// File: lib/openzeppelin-contracts/contracts/access/Ownable.sol



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

pragma solidity ^0.8.0;

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

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

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

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/utils/Base64.sol



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

        /// @solidity memory-safe-assembly
        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: lib/openzeppelin-contracts/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: src/contracts/interfaces/IOnChainMetadata.sol



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

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

interface IOnChainMetadata {
  /**
   * Mint new tokens.
   */
  function tokenURI(uint256 tokenId_) external view returns (string memory);

  function tokenImageDataURI(uint256 tokenId_) external view returns (string memory);
}

// File: src/contracts/libraries/Math.sol



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

library Math {
  function min(uint256 a, uint256 b) internal pure returns (uint256) {
    return a < b ? a : b;
  }

  function max(uint256 a, uint256 b) internal pure returns (uint256) {
    return a > b ? a : b;
  }

  function average(uint256 a, uint256 b) internal pure returns (uint256) {
    // (a + b) / 2 can overflow, so we distribute
    return (a / 2) + (b / 2) + (((a % 2) + (b % 2)) / 2);
  }

  function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
    return a / b + (a % b == 0 ? 0 : 1);
  }
}

// File: src/contracts/libraries/SymmetricEncryptionUtils.sol



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

import "@openzeppelin/contracts/utils/Base64.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

import "../interfaces/IOnChainMetadata.sol";
import "../tokens/erc721/custom-erc721/ERC721AEnumerable.sol";
import "../libraries/Math.sol";

library SymmetricEncryptionUtils {
  function bytesToBytes32Arr(bytes memory source) internal pure returns (bytes32[] memory) {
    uint256 sourceLen = source.length;
    bytes32[] memory result = new bytes32[](Math.ceilDiv(sourceLen, 32));

    for (uint256 i = 0; i < result.length; i++) {
      for (uint256 j = 0; j < 32; j++) {
        uint256 index = i * 32 + j;
        if (index >= sourceLen) {
          result[i] |= bytes32(0) >> (8 * j);
        } else {
          result[i] |= bytes32(source[index]) >> (8 * j);
        }
      }
    }
    return result;
  }

  function bytes32ArrToBytes(bytes32[] memory source) internal pure returns (bytes memory) {
    bytes memory result = new bytes(source.length * 32);
    for (uint256 i = 0; i < source.length; i++) {
      for (uint256 j = 0; j < 32; j++) {
        result[i * 32 + j] = bytes1(source[i] << (8 * j));
      }
    }
    return result;
  }

  function encrypt(
    bytes32 decryptionKey,
    bytes32[] memory secret
  ) internal pure returns (bytes32[] memory) {
    bytes32[] memory encrypted = new bytes32[](secret.length);
    for (uint256 i = 0; i < secret.length; i++) {
      encrypted[i] = secret[i] ^ decryptionKey;
    }
    return encrypted;
  }

  function bytesTrimEnd(bytes memory source) internal pure returns (bytes memory result) {
    uint256 len = 0;
    for (uint256 i = 0; i < source.length; i++) {
      if (source[i] == 0) {
        len = i;
        break;
      }
    }
    result = new bytes(len);
    for (uint256 i = 0; i < len; i++) {
      result[i] = source[i];
    }
    return result;
  }
}

// File: src/contracts/pre-mint/MTE.sol



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

import "@openzeppelin/contracts/utils/Base64.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

import "../interfaces/IOnChainMetadata.sol";
import "../tokens/erc721/custom-erc721/ERC721AEnumerable.sol";
import "../libraries/SymmetricEncryptionUtils.sol";

// import "@forge-std/src/console.sol";

error NotUnlockedYet();
error AlreadyUnlocked();
error MaxSupplyReached();
error AlreadyClaimed();
error InvalidSecret();
error InsufficientFunds();
error InvalidAmount();

