Abstract Testnet

Contract Diff Checker

Contract Name:
DogTest

Contract Source Code:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./DogData.sol";
import "erc721a/contracts/ERC721A.sol";
import "base64-sol/base64.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

contract DogTest is ERC721A, Ownable, DogData, ReentrancyGuard  {  

    address public deployer;
    bytes32 private lastBlockHash;
    uint256 private lastBlockNumber;

    /// Mint Settings
    uint     public maxSupply    = 2500;
    uint     public mintPrice    = 0.003 ether;
    bool     public mintEnabled  = false;

    /// Mint Rules
    uint     public maxMintPerTrans = 100;
    uint     public maxMintPerWallet = 100;

    /// Whitelist Settings
    mapping(address => uint) public mintAmount;
    mapping(address => bool) public whiteListed;

    /// Whitelist setup
    address public listController;

    modifier onlylistController() {
        require(msg.sender == listController, "Controller Only");
        _;
    }


     constructor()
        ERC721A("Pocket Dogs", "POKEDOGS")
    {
        lastBlockHash = blockhash(block.number - 1);
        lastBlockNumber = block.number;
        _transferOwnership(msg.sender);
    }

    function _startTokenId() internal pure override returns (uint256) {
        return 1;
    }

    function mint(uint256 quantity) external payable {
        uint256 cost = mintPrice;
        require(mintEnabled, "Mint not ready yet");
        require(msg.value == quantity * cost, "Please send the exact ETH amount");
        require(quantity <= maxMintPerTrans, "Exceeds max mint per transaction");

        // Check if the mint quantity exceeds the per wallet limit
        uint256 totalMintedByWallet = mintAmount[msg.sender] + quantity;
        require(totalMintedByWallet <= maxMintPerWallet, "Exceeds max mint per wallet");
        mintAmount[msg.sender] = mintAmount[msg.sender] + totalMintedByWallet;

        // Start minting
        _internalMint(quantity);
    }

   

    function _internalMint(uint256 quantity) internal  {

        require(_totalMinted() + quantity <= maxSupply, "Sold Out!");
       

        // What token do we start minting with?
        uint startTokenID = _startTokenId() + _totalMinted();
        uint mintUntilTokenID =  quantity + startTokenID;

        for(uint256 tokenId = startTokenID; tokenId < mintUntilTokenID; tokenId++) {

            /// got get our random traits
            uint[6] memory randomSeeds = _randomSeed(lastBlockHash,tokenId);

            /// set this new Dog traits!
            _setDogTraits(tokenId, randomSeeds);

       

        }
        lastBlockHash = blockhash(block.number - 1);
        lastBlockNumber = block.number;
        _safeMint(msg.sender, quantity);

    }

    function _randomSeed(bytes32 _lastBlockHash, uint256 _tokenId) internal pure returns (uint[6] memory _randomSeeds) {
        // Initial seed
        _randomSeeds[0] = uint256(keccak256(abi.encodePacked(_lastBlockHash, _tokenId))) % 101;

        // Generate subsequent seeds
        for (uint i = 1; i < 6; i++) {
            _randomSeeds[i] = uint256(keccak256(abi.encodePacked(_randomSeeds[i - 1], _tokenId))) % 101;
        }

        return _randomSeeds;
    }

    function _setDogTraits(uint _tokenID, uint[6] memory _randomSeeds) internal {
        // Randomly select traits
        uint randFur   = _pickTraitByProbability(_randomSeeds[0], fur_data, fur_probability);
        uint randEyes = _pickTraitByProbability(_randomSeeds[1], eyes_data, eyes_probability);
        uint randHead   = _pickTraitByProbability(_randomSeeds[2], head_data, head_probability);
        uint randMouth   = _pickTraitByProbability(_randomSeeds[3], mouth_data, mouth_probability);
        uint randMark   = _pickTraitByProbability(_randomSeeds[4], mark_data, mark_probability);
        uint randBoard = _pickTraitByProbability(_randomSeeds[5], board_data, board_probability);
   


        TraitStruct memory newTraits = TraitStruct({
            fur: randFur,
            eyes: randEyes,
            head: randHead,
            mouth: randMouth,
            mark: randMark,
            board: randBoard
          
        });

        // Assign the generated traits to the token
        tokenTraits[_tokenID] = newTraits;

    }

        function _pickTraitByProbability(uint seed, bytes[] memory traitArray, uint[] memory traitProbability) internal pure returns (uint) {
    require(traitArray.length > 0, "Elements array is empty");
    require(traitArray.length == traitProbability.length, "Elements and weights length mismatch");
     
    for (uint i = 0; i < traitProbability.length; i++) {
        if(seed < traitProbability[i]) {
            return i;
        }
    }
    // Fallback, return first element as a safe default
    return 0;
}

 

  


