// File: /var/app/current/contracts/IndelibleERC721A.sol




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

    import "erc721a/contracts/ERC721A.sol";
    import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/utils/Base64.sol";
    import "./SSTORE2.sol";
    import "./DynamicBuffer.sol";
    import "./HelperLib.sol";

    contract IndelibleERC721A is ERC721A, ReentrancyGuard, Ownable {
        using HelperLib for uint256;
        using DynamicBuffer for bytes;

        struct TraitDTO {
            string name;
            string mimetype;
            bytes data;
        }
        
        struct Trait {
            string name;
            string mimetype;
        }

        struct ContractData {
            string name;
            string description;
            string image;
            string banner;
            string website;
            uint256 royalties;
            string royaltiesRecipient;
        }

        mapping(uint256 => uint256) internal _tokenIdToRandomBytes;
        mapping(uint256 => address[]) internal _traitDataPointers;
        mapping(uint256 => mapping(uint256 => Trait)) internal _traitDetails;
        mapping(uint256 => bool) internal _renderTokenOffChain;

        uint256 private constant NUM_LAYERS = 8;
        uint256 private constant MAX_BATCH_MINT = 20;
        uint256[][NUM_LAYERS] private TIERS;
        string[] private LAYER_NAMES = [unicode"Foreground 1", unicode"Foreground 2", unicode"Foreground 3", unicode"Middle Ground 1", unicode"Middle Ground 2", unicode"Background 1", unicode"Background 2", unicode"Background"];
        bool private shouldWrapSVG = true;
        uint256 public constant maxTokens = 600;
        uint256 public maxPerAddress = 100;
        uint256 public maxFreePerAddress = 0;
        uint256 public mintPrice = 0.04 ether;
        string public baseURI = "";
        bool public isMintingPaused = true;
        ContractData public contractData = ContractData(unicode"Still Lifes", unicode"Édouard Manet once called still life 'the touchstone of painting'. Characterized by an interest in the insentient, this genre of art has been popular across movements, cultures, and periods, with major figures like Paul Cézanne and Pablo Picasso.", "https://indeliblelabs-prod.s3.us-east-2.amazonaws.com/profile/9b0638f3-e513-43a5-b47a-77b73111bcb6", "https://indeliblelabs-prod.s3.us-east-2.amazonaws.com/banner/9b0638f3-e513-43a5-b47a-77b73111bcb6", "", 500, "0xf98537696e2Cf486F8F32604B2Ca2CDa120DBBa8");

        constructor() ERC721A(unicode"Still Lifes", unicode"SL") {
            TIERS[0] = [120,480];
TIERS[1] = [20,20,25,38,38,38,40,40,41,300];
TIERS[2] = [18,32,40,45,50,50,50,50,50,50,50,115];
TIERS[3] = [40,50,50,50,50,50,50,55,205];
TIERS[4] = [20,25,25,25,35,40,40,40,40,40,40,50,180];
TIERS[5] = [10,25,40,45,50,430];
TIERS[6] = [60,540];
TIERS[7] = [600];
        }

        modifier whenPublicMintActive() {
            require(isPublicMintActive(), "Public sale not open");
            _;
        }

        function rarityGen(uint256 _randinput, uint256 _rarityTier)
            internal
            view
            returns (uint256)
        {
            uint256 currentLowerBound = 0;
            for (uint256 i = 0; i < TIERS[_rarityTier].length; i++) {
                uint256 thisPercentage = TIERS[_rarityTier][i];
                if (
                    _randinput >= currentLowerBound &&
                    _randinput < currentLowerBound + thisPercentage
                ) return i;
                currentLowerBound = currentLowerBound + thisPercentage;
            }

            revert();
        }

        function hashFromRandomBytes(
            uint256 _randomBytes,
            uint256 _tokenId,
            uint256 _startingTokenId
        ) internal view returns (string memory) {
            require(_exists(_tokenId), "Invalid token");
            // This will generate a NUM_LAYERS * 3 character string.
            bytes memory hashBytes = DynamicBuffer.allocate(NUM_LAYERS * 4);

            for (uint256 i = 0; i < NUM_LAYERS; i++) {
                uint256 _randinput = uint256(
                    uint256(
                        keccak256(
                            abi.encodePacked(
                                _randomBytes,
                                _tokenId,
                                _startingTokenId,
                                _tokenId + i
                            )
                        )
                    ) % maxTokens
                );

                uint256 rarity = rarityGen(_randinput, i);

                if (rarity < 10) {
                    hashBytes.appendSafe("00");
                } else if (rarity < 100) {
                    hashBytes.appendSafe("0");
                }
                if (rarity > 999) {
                    hashBytes.appendSafe("999");
                } else {
                    hashBytes.appendSafe(bytes(_toString(rarity)));
                }
            }

