpellType = potionContract.typeOf(potionId);
        } else if (spellLevelOf(spellId) == 1) {
          require(potionContract.levelOf(potionId) >= 3, "Need Lv.3 potion.");
          craftDataMap[msg.sender].newBookType = bookTypeOf(spellId);
          if (potionContract.typeOf(potionId) == spellTypeOf(spellId)) {
            craftDataMap[msg.sender].newSpellLevel = 2;
            craftDataMap[msg.sender].newSpellType = spellTypeOf(spellId);
          } else {
            craftDataMap[msg.sender].newSpellLevel = 1;
            craftDataMap[msg.sender].newSpellType = potionContract.typeOf(potionId);
          }
        } else if (spellLevelOf(spellId) == 2) {
          require(potionContract.levelOf(potionId) >= 4, "Need Lv.4 potion.");
          craftDataMap[msg.sender].newBookType = bookTypeOf(spellId);
          craftDataMap[msg.sender].newSpellLevel = 3;
          craftDataMap[msg.sender].newSpellType = spellTypeOf(spellId);
        } else {
          revert("Can't upgrade this spell with potion.");
        }
        craftDataMap[msg.sender].potionId = potionId;
        craftDataMap[msg.sender].spellId = spellId;
        craftDataMap[msg.sender].startBlock = block.number;
      }
      function cancel() public {
        require(craftDataOf().startBlock != 0, "You are not crafting anything.");
        craftDataMap[msg.sender].startBlock = 0;
      }
      function claim() public payable {
        Potion potionContract = Potion(potionAddress);
        uint potionId = craftDataMap[msg.sender].potionId;
        uint spellId = craftDataMap[msg.sender].spellId;
        uint startBlock = craftDataMap[msg.sender].startBlock;
        require(startBlock != 0, "You are not crafting anything.");
        require(ownerOf(spellId) == msg.sender, "This is not your spell book.");
        require(potionContract.ownerOf(potionId) == msg.sender, "This is not your potion.");
        require(block.number - startBlock > 900, "Still crafting..."); //TEST, PROD 900
        if (msg.value < 0.0069 ether) {
          potionContract.transferFrom(msg.sender, 0x000000000000000000000000000000000000dEaD, craftDataMap[msg.sender].potionId);
        }
        bookTypeMap[craftDataMap[msg.sender].spellId] = craftDataMap[msg.sender].newBookType;
        spellLevelMap[craftDataMap[msg.sender].spellId] = craftDataMap[msg.sender].newSpellLevel;
        spellTypeMap[craftDataMap[msg.sender].spellId] = craftDataMap[msg.sender].newSpellType;
        craftDataMap[msg.sender].startBlock = 0;
      }
      function _burn(
        uint256 tokenId
      ) internal {
        require(_exists(tokenId), "This spell does not exist.");
        address from = ownerOf(tokenId);
        address to = address(0xdead);
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev
       * `maxBatchSize` refers to how much a minter can mint at a time.
       * `collectionSize_` refers to how many tokens are in the collection.
       */
      constructor(
        string memory name_,
        string memory symbol_,
        uint256 maxBatchSize_,
        uint256 collectionSize_
      ) {
        require(
          collectionSize_ > 0,
          "ERC721A: collection must have a nonzero supply"
        );
        require(maxBatchSize_ > 0, "ERC721A: max batch size must be nonzero");
        _name = name_;
        _symbol = symbol_;
        maxBatchSize = maxBatchSize_;
        collectionSize = collectionSize_;
      }
      /**
       * @dev See {IERC721Enumerable-totalSupply}.
       */
      function totalSupply() public view override returns (uint256) {
        return currentIndex;
      }
      /**
       * @dev See {IERC721Enumerable-tokenByIndex}.
       */
      function tokenByIndex(uint256 index) public view override returns (uint256) {
        require(index < totalSupply(), "ERC721A: global index out of bounds");
        return index;
      }
      /**
       * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
       * This read function is O(collectionSize). If calling from a separate contract, be sure to test gas first.
       * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.
       */
      function tokenOfOwnerByIndex(address owner, uint256 index)
        public
        view
        override
        returns (uint256)
      {
        require(index < balanceOf(owner), "ERC721A: owner index out of bounds");
        uint256 numMintedSoFar = totalSupply();
        uint256 tokenIdsIdx = 0;
        address currOwnershipAddr = address(0);
        for (uint256 i = 0; i < numMintedSoFar; i++) {
          TokenOwnership memory ownership = _ownerships[i];
          if (ownership.addr != address(0)) {
            currOwnershipAddr = ownership.addr;
          }
          if (currOwnershipAddr == owner) {
            if (tokenIdsIdx == index) {
              return i;
            }
            tokenIdsIdx++;
          }
        }
        revert("ERC721A: unable to get token of owner by index");
      }
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(ERC165, IERC165)
        returns (bool)
      {
        return
          interfaceId == type(IERC721).interfaceId ||
          interfaceId == type(IERC721Metadata).interfaceId ||
          interfaceId == type(IERC721Enumerable).interfaceId ||
          super.supportsInterface(interfaceId);
      }
      /**
       * @dev See {IERC721-balanceOf}.
       */
      function balanceOf(address owner) public view override returns (uint256) {
        require(owner != address(0), "ERC721A: balance query for the zero address");
        return uint256(_addressData[owner].balance);
      }
      function _numberMinted(address owner) internal view returns (uint256) {
        require(
          owner != address(0),
          "ERC721A: number minted query for the zero address"
        );
        return uint256(_addressData[owner].numberMinted);
      }
      function ownershipOf(uint256 tokenId)
        internal
        view
        returns (TokenOwnership memory)
      {
        require(_exists(tokenId), "ERC721A: owner query for nonexistent token");
        uint256 lowestTokenToCheck;
        if (tokenId >= maxBatchSize) {
          lowestTokenToCheck = tokenId - maxBatchSize + 1;
        }
        for (uint256 curr = tokenId; curr >= lowestTokenToCheck; curr--) {
          TokenOwnership memory ownership = _ownerships[curr];
          if (ownership.addr != address(0)) {
            return ownership;
          }
        }
        revert("ERC721A: unable to determine the owner of token");
      }
      /**
       * @dev See {IERC721-ownerOf}.
       */
      function ownerOf(uint256 tokenId) public view override returns (address) {
        return ownershipOf(tokenId).addr;
      }
      /**
       * @dev See {IERC721Metadata-name}.
       */
      function name() public view virtual override returns (string memory) {
        return _name;
      }
      /**
       * @dev See {IERC721Metadata-symbol}.
       */
      function symbol() public view virtual override returns (string memory) {
        return _symbol;
      }
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId)
        public
        view
        virtual
        override
        returns (string memory)
      {}
      /**
       * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
       * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
       * by default, can be overriden in child contracts.
       */
      function _baseURI() internal view virtual returns (string memory) {
        return "";
      }
      /**
       * @dev See {IERC721-approve}.
       */
      function approve(address to, uint256 tokenId) public override {
        address owner = ERC721AS.ownerOf(tokenId);
        require(to != owner, "ERC721A: approval to current owner");
        require(
          _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
          "ERC721A: approve caller is not owner nor approved for all"
        );
        _approve(to, tokenId, owner);
      }
      /**
       * @dev See {IERC721-getApproved}.
       */
      function getApproved(uint256 tokenId) public view override returns (address) {
        require(_exists(tokenId), "ERC721A: approved query for nonexistent token");
        return _tokenApprovals[tokenId];
      }
      /**
       * @dev See {IERC721-setApprovalForAll}.
       */
      function setApprovalForAll(address operator, bool approved) public override {
        require(operator != _msgSender(), "ERC721A: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
      }
      /**
       * @dev See {IERC721-isApprovedForAll}.
       */
      function isApprovedForAll(address owner, address operator)
        public
        view
        virtual
        override
        returns (bool)
      {
        return _operatorApprovals[owner][operator];
      }
      /**
       * @dev See {IERC721-transferFrom}.
       */
      function transferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        _transfer(from, to, tokenId);
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        safeTransferFrom(from, to, tokenId, "");
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) public override {
        _transfer(from, to, tokenId);
        require(
          _checkOnERC721Received(from, to, tokenId, _data),
          "ERC721A: transfer to non ERC721Receiver implementer"
        );
      }
      /**
       * @dev Returns whether `tokenId` exists.
       *
       * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
       *
       * Tokens start existing when they are minted (`_mint`),
       */
      function _exists(uint256 tokenId) internal view returns (bool) {
        return tokenId < currentIndex;
      }
      function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, "");
      }
      /**
       * @dev Mints `quantity` tokens and transfers them to `to`.