    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        // Get image
        string memory image = buildSVG(tokenId);

        // Encode SVG data to base64
        string memory base64Image = Base64.encode(bytes(image));

        // Build JSON metadata
        string memory json = string(
            abi.encodePacked(
            '{"name": "Pocket Dogs #', Strings.toString(tokenId), '",',
            '"description": "Fully Onchain Pocket Dogs on Abstract Chain",',
            '"attributes": [', _getDogTraits(tokenId), '],',
            '"image": "data:image/svg+xml;base64,', base64Image, '"}'
            )
        );

        // Encode JSON data to base64
        string memory base64Json = Base64.encode(bytes(json));

        // Construct final URI
        return string(abi.encodePacked('data:application/json;base64,', base64Json));
    }

    function buildSVG(uint tokenid) public view returns (string memory) {

        require(_exists(tokenid), "Token does not exist");

        TraitStruct memory localTraits = tokenTraits[tokenid];

        string memory svg = string(abi.encodePacked(
        '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" shape-rendering="crispEdges" width="512" height="512">',
        '<rect width="16" height="16" fill="#01CA6A"/>',
            _getSVGTraitData(fur_data[localTraits.fur]),
            _getSVGTraitData(eyes_data[localTraits.eyes]),
            _getSVGTraitData(head_data[localTraits.head]),
            _getSVGTraitData(mouth_data[localTraits.mouth]),
            _getSVGTraitData(mark_data[localTraits.mark]),
            _getSVGTraitData(board_data[localTraits.board]),
        '</svg>'
        ));
        return svg;

    }

    function _getSVGTraitData(bytes memory data) internal pure returns (string memory) {

        require(data.length % 5 == 0, "Invalid number of reacts");

        /// if empty this is a transparent react
        if (data.length == 0) {
             return "<rect x=\"0\" y=\"0\" width=\"0\" height=\"0\" fill=\"rgb(0,0,0)\"/>"; 
        }

        // Initialize arrays to store values
        uint reactCount = data.length / 5;


        /// react string to return
        string memory rects;

        uint[] memory x = new uint[](reactCount);
        uint[] memory y = new uint[](reactCount);
        uint[] memory r = new uint[](reactCount);
        uint[] memory g = new uint[](reactCount);
        uint[] memory b = new uint[](reactCount);

        // Iterate through each react and get the values we need
        for (uint i = 0; i < reactCount; i++) {

            // Convert and assign values to respective arrays
            x[i] = uint8(data[i * 5]);
            y[i] = uint8(data[i * 5 + 1]);
            r[i] = uint8(data[i * 5 + 2]);
            g[i] = uint8(data[i * 5 + 3]);
            b[i] = uint8(data[i * 5 + 4]);

            // Convert uint values to strings
            string memory xStr = Strings.toString(x[i]);
            string memory yStr = Strings.toString(y[i]);
            string memory rStr = Strings.toString(r[i]);
            string memory gStr = Strings.toString(g[i]);
            string memory bStr = Strings.toString(b[i]);

            rects = string(abi.encodePacked(rects, '<rect x="', xStr, '" y="', yStr, '" width="1" height="1" fill="rgb(', rStr, ',', gStr, ',', bStr, ')" />'));
        }

        return rects;
    }

    function _getDogTraits(uint tokenid) internal view returns (string memory) {

        TraitStruct memory traits = tokenTraits[tokenid];

        string memory metadata = string(abi.encodePacked(
        '{"trait_type":"Fur", "value":"', fur_traits[traits.fur], '"},',
        '{"trait_type":"Eyes", "value":"', eyes_traits[traits.eyes], '"},',
        '{"trait_type":"Head", "value":"', head_traits[traits.head], '"},',
        '{"trait_type":"Mouth", "value":"', mouth_traits[traits.mouth], '"},',
        '{"trait_type":"Mark", "value":"', mark_traits[traits.mark], '"},',
        '{"trait_type":"Board", "value":"', board_traits[traits.board], '"}'
        
        ));

        return metadata;

    }


//// Admin methods
    function toggleMinting() external onlyOwner {
        mintEnabled = !mintEnabled;
    }


    function devMint(uint _quantity) external onlyOwner {
        _internalMint(_quantity);
    }

    function addToWhiteList(address[] calldata addresses) external onlylistController nonReentrant {
        for (uint i = 0; i < addresses.length; i++) {
            whiteListed[addresses[i]] = true;
        }
    }

    function changelistController(address _address) external onlyOwner {
        listController = _address;
    }

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

}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract DogData {


    struct TraitStruct {
        uint fur;
        uint eyes;
        uint head;
        uint mouth;
        uint mark;
        uint board;
    