            return string(hashBytes);
        }

        function mint(uint256 _count) external payable nonReentrant whenPublicMintActive returns (uint256) {
            uint256 totalMinted = _totalMinted();
            require(_count > 0, "Invalid token count");
            require(totalMinted + _count <= maxTokens, "All tokens are gone");
            require(_count * mintPrice == msg.value, "Incorrect amount of ether sent");
            require(balanceOf(msg.sender) + _count <= maxPerAddress, "Exceeded max mints allowed.");

            uint256 batchCount = _count / MAX_BATCH_MINT;
            uint256 remainder = _count % MAX_BATCH_MINT;

            uint256 randomBytes = uint256(
                keccak256(
                    abi.encodePacked(
                        tx.gasprice,
                        block.number,
                        block.timestamp,
                        block.difficulty,
                        blockhash(block.number - 1),
                        msg.sender
                    )
                )
            );

            for (uint256 i = 0; i < batchCount; i++) {
                if (i == 0) {
                    _tokenIdToRandomBytes[totalMinted] = randomBytes;
                } else {
                    _tokenIdToRandomBytes[totalMinted + (i * MAX_BATCH_MINT)] = randomBytes;
                }
        
                _mint(msg.sender, MAX_BATCH_MINT);
            }

            if (remainder > 0) {
                if (batchCount == 0) {
                    _tokenIdToRandomBytes[totalMinted] = randomBytes;
                } else {
                    _tokenIdToRandomBytes[totalMinted + (batchCount * MAX_BATCH_MINT)] = randomBytes;
                }

                _mint(msg.sender, remainder);
            }

            return totalMinted;
        }

        function isPublicMintActive() public view returns (bool) {
            return _totalMinted() < maxTokens && isMintingPaused == false;
        }

        function hashToSVG(string memory _hash)
            public
            view
            returns (string memory)
        {
            uint256 thisTraitIndex;
            
            bytes memory svgBytes = DynamicBuffer.allocate(1024 * 128);
            svgBytes.appendSafe('<svg width="1200" height="1200" viewBox="0 0 1200 1200" version="1.2" xmlns="http://www.w3.org/2000/svg" style="background-image:url(');

            for (uint256 i = 0; i < NUM_LAYERS - 1; i++) {
                thisTraitIndex = HelperLib.parseInt(
                    HelperLib._substring(_hash, (i * 3), (i * 3) + 3)
                );
                svgBytes.appendSafe(
                    abi.encodePacked(
                        "data:",
                        _traitDetails[i][thisTraitIndex].mimetype,
                        ";base64,",
                        Base64.encode(SSTORE2.read(_traitDataPointers[i][thisTraitIndex])),
                        "),url("
                    )
                );
            }

            thisTraitIndex = HelperLib.parseInt(
                HelperLib._substring(_hash, (NUM_LAYERS * 3) - 3, NUM_LAYERS * 3)
            );

            svgBytes.appendSafe(
                abi.encodePacked(
                    "data:",
                    _traitDetails[NUM_LAYERS - 1][thisTraitIndex].mimetype,
                    ";base64,",
                    Base64.encode(SSTORE2.read(_traitDataPointers[NUM_LAYERS - 1][thisTraitIndex])),
                    ');background-repeat:no-repeat;background-size:contain;background-position:center;image-rendering:-webkit-optimize-contrast;-ms-interpolation-mode:nearest-neighbor;image-rendering:-moz-crisp-edges;image-rendering:pixelated;"></svg>'
                )
            );

            return string(
                abi.encodePacked(
                    "data:image/svg+xml;base64,",
                    Base64.encode(svgBytes)
                )
            );
        }

        function hashToMetadata(string memory _hash)
            public
            view
            returns (string memory)
        {
            bytes memory metadataBytes = DynamicBuffer.allocate(1024 * 128);
            metadataBytes.appendSafe("[");

            for (uint256 i = 0; i < NUM_LAYERS; i++) {
                uint256 thisTraitIndex = HelperLib.parseInt(
                    HelperLib._substring(_hash, (i * 3), (i * 3) + 3)
                );
                metadataBytes.appendSafe(
                    abi.encodePacked(
                        '{"trait_type":"',
                        LAYER_NAMES[i],
                        '","value":"',
                        _traitDetails[i][thisTraitIndex].name,
                        '"}'
                    )
                );
                
                if (i == NUM_LAYERS - 1) {
                    metadataBytes.appendSafe("]");
                } else {
                    metadataBytes.appendSafe(",");
                }
            }

            return string(metadataBytes);
        }

        function tokenURI(uint256 _tokenId)
            public
            view
            override
            returns (string memory)
        {
            require(_exists(_tokenId), "Invalid token");
            require(_traitDataPointers[0].length > 0,  "Traits have not been added");

            string memory tokenHash = tokenIdToHash(_tokenId);

            bytes memory jsonBytes = DynamicBuffer.allocate(1024 * 128);
            jsonBytes.appendSafe(unicode"{\"name\":\"Still Lifes #");

            jsonBytes.appendSafe(
                abi.encodePacked(
                    _toString(_tokenId),
                    "\",\"description\":\"",
                    contractData.description,
                    "\","
                )
            );