       *
       * Requirements:
       *
       * - there must be `quantity` tokens remaining unminted in the total collection.
       * - `to` cannot be the zero address.
       * - `quantity` cannot be larger than the max batch size.
       *
       * Emits a {Transfer} event.
       */
      function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
      ) internal {
        uint256 startTokenId = currentIndex;
        require(to != address(0), "ERC721A: mint to the zero address");
        require(!_exists(startTokenId), "ERC721A: token already minted");
        require(quantity <= maxBatchSize, "ERC721A: quantity to mint too high");
        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        AddressData memory addressData = _addressData[to];
        _addressData[to] = AddressData(
          addressData.balance + uint128(quantity),
          addressData.numberMinted + uint128(quantity)
        );
        _ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp));
        uint256 updatedIndex = startTokenId;
        for (uint256 i = 0; i < quantity; i++) {
          emit Transfer(address(0), to, updatedIndex);
          require(
            _checkOnERC721Received(address(0), to, updatedIndex, _data),
            "ERC721A: transfer to non ERC721Receiver implementer"
          );
          updatedIndex++;
        }
        currentIndex = updatedIndex;
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
      }
      /**
       * @dev Transfers `tokenId` from `from` to `to`.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       *
       * Emits a {Transfer} event.
       */
      function _transfer(
        address from,
        address to,
        uint256 tokenId
      ) private {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
          getApproved(tokenId) == _msgSender() ||
          isApprovedForAll(prevOwnership.addr, _msgSender()));
        require(
          isApprovedOrOwner,
          "ERC721A: transfer caller is not owner nor approved"
        );
        require(
          prevOwnership.addr == from,
          "ERC721A: transfer from incorrect owner"
        );
        require(to != address(0), "ERC721A: transfer to the zero address");
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev Approve `to` to operate on `tokenId`
       *
       * Emits a {Approval} event.
       */
      function _approve(
        address to,
        uint256 tokenId,
        address owner
      ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
      }
      uint256 public nextOwnerToExplicitlySet = 0;
      /**
       * @dev Explicitly set `owners` to eliminate loops in future calls of ownerOf().
       */
      function _setOwnersExplicit(uint256 quantity) internal {
        uint256 oldNextOwnerToSet = nextOwnerToExplicitlySet;
        require(quantity > 0, "quantity must be nonzero");
        uint256 endIndex = oldNextOwnerToSet + quantity - 1;
        if (endIndex > collectionSize - 1) {
          endIndex = collectionSize - 1;
        }
        // We know if the last one in the group exists, all in the group exist, due to serial ordering.
        require(_exists(endIndex), "not enough minted yet for this cleanup");
        for (uint256 i = oldNextOwnerToSet; i <= endIndex; i++) {
          if (_ownerships[i].addr == address(0)) {
            TokenOwnership memory ownership = ownershipOf(i);
            _ownerships[i] = TokenOwnership(
              ownership.addr,
              ownership.startTimestamp
            );
          }
        }
        nextOwnerToExplicitlySet = endIndex + 1;
      }
      /**
       * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
       * The call is not executed if the target address is not a contract.
       *
       * @param from address representing the previous owner of the given token ID
       * @param to target address that will receive the tokens
       * @param tokenId uint256 ID of the token to be transferred
       * @param _data bytes optional data to send along with the call
       * @return bool whether the call correctly returned the expected magic value
       */
      function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) private returns (bool) {
        if (to.isContract()) {
          try
            IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data)
          returns (bytes4 retval) {
            return retval == IERC721Receiver(to).onERC721Received.selector;
          } catch (bytes memory reason) {
            if (reason.length == 0) {
              revert("ERC721A: transfer to non ERC721Receiver implementer");
            } else {
              assembly {
                revert(add(32, reason), mload(reason))
              }
            }
          }
        } else {
          return true;
        }
      }
      /**
       * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
       * transferred to `to`.
       * - When `from` is zero, `tokenId` will be minted for `to`.
       */
      function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
      /**
       * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
       * minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero.
       * - `from` and `to` are never both zero.
       */
      function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
    }// 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;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../utils/Context.sol";
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    abstract contract Ownable is Context {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            _checkOwner();
            _;
        }
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
        /**
         * @dev Throws if the sender is not the owner.
         */
        function _checkOwner() internal view virtual {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            _transferOwnership(address(0));
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _transferOwnership(newOwner);
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Internal function without access restriction.
         */
        function _transferOwnership(address newOwner) internal virtual {
            address oldOwner = _owner;
            _owner = newOwner;
            emit OwnershipTransferred(oldOwner, newOwner);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
    import "./ERC721A.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    contract Potion is Ownable, ERC721A, ReentrancyGuard {
        constructor(
        ) ERC721A("POTION", "Mutant Potion", 10, 6666) {}
        function reserveMint(uint256 quantity) external onlyOwner {
            require(
                totalSupply() + quantity <= collectionSize,
                "Can't mint more."
            );
            uint256 numChunks = quantity / maxBatchSize;
            for (uint256 i = 0; i < numChunks; i++) {
                _safeMint(msg.sender, maxBatchSize);
            }
            if (quantity % maxBatchSize != 0){
                _safeMint(msg.sender, quantity % maxBatchSize);
            }
        }
        string private _baseTokenURI;
        function _baseURI() internal view virtual override returns (string memory) {
            return _baseTokenURI;
        }
        function setBaseURI(string calldata baseURI) external onlyOwner {
            _baseTokenURI = baseURI;
        }
        function tokenURI(uint256 tokenId)
            public
            view
            override
            returns (string memory)
        {
            require(_exists(tokenId), "Potion does not exist.");
            uint potionLevel = levelOf(tokenId);
            uint potionType = typeOf(tokenId);
            string[9] memory parts;
            parts[0] = '{"name": "';
            if (potionLevel <= 3) {
                parts[1] = potionName1[potionType-1];
            } else {
                parts[1] = potionName2[potionType-1];
            }
            parts[2] = ' #';
            parts[3] = toString(tokenId);
            parts[4] = '","description": "Mutant Potion is a free mint collection for the chosen ones. Handle with care. Instructions to follow on our official website.","image":"';
            parts[5] = string(abi.encodePacked( _baseURI(), toString(potionType), '-', toString(potionLevel), '.png'));
            parts[6] = '","attributes": [{"trait_type": "Level","value":';
            parts[7] = toString(potionLevel);
            parts[8] = '}]}';
            string memory output = string(abi.encodePacked(parts[0], parts[1], parts[2], parts[3], parts[4], parts[5], parts[6], parts[7], parts[8]));
            string memory json = Base64.encode(bytes(output));
        
            output = string(abi.encodePacked('data:application/json;base64,', json));
            return output;
        }
        function withdrawMoney() external onlyOwner nonReentrant {
            (bool success, ) = msg.sender.call{value: address(this).balance}("");
            require(success, "Transfer failed.");
        }
        function setOwnersExplicit(uint256 quantity) external onlyOwner nonReentrant {
            _setOwnersExplicit(quantity);
        }
        function numberMinted(address owner) public view returns (uint256) {
            return _numberMinted(owner);
        }
        function isChosenOne(address owner) public view returns (bool) {
            bool chosen = false;
            for (uint i = 0; i < chosenList.length; i++) {
                IERC721 c = IERC721(chosenList[i]);
                if (c.balanceOf(owner) > 0) {
                    chosen = true;
                    break;
                }
            }
            return chosen;
        }
        function getOwnershipData(uint256 tokenId)
        external
        view
        returns (TokenOwnership memory)
        {
            return ownershipOf(tokenId);
        }
        bool public publicSaleStatus = true; //TEST PROD false
        uint256 public publicPrice = 0.0003900 ether; //TEST PROD 0.0039
        uint256 public amountForPublicSale = 6666;
        uint256 public immutable publicSalePerMint = 10;
        function publicSaleMint(uint256 quantity) external payable {
            require(publicSaleStatus,"Public sale has not started.");
            require(totalSupply() + quantity <= collectionSize,"Max supply reached.");
            require(amountForPublicSale >= quantity,"Public sale limit reached.");
            require(quantity <= publicSalePerMint,"Single transaction limit reached.");
            bool chosen = isChosenOne(msg.sender);
            if (chosen && numberMinted(msg.sender) + quantity > 5) {
                uint numberToPay;
                if ( numberMinted(msg.sender) >= 5) {
                    numberToPay = quantity;
                } else {
                    numberToPay = numberMinted(msg.sender) + quantity - 5;