/// @title A title that should describe the contract/interface
/// @author The name of the author
/// @notice Explain to an end user what this does
/// @dev Explain to a developer any extra details
contract MTE is ERC721AEnumerable, Ownable {
  IOnChainMetadata public metadata;
  bytes32 internal immutable secretHash;
  bytes internal hiddenLore;

  uint256 public immutable price;
  uint256 public immutable maxSupply;
  mapping(address => bool) public hasClaimed;
  string public externalUrl;

  mapping(uint256 => uint256) public tokenTypes;
  uint256 public constant CHOSEN_ONE = 1;
  uint256 public constant FREE_MINT = 2;
  uint256 public constant PREMIUM_MINT = 3;

  event Unlocked(address user);

  constructor(
    string memory name_,
    string memory symbol_,
    IOnChainMetadata metadataAddr_,
    bytes32 secretHash_,
    bytes memory hiddenLore_,
    uint256 maxSupply_,
    uint256 price_,
    string memory externalUrl_
  ) ERC721AEnumerable(name_, symbol_) {
    metadata = metadataAddr_;
    secretHash = secretHash_;
    hiddenLore = hiddenLore_;
    maxSupply = maxSupply_;
    price = price_;
    externalUrl = externalUrl_;
  }

  function setName(string memory name_) external onlyOwner {
    _name = name_;
  }

  function setSymbol(string memory symbol_) external onlyOwner {
    _symbol = symbol_;
  }

  function unlock(string memory secret) external {
    if (totalSupply() > 0) revert AlreadyUnlocked();
    if (totalSupply() >= maxSupply) revert MaxSupplyReached();
    if (keccak256(abi.encodePacked(secret)) != secretHash) revert InvalidSecret();
    emit Unlocked(msg.sender);
    tokenTypes[_nextTokenId()] = CHOSEN_ONE;
    _safeMint(msg.sender, 1);
  }

  function isUnlocked() external view returns (bool) {
    return totalSupply() > 0;
  }

  function mint(uint8 amount_) external payable {
    if (totalSupply() == 0) revert NotUnlockedYet();
    if (totalSupply() + amount_ > maxSupply) revert MaxSupplyReached();
    if (amount_ == 0) revert InvalidAmount();
    if (hasClaimed[msg.sender]) revert AlreadyClaimed();
    hasClaimed[msg.sender] = true;

    if (amount_ == 1) {
      tokenTypes[_nextTokenId()] = FREE_MINT;
      _safeMint(msg.sender, 1);
    } else if (amount_ == 2) {
      if (msg.value != price) revert InsufficientFunds();
      uint256 tokenId = _nextTokenId();
      tokenTypes[tokenId] = FREE_MINT;
      tokenTypes[tokenId + 1] = PREMIUM_MINT;
      _safeMint(msg.sender, 2);
    } else revert InvalidAmount();
  }

  function tokenURI(
    uint256 tokenId
  ) public view virtual override(IERC721A, ERC721A) returns (string memory) {
    if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
    return metadata.tokenURI(tokenId);
  }

  function setExternalUrl(string memory externalUrl_) external onlyOwner {
    externalUrl = externalUrl_;
  }

  function h1dd3n(string memory secretKey) external view returns (string memory) {
    require(totalSupply() > 0, "Not unlocked yet");
    bytes32 decryptionKey = keccak256(abi.encodePacked(secretKey));

    return
      string(
        SymmetricEncryptionUtils.bytesTrimEnd(
          SymmetricEncryptionUtils.bytes32ArrToBytes(
            SymmetricEncryptionUtils.encrypt(
              decryptionKey,
              SymmetricEncryptionUtils.bytesToBytes32Arr(hiddenLore)
            )
          )
        )
      );
  }

  function reveal(IOnChainMetadata revealOnChainMetadataAddr_) external onlyOwner {
    metadata = revealOnChainMetadataAddr_;
  }

  function withdraw() external onlyOwner {
    payable(msg.sender).transfer(address(this).balance);
  }
}
// On Tupac's Soul

// File: src/contracts/tokens/erc721/custom-erc721/ERC721A.sol



// SPDX-License-Identifier: MIT
// Based on ERC721A Contracts v4.2.3 from Chiru Labs and Citizens of Tajigen's Tiny ERC721 using Mason and Chance's optimizations
// added modifications on top

pragma solidity ^0.8.4;

import "./IERC721A.sol";