            if (bytes(baseURI).length > 0 && _renderTokenOffChain[_tokenId]) {
                jsonBytes.appendSafe(
                    abi.encodePacked(
                        '"image":"',
                        baseURI,
                        _toString(_tokenId),
                        "?dna=",
                        tokenHash,
                        '&network=mainnet",'
                    )
                );
            } else {
                string memory svgCode = "";
                if (shouldWrapSVG) {
                    string memory svgString = hashToSVG(tokenHash);
                    svgCode = string(
                        abi.encodePacked(
                            "data:image/svg+xml;base64,",
                            Base64.encode(
                                abi.encodePacked(
                                    '<svg width="100%" height="100%" viewBox="0 0 1200 1200" version="1.2" xmlns="http://www.w3.org/2000/svg"><image width="1200" height="1200" href="',
                                    svgString,
                                    '"></image></svg>'
                                )
                            )
                        )
                    );
                    jsonBytes.appendSafe(
                        abi.encodePacked(
                            '"svg_image_data":"',
                            svgString,
                            '",'
                        )
                    );
                } else {
                    svgCode = hashToSVG(tokenHash);
                }

                jsonBytes.appendSafe(
                    abi.encodePacked(
                        '"image_data":"',
                        svgCode,
                        '",'
                    )
                );
            }

            jsonBytes.appendSafe(
                abi.encodePacked(
                    '"attributes":',
                    hashToMetadata(tokenHash),
                    "}"
                )
            );

            return string(
                abi.encodePacked(
                    "data:application/json;base64,",
                    Base64.encode(jsonBytes)
                )
            );
        }

        function contractURI()
            public
            view
            returns (string memory)
        {
            return string(
                abi.encodePacked(
                    "data:application/json;base64,",
                    Base64.encode(
                        abi.encodePacked(
                            '{"name":"',
                            contractData.name,
                            '","description":"',
                            contractData.description,
                            '","image":"',
                            contractData.image,
                            '","banner":"',
                            contractData.banner,
                            '","external_link":"',
                            contractData.website,
                            '","seller_fee_basis_points":',
                            _toString(contractData.royalties),
                            ',"fee_recipient":"',
                            contractData.royaltiesRecipient,
                            '"}'
                        )
                    )
                )
            );
        }

        function tokenIdToHash(uint256 _tokenId)
            public
            view
            returns (string memory)
        {
            // decrement to find first token in batch
            for (uint256 i = 0; i < MAX_BATCH_MINT; i++) {
                if (_tokenIdToRandomBytes[_tokenId - i] > 0) {
                    return hashFromRandomBytes(_tokenIdToRandomBytes[_tokenId - i], _tokenId, _tokenId - i);
                }
            }
            revert();
        }

        function tokenIdToSVG(uint256 _tokenId)
            public
            view
            returns (string memory)
        {
            return hashToSVG(tokenIdToHash(_tokenId));
        }

        function traitDetails(uint256 _layerIndex, uint256 _traitIndex)
            public
            view
            returns (Trait memory)
        {
            return _traitDetails[_layerIndex][_traitIndex];
        }

        function traitData(uint256 _layerIndex, uint256 _traitIndex)
            public
            view
            returns (string memory)
        {
            return string(SSTORE2.read(_traitDataPointers[_layerIndex][_traitIndex]));
        }

        function addLayer(uint256 _layerIndex, TraitDTO[] memory traits)
            public
            onlyOwner
        {
            require(TIERS[_layerIndex].length == traits.length, "Traits size does not match tiers for this index");
            require(traits.length < 100, "There cannot be over 99 traits per layer");
            address[] memory dataPointers = new address[](traits.length);
            for (uint256 i = 0; i < traits.length; i++) {
                dataPointers[i] = SSTORE2.write(traits[i].data);
                _traitDetails[_layerIndex][i] = Trait(traits[i].name, traits[i].mimetype);
            }
            _traitDataPointers[_layerIndex] = dataPointers;
            return;
        }

        function addTrait(uint256 _layerIndex, uint256 _traitIndex, TraitDTO memory trait)
            public
            onlyOwner
        {
            require(_traitIndex < 99, "There cannot be over 99 traits per layer");
            _traitDetails[_layerIndex][_traitIndex] = Trait(trait.name, trait.mimetype);
            address[] memory dataPointers = _traitDataPointers[_layerIndex];
            dataPointers[_traitIndex] = SSTORE2.write(trait.data);
            _traitDataPointers[_layerIndex] = dataPointers;
            return;
        }

        function changeContractData(ContractData memory _contractData) external onlyOwner {
            contractData = _contractData;
        }

        function changeMaxPerAddress(uint256 _maxPerAddress) external onlyOwner {
            maxPerAddress = _maxPerAddress;
        }

        function changeBaseURI(string memory _baseURI) external onlyOwner {
            baseURI = _baseURI;
        }

        function changeRenderOfTokenId(uint256 _tokenId, bool _renderOffChain) external {
            require(msg.sender == ownerOf(_tokenId), "Only the token owner can change the render method");
            _renderTokenOffChain[_tokenId] = _renderOffChain;
        }

        function toggleWrapSVG() external onlyOwner {
            shouldWrapSVG = !shouldWrapSVG;
        }

        function toggleMinting() external onlyOwner {
            isMintingPaused = !isMintingPaused;
        }

        function withdraw() external onlyOwner nonReentrant {
            (bool success,) = msg.sender.call{value : address(this).balance}("");
            require(success, "Withdrawal failed");
        }
    }