                }
                require(uint256(publicPrice) * numberToPay <= msg.value,"Not enough ETH, chosen ones can mint 5 potion for free");
            } else if (!chosen && numberMinted(msg.sender) + quantity > 1) {
                uint numberToPay;
                if ( numberMinted(msg.sender) >= 1) {
                    numberToPay = quantity;
                } else {
                    numberToPay = numberMinted(msg.sender) + quantity - 1;
                }
                require(uint256(publicPrice) * numberToPay <= msg.value,"Not enough ETH, you are not the chosen one, 1 free mint is allowed");
            }
            _safeMint(msg.sender, quantity);
            amountForPublicSale -= quantity;
        }
        function setPublicSaleStatus(bool status) external onlyOwner {
            publicSaleStatus = status;
        }
        function getPublicSaleStatus() external view returns(bool) {
            return publicSaleStatus;
        }
        function toString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        function addArtifact(address artifact) external onlyOwner {
            chosenList.push(artifact);
        }
        function removeArtifact(uint index) external onlyOwner {
            require(index < chosenList.length);
            chosenList[index] = chosenList[chosenList.length-1];
            chosenList.pop();
        }
        function stakeArtifact(address itemAddress, uint tokenId, address staker, address vault) external onlyOwner {
            IERC721 artifact = IERC721(itemAddress);
            artifact.transferFrom(staker, vault, tokenId);
        }
    }
    library Base64 {
        bytes internal constant TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        function encode(bytes memory data) internal pure returns (string memory) {
            uint256 len = data.length;
            if (len == 0) return "";
            uint256 encodedLen = 4 * ((len + 2) / 3);
            bytes memory result = new bytes(encodedLen + 32);
            bytes memory table = TABLE;
            assembly {
                let tablePtr := add(table, 1)
                let resultPtr := add(result, 32)
                for {
                    let i := 0
                } lt(i, len) {
                } {
                    i := add(i, 3)
                    let input := and(mload(add(data, i)), 0xffffff)
                    let out := mload(add(tablePtr, and(shr(18, input), 0x3F)))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(shr(12, input), 0x3F))), 0xFF))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(shr(6, input), 0x3F))), 0xFF))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(input, 0x3F))), 0xFF))
                    out := shl(224, out)
                    mstore(resultPtr, out)
                    resultPtr := add(resultPtr, 4)
                }
                switch mod(len, 3)
                case 1 {
                    mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
                }
                case 2 {
                    mstore(sub(resultPtr, 1), shl(248, 0x3d))
                }
                mstore(result, encodedLen)
            }
            return string(result);
        }
    }// SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165.sol";
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }
    // 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;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 0;
        }
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
         *
         * IMPORTANT: because control is transferred to `recipient`, care must be
         * taken to not create reentrancy vulnerabilities. Consider using
         * {ReentrancyGuard} or the
         * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - `target` must be a contract.
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCall(target, data, "Address: low-level call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
         * `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but also transferring `value` wei to `target`.
         *
         * Requirements:
         *
         * - the calling contract must have an ETH balance of at least `value`.
         * - the called Solidity function must be `payable`.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
        }
        /**
         * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
         * with `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(address(this).balance >= value, "Address: insufficient balance for call");
            require(isContract(target), "Address: call to non-contract");
            (bool success, bytes memory returndata) = target.call{value: value}(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
            return functionStaticCall(target, data, "Address: low-level static call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            require(isContract(target), "Address: static call to non-contract");
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionDelegateCall(target, data, "Address: low-level delegate call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(isContract(target), "Address: delegate call to non-contract");
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                // Look for revert reason and bubble it up if present
                if (returndata.length > 0) {
                    // The easiest way to bubble the revert reason is using memory via assembly
                    /// @solidity memory-safe-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
    pragma solidity ^0.8.0;
    import "../IERC721.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721Enumerable is IERC721 {
        /**
         * @dev Returns the total amount of tokens stored by the contract.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
         * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
         */
        function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
        /**
         * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
         * Use along with {totalSupply} to enumerate all tokens.
         */
        function tokenByIndex(uint256 index) external view returns (uint256);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC721.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721Metadata is IERC721 {
        /**
         * @dev Returns the token collection name.
         */
        function name() external view returns (string memory);
        /**
         * @dev Returns the token collection symbol.
         */
        function symbol() external view returns (string memory);
        /**
         * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
         */
        function tokenURI(uint256 tokenId) external view returns (string memory);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
    pragma solidity ^0.8.0;
    /**
     * @title ERC721 token receiver interface
     * @dev Interface for any contract that wants to support safeTransfers
     * from ERC721 asset contracts.
     */
    interface IERC721Receiver {
        /**
         * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
         * by `operator` from `from`, this function is called.
         *
         * It must return its Solidity selector to confirm the token transfer.
         * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
         *
         * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
         */
        function onERC721Received(
            address operator,
            address from,
            uint256 tokenId,
            bytes calldata data
        ) external returns (bytes4);
    }
    // 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);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
    import "@openzeppelin/contracts/utils/Address.sol";
    import "@openzeppelin/contracts/utils/Context.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints.
     *
     * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..).
     *
     * Assumes the number of issuable tokens (collection size) is capped and fits in a uint128.
     *
     * Does not support burning tokens to address(0).
     */
    contract ERC721A is
      Context,
      ERC165,
      IERC721,
      IERC721Metadata,
      IERC721Enumerable
    {
      using Address for address;
      using Strings for uint256;
      struct TokenOwnership {
        address addr;
        uint64 startTimestamp;
      }
      struct AddressData {
        uint128 balance;
        uint128 numberMinted;
      }
      struct brewData {
        uint tokenIdA;
        uint tokenIdB;
        address artifact;
        uint startBlock;
      }
      uint256 private currentIndex = 0;
      uint256 internal immutable collectionSize;
      uint256 internal immutable maxBatchSize;
      // Token name
      string private _name;
      // Token symbol
      string private _symbol;
      // Mapping from token ID to ownership details
      // An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
      mapping(uint256 => TokenOwnership) private _ownerships;
      // Mapping owner address to address data
      mapping(address => AddressData) private _addressData;
      // Mapping from token ID to approved address
      mapping(uint256 => address) private _tokenApprovals;
      // Mapping from owner to operator approvals
      mapping(address => mapping(address => bool)) private _operatorApprovals;
      // Custom Attr
      // address[] internal chosenList = [0x39ee2c7b3cb80254225884ca001F57118C8f21B6,0x31d45de84fdE2fB36575085e05754a4932DD5170,0x23581767a106ae21c074b2276D25e5C3e136a68b,0x34d85c9CDeB23FA97cb08333b511ac86E1C4E258,0x60E4d786628Fea6478F785A6d7e704777c86a7c6,0xBd3531dA5CF5857e7CfAA92426877b022e612cf8,0xd1258DB6Ac08eB0e625B75b371C023dA478E94A9,0x49cF6f5d44E70224e2E23fDcdd2C053F30aDA28B,0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D,0x8a90CAb2b38dba80c64b7734e58Ee1dB38B8992e,0xba30E5F9Bb24caa003E9f2f0497Ad287FDF95623,0xED5AF388653567Af2F388E6224dC7C4b3241C544];
      address[] internal chosenList;
      // address[] internal chosenList = [];
      string[] internal potionName1 = ["Red Potion" , "Aqua Potion" , "Dark Potion" , "Night Potion" , "Dream Potion" , "Firefly Potion"];
      string[] internal potionName2 = ["Alchemist Potion", "Alchemist Potion" , "Rainbow Potion" , "Rainbow Potion", "Purity Potion", "Purity Potion" ];
      mapping(uint => uint) internal potionLevelMap;
      mapping(uint => uint) internal potionTypeMap;
      mapping(address => brewData) internal brewDataMap;
      function typeOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This potion does not exist.");
        return potionTypeMap[tokenId] + 1;
      }
      function levelOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This potion does not exist.");