    }


    mapping(uint => TraitStruct) public tokenTraits;


    mapping(uint => uint) public CowBarn;


        bytes[] internal fur_data = [
         	bytes(hex'0805df71260706df71260906df71260a06df71260b06df71260207df71260807df71260907ffffff0a07df71260b07ffffff0308df71260808df71260908df71260a08df71260b088843140c088843140409df71260509df71260609df71260709df71260809df71260909df71260a09df71260b09df7126040adf7126050adf7126060adf7126070adf7126080adf7126090adf71260a0adf71260b0adf7126040bdf7126050bdf7126060bdf7126070bdf7126080bdf7126090bdf71260a0bdf71260b0bdf7126040cdf7126060cdf7126090cdf71260b0cdf7126'),
		bytes(hex'0805a0bdfa0706a0bdfa0906a0bdfa0a06a0bdfa0b06a0bdfa0207a0bdfa0807a0bdfa0907ffffff0a07a0bdfa0b07ffffff0308a0bdfa0808a0bdfa0908a0bdfa0a08a0bdfa0b08759ff70c08759ff70409a0bdfa0509a0bdfa0609a0bdfa0709a0bdfa0809a0bdfa0909a0bdfa0a09a0bdfa0b09a0bdfa040aa0bdfa050aa0bdfa060aa0bdfa070aa0bdfa080aa0bdfa090aa0bdfa0a0aa0bdfa0b0aa0bdfa040ba0bdfa050ba0bdfa060ba0bdfa070ba0bdfa080ba0bdfa090ba0bdfa0a0ba0bdfa0b0ba0bdfa040ca0bdfa060ca0bdfa090ca0bdfa0b0ca0bdfa'),
		bytes(hex'0805d77bba0706d77bba0906d77bba0a06d77bba0b06d77bba0207d77bba0807d77bba0907ffffff0a07d77bba0b07ffffff0308d77bba0808d77bba0908d77bba0a08d77bba0b08c7479f0c08c7479f0409d77bba0509d77bba0609d77bba0709d77bba0809d77bba0909d77bba0a09d77bba0b09d77bba040ad77bba050ad77bba060ad77bba070ad77bba080ad77bba090ad77bba0a0ad77bba0b0ad77bba040bd77bba050bd77bba060bd77bba070bd77bba080bd77bba090bd77bba0a0bd77bba0b0bd77bba040cd77bba060cd77bba090cd77bba0b0cd77bba'),
		bytes(hex'08055fcde407065fcde409065fcde40a065fcde40b065fcde402075fcde408075fcde40907ffffff0a075fcde40b07ffffff03085fcde408085fcde409085fcde40a085fcde40b081c8ea60c081c8ea604095fcde405095fcde406095fcde407095fcde408095fcde409095fcde40a095fcde40b095fcde4040a5fcde4050a5fcde4060a5fcde4070a5fcde4080a5fcde4090a5fcde40a0a5fcde40b0a5fcde4040b5fcde4050b5fcde4060b5fcde4070b5fcde4080b5fcde4090b5fcde40a0b5fcde40b0b5fcde4040c5fcde4060c5fcde4090c5fcde40b0c5fcde4'),
		bytes(hex'0805eec39a0706eec39a0906eec39a0a06eec39a0b06eec39a0207eec39a0807eec39a0907ffffff0a07eec39a0b07ffffff0308eec39a0808eec39a0908eec39a0a08eec39a0b08d9a0660c08d9a0660409eec39a0509eec39a0609eec39a0709eec39a0809eec39a0909eec39a0a09eec39a0b09eec39a040aeec39a050aeec39a060aeec39a070aeec39a080aeec39a090aeec39a0a0aeec39a0b0aeec39a040beec39a050beec39a060beec39a070beec39a080beec39a090beec39a0a0beec39a0b0beec39a040ceec39a060ceec39a090ceec39a0b0ceec39a'),
		bytes(hex'0805222034070622203409062220340a062220340b06222034020722203408072220340a072220340308222034080822203409082220340a082220340b081816210c081816210409222034050922203406092220340709222034080922203409092220340a092220340b09222034040a222034050a222034060a222034070a222034080a222034090a2220340a0a2220340b0a222034040b222034050b222034060b222034070b222034080b222034090b2220340a0b2220340b0b222034040c222034060c222034090c2220340b0c222034'),
		bytes(hex'08053f3f7407063f3f7409063f3f740a063f3f740b063f3f7402073f3f7408073f3f740907ffffff0a073f3f740b07ffffff03083f3f7408083f3f7409083f3f740a083f3f740b08282f670c08282f6704093f3f7405093f3f7406093f3f7407093f3f7408093f3f7409093f3f740a093f3f740b093f3f74040a3f3f74050a3f3f74060a3f3f74070a3f3f74080a3f3f74090a3f3f740a0a3f3f740b0a3f3f74040b3f3f74050b3f3f74060b3f3f74070b3f3f74080b3f3f74090b3f3f740a0b3f3f740b0b3f3f74040c3f3f74060c3f3f74090c3f3f740b0c3f3f74'),
		bytes(hex'0805fbf2360706fbf2360906fbf2360a06fbf2360b06fbf2360207fbf2360807fbf2360907ffffff0a07fbf2360b07ffffff0308fbf2360808fbf2360908fbf2360a08fbf2360b08b3ab040c08b3ab040409fbf2360509fbf2360609fbf2360709fbf2360809fbf2360909fbf2360a09fbf2360b09fbf236040afbf236050afbf236060afbf236070afbf236080afbf236090afbf2360a0afbf2360b0afbf236040bfbf236050bfbf236060bfbf236070bfbf236080bfbf236090bfbf2360a0bfbf2360b0bfbf236040cfbf236060cfbf236090cfbf2360b0cfbf236')
];