// File: /var/app/current/contracts/DynamicBuffer.sol



// SPDX-License-Identifier: MIT
// Copyright (c) 2021 the ethier authors (github.com/divergencetech/ethier)

pragma solidity >=0.8.0;

/// @title DynamicBuffer
/// @author David Huber (@cxkoda) and Simon Fremaux (@dievardump). See also
///         https://raw.githubusercontent.com/dievardump/solidity-dynamic-buffer
/// @notice This library is used to allocate a big amount of container memory
//          which will be subsequently filled without needing to reallocate
///         memory.
/// @dev First, allocate memory.
///      Then use `buffer.appendUnchecked(theBytes)` or `appendSafe()` if
///      bounds checking is required.
library DynamicBuffer {
    /// @notice Allocates container space for the DynamicBuffer
    /// @param capacity The intended max amount of bytes in the buffer
    /// @return buffer The memory location of the buffer
    /// @dev Allocates `capacity + 0x60` bytes of space
    ///      The buffer array starts at the first container data position,
    ///      (i.e. `buffer = container + 0x20`)
    function allocate(uint256 capacity)
        internal
        pure
        returns (bytes memory buffer)
    {
        assembly {
            // Get next-free memory address
            let container := mload(0x40)

            // Allocate memory by setting a new next-free address
            {
                // Add 2 x 32 bytes in size for the two length fields
                // Add 32 bytes safety space for 32B chunked copy
                let size := add(capacity, 0x60)
                let newNextFree := add(container, size)
                mstore(0x40, newNextFree)
            }

            // Set the correct container length
            {
                let length := add(capacity, 0x40)
                mstore(container, length)
            }

            // The buffer starts at idx 1 in the container (0 is length)
            buffer := add(container, 0x20)

            // Init content with length 0
            mstore(buffer, 0)
        }

        return buffer;
    }

    /// @notice Appends data to buffer, and update buffer length
    /// @param buffer the buffer to append the data to
    /// @param data the data to append
    /// @dev Does not perform out-of-bound checks (container capacity)
    ///      for efficiency.
    function appendUnchecked(bytes memory buffer, bytes memory data)
        internal
        pure
    {
        assembly {
            let length := mload(data)
            for {
                data := add(data, 0x20)
                let dataEnd := add(data, length)
                let copyTo := add(buffer, add(mload(buffer), 0x20))
            } lt(data, dataEnd) {
                data := add(data, 0x20)
                copyTo := add(copyTo, 0x20)
            } {
                // Copy 32B chunks from data to buffer.
                // This may read over data array boundaries and copy invalid
                // bytes, which doesn't matter in the end since we will
                // later set the correct buffer length, and have allocated an
                // additional word to avoid buffer overflow.
                mstore(copyTo, mload(data))
            }

            // Update buffer length
            mstore(buffer, add(mload(buffer), length))
        }
    }

    /// @notice Appends data to buffer, and update buffer length
    /// @param buffer the buffer to append the data to
    /// @param data the data to append
    /// @dev Performs out-of-bound checks and calls `appendUnchecked`.
    function appendSafe(bytes memory buffer, bytes memory data) internal pure {
        uint256 capacity;
        uint256 length;
        assembly {
            capacity := sub(mload(sub(buffer, 0x20)), 0x40)
            length := mload(buffer)
        }

        require(
            length + data.length <= capacity,
            "DynamicBuffer: Appending out of bounds."
        );
        appendUnchecked(buffer, data);
    }
}
// File: /var/app/current/contracts/HelperLib.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.14;

library HelperLib {
    function parseInt(string memory _a)
        internal
        pure
        returns (uint8 _parsedInt)
    {
        bytes memory bresult = bytes(_a);
        uint8 mint = 0;
        for (uint8 i = 0; i < bresult.length; i++) {
            if (
                (uint8(uint8(bresult[i])) >= 48) &&
                (uint8(uint8(bresult[i])) <= 57)
            ) {
                mint *= 10;
                mint += uint8(bresult[i]) - 48;
            }
        }
        return mint;
    }

    function _substring(
        string memory str,
        uint256 startIndex,
        uint256 endIndex
    ) internal pure returns (string memory) {
        bytes memory strBytes = bytes(str);
        bytes memory result = new bytes(endIndex - startIndex);
        for (uint256 i = startIndex; i < endIndex; i++) {
            result[i - startIndex] = strBytes[i];
        }
        return string(result);
    }
}
// File: /var/app/current/contracts/SSTORE2.sol



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

import "./utils/Bytecode.sol";

