Based Goblins

// SPDX-License-Identifier: MIT

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pragma solidity 0.8.17;

interface IERC721A {

    error ApprovalCallerNotOwnerNorApproved();

    error ApprovalQueryForNonexistentToken();

    error ApproveToCaller();

    error BalanceQueryForZeroAddress();

    error MintToZeroAddress();

    error MintZeroQuantity();

    error OwnerQueryForNonexistentToken();

    error TransferCallerNotOwnerNorApproved();

    error TransferFromIncorrectOwner();

    error TransferToNonERC721ReceiverImplementer();

    error TransferToZeroAddress();

    error URIQueryForNonexistentToken();

    error MintERC2309QuantityExceedsLimit();

    error OwnershipNotInitializedForExtraData();

    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;
    }

    function totalSupply() external view returns (uint256);

    function supportsInterface(bytes4 interfaceId) external view returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function balanceOf(address owner) external view returns (uint256 balance);

    function ownerOf(uint256 tokenId) external view returns (address owner);

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    function approve(address to, uint256 tokenId) external;

    function setApprovalForAll(address operator, bool _approved) external;

    function getApproved(uint256 tokenId) external view returns (address operator);

    function isApprovedForAll(address owner, address operator) external view returns (bool);
    
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function tokenURI(uint256 tokenId) external view returns (string memory);

    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}
contract BasedGoblin is IERC721A { 
address private _owner;
    function owner() public view returns(address){
        return _owner;
    }

    uint256 public constant MAX_SUPPLY = 6969;
    uint256 public MAX_FREE = 6000;
    uint256 public MAX_FREE_PER_WALLET = 2;
    uint256 public COST = 0.00069 ether;
    string private constant _name = "Based Goblins";
    string private constant _symbol = "bGoblin";
    string private _baseURI = "bafybeicofy474zdb4mmfknrqxysualmpl3bq6xjnog4bh7tdoxsgbbm6ji";

    constructor() {
        _owner = msg.sender;
    }

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

        require(totalSupply() + amount <= MAX_SUPPLY, "Goblins Sold Out");
        require(amount*COST <= msg.value, "Value to Low");

        _mint(_caller, amount);
    }

    function freeMint() external nob{
        address _caller = _msgSenderERC721A();
        uint256 amount = MAX_FREE_PER_WALLET;

        require(totalSupply() + amount <= MAX_FREE, "Freemint of Goblins Sold Out");
        require(amount + _numberMinted(_caller) <= MAX_FREE_PER_WALLET, "Max per Wallet");

        _mint(_caller, amount);
    }

    // Mask of an entry in packed address data.
    uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

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

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

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

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

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

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

    // The bit position of the `nextInitialized` bit in packed ownership.
    uint256 private constant BITPOS_NEXT_INITIALIZED = 225;

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

    // The tokenId of the next token to be minted.
    uint256 private _currentIndex = 0;

    mapping(uint256 => uint256) private _packedOwnerships;

    mapping(address => uint256) private _packedAddressData;

    // Mapping from token ID to approved address.
    mapping(uint256 => address) private _tokenApprovals;

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

    function setConfig(uint _MAX_FREE, uint _COST, uint _MAX_FREE_PER_WALLET) external onlyOwner{
        MAX_FREE = _MAX_FREE;
        COST = _COST;
        MAX_FREE_PER_WALLET = _MAX_FREE_PER_WALLET;
    }

    function setData(string memory _base) external onlyOwner{
        _baseURI = _base;
    }

    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    function _nextTokenId() internal view returns (uint256) {
        return _currentIndex;
    }

    function totalSupply() public view override returns (uint256) {

        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    function _totalMinted() internal view returns (uint256) {

        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return
            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }

    function balanceOf(address owner) public view override returns (uint256) {
        if (_addressToUint256(owner) == 0) revert BalanceQueryForZeroAddress();
        return _packedAddressData[owner] & BITMASK_ADDRESS_DATA_ENTRY;
    }

    function _numberMinted(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> BITPOS_NUMBER_MINTED) & BITMASK_ADDRESS_DATA_ENTRY;
    }

    function _getAux(address owner) internal view returns (uint64) {
        return uint64(_packedAddressData[owner] >> BITPOS_AUX);
    }