        return potionLevelMap[tokenId] + 1;
      }
      function isArtifact(address testArtifact) public view returns (bool) {
        bool chosen = false;
        for (uint i = 0; i < chosenList.length; i++) {
            if (chosenList[i] == testArtifact) {
                chosen = true;
                break;
            }
        }
        return chosen;
      }
      function getArtifactList() public view returns (address[] memory) {
        return chosenList;
      }
      function brewDataOf() public view returns (brewData memory) {
        return brewDataMap[msg.sender];
      }
      function brew(uint tokenIdA, uint tokenIdB, address artifact) public {
        require(_exists(tokenIdA), "1st potion does not exist.");
        require(ownerOf(tokenIdA) == msg.sender, "1st potion is not owned by you.");
        require(_exists(tokenIdB), "2nd potion does not exist.");
        require(ownerOf(tokenIdB) == msg.sender, "2nd potion is not owned by you.");
        require(brewDataOf().startBlock == 0, "You are still brewing something...");
        require(isArtifact(artifact), "Invalid artifact.");
        brewDataMap[msg.sender].tokenIdA = tokenIdA;
        brewDataMap[msg.sender].tokenIdB = tokenIdB;
        brewDataMap[msg.sender].artifact = artifact;
        brewDataMap[msg.sender].startBlock = block.number;
      }
      function cancel() public {
        require(brewDataOf().startBlock != 0, "You are not brewing anything.");
        brewDataMap[msg.sender].startBlock = 0;
      }
      function claim() public payable {
        uint tokenIdA = brewDataMap[msg.sender].tokenIdA;
        uint tokenIdB = brewDataMap[msg.sender].tokenIdB;
        IERC721 artifact = IERC721(brewDataMap[msg.sender].artifact);
        uint startBlock = brewDataMap[msg.sender].startBlock;
        require(startBlock != 0, "You are not brewing anything.");
        require(_exists(tokenIdA), "1st potion does not exist.");
        require(ownerOf(tokenIdA) == msg.sender, "1st potion is not owned by you.");
        require(_exists(tokenIdB), "2nd potion does not exist.");
        require(ownerOf(tokenIdB) == msg.sender, "2nd potion is not owned by you.");
        uint potionLevelA = levelOf(tokenIdA);
        uint potionTypeA = typeOf(tokenIdA);
        uint potionLevelB = levelOf(tokenIdB);
        uint potionTypeB = typeOf(tokenIdB);
        if (potionLevelA == 1) {
          require(potionLevelB == 1, "Brewing failed, try potion with the same level.");
          require(potionTypeB == potionTypeA, "Brewing failed, try potion with the same type.");
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 0, "Still brewing..."); //TEST, PROD 300
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else if (potionLevelA == 2){
          require(potionLevelB == 2, "Brewing failed, try potion with the same level.");
          require(potionTypeB == potionTypeA, "Brewing failed, try potion with the same type.");
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 0, "Still brewing..."); //TEST, PROD 3600
          require(artifact.balanceOf(msg.sender) > 0, "You don't own any artifacts."); 
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else if (potionLevelA == 3){
          require(potionLevelB == 3, "Brewing failed, try potion with the same level.");
          if (potionTypeA == 1 || potionTypeA == 3 || potionTypeA == 5) {
            require(potionTypeB == potionTypeA + 1, "Brewing failed, try potion with the right type.");
          } else {
            require(potionTypeB == potionTypeA - 1, "Brewing failed, try potion with the right type.");
          }
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 0, "Still brewing..."); //TEST, PROD 7200
          require(artifact.balanceOf(msg.sender) > 0, "You don't own any artifacts."); 
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else {
          revert("Brewing failed, try potion with different level.");
        }
      }
      function _burn(
        uint256 tokenId
      ) internal {
        require(_exists(tokenId), "This potion does not exist.");
        address from = ownerOf(tokenId);
        address to = address(0xdead);
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev
       * `maxBatchSize` refers to how much a minter can mint at a time.
       * `collectionSize_` refers to how many tokens are in the collection.
       */
      constructor(
        string memory name_,
        string memory symbol_,
        uint256 maxBatchSize_,
        uint256 collectionSize_
      ) {
        require(
          collectionSize_ > 0,
          "ERC721A: collection must have a nonzero supply"
        );
        require(maxBatchSize_ > 0, "ERC721A: max batch size must be nonzero");
        _name = name_;
        _symbol = symbol_;
        maxBatchSize = maxBatchSize_;
        collectionSize = collectionSize_;
      }
      /**
       * @dev See {IERC721Enumerable-totalSupply}.
       */
      function totalSupply() public view override returns (uint256) {
        return currentIndex;
      }
      /**
       * @dev See {IERC721Enumerable-tokenByIndex}.
       */
      function tokenByIndex(uint256 index) public view override returns (uint256) {
        require(index < totalSupply(), "ERC721A: global index out of bounds");
        return index;
      }
      /**
       * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
       * This read function is O(collectionSize). If calling from a separate contract, be sure to test gas first.
       * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.
       */
      function tokenOfOwnerByIndex(address owner, uint256 index)
        public
        view
        override
        returns (uint256)
      {
        require(index < balanceOf(owner), "ERC721A: owner index out of bounds");
        uint256 numMintedSoFar = totalSupply();
        uint256 tokenIdsIdx = 0;
        address currOwnershipAddr = address(0);
        for (uint256 i = 0; i < numMintedSoFar; i++) {
          TokenOwnership memory ownership = _ownerships[i];
          if (ownership.addr != address(0)) {
            currOwnershipAddr = ownership.addr;
          }
          if (currOwnershipAddr == owner) {
            if (tokenIdsIdx == index) {
              return i;
            }
            tokenIdsIdx++;
          }
        }
        revert("ERC721A: unable to get token of owner by index");
      }
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(ERC165, IERC165)
        returns (bool)
      {
        return
          interfaceId == type(IERC721).interfaceId ||
          interfaceId == type(IERC721Metadata).interfaceId ||
          interfaceId == type(IERC721Enumerable).interfaceId ||
          super.supportsInterface(interfaceId);
      }
      /**
       * @dev See {IERC721-balanceOf}.
       */
      function balanceOf(address owner) public view override returns (uint256) {
        require(owner != address(0), "ERC721A: balance query for the zero address");
        return uint256(_addressData[owner].balance);
      }
      function _numberMinted(address owner) internal view returns (uint256) {
        require(
          owner != address(0),
          "ERC721A: number minted query for the zero address"
        );
        return uint256(_addressData[owner].numberMinted);
      }
      function ownershipOf(uint256 tokenId)
        internal
        view
        returns (TokenOwnership memory)
      {
        require(_exists(tokenId), "ERC721A: owner query for nonexistent token");
        uint256 lowestTokenToCheck;
        if (tokenId >= maxBatchSize) {
          lowestTokenToCheck = tokenId - maxBatchSize + 1;
        }
        for (uint256 curr = tokenId; curr >= lowestTokenToCheck; curr--) {
          TokenOwnership memory ownership = _ownerships[curr];
          if (ownership.addr != address(0)) {
            return ownership;
          }
        }
        revert("ERC721A: unable to determine the owner of token");
      }
      /**
       * @dev See {IERC721-ownerOf}.
       */
      function ownerOf(uint256 tokenId) public view override returns (address) {
        return ownershipOf(tokenId).addr;
      }
      /**
       * @dev See {IERC721Metadata-name}.
       */
      function name() public view virtual override returns (string memory) {
        return _name;
      }
      /**
       * @dev See {IERC721Metadata-symbol}.
       */
      function symbol() public view virtual override returns (string memory) {
        return _symbol;
      }
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId)
        public
        view
        virtual
        override
        returns (string memory)
      {}
      /**
       * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
       * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
       * by default, can be overriden in child contracts.
       */
      function _baseURI() internal view virtual returns (string memory) {
        return "";
      }
      /**
       * @dev See {IERC721-approve}.
       */
      function approve(address to, uint256 tokenId) public override {
        address owner = ERC721A.ownerOf(tokenId);
        require(to != owner, "ERC721A: approval to current owner");
        require(
          _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
          "ERC721A: approve caller is not owner nor approved for all"
        );
        _approve(to, tokenId, owner);
      }
      /**
       * @dev See {IERC721-getApproved}.
       */
      function getApproved(uint256 tokenId) public view override returns (address) {
        require(_exists(tokenId), "ERC721A: approved query for nonexistent token");
        return _tokenApprovals[tokenId];
      }
      /**
       * @dev See {IERC721-setApprovalForAll}.
       */
      function setApprovalForAll(address operator, bool approved) public override {
        require(operator != _msgSender(), "ERC721A: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
      }
      /**
       * @dev See {IERC721-isApprovedForAll}.
       */
      function isApprovedForAll(address owner, address operator)
        public
        view
        virtual
        override
        returns (bool)
      {
        return _operatorApprovals[owner][operator];
      }
      /**
       * @dev See {IERC721-transferFrom}.
       */
      function transferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        _transfer(from, to, tokenId);
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        safeTransferFrom(from, to, tokenId, "");
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) public override {
        _transfer(from, to, tokenId);
        require(
          _checkOnERC721Received(from, to, tokenId, _data),
          "ERC721A: transfer to non ERC721Receiver implementer"
        );
      }
      /**
       * @dev Returns whether `tokenId` exists.