/**
  @title A key-value storage with auto-generated keys for storing chunks of data with a lower write & read cost.
  @author Agustin Aguilar <aa@horizon.io>

  Readme: https://github.com/0xsequence/sstore2#readme
*/
library SSTORE2 {
  error WriteError();

  /**
    @notice Stores `_data` and returns `pointer` as key for later retrieval
    @dev The pointer is a contract address with `_data` as code
    @param _data to be written
    @return pointer Pointer to the written `_data`
  */
  function write(bytes memory _data) internal returns (address pointer) {
    // Append 00 to _data so contract can't be called
    // Build init code
    bytes memory code = Bytecode.creationCodeFor(
      abi.encodePacked(
        hex'00',
        _data
      )
    );

    // Deploy contract using create
    assembly { pointer := create(0, add(code, 32), mload(code)) }

    // Address MUST be non-zero
    if (pointer == address(0)) revert WriteError();
  }

  /**
    @notice Reads the contents of the `_pointer` code as data, skips the first byte 
    @dev The function is intended for reading pointers generated by `write`
    @param _pointer to be read
    @return data read from `_pointer` contract
  */
  function read(address _pointer) internal view returns (bytes memory) {
    return Bytecode.codeAt(_pointer, 1, type(uint256).max);
  }

  /**
    @notice Reads the contents of the `_pointer` code as data, skips the first byte 
    @dev The function is intended for reading pointers generated by `write`
    @param _pointer to be read
    @param _start number of bytes to skip
    @return data read from `_pointer` contract
  */
  function read(address _pointer, uint256 _start) internal view returns (bytes memory) {
    return Bytecode.codeAt(_pointer, _start + 1, type(uint256).max);
  }

  /**
    @notice Reads the contents of the `_pointer` code as data, skips the first byte 
    @dev The function is intended for reading pointers generated by `write`
    @param _pointer to be read
    @param _start number of bytes to skip
    @param _end index before which to end extraction
    @return data read from `_pointer` contract
  */
  function read(address _pointer, uint256 _start, uint256 _end) internal view returns (bytes memory) {
    return Bytecode.codeAt(_pointer, _start + 1, _end + 1);
  }
}
// File: /var/app/current/contracts/utils/Bytecode.sol



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


library Bytecode {
  error InvalidCodeAtRange(uint256 _size, uint256 _start, uint256 _end);

  /**
    @notice Generate a creation code that results on a contract with `_code` as bytecode
    @param _code The returning value of the resulting `creationCode`
    @return creationCode (constructor) for new contract
  */
  function creationCodeFor(bytes memory _code) internal pure returns (bytes memory) {
    /*
      0x00    0x63         0x63XXXXXX  PUSH4 _code.length  size
      0x01    0x80         0x80        DUP1                size size
      0x02    0x60         0x600e      PUSH1 14            14 size size
      0x03    0x60         0x6000      PUSH1 00            0 14 size size
      0x04    0x39         0x39        CODECOPY            size
      0x05    0x60         0x6000      PUSH1 00            0 size
      0x06    0xf3         0xf3        RETURN
      <CODE>
    */

    return abi.encodePacked(
      hex"63",
      uint32(_code.length),
      hex"80_60_0E_60_00_39_60_00_F3",
      _code
    );
  }

  /**
    @notice Returns the size of the code on a given address
    @param _addr Address that may or may not contain code
    @return size of the code on the given `_addr`
  */
  function codeSize(address _addr) internal view returns (uint256 size) {
    assembly { size := extcodesize(_addr) }
  }

  /**
    @notice Returns the code of a given address
    @dev It will fail if `_end < _start`
    @param _addr Address that may or may not contain code
    @param _start number of bytes of code to skip on read
    @param _end index before which to end extraction
    @return oCode read from `_addr` deployed bytecode

    Forked from: https://gist.github.com/KardanovIR/fe98661df9338c842b4a30306d507fbd
  */
  function codeAt(address _addr, uint256 _start, uint256 _end) internal view returns (bytes memory oCode) {
    uint256 csize = codeSize(_addr);
    if (csize == 0) return bytes("");

    if (_start > csize) return bytes("");
    if (_end < _start) revert InvalidCodeAtRange(csize, _start, _end); 

    unchecked {
      uint256 reqSize = _end - _start;
      uint256 maxSize = csize - _start;

      uint256 size = maxSize < reqSize ? maxSize : reqSize;

      assembly {
        // allocate output byte array - this could also be done without assembly
        // by using o_code = new bytes(size)
        oCode := mload(0x40)
        // new "memory end" including padding
        mstore(0x40, add(oCode, and(add(add(size, 0x20), 0x1f), not(0x1f))))
        // store length in memory
        mstore(oCode, size)
        // actually retrieve the code, this needs assembly
        extcodecopy(_addr, add(oCode, 0x20), _start, size)
      }
    }
  }
}
// File: @openzeppelin/contracts/access/Ownable.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

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

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

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

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

        _;