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

/**
 * @title ERC721A
 *
 * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
 * Non-Fungible Token Standard, including the Metadata extension.
 * Optimized for lower gas during batch mints.
 *
 * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
 * starting from `_startTokenId()`.
 *
 * Assumptions:
 *
 * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
  // Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
  struct TokenApprovalRef {
    address value;
  }

  // =============================================================
  //                           CONSTANTS
  // =============================================================

  // 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 bit position of `extraData` in packed ownership.
  uint256 private constant _BITPOS_EXTRA_DATA = 232;

  // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
  uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;

  // The mask of the lower 160 bits for addresses.
  uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;

  // The maximum `quantity` that can be minted with {_mintERC2309}.
  // This limit is to prevent overflows on the address data entries.
  // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
  // is required to cause an overflow, which is unrealistic.
  uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;

  // The `Transfer` event signature is given by:
  // `keccak256(bytes("Transfer(address,address,uint256)"))`.
  bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
    0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

  // =============================================================
  //                            STORAGE
  // =============================================================

  // The next token ID to be minted.
  uint256 private _currentIndex;

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

  // Token name
  string internal _name;

  // Token symbol
  string internal _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`
  // - [232..255] `extraData`
  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 => TokenApprovalRef) private _tokenApprovals;

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

  // =============================================================
  //                          CONSTRUCTOR
  // =============================================================

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

  // =============================================================
  //                   TOKEN COUNTING OPERATIONS
  // =============================================================

  /**
   * @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 virtual 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 virtual 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 virtual 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 virtual returns (uint256) {
    return _burnCounter;
  }

  // =============================================================
  //                    ADDRESS DATA OPERATIONS
  // =============================================================

  /**
   * @dev Returns the number of tokens in `owner`'s account.
   */
  function balanceOf(address owner) public view virtual 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 auxiliary 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 auxiliary 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 virtual {
    uint256 packed = _packedAddressData[owner];
    uint256 auxCasted;
    // Cast `aux` with assembly to avoid redundant masking.
    assembly {
      auxCasted := aux
    }
    packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
    _packedAddressData[owner] = packed;
  }

  // =============================================================
  //                            IERC165
  // =============================================================

  /**
   * @dev Returns true if this contract implements the interface defined by
   * `interfaceId`. See the corresponding
   * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
   * to learn more about how these ids are created.
   *
   * This function call must use less than 30000 gas.
   */
  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: [ERC165](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.
      interfaceId == type(IERC721A).interfaceId;
  }

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

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

  /**
   * @dev Returns the token collection symbol.
   */
  function symbol() public view virtual override returns (string memory) {
    return _symbol;
  }

  /**
   * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
   */
  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, it can be overridden in child contracts.
   */
  function _baseURI() internal view virtual returns (string memory) {
    return "";
  }

  // =============================================================
  //                     OWNERSHIPS OPERATIONS
  // =============================================================

  /**
   * @dev Returns the owner of the `tokenId` token.
   *
   * Requirements:
   *
   * - `tokenId` must exist.
   */
  function ownerOf(uint256 tokenId) public view virtual override returns (address) {
    return address(uint160(_packedOwnershipOf(tokenId)));
  }

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

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

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

  /**
   * Returns the packed ownership data of `tokenId`.
   */
  function _packedOwnershipOf(uint256 tokenId) private view returns (uint256 packed) {
    if (_startTokenId() <= tokenId) {
      packed = _packedOwnerships[tokenId];
      // If not burned.
      if (packed & _BITMASK_BURNED == 0) {
        // If the data at the starting slot does not exist, start the scan.
        if (packed == 0) {
          if (tokenId >= _currentIndex) revert OwnerQueryForNonexistentToken();
          // Invariant:
          // There will always be an initialized ownership slot
          // (i.e. `ownership.addr != address(0) && ownership.burned == false`)
          // before an unintialized ownership slot
          // (i.e. `ownership.addr == address(0) && ownership.burned == false`)
          // Hence, `tokenId` will not underflow.
          //
          // We can directly compare the packed value.
          // If the address is zero, packed will be zero.
          for (;;) {
            unchecked {
              packed = _packedOwnerships[--tokenId];
            }
            if (packed == 0) continue;
            return packed;
          }
        }
        // Otherwise, the data exists and is not burned. We can skip the scan.
        // This is possible because we have already achieved the target condition.
        // This saves 2143 gas on transfers of initialized tokens.
        return packed;
      }
    }
    revert OwnerQueryForNonexistentToken();
  }