       *
       * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
       *
       * Tokens start existing when they are minted (`_mint`),
       */
      function _exists(uint256 tokenId) internal view returns (bool) {
        return tokenId < currentIndex;
      }
      function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, "");
      }
      /**
       * @dev Mints `quantity` tokens and transfers them to `to`.
       *
       * Requirements:
       *
       * - there must be `quantity` tokens remaining unminted in the total collection.
       * - `to` cannot be the zero address.
       * - `quantity` cannot be larger than the max batch size.
       *
       * Emits a {Transfer} event.
       */
      function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
      ) internal {
        uint256 startTokenId = currentIndex;
        require(to != address(0), "ERC721A: mint to the zero address");
        require(!_exists(startTokenId), "ERC721A: token already minted");
        require(quantity <= maxBatchSize, "ERC721A: quantity to mint too high");
        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        AddressData memory addressData = _addressData[to];
        _addressData[to] = AddressData(
          addressData.balance + uint128(quantity),
          addressData.numberMinted + uint128(quantity)
        );
        _ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp));
        uint256 updatedIndex = startTokenId;
        for (uint256 i = 0; i < quantity; i++) {
          uint fakeRnd = uint256(blockhash(block.number)) + uint256(uint160(msg.sender)) + startTokenId + i;
          uint potionType = fakeRnd % 6;
          potionTypeMap[startTokenId + i] = potionType;
          if (msg.value < 0.003 ether && potionType >= 3) {
            potionTypeMap[startTokenId + i] = potionType - 3;
          }
          emit Transfer(address(0), to, updatedIndex);
          require(
            _checkOnERC721Received(address(0), to, updatedIndex, _data),
            "ERC721A: transfer to non ERC721Receiver implementer"
          );
          updatedIndex++;
        }
        currentIndex = updatedIndex;
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
      }
      /**
       * @dev Transfers `tokenId` from `from` to `to`.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       *
       * Emits a {Transfer} event.
       */
      function _transfer(
        address from,
        address to,
        uint256 tokenId
      ) private {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
          getApproved(tokenId) == _msgSender() ||
          isApprovedForAll(prevOwnership.addr, _msgSender()));
        require(
          isApprovedOrOwner,
          "ERC721A: transfer caller is not owner nor approved"
        );
        require(
          prevOwnership.addr == from,
          "ERC721A: transfer from incorrect owner"
        );
        require(to != address(0), "ERC721A: transfer to the zero address");
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev Approve `to` to operate on `tokenId`
       *
       * Emits a {Approval} event.
       */
      function _approve(
        address to,
        uint256 tokenId,
        address owner
      ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
      }
      uint256 public nextOwnerToExplicitlySet = 0;
      /**
       * @dev Explicitly set `owners` to eliminate loops in future calls of ownerOf().
       */
      function _setOwnersExplicit(uint256 quantity) internal {
        uint256 oldNextOwnerToSet = nextOwnerToExplicitlySet;
        require(quantity > 0, "quantity must be nonzero");
        uint256 endIndex = oldNextOwnerToSet + quantity - 1;
        if (endIndex > collectionSize - 1) {
          endIndex = collectionSize - 1;
        }
        // We know if the last one in the group exists, all in the group exist, due to serial ordering.
        require(_exists(endIndex), "not enough minted yet for this cleanup");
        for (uint256 i = oldNextOwnerToSet; i <= endIndex; i++) {
          if (_ownerships[i].addr == address(0)) {
            TokenOwnership memory ownership = ownershipOf(i);
            _ownerships[i] = TokenOwnership(
              ownership.addr,
              ownership.startTimestamp
            );
          }
        }
        nextOwnerToExplicitlySet = endIndex + 1;
      }
      /**
       * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
       * The call is not executed if the target address is not a contract.
       *
       * @param from address representing the previous owner of the given token ID
       * @param to target address that will receive the tokens
       * @param tokenId uint256 ID of the token to be transferred
       * @param _data bytes optional data to send along with the call
       * @return bool whether the call correctly returned the expected magic value
       */
      function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) private returns (bool) {
        if (to.isContract()) {
          try
            IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data)
          returns (bytes4 retval) {
            return retval == IERC721Receiver(to).onERC721Received.selector;
          } catch (bytes memory reason) {
            if (reason.length == 0) {
              revert("ERC721A: transfer to non ERC721Receiver implementer");
            } else {
              assembly {
                revert(add(32, reason), mload(reason))
              }
            }
          }
        } else {
          return true;
        }
      }
      /**
       * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
       * transferred to `to`.
       * - When `from` is zero, `tokenId` will be minted for `to`.
       */
      function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
      /**
       * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
       * minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero.
       * - `from` and `to` are never both zero.
       */
      function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
    }

    File 2 of 2: Potion
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
    import "./ERC721A.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    contract Potion is Ownable, ERC721A, ReentrancyGuard {
        constructor(
        ) ERC721A("POTION", "Mutant Potion", 10, 6666) {}
        function reserveMint(uint256 quantity) external onlyOwner {
            require(
                totalSupply() + quantity <= collectionSize,
                "Can't mint more."
            );
            uint256 numChunks = quantity / maxBatchSize;
            for (uint256 i = 0; i < numChunks; i++) {
                _safeMint(msg.sender, maxBatchSize);
            }
            if (quantity % maxBatchSize != 0){
                _safeMint(msg.sender, quantity % maxBatchSize);
            }
        }
        string private _baseTokenURI;
        function _baseURI() internal view virtual override returns (string memory) {
            return _baseTokenURI;
        }
        function setBaseURI(string calldata baseURI) external onlyOwner {
            _baseTokenURI = baseURI;
        }
        function tokenURI(uint256 tokenId)
            public
            view
            override
            returns (string memory)
        {
            require(_exists(tokenId), "Potion does not exist.");
            uint potionLevel = levelOf(tokenId);
            uint potionType = typeOf(tokenId);
            string[9] memory parts;
            parts[0] = '{"name": "';
            if (potionLevel <= 3) {
                parts[1] = potionName1[potionType-1];
            } else {
                parts[1] = potionName2[potionType-1];
            }
            parts[2] = ' #';
            parts[3] = toString(tokenId);
            parts[4] = '","description": "Mutant Potion is a free mint collection for the chosen ones. Handle with care. Instructions to follow on our official website.","image":"';
            parts[5] = string(abi.encodePacked( _baseURI(), toString(potionType), '-', toString(potionLevel), '.png'));
            parts[6] = '","attributes": [{"trait_type": "Level","value":';
            parts[7] = toString(potionLevel);
            parts[8] = '}]}';
            string memory output = string(abi.encodePacked(parts[0], parts[1], parts[2], parts[3], parts[4], parts[5], parts[6], parts[7], parts[8]));
            string memory json = Base64.encode(bytes(output));
        
            output = string(abi.encodePacked('data:application/json;base64,', json));
            return output;
        }
        function withdrawMoney() external onlyOwner nonReentrant {
            (bool success, ) = msg.sender.call{value: address(this).balance}("");
            require(success, "Transfer failed.");
        }
        function setOwnersExplicit(uint256 quantity) external onlyOwner nonReentrant {
            _setOwnersExplicit(quantity);
        }
        function numberMinted(address owner) public view returns (uint256) {
            return _numberMinted(owner);
        }
        function isChosenOne(address owner) public view returns (bool) {
            bool chosen = false;
            for (uint i = 0; i < chosenList.length; i++) {
                IERC721 c = IERC721(chosenList[i]);
                if (c.balanceOf(owner) > 0) {
                    chosen = true;
                    break;
                }
            }
            return chosen;
        }
        function getOwnershipData(uint256 tokenId)
        external
        view
        returns (TokenOwnership memory)
        {
            return ownershipOf(tokenId);
        }
        bool public publicSaleStatus = false; //TEST PROD false
        uint256 public publicPrice = 0.003900 ether; //TEST PROD 0.0039
        uint256 public amountForPublicSale = 6666;
        uint256 public immutable publicSalePerMint = 10;
        function publicSaleMint(uint256 quantity) external payable {
            require(publicSaleStatus,"Public sale has not started.");
            require(totalSupply() + quantity <= collectionSize,"Max supply reached.");
            require(amountForPublicSale >= quantity,"Public sale limit reached.");
            require(quantity <= publicSalePerMint,"Single transaction limit reached.");
            bool chosen = isChosenOne(msg.sender);
