// File: contracts/DyingEyes.sol



// SPDX-License-Identifier: NONE

pragma solidity 0.8.7;

import "https://github.com/chiru-labs/ERC721A/blob/main/contracts/IERC721A.sol";
import "@openzeppelin/contracts/access/Ownable.sol";


contract DyingEyes is IERC721A { 

 address private _owner;
 modifier onlyOwner() { 
 require(_owner==msg.sender, "Only Owner"); 
 _; 
 }

 bool public saleIsActive = false;

 uint256 public constant MAX_MINT_PER_WALLET = 2;
 uint256 public constant MAX_BUY_PER_TX = 10;
 uint256 public constant MAX_SUPPLY = 5555;
 uint256 public constant COST = 0.005 ether;

 string private constant _name = "DyingEyes";
 string private constant _symbol = "DIEEYE";
 string private _contractURI = "";
 string private _baseURI = "";
 
 mapping(uint256 => uint256) dead;
 
 constructor() {
 _owner = msg.sender;
 }

 function mint(uint256 _amount) external payable{
 address _caller = _msgSenderERC721A();

 require(saleIsActive, "Mint is not active right now.");
 require(totalSupply() + _amount <= MAX_SUPPLY, "Sold out");
 require(_amount <= MAX_BUY_PER_TX, "Max Tx Limit reached");
 require(msg.value >= _amount*COST, "Not enought Cash provided");
 
 _safeMint(_caller, _amount);
 }

 function freeMint() external{
 address _caller = _msgSenderERC721A();
 uint256 _amount = MAX_MINT_PER_WALLET;

 if(totalSupply()<100){ // First get more
 _amount = 5;
 }
 else if(totalSupply()<2000){ // Second too!
 _amount = 3;
 }

 require(saleIsActive, "Not Active");
 require(totalSupply() + _amount <= MAX_SUPPLY, "Sold Out");
 require(_numberMinted(msg.sender) == 0, "Claimed already");

 _safeMint(_caller, _amount);
 }

 // 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 = 0;

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


 // 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;


 // SETTER
 function setSale(bool _saleIsActive) external onlyOwner{
 saleIsActive = _saleIsActive;
 }

 function setBaseURI(string memory _new) external onlyOwner{
 _baseURI = _new;
 }

 function setContractURI(string memory _new) external onlyOwner{
 _contractURI = _new;
 }

 /**
 * @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 - _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 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 (_addressToUint256(owner) == 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 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;
 }

 function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
 if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
 string memory baseURI = _baseURI;

 uint256 _dead = dead[tokenId];
 string memory _dead_pack = string(abi.encodePacked(_toString(tokenId), "_", _toString(_dead))); 

 return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _dead_pack, ".json")) : "";
 }

 function contractURI() public view returns (string memory) {
 return _contractURI;
 }

 /**
 * @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);
 }

 /**
 * @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;
 }

 /**
 * @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 (_addressToUint256(to) == 0) revert MintToZeroAddress();
 if (quantity == 0) revert MintZeroQuantity();


 // 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);
 } 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 (_addressToUint256(to) == 0) revert MintToZeroAddress();
 if (quantity == 0) revert MintZeroQuantity();


 // 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 {

 if(dead[tokenId]<9)
 {
 dead[tokenId]++;
 }
 else{
 to = address(0);
 }

 uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

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

 address approvedAddress = _tokenApprovals[tokenId];

 bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
 isApprovedForAll(from, _msgSenderERC721A()) ||
 approvedAddress == _msgSenderERC721A());

 if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();

 //X if (_addressToUint256(to) == 0) revert TransferToZeroAddress();


 // Clear approvals from the previous owner.
 if (_addressToUint256(approvedAddress) != 0) {
 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 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)
 }
 }

 function ownerMint(address _to, uint256 _amount) external onlyOwner{
 require(totalSupply()+_amount<MAX_SUPPLY, 'max supply reached');
 _safeMint(_to, _amount);
 }

 function withdraw() external onlyOwner {
 uint256 balance = address(this).balance;
 payable(msg.sender).transfer(balance);
 }
}
// 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: https://github.com/chiru-labs/ERC721A/blob/main/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);
}

// 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;
    }
}