  /**
   * @dev 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;
    ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
  }

  /**
   * @dev Packs ownership data into a single uint256.
   */
  function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
    assembly {
      // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
      owner := and(owner, _BITMASK_ADDRESS)
      // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
      result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
    }
  }

  /**
   * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
   */
  function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
    // For branchless setting of the `nextInitialized` flag.
    assembly {
      // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
      result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
    }
  }

  // =============================================================
  //                      APPROVAL OPERATIONS
  // =============================================================

  /**
   * @dev Gives permission to `to` to transfer `tokenId` token to another account. See {ERC721A-_approve}.
   *
   * Requirements:
   *
   * - The caller must own the token or be an approved operator.
   */
  function approve(address to, uint256 tokenId) public payable virtual override {
    _approve(to, tokenId, true);
  }

  /**
   * @dev Returns the account approved for `tokenId` token.
   *
   * Requirements:
   *
   * - `tokenId` must exist.
   */
  function getApproved(uint256 tokenId) public view virtual override returns (address) {
    if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

    return _tokenApprovals[tokenId].value;
  }

  /**
   * @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) public virtual override {
    _operatorApprovals[_msgSenderERC721A()][operator] = approved;
    emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
  }

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

  /**
   * @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. See {_mint}.
   */
  function _exists(uint256 tokenId) internal view virtual returns (bool) {
    return
      _startTokenId() <= tokenId &&
      tokenId < _currentIndex && // If within bounds,
      _packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
  }

  /**
   * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
   */
  function _isSenderApprovedOrOwner(
    address approvedAddress,
    address owner,
    address msgSender
  ) private pure returns (bool result) {
    assembly {
      // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
      owner := and(owner, _BITMASK_ADDRESS)
      // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
      msgSender := and(msgSender, _BITMASK_ADDRESS)
      // `msgSender == owner || msgSender == approvedAddress`.
      result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
    }
  }

  /**
   * @dev Returns the storage slot and value for the approved address of `tokenId`.
   */
  function _getApprovedSlotAndAddress(
    uint256 tokenId
  ) private view returns (uint256 approvedAddressSlot, address approvedAddress) {
    TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
    // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
    assembly {
      approvedAddressSlot := tokenApproval.slot
      approvedAddress := sload(approvedAddressSlot)
    }
  }

  // =============================================================
  //                      TRANSFER OPERATIONS
  // =============================================================

  /**
   * @dev Transfers `tokenId` from `from` to `to`.
   *
   * 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) public payable virtual override {
    uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

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

    (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

    // The nested ifs save around 20+ gas over a compound boolean condition.
    if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
      if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();

    if (to == address(0)) revert TransferToZeroAddress();

    _beforeTokenTransfers(from, to, tokenId, 1);

    // Clear approvals from the previous owner.
    assembly {
      if approvedAddress {
        // This is equivalent to `delete _tokenApprovals[tokenId]`.
        sstore(approvedAddressSlot, 0)
      }
    }

    // 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] = _packOwnershipData(
        to,
        _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
      );

      // 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 `safeTransferFrom(from, to, tokenId, '')`.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public payable virtual override {
    safeTransferFrom(from, to, tokenId, "");
  }

  /**
   * @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 memory _data
  ) public payable virtual override {
    transferFrom(from, to, tokenId);
    if (to.code.length != 0)
      if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
        revert TransferToNonERC721ReceiverImplementer();
      }
  }

  /**
   * @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 Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
   *
   * `from` - Previous owner of the given token ID.
   * `to` - Target address that will receive the token.
   * `tokenId` - Token ID to be transferred.
   * `_data` - Optional data to send along with the call.
   *
   * Returns 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))
        }
      }
    }
  }

  // =============================================================
  //                        MINT OPERATIONS
  // =============================================================