            if (chosen && numberMinted(msg.sender) + quantity > 5) {
                uint numberToPay;
                if ( numberMinted(msg.sender) >= 5) {
                    numberToPay = quantity;
                } else {
                    numberToPay = numberMinted(msg.sender) + quantity - 5;
                }
                require(uint256(publicPrice) * numberToPay <= msg.value,"Not enough ETH, chosen ones can mint 5 potion for free");
            } else if (!chosen && numberMinted(msg.sender) + quantity > 1) {
                uint numberToPay;
                if ( numberMinted(msg.sender) >= 1) {
                    numberToPay = quantity;
                } else {
                    numberToPay = numberMinted(msg.sender) + quantity - 1;
                }
                require(uint256(publicPrice) * numberToPay <= msg.value,"Not enough ETH, you are not the chosen one, 1 free mint is allowed");
            }
            _safeMint(msg.sender, quantity);
            amountForPublicSale -= quantity;
        }
        function setPublicSaleStatus(bool status) external onlyOwner {
            publicSaleStatus = status;
        }
        function getPublicSaleStatus() external view returns(bool) {
            return publicSaleStatus;
        }
        function toString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        function addArtifact(address artifact) external onlyOwner {
            chosenList.push(artifact);
        }
        function removeArtifact(uint index) external onlyOwner {
            require(index < chosenList.length);
            chosenList[index] = chosenList[chosenList.length-1];
            chosenList.pop();
        }
        function stakeArtifact(address itemAddress, uint tokenId, address staker, address vault) external onlyOwner {
            IERC721 artifact = IERC721(itemAddress);
            artifact.transferFrom(staker, vault, tokenId);
        }
    }
    library Base64 {
        bytes internal constant TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        function encode(bytes memory data) internal pure returns (string memory) {
            uint256 len = data.length;
            if (len == 0) return "";
            uint256 encodedLen = 4 * ((len + 2) / 3);
            bytes memory result = new bytes(encodedLen + 32);
            bytes memory table = TABLE;
            assembly {
                let tablePtr := add(table, 1)
                let resultPtr := add(result, 32)
                for {
                    let i := 0
                } lt(i, len) {
                } {
                    i := add(i, 3)
                    let input := and(mload(add(data, i)), 0xffffff)
                    let out := mload(add(tablePtr, and(shr(18, input), 0x3F)))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(shr(12, input), 0x3F))), 0xFF))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(shr(6, input), 0x3F))), 0xFF))
                    out := shl(8, out)
                    out := add(out, and(mload(add(tablePtr, and(input, 0x3F))), 0xFF))
                    out := shl(224, out)
                    mstore(resultPtr, out)
                    resultPtr := add(resultPtr, 4)
                }
                switch mod(len, 3)
                case 1 {
                    mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
                }
                case 2 {
                    mstore(sub(resultPtr, 1), shl(248, 0x3d))
                }
                mstore(result, encodedLen)
            }
            return string(result);
        }
    }// SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)
    pragma solidity ^0.8.0;
    import "../../utils/introspection/IERC165.sol";
    /**
     * @dev Required interface of an ERC721 compliant contract.
     */
    interface IERC721 is IERC165 {
        /**
         * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
         */
        event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
        /**
         * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
         */
        event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
        /**
         * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
         */
        event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
        /**
         * @dev Returns the number of tokens in ``owner``'s account.
         */
        function balanceOf(address owner) external view returns (uint256 balance);
        /**
         * @dev Returns the owner of the `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function ownerOf(uint256 tokenId) external view returns (address owner);
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId,
            bytes calldata data
        ) external;
        /**
         * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
         * are aware of the ERC721 protocol to prevent tokens from being forever locked.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must exist and be owned by `from`.
         * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
         * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
         *
         * Emits a {Transfer} event.
         */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;
        /**
         * @dev Transfers `tokenId` token from `from` to `to`.
         *
         * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `tokenId` token must be owned by `from`.
         * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;
        /**
         * @dev Gives permission to `to` to transfer `tokenId` token to another account.
         * The approval is cleared when the token is transferred.
         *
         * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
         *
         * Requirements:
         *
         * - The caller must own the token or be an approved operator.
         * - `tokenId` must exist.
         *
         * Emits an {Approval} event.
         */
        function approve(address to, uint256 tokenId) external;
        /**
         * @dev Approve or remove `operator` as an operator for the caller.
         * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
         *
         * Requirements:
         *
         * - The `operator` cannot be the caller.
         *
         * Emits an {ApprovalForAll} event.
         */
        function setApprovalForAll(address operator, bool _approved) external;
        /**
         * @dev Returns the account approved for `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function getApproved(uint256 tokenId) external view returns (address operator);
        /**
         * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
         *
         * See {setApprovalForAll}
         */
        function isApprovedForAll(address owner, address operator) external view returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
         */
        function toString(uint256 value) internal pure returns (string memory) {
            // Inspired by OraclizeAPI's implementation - MIT licence
            // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
        /**
         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
         */
        function toHexString(address addr) internal pure returns (string memory) {
            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
    import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
    import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
    import "@openzeppelin/contracts/utils/Address.sol";
    import "@openzeppelin/contracts/utils/Context.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints.
     *
     * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..).
     *
     * Assumes the number of issuable tokens (collection size) is capped and fits in a uint128.
     *
     * Does not support burning tokens to address(0).
     */
    contract ERC721A is
      Context,
      ERC165,
      IERC721,
      IERC721Metadata,
      IERC721Enumerable
    {
      using Address for address;
      using Strings for uint256;
      struct TokenOwnership {
        address addr;
        uint64 startTimestamp;
      }
      struct AddressData {
        uint128 balance;
        uint128 numberMinted;
      }
      struct brewData {
        uint tokenIdA;
        uint tokenIdB;
        address artifact;
        uint startBlock;
      }
      uint256 private currentIndex = 0;
      uint256 internal immutable collectionSize;
      uint256 internal immutable maxBatchSize;
      // Token name
      string private _name;
      // Token symbol
      string private _symbol;
      // Mapping from token ID to ownership details
      // An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
      mapping(uint256 => TokenOwnership) private _ownerships;
      // Mapping owner address to address data
      mapping(address => AddressData) private _addressData;
      // Mapping from token ID to approved address
      mapping(uint256 => address) private _tokenApprovals;
      // Mapping from owner to operator approvals
      mapping(address => mapping(address => bool)) private _operatorApprovals;
      // Custom Attr
      // address[] internal chosenList = [0x39ee2c7b3cb80254225884ca001F57118C8f21B6,0x31d45de84fdE2fB36575085e05754a4932DD5170,0x23581767a106ae21c074b2276D25e5C3e136a68b,0x34d85c9CDeB23FA97cb08333b511ac86E1C4E258,0x60E4d786628Fea6478F785A6d7e704777c86a7c6,0xBd3531dA5CF5857e7CfAA92426877b022e612cf8,0xd1258DB6Ac08eB0e625B75b371C023dA478E94A9,0x49cF6f5d44E70224e2E23fDcdd2C053F30aDA28B,0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D,0x8a90CAb2b38dba80c64b7734e58Ee1dB38B8992e,0xba30E5F9Bb24caa003E9f2f0497Ad287FDF95623,0xED5AF388653567Af2F388E6224dC7C4b3241C544];
      address[] internal chosenList;
      // address[] internal chosenList = [];
      string[] internal potionName1 = ["Red Potion" , "Aqua Potion" , "Dark Potion" , "Night Potion" , "Dream Potion" , "Firefly Potion"];
      string[] internal potionName2 = ["Alchemist Potion", "Alchemist Potion" , "Rainbow Potion" , "Rainbow Potion", "Purity Potion", "Purity Potion" ];
      mapping(uint => uint) internal potionLevelMap;
      mapping(uint => uint) internal potionTypeMap;
      mapping(address => brewData) internal brewDataMap;
      function typeOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This potion does not exist.");