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

        unchecked {
            if (_startTokenId() <= curr)
                if (curr < _currentIndex) {
                    uint256 packed = _packedOwnerships[curr];
                    // If not burned.
                    if (packed & BITMASK_BURNED == 0) {

                        while (packed == 0) {
                            packed = _packedOwnerships[--curr];
                        }
                        return packed;
                    }
                }
        }
        revert OwnerQueryForNonexistentToken();
    }

    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;
    }

    function _ownershipAt(uint256 index) internal view returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }

    function _initializeOwnershipAt(uint256 index) internal {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    function ownerOf(uint256 tokenId) public view override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
        string memory baseURI = _baseURI;
        return bytes(baseURI).length != 0 ? string(abi.encodePacked("ipfs://", baseURI, "/", _toString(tokenId), ".json")) : "";
    }

    function _addressToUint256(address value) private pure returns (uint256 result) {
        assembly {
            result := value
        }
    }

    function _boolToUint256(bool value) private pure returns (uint256 result) {
        assembly {
            result := value
        }
    }

    function approve(address to, uint256 tokenId) public override {
        address owner = address(uint160(_packedOwnershipOf(tokenId)));
        if (to == owner) revert();

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

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

    function getApproved(uint256 tokenId) public view override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId];
    }

    function setApprovalForAll(address operator, bool approved) public virtual override {
        if (operator == _msgSenderERC721A()) revert ApproveToCaller();

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

    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    function transferFrom(
            address from,
            address to,
            uint256 tokenId
            ) public virtual override {
        _transfer(from, to, tokenId);
    }

    function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId
            ) public virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
            ) public virtual override {
        _transfer(from, to, tokenId);
    }

    function _exists(uint256 tokenId) internal view returns (bool) {
        return
            _startTokenId() <= tokenId &&
            tokenId < _currentIndex;
    }

    function _mint(address to, uint256 quantity) internal {
        uint256 startTokenId = _currentIndex;
        if (_addressToUint256(to) == 0) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        unchecked {

            _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);

            _packedOwnerships[startTokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                (_boolToUint256(quantity == 1) << BITPOS_NEXT_INITIALIZED);

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

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

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

    function _transfer(
            address from,
            address to,
            uint256 tokenId
            ) private {

        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

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

        address approvedAddress = _tokenApprovals[tokenId];

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

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();

        if (_addressToUint256(approvedAddress) != 0) {
            delete _tokenApprovals[tokenId];
        }

        unchecked {
            // We can directly increment and decrement the balances.
            --_packedAddressData[from]; // Updates: `balance -= 1`.
            ++_packedAddressData[to]; // Updates: `balance += 1`.

            _packedOwnerships[tokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                BITMASK_NEXT_INITIALIZED;

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

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

    function _afterTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
            ) internal virtual {}

    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }

    function _toString(uint256 value) internal pure returns (string memory ptr) {
        assembly {

            ptr := add(mload(0x40), 128)

         // Update the free memory pointer to allocate.
         mstore(0x40, ptr)

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

         for { 
             // Initialize and perform the first pass without check.
             let temp := value
                 // Move the pointer 1 byte leftwards to point to an empty character slot.
                 ptr := sub(ptr, 1)
                 // Write the character to the pointer. 48 is the ASCII index of '0'.
                 mstore8(ptr, add(48, mod(temp, 10)))
                 temp := div(temp, 10)
         } temp { 
             // Keep dividing `temp` until zero.
        temp := div(temp, 10)
         } { 
             // Body of the for loop.
        ptr := sub(ptr, 1)
         mstore8(ptr, add(48, mod(temp, 10)))
         }

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

    modifier onlyOwner() { 
        require(_owner==msg.sender, "not Owner");
        _; 
    }

    modifier nob() {
        require(tx.origin==msg.sender, "no Script");
        _;
    }

    function withdraw() external onlyOwner {
        uint256 balance = address(this).balance;
        payable(msg.sender).transfer(balance);
    }
}

{
  "compilationTarget": {
    "BasedGoblin.sol": "BasedGoblin"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}