  /**
   * @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 for each mint.
   */
  function _mint(address to, uint256 quantity) internal virtual {
    uint256 startTokenId = _currentIndex;
    if (quantity == 0) revert MintZeroQuantity();

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

    // Overflows are incredibly unrealistic.
    // `balance` and `numberMinted` have a maximum limit of 2**64.
    // `tokenId` has a maximum limit of 2**256.
    unchecked {
      // Updates:
      // - `balance += quantity`.
      // - `numberMinted += quantity`.
      //
      // We can directly add to the `balance` and `numberMinted`.
      _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] = _packOwnershipData(
        to,
        _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
      );

      uint256 toMasked;
      uint256 end = startTokenId + quantity;

      // Use assembly to loop and emit the `Transfer` event for gas savings.
      // The duplicated `log4` removes an extra check and reduces stack juggling.
      // The assembly, together with the surrounding Solidity code, have been
      // delicately arranged to nudge the compiler into producing optimized opcodes.
      assembly {
        // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
        toMasked := and(to, _BITMASK_ADDRESS)
        // Emit the `Transfer` event.
        log4(
          0, // Start of data (0, since no data).
          0, // End of data (0, since no data).
          _TRANSFER_EVENT_SIGNATURE, // Signature.
          0, // `address(0)`.
          toMasked, // `to`.
          startTokenId // `tokenId`.
        )

        // The `iszero(eq(,))` check ensures that large values of `quantity`
        // that overflows uint256 will make the loop run out of gas.
        // The compiler will optimize the `iszero` away for performance.
        for {
          let tokenId := add(startTokenId, 1)
        } iszero(eq(tokenId, end)) {
          tokenId := add(tokenId, 1)
        } {
          // Emit the `Transfer` event. Similar to above.
          log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
        }
      }
      if (toMasked == 0) revert MintToZeroAddress();

      _currentIndex = end;
    }
    _afterTokenTransfers(address(0), to, startTokenId, quantity);
  }

  /**
   * @dev Mints `quantity` tokens and transfers them to `to`.
   *
   * This function is intended for efficient minting only during contract creation.
   *
   * It emits only one {ConsecutiveTransfer} as defined in
   * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
   * instead of a sequence of {Transfer} event(s).
   *
   * Calling this function outside of contract creation WILL make your contract
   * non-compliant with the ERC721 standard.
   * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
   * {ConsecutiveTransfer} event is only permissible during contract creation.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - `quantity` must be greater than 0.
   *
   * Emits a {ConsecutiveTransfer} event.
   */
  function _mintERC2309(address to, uint256 quantity) internal virtual {
    uint256 startTokenId = _currentIndex;
    if (to == address(0)) revert MintToZeroAddress();
    if (quantity == 0) revert MintZeroQuantity();
    if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();

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

    // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
    unchecked {
      // Updates:
      // - `balance += quantity`.
      // - `numberMinted += quantity`.
      //
      // We can directly add to the `balance` and `numberMinted`.
      _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] = _packOwnershipData(
        to,
        _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
      );

      emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);

      _currentIndex = startTokenId + quantity;
    }
    _afterTokenTransfers(address(0), to, startTokenId, 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.
   *
   * See {_mint}.
   *
   * Emits a {Transfer} event for each mint.
   */
  function _safeMint(address to, uint256 quantity, bytes memory _data) internal virtual {
    _mint(to, quantity);

    unchecked {
      if (to.code.length != 0) {
        uint256 end = _currentIndex;
        uint256 index = end - quantity;
        do {
          if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
            revert TransferToNonERC721ReceiverImplementer();
          }
        } while (index < end);
        // Reentrancy protection.
        if (_currentIndex != end) revert();
      }
    }
  }

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

  // =============================================================
  //                       APPROVAL OPERATIONS
  // =============================================================

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

  /**
   * @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:
   *
   * - `tokenId` must exist.
   *
   * Emits an {Approval} event.
   */
  function _approve(address to, uint256 tokenId, bool approvalCheck) internal virtual {
    address owner = ownerOf(tokenId);

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

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

  // =============================================================
  //                        BURN OPERATIONS
  // =============================================================

  /**
   * @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));

