// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library Address {
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly {size := extcodesize(account)}
        return size > 0;
    }
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}('');
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, 'Address: low-level static call failed');
    }
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            if (returndata.length > 0) {
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

library Counters {
    struct Counter {
        uint256 _value;
    }
    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }
    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }
    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counters: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }
}

library Strings {
    bytes16 private constant alphabet = '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] = alphabet[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        this;
        return msg.data;
    }
}

abstract contract Pausable is Context {
    event Paused(address account);
    event Unpaused(address account);
    bool private _paused;
    constructor() {
        _paused = false;
    }
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    constructor() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

interface IST20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

interface IERC165 {
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

interface IERC721 is IERC165 {
    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) external;
    function transferFrom(address from, address to, uint256 tokenId) external;
    function approve(address to, uint256 tokenId) external;
    function getApproved(uint256 tokenId) external view returns (address operator);
    function setApprovalForAll(address operator, bool _approved) external;
    function isApprovedForAll(address owner, address operator) external view returns (bool);
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
}

interface IERC721Receiver {
    function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
}

interface IERC721Metadata is IERC721 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

abstract contract ERC165 is IERC165 {
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;
    string private _name;
    string private _symbol;
    mapping(uint256 => address) private _owners;
    mapping(address => uint256) private _balances;
    mapping(uint256 => address) private _tokenApprovals;
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC721Metadata).interfaceId || super.supportsInterface(interfaceId);
    }
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }
    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) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
    }
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");
        require(_msgSender() == owner || isApprovedForAll(owner, _msgSender()), "ERC721: approve caller is not owner nor approved for all");
        _approve(to, tokenId);
    }
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");
        return _tokenApprovals[tokenId];
    }
    function setApprovalForAll(address operator, bool approved) public virtual override {
        require(operator != _msgSender(), "ERC721: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), 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 {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _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 {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }
    function _safeTransfer(address from, address to, uint256 tokenId, bytes memory _data) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, '');
    }
    function _safeMint(address to, uint256 tokenId, bytes memory _data) internal virtual {
        _mint(to, tokenId);
        require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");
        _beforeTokenTransfer(address(0), to, tokenId);
        _balances[to] += 1;
        _owners[tokenId] = to;
        emit Transfer(address(0), to, tokenId);
    }
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);
        _beforeTokenTransfer(owner, address(0), tokenId);
        _approve(address(0), tokenId);
        _balances[owner] -= 1;
        delete _owners[tokenId];
        emit Transfer(owner, address(0), tokenId);
    }
    function _transfer(address from, address to, uint256 tokenId) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
        require(to != address(0), "ERC721: transfer to the zero address");
        _beforeTokenTransfer(from, to, tokenId);
        _approve(address(0), tokenId);
        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;
        emit Transfer(from, to, tokenId);
    }
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }
    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }
    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual {}
}

interface IERC721Enumerable is IERC721 {
    function totalSupply() external view returns (uint256);
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
    function tokenByIndex(uint256 index) external view returns (uint256);
}

abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
    mapping(uint256 => uint256) private _ownedTokensIndex;
    uint256[] private _allTokens;
    mapping(uint256 => uint256) private _allTokensIndex;
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
        return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
    }
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
        return _ownedTokens[owner][index];
    }
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
        return _allTokens[index];
    }
    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override {
        super._beforeTokenTransfer(from, to, tokenId);
        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
            _ownedTokens[from][tokenIndex] = lastTokenId;
            _ownedTokensIndex[lastTokenId] = tokenIndex;
        }
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];
        uint256 lastTokenId = _allTokens[lastTokenIndex];
        _allTokens[tokenIndex] = lastTokenId;
        _allTokensIndex[lastTokenId] = tokenIndex;
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}

abstract contract ERC721URIStorage is ERC721 {
    using Strings for uint256;
    mapping(uint256 => string) private _tokenURIs;
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721URIStorage: URI query for nonexistent token");
        string memory _tokenURI = _tokenURIs[tokenId];
        string memory base = _baseURI();
        if (bytes(base).length == 0) {
            return _tokenURI;
        }
        if (bytes(_tokenURI).length > 0) {
            return string(abi.encodePacked(base, _tokenURI));
        }
        return super.tokenURI(tokenId);
    }
    function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
        require(_exists(tokenId), "ERC721URIStorage: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }
    function _burn(uint256 tokenId) internal virtual override {
        super._burn(tokenId);
        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
    }
}

abstract contract ERC721Burnable is Context, ERC721 {
    function burn(uint256 tokenId) public virtual {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
        _burn(tokenId);
    }
}

contract CB_Non_Fungible_Token is Ownable, Pausable, ERC721, ERC721Enumerable, ERC721URIStorage, ERC721Burnable {
    using Counters for Counters.Counter;
    Counters.Counter private _tokenIdCounter;
    mapping(address => bool) public whitelistedAddress;
    mapping(address => bool) public waitlistedAddress;
    uint256 public mintPrice;
    uint256 public whitelistMintPrice;
    uint256 public waitlistMintPrice;
    uint256 public maxNFT;
    string public baseURI;
    string private _name;
    string private _symbol;
    uint256 public whitelistStartTime = 1660575600;
    uint256 public whitelistEndTime = 1660586400;
    uint256 public waitlistStartTime = 1660586401;
    uint256 public waitlistEndTime = 1660662000;
    bool public mintStarted = false;