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

// File: @openzeppelin/contracts/utils/Base64.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Base64.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides a set of functions to operate with Base64 strings.
 *
 * _Available since v4.5._
 */
library Base64 {
    /**
     * @dev Base64 Encoding/Decoding Table
     */
    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    /**
     * @dev Converts a `bytes` to its Bytes64 `string` representation.
     */
    function encode(bytes memory data) internal pure returns (string memory) {
        /**
         * Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
         * https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
         */
        if (data.length == 0) return "";

        // Loads the table into memory
        string memory table = _TABLE;

        // Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
        // and split into 4 numbers of 6 bits.
        // The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
        // - `data.length + 2`  -> Round up
        // - `/ 3`              -> Number of 3-bytes chunks
        // - `4 *`              -> 4 characters for each chunk
        string memory result = new string(4 * ((data.length + 2) / 3));

        assembly {
            // Prepare the lookup table (skip the first "length" byte)
            let tablePtr := add(table, 1)

            // Prepare result pointer, jump over length
            let resultPtr := add(result, 32)

            // Run over the input, 3 bytes at a time
            for {
                let dataPtr := data
                let endPtr := add(data, mload(data))
            } lt(dataPtr, endPtr) {

            } {
                // Advance 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // To write each character, shift the 3 bytes (18 bits) chunk
                // 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
                // and apply logical AND with 0x3F which is the number of
                // the previous character in the ASCII table prior to the Base64 Table
                // The result is then added to the table to get the character to write,
                // and finally write it in the result pointer but with a left shift
                // of 256 (1 byte) - 8 (1 ASCII char) = 248 bits

                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance
            }

            // When data `bytes` is not exactly 3 bytes long
            // it is padded with `=` characters at the end
            switch mod(mload(data), 3)
            case 1 {
                mstore8(sub(resultPtr, 1), 0x3d)
                mstore8(sub(resultPtr, 2), 0x3d)
            }
            case 2 {
                mstore8(sub(resultPtr, 1), 0x3d)
            }
        }

        return result;
    }
}

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



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

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: erc721a/contracts/ERC721A.sol



// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.0.0
// Creator: Chiru Labs

pragma solidity ^0.8.4;

import './IERC721A.sol';

/**
 * @dev ERC721 token receiver interface.
 */
interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension. Built to optimize for lower gas during batch mints.
 *
 * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
 *
 * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 *
 * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
    // Mask of an entry in packed address data.
    uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

    // The bit position of `numberMinted` in packed address data.
    uint256 private constant BITPOS_NUMBER_MINTED = 64;

    // The bit position of `numberBurned` in packed address data.
    uint256 private constant BITPOS_NUMBER_BURNED = 128;

    // The bit position of `aux` in packed address data.
    uint256 private constant BITPOS_AUX = 192;

    // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
    uint256 private constant BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

    // The bit position of `startTimestamp` in packed ownership.
    uint256 private constant BITPOS_START_TIMESTAMP = 160;

    // The bit mask of the `burned` bit in packed ownership.
    uint256 private constant BITMASK_BURNED = 1 << 224;
    
    // The bit position of the `nextInitialized` bit in packed ownership.
    uint256 private constant BITPOS_NEXT_INITIALIZED = 225;

    // The bit mask of the `nextInitialized` bit in packed ownership.
    uint256 private constant BITMASK_NEXT_INITIALIZED = 1 << 225;

    // The tokenId of the next token to be minted.
    uint256 private _currentIndex;

    // The number of tokens burned.
    uint256 private _burnCounter;

    // 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 `_packedOwnershipOf` implementation for details.
    //
    // Bits Layout:
    // - [0..159]   `addr`
    // - [160..223] `startTimestamp`
    // - [224]      `burned`
    // - [225]      `nextInitialized`
    mapping(uint256 => uint256) private _packedOwnerships;

    // Mapping owner address to address data.
    //
    // Bits Layout:
    // - [0..63]    `balance`
    // - [64..127]  `numberMinted`
    // - [128..191] `numberBurned`
    // - [192..255] `aux`
    mapping(address => uint256) private _packedAddressData;

    // 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;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    /**
     * @dev Returns the starting token ID. 
     * To change the starting token ID, please override this function.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Returns the next token ID to be minted.
     */
    function _nextTokenId() internal view returns (uint256) {
        return _currentIndex;
    }

    /**
     * @dev Returns the total number of tokens in existence.
     * Burned tokens will reduce the count. 
     * To get the total number of tokens minted, please see `_totalMinted`.
     */
    function totalSupply() public view override returns (uint256) {
        // Counter underflow is impossible as _burnCounter cannot be incremented
        // more than `_currentIndex - _startTokenId()` times.
        unchecked {
            return _currentIndex - _burnCounter - _startTokenId();
        }
    }