    (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

    if (approvalCheck) {
      // The nested ifs save around 20+ gas over a compound boolean condition.
      if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
        if (!isApprovedForAll(from, _msgSenderERC721A()))
          revert TransferCallerNotOwnerNorApproved();
    }

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

    // Clear approvals from the previous owner.
    assembly {
      if approvedAddress {
        // This is equivalent to `delete _tokenApprovals[tokenId]`.
        sstore(approvedAddressSlot, 0)
      }
    }

    // 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] = _packOwnershipData(
        from,
        (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) |
          _nextExtraData(from, address(0), prevOwnershipPacked)
      );

      // 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++;
    }
  }

  // =============================================================
  //                     EXTRA DATA OPERATIONS
  // =============================================================

  /**
   * @dev Directly sets the extra data for the ownership data `index`.
   */
  function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
    uint256 packed = _packedOwnerships[index];
    if (packed == 0) revert OwnershipNotInitializedForExtraData();
    uint256 extraDataCasted;
    // Cast `extraData` with assembly to avoid redundant masking.
    assembly {
      extraDataCasted := extraData
    }
    packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
    _packedOwnerships[index] = packed;
  }

  /**
   * @dev Called during each token transfer to set the 24bit `extraData` field.
   * Intended to be overridden by the cosumer contract.
   *
   * `previousExtraData` - the value of `extraData` before transfer.
   *
   * 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 _extraData(
    address from,
    address to,
    uint24 previousExtraData
  ) internal view virtual returns (uint24) {}

  /**
   * @dev Returns the next extra data for the packed ownership data.
   * The returned result is shifted into position.
   */
  function _nextExtraData(
    address from,
    address to,
    uint256 prevOwnershipPacked
  ) private view returns (uint256) {
    uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
    return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
  }

  // =============================================================
  //                       OTHER OPERATIONS
  // =============================================================

  /**
   * @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 virtual returns (string memory str) {
    assembly {
      // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
      // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
      // We will need 1 word for the trailing zeros padding, 1 word for the length,
      // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
      let m := add(mload(0x40), 0xa0)
      // Update the free memory pointer to allocate.
      mstore(0x40, m)
      // Assign the `str` to the end.
      str := sub(m, 0x20)
      // Zeroize the slot after the string.
      mstore(str, 0)

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

      // We write the string from rightmost digit to leftmost digit.
      // The following is essentially a do-while loop that also handles the zero case.
      // prettier-ignore
      for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

      let length := sub(end, str)
      // Move the pointer 32 bytes leftwards to make room for the length.
      str := sub(str, 0x20)
      // Store the length.
      mstore(str, length)
    }
  }
}

// File: src/contracts/tokens/erc721/custom-erc721/ERC721AEnumerable.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.8;

/// @title ERC721AEnumerable
/// @author MilkyTaste @ Ao Collaboration Ltd.
/// https://block.aocollab.tech
/// An enumerable extension to ERC721A that does not increase gas costs.

import "./IERC721AEnumerable.sol";
import "./ERC721A.sol";

error IndexOutOfBounds();
error QueryForZeroAddress();

contract ERC721AEnumerable is IERC721AEnumerable, ERC721A {
  constructor(
    string memory name_,
    string memory symbol_
  ) ERC721A(name_, symbol_) {}

  /**
   * @dev Returns the total amount of tokens stored by the contract.
   * Uses the ERC721A implementation.
   */
  function totalSupply()
    public
    view
    override(ERC721A, IERC721AEnumerable)
    returns (uint256)
  {
    return ERC721A.totalSupply();
  }

  /**
   * @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.
   * @notice This method is intended for read only purposes.
   */
  function tokenOfOwnerByIndex(
    address owner,
    uint256 index
  ) external view override returns (uint256 tokenId) {
    if (owner == address(0)) revert QueryForZeroAddress();
    if (balanceOf(owner) <= index) revert IndexOutOfBounds();

    uint256 upToIndex = 0;
    uint256 highestTokenId = _startTokenId() + _totalMinted();
    for (uint256 i = _startTokenId(); i < highestTokenId; i++) {
      if (_ownerOfWithoutError(i) == owner) {
        if (upToIndex == index) return i;
        upToIndex++;
      }
    }
    // Should never reach this case
    revert IndexOutOfBounds();
  }