	string[] internal fur_traits = [
                'Autumn',
                'Blue',
                'Bubblegum',
                'Cottoncandy',
                'Cream',
                'Dark',
                'Night',
                'Yellow'
    ];

        uint[] internal  fur_probability = [15,30,48,58,64,80,90,100];


        bytes[] internal eyes_data = [
                bytes(hex'09070000000b07000000'),
		bytes(hex'0907ff00000a07ff00000b07ff00000c07ff00000d07ff00000e07ff0000'),
		bytes(hex'0906ffffff0a06ffffff0b06ffffff0807ffffff09070000000a07ffffff0b070000000908ffffff0a08ffffff'),
		bytes(hex'09060000000a060000000b0600000008070000000907ffffff0a070000000b07ffffff09080000000a08000000'),
		bytes(hex'09060000000a060000000b060000000807000000090768ff000a0768ff000b0768ff0009080000000a08000000'),
		bytes(hex'0906fbf2360b06fbf2360807fbf2360907ffffff0a07fbf2360b07ffffff0c07fbf2360908fbf236'),
		bytes(hex'09069badb70a069badb70b069badb708079badb709070000000a070000000b0700000009089badb70a089badb7'),
		bytes(hex'0907ffffff0b07ffffff')
        ];

	string[] internal eyes_traits = [
        'Black',  
        'LAZEEERRRR',   
        'Mask White',  
        'Mask Black',      
        'NV Googles',  
        'Sparkling',     
        'VR',
        'White'
       
	];

        uint[] internal  eyes_probability = [20, 30, 45, 60, 70, 80, 90, 100];


        bytes[] internal head_data = [
       	        bytes(hex'0a03fff3000904fff3000a04ff00000b04fff30009050037ff0a050037ff0b050037ff'),
		bytes(hex'0805196cff0905196cff0a05196cff0b05196cff0806196cff0906196cff0a06196cff0b06196cff0c06196cff'),
		bytes(hex'0903c9c9c90a03c9c9c90b03c9c9c90904ffffff0a04ffffff0b04ffffff0905ffffff0a05ffffff0b05ffffff'),
		bytes(hex'0904ffe1f60a04ffe1f60b04ffe1f60805ff5a5a0905ffccef0a05ffccef0b05ffccef0c05ff5a5a'),
		bytes(hex'0804f5ec230a04f5ec230c04f5ec230805f5ec230905f5ec230a05f5ec230b05f5ec230c05f5ec23'),
		bytes(hex'0804ac32320c04ac32320905ac32320b05ac3232'),
		bytes(hex'0704d9a0660904df71260a04df71260b04df71260d04d9a0660805d9a0660905d9a0660a05d9a0660b05d9a0660c05d9a066'),
		bytes(hex'0904aa70540a04aa70540b04aa705408058f563b09058f563b0a058f563b0b058f563b0c058f563b'),
		bytes(hex'0902fbf2360a02fbf2360b02fbf2360803fbf2360c03fbf2360904fbf2360a04fbf2360b04fbf236'),
		bytes(hex'0a03fff74e0b03fff74e0904fff74e0a04fff74e0b04fff74e0805fff74e0905fff74e0a05fff74e0b05fff74e'),
		bytes(hex'0a03ff00000b03ff00000904ff00000a04ff00000b04ff00000805ff00000905ff00000a05ff00000b05ff0000'),
		bytes(hex''),
		bytes(hex'0903ffffff0a03ffffff0b03ffffff0904c9c9c90a04c9c9c90b04c9c9c90805ffffff0905ffffff0a05ffffff0b05ffffff0c05ffffff'),
		bytes(hex'09040000000a040000000b040000000905f219190a05f219190b05f21919080600000009060000000a060000000b060000000c06000000')
      
        
        ];

	string[] internal head_traits = [
          'Beanie Cap',      
         'Blue Cap',
        'Chef hat',       
         'Cotton hat',
        'Crown', 
         'Devil horns',
  'Farmer hat',       
   'Fedora',
  'Halo',     
    'Mohawk Golden',
  'Mohawk Red',         
  'None',
  'Top hat white',
  'Top hat black'
  