    /**
     * @dev Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view returns (uint256) {
        // Counter underflow is impossible as _currentIndex does not decrement,
        // and it is initialized to `_startTokenId()`
        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    /**
     * @dev Returns the total number of tokens burned.
     */
    function _totalBurned() internal view returns (uint256) {
        return _burnCounter;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        // The interface IDs are constants representing the first 4 bytes of the XOR of
        // all function selectors in the interface. See: https://eips.ethereum.org/EIPS/eip-165
        // e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`
        return
            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return _packedAddressData[owner] & BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the number of tokens minted by `owner`.
     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> BITPOS_NUMBER_MINTED) & BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the number of tokens burned by or on behalf of `owner`.
     */
    function _numberBurned(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> BITPOS_NUMBER_BURNED) & BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     */
    function _getAux(address owner) internal view returns (uint64) {
        return uint64(_packedAddressData[owner] >> BITPOS_AUX);
    }

    /**
     * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     * If there are multiple variables, please pack them into a uint64.
     */
    function _setAux(address owner, uint64 aux) internal {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        assembly { // Cast aux without masking.
            auxCasted := aux
        }
        packed = (packed & BITMASK_AUX_COMPLEMENT) | (auxCasted << BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }

    /**
     * Returns the packed ownership data of `tokenId`.
     */
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr)
                if (curr < _currentIndex) {
                    uint256 packed = _packedOwnerships[curr];
                    // If not burned.
                    if (packed & BITMASK_BURNED == 0) {
                        // Invariant:
                        // There will always be an ownership that has an address and is not burned
                        // before an ownership that does not have an address and is not burned.
                        // Hence, curr will not underflow.
                        //
                        // We can directly compare the packed value.
                        // If the address is zero, packed is zero.
                        while (packed == 0) {
                            packed = _packedOwnerships[--curr];
                        }
                        return packed;
                    }
                }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**
     * Returns the unpacked `TokenOwnership` struct from `packed`.
     */
    function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
        ownership.addr = address(uint160(packed));
        ownership.startTimestamp = uint64(packed >> BITPOS_START_TIMESTAMP);
        ownership.burned = packed & BITMASK_BURNED != 0;
    }

    /**
     * Returns the unpacked `TokenOwnership` struct at `index`.
     */
    function _ownershipAt(uint256 index) internal view returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }

    /**
     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
     */
    function _initializeOwnershipAt(uint256 index) internal {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    /**
     * Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around in the collection over time.
     */
    function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    /**
     * @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) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

        string memory baseURI = _baseURI();
        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
    }

    /**
     * @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 Casts the address to uint256 without masking.
     */
    function _addressToUint256(address value) private pure returns (uint256 result) {
        assembly {
            result := value
        }
    }

    /**
     * @dev Casts the boolean to uint256 without branching.
     */
    function _boolToUint256(bool value) private pure returns (uint256 result) {
        assembly {
            result := value
        }
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public override {
        address owner = address(uint160(_packedOwnershipOf(tokenId)));
        if (to == owner) revert ApprovalToCurrentOwner();

        if (_msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }

        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        if (operator == _msgSenderERC721A()) revert ApproveToCaller();

        _operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }

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

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

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

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        _transfer(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }

    /**
     * @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
            _startTokenId() <= tokenId &&
            tokenId < _currentIndex && // If within bounds,
            _packedOwnerships[tokenId] & BITMASK_BURNED == 0; // and not burned.
    }

    /**
     * @dev Equivalent to `_safeMint(to, quantity, '')`.
     */
    function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, '');
    }

    /**
     * @dev Safely mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement
     *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
        // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the balance and number minted.
            _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);

            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            _packedOwnerships[startTokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                (_boolToUint256(quantity == 1) << BITPOS_NEXT_INITIALIZED);

            uint256 updatedIndex = startTokenId;
            uint256 end = updatedIndex + quantity;

            if (to.code.length != 0) {
                do {
                    emit Transfer(address(0), to, updatedIndex);
                    if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (updatedIndex < end);
                // Reentrancy protection
                if (_currentIndex != startTokenId) revert();
            } else {
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex < end);
            }
            _currentIndex = updatedIndex;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 quantity) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
        // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the balance and number minted.
            _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);

            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            _packedOwnerships[startTokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                (_boolToUint256(quantity == 1) << BITPOS_NEXT_INITIALIZED);

            uint256 updatedIndex = startTokenId;
            uint256 end = updatedIndex + quantity;

            do {
                emit Transfer(address(0), to, updatedIndex++);
            } while (updatedIndex < end);

            _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 {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

        bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
            isApprovedForAll(from, _msgSenderERC721A()) ||
            getApproved(tokenId) == _msgSenderERC721A());

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner.
        delete _tokenApprovals[tokenId];

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            // We can directly increment and decrement the balances.
            --_packedAddressData[from]; // Updates: `balance -= 1`.
            ++_packedAddressData[to]; // Updates: `balance += 1`.