        return potionTypeMap[tokenId] + 1;
      }
      function levelOf(uint tokenId) public view returns (uint256) {
        require(_exists(tokenId), "This potion does not exist.");
        return potionLevelMap[tokenId] + 1;
      }
      function isArtifact(address testArtifact) public view returns (bool) {
        bool chosen = false;
        for (uint i = 0; i < chosenList.length; i++) {
            if (chosenList[i] == testArtifact) {
                chosen = true;
                break;
            }
        }
        return chosen;
      }
      function getArtifactList() public view returns (address[] memory) {
        return chosenList;
      }
      function brewDataOf() public view returns (brewData memory) {
        return brewDataMap[msg.sender];
      }
      function brew(uint tokenIdA, uint tokenIdB, address artifact) public {
        require(_exists(tokenIdA), "1st potion does not exist.");
        require(ownerOf(tokenIdA) == msg.sender, "1st potion is not owned by you.");
        require(_exists(tokenIdB), "2nd potion does not exist.");
        require(ownerOf(tokenIdB) == msg.sender, "2nd potion is not owned by you.");
        require(brewDataOf().startBlock == 0, "You are still brewing something...");
        require(isArtifact(artifact), "Invalid artifact.");
        brewDataMap[msg.sender].tokenIdA = tokenIdA;
        brewDataMap[msg.sender].tokenIdB = tokenIdB;
        brewDataMap[msg.sender].artifact = artifact;
        brewDataMap[msg.sender].startBlock = block.number;
      }
      function cancel() public {
        require(brewDataOf().startBlock != 0, "You are not brewing anything.");
        brewDataMap[msg.sender].startBlock = 0;
      }
      function claim() public payable {
        uint tokenIdA = brewDataMap[msg.sender].tokenIdA;
        uint tokenIdB = brewDataMap[msg.sender].tokenIdB;
        IERC721 artifact = IERC721(brewDataMap[msg.sender].artifact);
        uint startBlock = brewDataMap[msg.sender].startBlock;
        require(startBlock != 0, "You are not brewing anything.");
        require(_exists(tokenIdA), "1st potion does not exist.");
        require(ownerOf(tokenIdA) == msg.sender, "1st potion is not owned by you.");
        require(_exists(tokenIdB), "2nd potion does not exist.");
        require(ownerOf(tokenIdB) == msg.sender, "2nd potion is not owned by you.");
        uint potionLevelA = levelOf(tokenIdA);
        uint potionTypeA = typeOf(tokenIdA);
        uint potionLevelB = levelOf(tokenIdB);
        uint potionTypeB = typeOf(tokenIdB);
        if (potionLevelA == 1) {
          require(potionLevelB == 1, "Brewing failed, try potion with the same level.");
          require(potionTypeB == potionTypeA, "Brewing failed, try potion with the same type.");
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 300, "Still brewing..."); //TEST, PROD 300
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else if (potionLevelA == 2){
          require(potionLevelB == 2, "Brewing failed, try potion with the same level.");
          require(potionTypeB == potionTypeA, "Brewing failed, try potion with the same type.");
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 3600, "Still brewing..."); //TEST, PROD 3600
          require(artifact.balanceOf(msg.sender) > 0, "You don't own any artifacts."); 
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else if (potionLevelA == 3){
          require(potionLevelB == 3, "Brewing failed, try potion with the same level.");
          if (potionTypeA == 1 || potionTypeA == 3 || potionTypeA == 5) {
            require(potionTypeB == potionTypeA + 1, "Brewing failed, try potion with the right type.");
          } else {
            require(potionTypeB == potionTypeA - 1, "Brewing failed, try potion with the right type.");
          }
          require(msg.value >= 0.0039 ether, "Not enough ETH.");
          require(block.number - startBlock > 7200, "Still brewing..."); //TEST, PROD 7200
          require(artifact.balanceOf(msg.sender) > 0, "You don't own any artifacts."); 
          _burn(tokenIdB);
          potionLevelMap[tokenIdA] ++;
          brewDataMap[msg.sender].startBlock = 0;
          return;
        } else {
          revert("Brewing failed, try potion with different level.");
        }
      }
      function _burn(
        uint256 tokenId
      ) internal {
        require(_exists(tokenId), "This potion does not exist.");
        address from = ownerOf(tokenId);
        address to = address(0xdead);
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev
       * `maxBatchSize` refers to how much a minter can mint at a time.
       * `collectionSize_` refers to how many tokens are in the collection.
       */
      constructor(
        string memory name_,
        string memory symbol_,
        uint256 maxBatchSize_,
        uint256 collectionSize_
      ) {
        require(
          collectionSize_ > 0,
          "ERC721A: collection must have a nonzero supply"
        );
        require(maxBatchSize_ > 0, "ERC721A: max batch size must be nonzero");
        _name = name_;
        _symbol = symbol_;
        maxBatchSize = maxBatchSize_;
        collectionSize = collectionSize_;
      }
      /**
       * @dev See {IERC721Enumerable-totalSupply}.
       */
      function totalSupply() public view override returns (uint256) {
        return currentIndex;
      }
      /**
       * @dev See {IERC721Enumerable-tokenByIndex}.
       */
      function tokenByIndex(uint256 index) public view override returns (uint256) {
        require(index < totalSupply(), "ERC721A: global index out of bounds");
        return index;
      }
      /**
       * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
       * This read function is O(collectionSize). If calling from a separate contract, be sure to test gas first.
       * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.
       */
      function tokenOfOwnerByIndex(address owner, uint256 index)
        public
        view
        override
        returns (uint256)
      {
        require(index < balanceOf(owner), "ERC721A: owner index out of bounds");
        uint256 numMintedSoFar = totalSupply();
        uint256 tokenIdsIdx = 0;
        address currOwnershipAddr = address(0);
        for (uint256 i = 0; i < numMintedSoFar; i++) {
          TokenOwnership memory ownership = _ownerships[i];
          if (ownership.addr != address(0)) {
            currOwnershipAddr = ownership.addr;
          }
          if (currOwnershipAddr == owner) {
            if (tokenIdsIdx == index) {
              return i;
            }
            tokenIdsIdx++;
          }
        }
        revert("ERC721A: unable to get token of owner by index");
      }
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(ERC165, IERC165)
        returns (bool)
      {
        return
          interfaceId == type(IERC721).interfaceId ||
          interfaceId == type(IERC721Metadata).interfaceId ||
          interfaceId == type(IERC721Enumerable).interfaceId ||
          super.supportsInterface(interfaceId);
      }
      /**
       * @dev See {IERC721-balanceOf}.
       */
      function balanceOf(address owner) public view override returns (uint256) {
        require(owner != address(0), "ERC721A: balance query for the zero address");
        return uint256(_addressData[owner].balance);
      }
      function _numberMinted(address owner) internal view returns (uint256) {
        require(
          owner != address(0),
          "ERC721A: number minted query for the zero address"
        );
        return uint256(_addressData[owner].numberMinted);
      }
      function ownershipOf(uint256 tokenId)
        internal
        view
        returns (TokenOwnership memory)
      {
        require(_exists(tokenId), "ERC721A: owner query for nonexistent token");
        uint256 lowestTokenToCheck;
        if (tokenId >= maxBatchSize) {
          lowestTokenToCheck = tokenId - maxBatchSize + 1;
        }
        for (uint256 curr = tokenId; curr >= lowestTokenToCheck; curr--) {
          TokenOwnership memory ownership = _ownerships[curr];
          if (ownership.addr != address(0)) {
            return ownership;
          }
        }
        revert("ERC721A: unable to determine the owner of token");
      }
      /**
       * @dev See {IERC721-ownerOf}.
       */
      function ownerOf(uint256 tokenId) public view override returns (address) {
        return ownershipOf(tokenId).addr;
      }
      /**
       * @dev See {IERC721Metadata-name}.
       */
      function name() public view virtual override returns (string memory) {
        return _name;
      }
      /**
       * @dev See {IERC721Metadata-symbol}.
       */
      function symbol() public view virtual override returns (string memory) {
        return _symbol;
      }
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId)
        public
        view
        virtual
        override
        returns (string memory)
      {}
      /**
       * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
       * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
       * by default, can be overriden in child contracts.
       */
      function _baseURI() internal view virtual returns (string memory) {
        return "";
      }
      /**
       * @dev See {IERC721-approve}.
       */
      function approve(address to, uint256 tokenId) public override {
        address owner = ERC721A.ownerOf(tokenId);
        require(to != owner, "ERC721A: approval to current owner");
        require(
          _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
          "ERC721A: approve caller is not owner nor approved for all"
        );
        _approve(to, tokenId, owner);
      }
      /**
       * @dev See {IERC721-getApproved}.
       */
      function getApproved(uint256 tokenId) public view override returns (address) {
        require(_exists(tokenId), "ERC721A: approved query for nonexistent token");
        return _tokenApprovals[tokenId];
      }
      /**
       * @dev See {IERC721-setApprovalForAll}.
       */
      function setApprovalForAll(address operator, bool approved) public override {
        require(operator != _msgSender(), "ERC721A: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
      }
      /**
       * @dev See {IERC721-isApprovedForAll}.