  

	];

        uint[] internal  head_probability = [10,20,30,40,45,50,60,66,70,75,78,90,95,100];



        bytes[] internal mouth_data = [
               	bytes(hex'0a09f4f4f40b09f4f4f40c09f4f4f40d09f4f4f4'),
		bytes(hex'0e06ffffff0e07ffffff0b09f4f4f40c09f4f4f40d09f4f4f40e09ff0000'),
		bytes(hex'0e08fffcb30a09fbf2360b09fbf2360c09fbf2360e0afffcb30d0cfffcb3'),
		bytes(hex'0a094b692f0b09524b240c094b692f0d094b692f0e09ffffff0a0a524b240b0a4b692f0c0a524b24'),
		bytes(hex''),
		bytes(hex'0a09ffffff0b09ffffff0c09ffffff0d09ffffff0a0affffff0d0affffff'),
		bytes(hex'0e05ffffff0e07ffffff0b09c3dfff0c09c3dfff0d09c3dfff0e09003dff')
		
        ];

	string[] internal mouth_traits = [
       
  'Bone',
  'Cig',
  'Gold bar',
  'Grenade',
  'None',
  'Sabertooth',
  'Vape'
 
	];

      uint[] internal mouth_probability = [10,20,30,40, 80,90, 100];

        bytes[] internal mark_data = [
                 bytes(hex'090affffff'),
		bytes(hex'090affffff070bf4f4f4'),
		bytes(hex'050973eff7060973eff7070b73eff7080b73eff7'),
		bytes(hex'040ac7b6b6050ac7b6b6060ac7b6b6070ac7b6b6080ac7b6b6090ac7b6b60a0ac7b6b60b0ac7b6b6'),
		bytes(hex''),
                bytes(hex'05094447460809444746060a444746090a444746070b4447460a0b444746'),
		bytes(hex'080afb3838090afb3838070bfb3838')
        
        
        ];

	string[] internal mark_traits = [
          'DOT 1',
        'DOT 2',
  'Highlight',
  'Line',
  'None',
  'Stripes',
  'Scar'
	];

        uint[] internal mark_probability = [10, 20, 30, 40, 80, 90, 100];


        bytes[] internal board_data = [
                bytes(hex'020b272820020c272820030d272820040d272820050d272820060d272820070d272820080d272820090d2728200a0d2728200b0d2728200c0d272820060efff8c3070efff8c3080efff8c3090efff8c3'),
		bytes(hex'020bae81ff020cae81ff030dae81ff040dae81ff050dae81ff060dae81ff070dae81ff080dae81ff090dae81ff0a0dae81ff0b0dae81ff0c0dae81ff060efff8c3070efff8c3080efff8c3090efff8c3'),
		bytes(hex'020b66d9ef020c66d9ef030d66d9ef040d66d9ef050d66d9ef060d66d9ef070d66d9ef080d66d9ef090d66d9ef0a0d66d9ef0b0d66d9ef0c0d66d9ef060efff8c3070efff8c3080efff8c3090efff8c3'),
		bytes(hex'020be6db74020ce6db74030de6db74040de6db74050de6db74060de6db74070de6db74080de6db74090de6db740a0de6db740b0de6db740c0de6db74060efff8c3070efff8c3080efff8c3090efff8c3'),
		bytes(hex''),
		bytes(hex'020c823e2c0d0c823e2c030d823e2c040d823e2c050d823e2c060d823e2c070d823e2c080d823e2c090d823e2c0a0d823e2c0b0d823e2c0c0d823e2c050e16171a060e16171a090e16171a0a0e16171a'),
		bytes(hex'020c1008200d0c100820030d100820040d100820050d100820060d100820070d100820080d100820090d1008200a0d1008200b0d1008200c0d100820050e16171a060e16171a090e16171a0a0e16171a'),
		bytes(hex'020c10d2750d0c10d275030d10d275040d10d275050d10d275060d10d275070d10d275080d10d275090d10d2750a0d10d2750b0d10d2750c0d10d275050e16171a060e16171a090e16171a0a0e16171a'),
		bytes(hex'020c7f06220d0c7f0622030d7f0622040d7f0622050d7f0622060d7f0622070d7f0622080d7f0622090d7f06220a0d7f06220b0d7f06220c0d7f0622050e16171a060e16171a090e16171a0a0e16171a'),
		bytes(hex'020cfafdff0d0cfafdff030dfafdff040dfafdff050dfafdff060dfafdff070dfafdff080dfafdff090dfafdff0a0dfafdff0b0dfafdff0c0dfafdff050e16171a060e16171a090e16171a0a0e16171a'),
		bytes(hex'020c14121d020d14121d030d14121d040d14121d050d14121d060d14121d070d14121d080d14121d090d14121d0a0d14121d0b0d14121d0c0d14121d030e14121d040e14121d'),
		bytes(hex'020cfdc9c9020dfdc9c9030dfdc9c9040dfdc9c9050dfdc9c9060dfdc9c9070dfdc9c9080dfdc9c9090dfdc9c90a0dfdc9c90b0dfdc9c90c0dfdc9c9030efdc9c9040efdc9c9'),
		bytes(hex'020ceee6ea020deee6ea030deee6ea040deee6ea050deee6ea060deee6ea070deee6ea080deee6ea090deee6ea0a0deee6ea0b0deee6ea0c0deee6ea030eeee6ea040eeee6ea')
        ];