  /**
   * A copy of the ERC721A._ownershipOf implementation that returns address(0) when unowned instead of an error.
   */
  function _ownerOfWithoutError(
    uint256 tokenId
  ) internal view returns (address) {
    uint256 curr = tokenId;

    unchecked {
      if (_startTokenId() <= curr && curr < _nextTokenId()) {
        TokenOwnership memory ownership = _ownershipAt(curr);
        if (!ownership.burned) {
          if (ownership.addr != address(0)) return ownership.addr;

          // 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.
          while (true) {
            curr--;
            ownership = _ownershipAt(curr);
            if (ownership.addr != address(0)) return ownership.addr;
          }
        }
      }
    }
    return address(0);
  }

  /**
   * @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.
   * @notice This method is intended for read only purposes.
   */
  function tokenByIndex(
    uint256 index
  ) external view override returns (uint256) {
    uint256 highestTokenId = _startTokenId() + _totalMinted();
    if (index > highestTokenId) revert IndexOutOfBounds();

    uint256 indexedId = 0;
    for (uint256 i = _startTokenId(); i < highestTokenId; i++) {
      if (!_ownershipAt(i).burned) {
        if (indexedId == index) return i;
        indexedId++;
      }
    }
    revert IndexOutOfBounds();
  }

  /**
   * @dev Returns a list of token IDs owned by `owner`.
   * @notice This method is intended for read only purposes.
   */
  function tokensOfOwner(address owner) public view returns (uint256[] memory) {
    if (owner == address(0)) revert QueryForZeroAddress();

    uint256 balance = balanceOf(owner);
    uint256[] memory tokens = new uint256[](balance);

    uint256 index = 0;
    uint256 highestTokenId = _startTokenId() + _totalMinted();
    for (uint256 i = _startTokenId(); i < highestTokenId; i++) {
      if (_ownerOfWithoutError(i) == owner) {
        tokens[index] = i;
        index++;
        if (index == balance) break;
      }
    }
    return tokens;
  }
}

// File: src/contracts/tokens/erc721/custom-erc721/IERC721A.sol



// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs

pragma solidity ^0.8.4;

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

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

  /**
   * 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();

  /**
   * The `quantity` minted with ERC2309 exceeds the safety limit.
   */
  error MintERC2309QuantityExceedsLimit();

  /**
   * The `extraData` cannot be set on an unintialized ownership slot.
   */
  error OwnershipNotInitializedForExtraData();

  // =============================================================
  //                            STRUCTS
  // =============================================================

  struct TokenOwnership {
    // The address of the owner.
    address addr;
    // Stores the start time of ownership with minimal overhead for tokenomics.
    uint64 startTimestamp;
    // Whether the token has been burned.
    bool burned;
    // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
    uint24 extraData;
  }

  // =============================================================
  //                         TOKEN COUNTERS
  // =============================================================

  /**
   * @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() external view returns (uint256);

  // =============================================================
  //                            IERC165
  // =============================================================

  /**
   * @dev Returns true if this contract implements the interface defined by
   * `interfaceId`. See the corresponding
   * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
   * to learn more about how these ids are created.
   *
   * This function call must use less than 30000 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`,
   * 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,
    bytes calldata data
  ) external payable;

  /**
   * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId
  ) external payable;

  /**
   * @dev Transfers `tokenId` 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 payable;

  /**
   * @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 payable;

  /**
   * @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);

  // =============================================================
  //                           IERC2309
  // =============================================================

  /**
   * @dev Emitted when tokens in `fromTokenId` to `toTokenId`
   * (inclusive) is transferred from `from` to `to`, as defined in the
   * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
   *
   * See {_mintERC2309} for more details.
   */
  event ConsecutiveTransfer(
    uint256 indexed fromTokenId,
    uint256 toTokenId,
    address indexed from,
    address indexed to
  );
}

// File: src/contracts/tokens/erc721/custom-erc721/IERC721AEnumerable.sol



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

pragma solidity ^0.8.0;

import "./IERC721A.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721AEnumerable is IERC721A {
  /**
   * @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);
}