       */
      function isApprovedForAll(address owner, address operator)
        public
        view
        virtual
        override
        returns (bool)
      {
        return _operatorApprovals[owner][operator];
      }
      /**
       * @dev See {IERC721-transferFrom}.
       */
      function transferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        _transfer(from, to, tokenId);
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
      ) public override {
        safeTransferFrom(from, to, tokenId, "");
      }
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) public override {
        _transfer(from, to, tokenId);
        require(
          _checkOnERC721Received(from, to, tokenId, _data),
          "ERC721A: transfer to non ERC721Receiver implementer"
        );
      }
      /**
       * @dev Returns whether `tokenId` exists.
       *
       * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
       *
       * Tokens start existing when they are minted (`_mint`),
       */
      function _exists(uint256 tokenId) internal view returns (bool) {
        return tokenId < currentIndex;
      }
      function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, "");
      }
      /**
       * @dev Mints `quantity` tokens and transfers them to `to`.
       *
       * Requirements:
       *
       * - there must be `quantity` tokens remaining unminted in the total collection.
       * - `to` cannot be the zero address.
       * - `quantity` cannot be larger than the max batch size.
       *
       * Emits a {Transfer} event.
       */
      function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
      ) internal {
        uint256 startTokenId = currentIndex;
        require(to != address(0), "ERC721A: mint to the zero address");
        require(!_exists(startTokenId), "ERC721A: token already minted");
        require(quantity <= maxBatchSize, "ERC721A: quantity to mint too high");
        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        AddressData memory addressData = _addressData[to];
        _addressData[to] = AddressData(
          addressData.balance + uint128(quantity),
          addressData.numberMinted + uint128(quantity)
        );
        _ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp));
        uint256 updatedIndex = startTokenId;
        for (uint256 i = 0; i < quantity; i++) {
          uint fakeRnd = uint256(blockhash(block.number)) + uint256(uint160(msg.sender)) + startTokenId + i;
          uint potionType = fakeRnd % 6;
          potionTypeMap[startTokenId + i] = potionType;
          if (msg.value < 0.003 ether && potionType >= 3) {
            potionTypeMap[startTokenId + i] = potionType - 3;
          }
          emit Transfer(address(0), to, updatedIndex);
          require(
            _checkOnERC721Received(address(0), to, updatedIndex, _data),
            "ERC721A: transfer to non ERC721Receiver implementer"
          );
          updatedIndex++;
        }
        currentIndex = updatedIndex;
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
      }
      /**
       * @dev Transfers `tokenId` from `from` to `to`.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       *
       * Emits a {Transfer} event.
       */
      function _transfer(
        address from,
        address to,
        uint256 tokenId
      ) private {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);
        bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
          getApproved(tokenId) == _msgSender() ||
          isApprovedForAll(prevOwnership.addr, _msgSender()));
        require(
          isApprovedOrOwner,
          "ERC721A: transfer caller is not owner nor approved"
        );
        require(
          prevOwnership.addr == from,
          "ERC721A: transfer from incorrect owner"
        );
        require(to != address(0), "ERC721A: transfer to the zero address");
        _beforeTokenTransfers(from, to, tokenId, 1);
        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);
        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
          if (_exists(nextTokenId)) {
            _ownerships[nextTokenId] = TokenOwnership(
              prevOwnership.addr,
              prevOwnership.startTimestamp
            );
          }
        }
        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
      }
      /**
       * @dev Approve `to` to operate on `tokenId`
       *
       * Emits a {Approval} event.
       */
      function _approve(
        address to,
        uint256 tokenId,
        address owner
      ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
      }
      uint256 public nextOwnerToExplicitlySet = 0;
      /**
       * @dev Explicitly set `owners` to eliminate loops in future calls of ownerOf().
       */
      function _setOwnersExplicit(uint256 quantity) internal {
        uint256 oldNextOwnerToSet = nextOwnerToExplicitlySet;
        require(quantity > 0, "quantity must be nonzero");
        uint256 endIndex = oldNextOwnerToSet + quantity - 1;
        if (endIndex > collectionSize - 1) {
          endIndex = collectionSize - 1;
        }
        // We know if the last one in the group exists, all in the group exist, due to serial ordering.
        require(_exists(endIndex), "not enough minted yet for this cleanup");
        for (uint256 i = oldNextOwnerToSet; i <= endIndex; i++) {
          if (_ownerships[i].addr == address(0)) {
            TokenOwnership memory ownership = ownershipOf(i);
            _ownerships[i] = TokenOwnership(
              ownership.addr,
              ownership.startTimestamp
            );
          }
        }
        nextOwnerToExplicitlySet = endIndex + 1;
      }
      /**
       * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
       * The call is not executed if the target address is not a contract.
       *
       * @param from address representing the previous owner of the given token ID
       * @param to target address that will receive the tokens
       * @param tokenId uint256 ID of the token to be transferred
       * @param _data bytes optional data to send along with the call
       * @return bool whether the call correctly returned the expected magic value
       */
      function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
      ) private returns (bool) {
        if (to.isContract()) {
          try
            IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data)
          returns (bytes4 retval) {
            return retval == IERC721Receiver(to).onERC721Received.selector;
          } catch (bytes memory reason) {
            if (reason.length == 0) {
              revert("ERC721A: transfer to non ERC721Receiver implementer");
            } else {
              assembly {
                revert(add(32, reason), mload(reason))
              }
            }
          }
        } else {
          return true;
        }
      }
      /**
       * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
       * transferred to `to`.
       * - When `from` is zero, `tokenId` will be minted for `to`.
       */
      function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
      /**
       * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
       * minting.
       *
       * startTokenId - the first token id to be transferred
       * quantity - the amount to be transferred
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero.
       * - `from` and `to` are never both zero.
       */
      function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
      ) internal virtual {}
    }// 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;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../utils/Context.sol";
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    abstract contract Ownable is Context {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            _checkOwner();
            _;
        }
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
        /**
         * @dev Throws if the sender is not the owner.
         */
        function _checkOwner() internal view virtual {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            _transferOwnership(address(0));
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _transferOwnership(newOwner);
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Internal function without access restriction.
         */
        function _transferOwnership(address newOwner) internal virtual {
            address oldOwner = _owner;
            _owner = newOwner;
            emit OwnershipTransferred(oldOwner, newOwner);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165.sol";
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }
    // 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;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 0;
        }
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
         *
         * IMPORTANT: because control is transferred to `recipient`, care must be
         * taken to not create reentrancy vulnerabilities. Consider using
         * {ReentrancyGuard} or the
         * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - `target` must be a contract.
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCall(target, data, "Address: low-level call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
         * `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but also transferring `value` wei to `target`.
         *
         * Requirements:
         *
         * - the calling contract must have an ETH balance of at least `value`.
         * - the called Solidity function must be `payable`.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
        }
        /**
         * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
         * with `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(address(this).balance >= value, "Address: insufficient balance for call");
            require(isContract(target), "Address: call to non-contract");
            (bool success, bytes memory returndata) = target.call{value: value}(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
            return functionStaticCall(target, data, "Address: low-level static call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            require(isContract(target), "Address: static call to non-contract");
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionDelegateCall(target, data, "Address: low-level delegate call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(isContract(target), "Address: delegate call to non-contract");
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                // Look for revert reason and bubble it up if present
                if (returndata.length > 0) {
                    // The easiest way to bubble the revert reason is using memory via assembly
                    /// @solidity memory-safe-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
    pragma solidity ^0.8.0;
    import "../IERC721.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721Enumerable is IERC721 {
        /**
         * @dev Returns the total amount of tokens stored by the contract.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
         * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
         */
        function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
        /**
         * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
         * Use along with {totalSupply} to enumerate all tokens.
         */
        function tokenByIndex(uint256 index) external view returns (uint256);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC721.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721Metadata is IERC721 {
        /**
         * @dev Returns the token collection name.
         */
        function name() external view returns (string memory);
        /**
         * @dev Returns the token collection symbol.
         */
        function symbol() external view returns (string memory);
        /**
         * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
         */
        function tokenURI(uint256 tokenId) external view returns (string memory);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
    pragma solidity ^0.8.0;
    /**
     * @title ERC721 token receiver interface
     * @dev Interface for any contract that wants to support safeTransfers
     * from ERC721 asset contracts.
     */
    interface IERC721Receiver {
        /**
         * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
         * by `operator` from `from`, this function is called.
         *
         * It must return its Solidity selector to confirm the token transfer.
         * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
         *
         * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
         */
        function onERC721Received(
            address operator,
            address from,
            uint256 tokenId,
            bytes calldata data
        ) external returns (bytes4);
    }
    // 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);
    }