// SPDX-License-Identifier: MIT
// File: @openzeppelin/contracts/utils/Strings.sol


// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)


pragma solidity ^0.8.0;


library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    
    function toString(uint256 value) internal pure returns (string memory) {

        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);
    }

    
    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);
    }

    
    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);
    }
}

pragma solidity ^0.8.4;


interface IERC721A {
    
    error ApprovalCallerNotOwnerNorApproved();

    
    error ApprovalQueryForNonexistentToken();

    
    error ApproveToCaller();

    
    error ApprovalToCurrentOwner();

    
    error BalanceQueryForZeroAddress();

    
    error MintToZeroAddress();

    
    error MintZeroQuantity();

    
    error OwnerQueryForNonexistentToken();

    
    error TransferCallerNotOwnerNorApproved();

    
    error TransferFromIncorrectOwner();

    
    error TransferToNonERC721ReceiverImplementer();

    
    error TransferToZeroAddress();

    
    error URIQueryForNonexistentToken();

    struct TokenOwnership {
        address addr;
        uint64 startTimestamp;
        bool burned;
    }

    
    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);
}

pragma solidity ^0.8.4;



interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}


contract ERC721A is IERC721A {
    uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
    uint256 private constant BITPOS_NUMBER_MINTED = 64;
    uint256 private constant BITPOS_NUMBER_BURNED = 128;
    uint256 private constant BITPOS_AUX = 192;
    uint256 private constant BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
    uint256 private constant BITPOS_START_TIMESTAMP = 160;
    uint256 private constant BITMASK_BURNED = 1 << 224;
    uint256 private constant BITPOS_NEXT_INITIALIZED = 225;
    uint256 private constant BITMASK_NEXT_INITIALIZED = 1 << 225;
    uint256 private _currentIndex;
    uint256 private _burnCounter;
    string private _name;
    string private _symbol;
    mapping(uint256 => uint256) private _packedOwnerships;
    mapping(address => uint256) private _packedAddressData;
    mapping(uint256 => address) private _tokenApprovals;
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    
    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 - _burnCounter - _startTokenId();
        }
    }

    
    function _totalMinted() internal view returns (uint256) {
        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    
    function _totalBurned() internal view returns (uint256) {
        return _burnCounter;
    }

    
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return
            interfaceId == 0x01ffc9a7 ||
            interfaceId == 0x80ac58cd ||
            interfaceId == 0x5b5e139f;
    }

    
    function balanceOf(address owner) public view override returns (uint256) {
        if (owner == address(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 _numberBurned(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> BITPOS_NUMBER_BURNED) & BITMASK_ADDRESS_DATA_ENTRY;
    }

    
    function _getAux(address owner) internal view returns (uint64) {
        return uint64(_packedAddressData[owner] >> BITPOS_AUX);
    }

    
    function _setAux(address owner, uint64 aux) internal {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        assembly {
            auxCasted := aux
        }
        packed = (packed & BITMASK_AUX_COMPLEMENT) | (auxCasted << BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }

    
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr)
                if (curr < _currentIndex) {
                    uint256 packed = _packedOwnerships[curr];
                    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(baseURI, _toString(tokenId))) : '';
    }

    
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    
    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 ApprovalToCurrentOwner();

        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);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }

    
    function _exists(uint256 tokenId) internal view returns (bool) {
        return
            _startTokenId() <= tokenId &&
            tokenId < _currentIndex &&
            _packedOwnerships[tokenId] & BITMASK_BURNED == 0;
    }

    
    function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, '');
    }

    
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        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;

            if (to.code.length != 0) {
                do {
                    emit Transfer(address(0), to, updatedIndex);
                    if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (updatedIndex < end);
                if (_currentIndex != startTokenId) revert();
            } else {
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex < end);
            }
            _currentIndex = updatedIndex;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    
    function _mint(address to, uint256 quantity) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        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();

        bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
            isApprovedForAll(from, _msgSenderERC721A()) ||
            getApproved(tokenId) == _msgSenderERC721A());

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);
        delete _tokenApprovals[tokenId];
        unchecked {
            --_packedAddressData[from];
            ++_packedAddressData[to];
            _packedOwnerships[tokenId] =
                _addressToUint256(to) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                BITMASK_NEXT_INITIALIZED;
            if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                if (_packedOwnerships[nextTokenId] == 0) {
                    if (nextTokenId != _currentIndex) {
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

    
    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        address from = address(uint160(prevOwnershipPacked));

        if (approvalCheck) {
            bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
                isApprovedForAll(from, _msgSenderERC721A()) ||
                getApproved(tokenId) == _msgSenderERC721A());