	string[] internal board_traits = [
        'Hoverboard 1Bit',
        'Hoverboard Inked',
        'Hoverboard Sky',
        'Hoverboard tan',
        'None',
        'Skateboard Brown',
          'Skateboard Dark Blue',
         'Skateboard Green',
         'Skateboard Maroon',
        'Skateboard White',
         'Surfboard Dark',
      'Surfboard Faded',
      'Surfboard Smoke'
	];

        uint[] internal board_probability = [5,10,15,20,50,58,66,74,82,91,94,97,100];


}

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0;

/// @title Base64
/// @author Brecht Devos - <[email protected]>
/// @notice Provides functions for encoding/decoding base64
library Base64 {
    string internal constant TABLE_ENCODE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    bytes  internal constant TABLE_DECODE = hex"0000000000000000000000000000000000000000000000000000000000000000"
                                            hex"00000000000000000000003e0000003f3435363738393a3b3c3d000000000000"
                                            hex"00000102030405060708090a0b0c0d0e0f101112131415161718190000000000"
                                            hex"001a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132330000000000";

    function encode(bytes memory data) internal pure returns (string memory) {
        if (data.length == 0) return '';

        // load the table into memory
        string memory table = TABLE_ENCODE;

        // multiply by 4/3 rounded up
        uint256 encodedLen = 4 * ((data.length + 2) / 3);

        // add some extra buffer at the end required for the writing
        string memory result = new string(encodedLen + 32);

        assembly {
            // set the actual output length
            mstore(result, encodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

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

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

                // write 4 characters
                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr( 6, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(        input,  0x3F))))
                resultPtr := add(resultPtr, 1)
            }

            // padding with '='
            switch mod(mload(data), 3)
            case 1 { mstore(sub(resultPtr, 2), shl(240, 0x3d3d)) }
            case 2 { mstore(sub(resultPtr, 1), shl(248, 0x3d)) }
        }

        return result;
    }

    function decode(string memory _data) internal pure returns (bytes memory) {
        bytes memory data = bytes(_data);

        if (data.length == 0) return new bytes(0);
        require(data.length % 4 == 0, "invalid base64 decoder input");

        // load the table into memory
        bytes memory table = TABLE_DECODE;

        // every 4 characters represent 3 bytes
        uint256 decodedLen = (data.length / 4) * 3;

        // add some extra buffer at the end required for the writing
        bytes memory result = new bytes(decodedLen + 32);

        assembly {
            // padding with '='
            let lastBytes := mload(add(data, mload(data)))
            if eq(and(lastBytes, 0xFF), 0x3d) {
                decodedLen := sub(decodedLen, 1)
                if eq(and(lastBytes, 0xFFFF), 0x3d3d) {
                    decodedLen := sub(decodedLen, 1)
                }
            }

            // set the actual output length
            mstore(result, decodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

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

            // run over the input, 4 characters at a time
            for {} lt(dataPtr, endPtr) {}
            {
               // read 4 characters
               dataPtr := add(dataPtr, 4)
               let input := mload(dataPtr)

               // write 3 bytes
               let output := add(
                   add(
                       shl(18, and(mload(add(tablePtr, and(shr(24, input), 0xFF))), 0xFF)),
                       shl(12, and(mload(add(tablePtr, and(shr(16, input), 0xFF))), 0xFF))),
                   add(
                       shl( 6, and(mload(add(tablePtr, and(shr( 8, input), 0xFF))), 0xFF)),
                               and(mload(add(tablePtr, and(        input , 0xFF))), 0xFF)
                    )
                )
                mstore(resultPtr, shl(232, output))
                resultPtr := add(resultPtr, 3)
            }
        }

        return result;
    }
}

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

pragma solidity ^0.8.0;

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

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

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

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

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

        _;

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

// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.3.0
// Creator: Chiru Labs