            // Updates:
            // - `address` to the next owner.
            // - `startTimestamp` to the timestamp of transfering.
            // - `burned` to `false`.
            // - `nextInitialized` to `true`.
            _packedOwnerships[tokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                BITMASK_NEXT_INITIALIZED;

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (_packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != _currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**
     * @dev Equivalent to `_burn(tokenId, false)`.
     */
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

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

        address from = address(uint160(prevOwnershipPacked));

        if (approvalCheck) {
            bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
                isApprovedForAll(from, _msgSenderERC721A()) ||
                getApproved(tokenId) == _msgSenderERC721A());

            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner.
        delete _tokenApprovals[tokenId];

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            // Updates:
            // - `balance -= 1`.
            // - `numberBurned += 1`.
            //
            // We can directly decrement the balance, and increment the number burned.
            // This is equivalent to `packed -= 1; packed += 1 << BITPOS_NUMBER_BURNED;`.
            _packedAddressData[from] += (1 << BITPOS_NUMBER_BURNED) - 1;

            // Updates:
            // - `address` to the last owner.
            // - `startTimestamp` to the timestamp of burning.
            // - `burned` to `true`.
            // - `nextInitialized` to `true`.
            _packedOwnerships[tokenId] =
                _addressToUint256(from) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                BITMASK_BURNED | 
                BITMASK_NEXT_INITIALIZED;

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (_packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != _currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
        unchecked {
            _burnCounter++;
        }
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target 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 _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
            bytes4 retval
        ) {
            return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    /**
     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
     * And also called before burning one token.
     *
     * 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`.
     * - When `to` is zero, `tokenId` will be burned by `from`.
     * - `from` and `to` are never both zero.
     */
    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.
     * And also called after one token has been burned.
     *
     * 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` has been
     * transferred to `to`.
     * - When `from` is zero, `tokenId` has been minted for `to`.
     * - When `to` is zero, `tokenId` has been burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Returns the message sender (defaults to `msg.sender`).
     *
     * If you are writing GSN compatible contracts, you need to override this function.
     */
    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function _toString(uint256 value) internal pure returns (string memory ptr) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), 
            // but we allocate 128 bytes to keep the free memory pointer 32-byte word aliged.
            // We will need 1 32-byte word to store the length, 
            // and 3 32-byte words to store a maximum of 78 digits. Total: 32 + 3 * 32 = 128.
            ptr := add(mload(0x40), 128)
            // Update the free memory pointer to allocate.
            mstore(0x40, ptr)

            // Cache the end of the memory to calculate the length later.
            let end := ptr

            // We write the string from the rightmost digit to the leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // Costs a bit more than early returning for the zero case,
            // but cheaper in terms of deployment and overall runtime costs.
            for { 
                // Initialize and perform the first pass without check.
                let temp := value
                // Move the pointer 1 byte leftwards to point to an empty character slot.
                ptr := sub(ptr, 1)
                // Write the character to the pointer. 48 is the ASCII index of '0'.
                mstore8(ptr, add(48, mod(temp, 10)))
                temp := div(temp, 10)
            } temp { 
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
            } { // Body of the for loop.
                ptr := sub(ptr, 1)
                mstore8(ptr, add(48, mod(temp, 10)))
            }
            
            let length := sub(end, ptr)
            // Move the pointer 32 bytes leftwards to make room for the length.
            ptr := sub(ptr, 32)
            // Store the length.
            mstore(ptr, length)
        }
    }
}

// File: erc721a/contracts/IERC721A.sol



// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.0.0
// Creator: Chiru Labs

pragma solidity ^0.8.4;

/**
 * @dev Interface of an ERC721A compliant contract.
 */
interface IERC721A {
    /**
     * The caller must own the token or be an approved operator.
     */
    error ApprovalCallerNotOwnerNorApproved();

    /**
     * The token does not exist.
     */
    error ApprovalQueryForNonexistentToken();

    /**
     * The caller cannot approve to their own address.
     */
    error ApproveToCaller();

    /**
     * The caller cannot approve to the current owner.
     */
    error ApprovalToCurrentOwner();

    /**
     * Cannot query the balance for the zero address.
     */
    error BalanceQueryForZeroAddress();

    /**
     * Cannot mint to the zero address.
     */
    error MintToZeroAddress();

    /**
     * The quantity of tokens minted must be more than zero.
     */
    error MintZeroQuantity();

    /**
     * The token does not exist.
     */
    error OwnerQueryForNonexistentToken();

    /**
     * The caller must own the token or be an approved operator.
     */
    error TransferCallerNotOwnerNorApproved();

    /**
     * The token must be owned by `from`.
     */
    error TransferFromIncorrectOwner();

    /**
     * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
     */
    error TransferToNonERC721ReceiverImplementer();

    /**
     * Cannot transfer to the zero address.
     */
    error TransferToZeroAddress();

    /**
     * The token does not exist.
     */
    error URIQueryForNonexistentToken();

    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Keeps track of the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
    }

    /**
     * @dev Returns the total amount of tokens stored by the contract.
     *
     * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
     */
    function totalSupply() external view returns (uint256);

    // ==============================
    //            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);

    // ==============================
    //            IERC721
    // ==============================

    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

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

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

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

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

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

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

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

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

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

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

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

    // ==============================
    //        IERC721Metadata
    // ==============================

    /**
     * @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);
}