            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);
        delete _tokenApprovals[tokenId];
        unchecked {
            _packedAddressData[from] += (1 << BITPOS_NUMBER_BURNED) - 1;
            _packedOwnerships[tokenId] =
                _addressToUint256(from) |
                (block.timestamp << BITPOS_START_TIMESTAMP) |
                BITMASK_BURNED | 
                BITMASK_NEXT_INITIALIZED;
            if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                if (_packedOwnerships[nextTokenId] == 0) {
                    if (nextTokenId != _currentIndex) {
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);
        unchecked {
            _burnCounter++;
        }
    }

    
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
            bytes4 retval
        ) {
            return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    
    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)
            mstore(0x40, ptr)
            let end := ptr
            for {
                let temp := value
                ptr := sub(ptr, 1)
                mstore8(ptr, add(48, mod(temp, 10)))
                temp := div(temp, 10)
            } temp {
                temp := div(temp, 10)
            } {
                ptr := sub(ptr, 1)
                mstore8(ptr, add(48, mod(temp, 10)))
            }
            
            let length := sub(end, ptr)
            ptr := sub(ptr, 32)
            mstore(ptr, length)
        }
    }
}

pragma solidity ^0.8.0;


abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

pragma solidity ^0.8.0;



abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    
    constructor() {
        _transferOwnership(_msgSender());
    }

    
    function owner() public view virtual returns (address) {
        return _owner;
    }

    
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}



pragma solidity ^0.8.0;




contract KumoriGoblinFan is ERC721A, Ownable {
	using Strings for uint;

	uint public constant MAX_SUPPLY = 3333;
	uint public constant KumoriGoblinFan_LIMIT = 10;
	uint public constant FREE_LIMIT = 3333;
	uint public constant MINT_PRICE = 0.005 ether;
	
	address public immutable PAYMENT_PROCESSOR;

    bool public isMetadataLocked = false;
	bool public isPaused = false;
    string private _baseURL;
	uint private freeMinted = 0;
	string public prerevealURL = 'ipfs://QmeNZNfEDgKuLmxUGULfmjKReTYQYqxoKBf5S9HxmgtfcQ/';
	mapping(address => uint) private _KumoriGoblinFanWhisperCount;

	constructor(address paymentsAddress_) 
	ERC721A('KumoriGoblinFan', 'kgf') {
        PAYMENT_PROCESSOR = paymentsAddress_;
    }

	function _baseURI() internal view override returns (string memory) {
		return _baseURL;
	}

	function _startTokenId() internal pure override returns (uint) {
		return 1;
	}

    function lockMetadata() external onlyOwner {
        isMetadataLocked = true;
    }

	function reveal(string memory url) external onlyOwner {
        require(!isMetadataLocked, "KumoriGoblinFan: Metadata is finalized");
		_baseURL = url;
	}

    function mintedCount(address owner) external view returns (uint) {
        return _KumoriGoblinFanWhisperCount[owner];
    }

	function allowFreeMint() external view returns (bool) {
		return  FREE_LIMIT >= freeMinted + 2;
	}

	function freeMintedCount() external view returns (uint) {
        return freeMinted;
    }

	function setPause(bool value) external onlyOwner {
		isPaused = value;
	}

	function withdraw() external onlyOwner {
		uint balance = address(this).balance;
		require(balance > 0, 'Nothing to Withdraw');
		payable(PAYMENT_PROCESSOR).transfer(balance);
	}

	function airdrop(address to, uint count) external onlyOwner {
		require(
			_totalMinted() + count <= MAX_SUPPLY,
			'KumoriGoblinFan: Over limit'
		);
		_safeMint(to, count);
	}

	function tokenURI(uint tokenId)
		public
		view
		override
		returns (string memory)
	{
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

        return bytes(_baseURI()).length > 0 
            ? string(abi.encodePacked(_baseURI(), tokenId.toString(), ".json"))
            : prerevealURL;
	}

	function mint(uint count) external payable {
		require(!isPaused, 'KumoriGoblinFan: Sales are off');
		require(count <= KumoriGoblinFan_LIMIT,'KumoriGoblinFan: Over limit');
		require(_totalMinted() + count <= MAX_SUPPLY,'KumoriGoblinFan: Over limit');

        uint payForCount = count;
        if(_KumoriGoblinFanWhisperCount[msg.sender] < 2 && FREE_LIMIT >= freeMinted + 2) {
			if (_KumoriGoblinFanWhisperCount[msg.sender] == 0 && payForCount == 1) payForCount = 0;
			else payForCount = payForCount - (2 - _KumoriGoblinFanWhisperCount[msg.sender]);
			freeMinted = freeMinted + (count - payForCount);
        }

		require(
			msg.value >= payForCount * MINT_PRICE,
			'KumoriGoblinFan: Ether value sent is not sufficient'
		);

		_KumoriGoblinFanWhisperCount[msg.sender] += count;
		_safeMint(msg.sender, count);
	}
}