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()`.
 *
 * The `_sequentialUpTo()` function can be overriden to enable spot mints
 * (i.e. non-consecutive mints) for `tokenId`s greater than `_sequentialUpTo()`.
 *
 * 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 private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to ownership details
    // An empty struct value does not necessarily mean the token is unowned.
    // See {_packedOwnershipOf} implementation for details.
    //
    // Bits Layout:
    // - [0..159]   `addr`
    // - [160..223] `startTimestamp`
    // - [224]      `burned`
    // - [225]      `nextInitialized`
    // - [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;

    // The amount of tokens minted above `_sequentialUpTo()`.
    // We call these spot mints (i.e. non-sequential mints).
    uint256 private _spotMinted;

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

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

        if (_sequentialUpTo() < _startTokenId()) _revert(SequentialUpToTooSmall.selector);
    }

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

    /**
     * @dev Returns the starting token ID for sequential mints.
     *
     * Override this function to change the starting token ID for sequential mints.
     *
     * Note: The value returned must never change after any tokens have been minted.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Returns the maximum token ID (inclusive) for sequential mints.
     *
     * Override this function to return a value less than 2**256 - 1,
     * but greater than `_startTokenId()`, to enable spot (non-sequential) mints.
     *
     * Note: The value returned must never change after any tokens have been minted.
     */
    function _sequentialUpTo() internal view virtual returns (uint256) {
        return type(uint256).max;
    }

    /**
     * @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 result) {
        // Counter underflow is impossible as `_burnCounter` cannot be incremented
        // more than `_currentIndex + _spotMinted - _startTokenId()` times.
        unchecked {
            // With spot minting, the intermediate `result` can be temporarily negative,
            // and the computation must be unchecked.
            result = _currentIndex - _burnCounter - _startTokenId();
            if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
        }
    }

    /**
     * @dev Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view virtual returns (uint256 result) {
        // Counter underflow is impossible as `_currentIndex` does not decrement,
        // and it is initialized to `_startTokenId()`.
        unchecked {
            result = _currentIndex - _startTokenId();
            if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
        }
    }

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

    /**
     * @dev Returns the total number of tokens that are spot-minted.
     */
    function _totalSpotMinted() internal view virtual returns (uint256) {
        return _spotMinted;
    }

    // =============================================================
    //                    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.selector);
        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.
    }

    // =============================================================
    //                        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.selector);

        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 Returns whether the ownership slot at `index` is initialized.
     * An uninitialized slot does not necessarily mean that the slot has no owner.
     */
    function _ownershipIsInitialized(uint256 index) internal view virtual returns (bool) {
        return _packedOwnerships[index] != 0;
    }

    /**
     * @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);
        }
    }

    /**
     * @dev Returns the packed ownership data of `tokenId`.
     */
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256 packed) {
        if (_startTokenId() <= tokenId) {
            packed = _packedOwnerships[tokenId];

            if (tokenId > _sequentialUpTo()) {
                if (_packedOwnershipExists(packed)) return packed;
                _revert(OwnerQueryForNonexistentToken.selector);
            }

            // If the data at the starting slot does not exist, start the scan.
            if (packed == 0) {
                if (tokenId >= _currentIndex) _revert(OwnerQueryForNonexistentToken.selector);
                // 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;
                    if (packed & _BITMASK_BURNED == 0) return packed;
                    // Otherwise, the token is burned, and we must revert.
                    // This handles the case of batch burned tokens, where only the burned bit
                    // of the starting slot is set, and remaining slots are left uninitialized.
                    _revert(OwnerQueryForNonexistentToken.selector);
                }
            }
            // Otherwise, the data exists and 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.
            // If the token is not burned, return `packed`. Otherwise, revert.
            if (packed & _BITMASK_BURNED == 0) return packed;
        }
        _revert(OwnerQueryForNonexistentToken.selector);
    }

    /**
     * @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.selector);

        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 result) {
        if (_startTokenId() <= tokenId) {
            if (tokenId > _sequentialUpTo()) return _packedOwnershipExists(_packedOwnerships[tokenId]);

            if (tokenId < _currentIndex) {
                uint256 packed;
                while ((packed = _packedOwnerships[tokenId]) == 0) --tokenId;
                result = packed & _BITMASK_BURNED == 0;
            }
        }
    }

    /**
     * @dev Returns whether `packed` represents a token that exists.
     */
    function _packedOwnershipExists(uint256 packed) private pure returns (bool result) {
        assembly {
            // The following is equivalent to `owner != address(0) && burned == false`.
            // Symbolically tested.
            result := gt(and(packed, _BITMASK_ADDRESS), and(packed, _BITMASK_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);

        // Mask `from` to the lower 160 bits, in case the upper bits somehow aren't clean.
        from = address(uint160(uint256(uint160(from)) & _BITMASK_ADDRESS));

        if (address(uint160(prevOwnershipPacked)) != from) _revert(TransferFromIncorrectOwner.selector);

        (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.selector);

        _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;
                    }
                }
            }
        }

        // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
        uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;
        assembly {
            // 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.
                from, // `from`.
                toMasked, // `to`.
                tokenId // `tokenId`.
            )
        }
        if (toMasked == 0) _revert(TransferToZeroAddress.selector);

        _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.selector);
            }
    }

    /**
     * @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.selector);
            }
            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.selector);

        _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:
            // - `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)
            );

            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

            // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
            uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;

            if (toMasked == 0) _revert(MintToZeroAddress.selector);

            uint256 end = startTokenId + quantity;
            uint256 tokenId = startTokenId;

            if (end - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);

            do {
                assembly {
                    // 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`.
                        tokenId // `tokenId`.
                    )
                }
                // The `!=` check ensures that large values of `quantity`
                // that overflows uint256 will make the loop run out of gas.
            } while (++tokenId != end);

            _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.selector);
        if (quantity == 0) _revert(MintZeroQuantity.selector);
        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) _revert(MintERC2309QuantityExceedsLimit.selector);

        _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)
            );

            if (startTokenId + quantity - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);

            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.selector);
                    }
                } while (index < end);
                // This prevents reentrancy to `_safeMint`.
                // It does not prevent reentrancy to `_safeMintSpot`.
                if (_currentIndex != end) revert();
            }
        }
    }

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

    /**
     * @dev Mints a single token at `tokenId`.
     *
     * Note: A spot-minted `tokenId` that has been burned can be re-minted again.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` must be greater than `_sequentialUpTo()`.
     * - `tokenId` must not exist.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _mintSpot(address to, uint256 tokenId) internal virtual {
        if (tokenId <= _sequentialUpTo()) _revert(SpotMintTokenIdTooSmall.selector);
        uint256 prevOwnershipPacked = _packedOwnerships[tokenId];
        if (_packedOwnershipExists(prevOwnershipPacked)) _revert(TokenAlreadyExists.selector);

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

        // Overflows are incredibly unrealistic.
        // The `numberMinted` for `to` is incremented by 1, and has a max limit of 2**64 - 1.
        // `_spotMinted` is incremented by 1, and has a max limit of 2**256 - 1.
        unchecked {
            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `true` (as `quantity == 1`).
            _packedOwnerships[tokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(1) | _nextExtraData(address(0), to, prevOwnershipPacked)
            );

            // Updates:
            // - `balance += 1`.
            // - `numberMinted += 1`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _packedAddressData[to] += (1 << _BITPOS_NUMBER_MINTED) | 1;

            // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
            uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;

            if (toMasked == 0) _revert(MintToZeroAddress.selector);

            assembly {
                // 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`.
                    tokenId // `tokenId`.
                )
            }

            ++_spotMinted;
        }

        _afterTokenTransfers(address(0), to, tokenId, 1);
    }

    /**
     * @dev Safely mints a single token at `tokenId`.
     *
     * Note: A spot-minted `tokenId` that has been burned can be re-minted again.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}.
     * - `tokenId` must be greater than `_sequentialUpTo()`.
     * - `tokenId` must not exist.
     *
     * See {_mintSpot}.
     *
     * Emits a {Transfer} event.
     */
    function _safeMintSpot(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mintSpot(to, tokenId);

        unchecked {
            if (to.code.length != 0) {
                uint256 currentSpotMinted = _spotMinted;
                if (!_checkContractOnERC721Received(address(0), to, tokenId, _data)) {
                    _revert(TransferToNonERC721ReceiverImplementer.selector);
                }
                // This prevents reentrancy to `_safeMintSpot`.
                // It does not prevent reentrancy to `_safeMint`.
                if (_spotMinted != currentSpotMinted) revert();
            }
        }
    }

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

    // =============================================================
    //                       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 && _msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                _revert(ApprovalCallerNotOwnerNorApproved.selector);
            }

        _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.selector);
        }

        _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 + _spotMinted` 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.selector);
        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)
        }
    }

    /**
     * @dev For more efficient reverts.
     */
    function _revert(bytes4 errorSelector) internal pure {
        assembly {
            mstore(0x00, errorSelector)
            revert(0x00, 0x04)
        }
    }
}

// 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);
    }
}

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

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.3.0
// 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();

    /**
     * `_sequentialUpTo()` must be greater than `_startTokenId()`.
     */
    error SequentialUpToTooSmall();

    /**
     * The `tokenId` of a sequential mint exceeds `_sequentialUpTo()`.
     */
    error SequentialMintExceedsLimit();

    /**
     * Spot minting requires a `tokenId` greater than `_sequentialUpTo()`.
     */
    error SpotMintTokenIdTooSmall();

    /**
     * Cannot mint over a token that already exists.
     */
    error TokenAlreadyExists();

    /**
     * The feature is not compatible with spot mints.
     */
    error NotCompatibleWithSpotMints();

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

// 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;
    }
}

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