    constructor(string memory _name, string memory _symbol, uint256 _mintPrice, uint256 _maxNFT, uint256 _whitelistMintPrice, uint256 _waitlistMintPrice)
    ERC721 (_name, _symbol) payable public {
        mintPrice = _mintPrice;
        maxNFT = _maxNFT;
        whitelistMintPrice = _whitelistMintPrice;
        waitlistMintPrice = _waitlistMintPrice;
    }

    receive() external payable {}
    function _baseURI() internal view override returns (string memory) {
        return baseURI;
    }
    function tokenURI(uint256 tokenId) public view override(ERC721, ERC721URIStorage) returns (string memory) {
        return string(abi.encodePacked(super.tokenURI(tokenId), ".json"));
    }
    function supportsInterface(bytes4 interfaceId) public view override(ERC721, ERC721Enumerable) returns (bool) {
        return super.supportsInterface(interfaceId);
    }
    function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
        super._burn(tokenId);
    }
    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal override(ERC721, ERC721Enumerable) whenNotPaused {
        super._beforeTokenTransfer(from, to, tokenId);
    }
    function pause() public onlyOwner {
        _pause();
    }
    function unpause() public onlyOwner {
        _unpause();
    }
    function toggleMint() public onlyOwner {
        mintStarted = !mintStarted;
    }
    function setMintPrice(uint256 _mintPrice) public onlyOwner {
        mintPrice = _mintPrice;
    }
    function setBaseURI(string memory _baseURI) public onlyOwner {
        baseURI = _baseURI;
    }
    function internalMint(address to) internal {
        _safeMint(to, _tokenIdCounter.current());
        _tokenIdCounter.increment();
    }
    function ownerMintNFT(uint256 amount) public onlyOwner {
        require(amount <= maxNFT, "NFT: Max NFT limit exceeded!");
        for (uint256 i = 0; i < amount; i++) {
            internalMint(msg.sender);
        }
    }
    function setWhitelistTime(uint256 _whitelistStartTime, uint256 _whitelistEndTime) public onlyOwner {
        whitelistStartTime = _whitelistStartTime;
        whitelistEndTime = _whitelistEndTime;
    }
    function setWaitlistTime(uint256 _waitlistStartTime, uint256 _waitlistEndTime) public onlyOwner {
        waitlistStartTime = _waitlistStartTime;
        waitlistEndTime = _waitlistEndTime;
    }
    function addBatchToWhitelisted(address[] calldata _addresses) public onlyOwner {
        for (uint256 i = 0; i < _addresses.length; i++) {
            whitelistedAddress[_addresses[i]] = true;
        }
    }
    function addToWhitelisted(address _address) public onlyOwner {
        require(whitelistedAddress[_address], "NFT: Address is already whitelisted!");
        whitelistedAddress[_address] = true;
    }
    function removeFromWhitelisted(address _address) public onlyOwner {
        require(whitelistedAddress[_address], "NFT: Address is not whitelisted!");
        whitelistedAddress[_address] = false;
    }
    function addBatchToWaitlisted(address[] calldata _addresses) public onlyOwner {
        for (uint256 i = 0; i < _addresses.length; i++) {
            waitlistedAddress[_addresses[i]] = true;
        }
    }
    function addToWaitlisted(address _address) public onlyOwner {
        require(waitlistedAddress[_address], "NFT: Address is already waitlisted!");
        waitlistedAddress[_address] = true;
    }
    function removeFromWaitlisted(address _address) public onlyOwner {
        require(waitlistedAddress[_address], "NFT: Address is not waitlisted!");
        waitlistedAddress[_address] = false;
    }
    function whitelistMintNFT(uint256 amount) public payable {
        require(mintStarted == true, "NFT: Mint not started yet!");
        require(whitelistedAddress[msg.sender], "NFT: Address is not whitelisted!");
        require((block.timestamp > whitelistStartTime && block.timestamp < whitelistEndTime), "NFT: Either whitelist mint not started or expired!");
        require(msg.value >= whitelistMintPrice * amount, "NFT: Insufficient mint fees!");
        require(amount <= maxNFT, "NFT: Max NFT limit exceeded!");
        for (uint256 i = 0; i < amount; i++) {
            internalMint(msg.sender);
        }
    }
    function waitlistMintNFT(uint256 amount) public payable {
        require(mintStarted == true, "NFT: Mint not started yet!");
        require(whitelistedAddress[msg.sender], "NFT: Address is not whitelisted!");
        require(waitlistedAddress[msg.sender], "NFT: Address is not whitelisted!");
        require((block.timestamp > waitlistStartTime && block.timestamp < waitlistEndTime), "NFT: Either whitelist mint not started or expired!");
        require(msg.value >= waitlistMintPrice * amount, "NFT: Insufficient mint fees!");
        require(amount <= maxNFT, "NFT: Max NFT limit exceeded!");
        for (uint256 i = 0; i < amount; i++) {
            internalMint(msg.sender);
        }
    }
    function mintNFT(uint256 amount) public payable {
        require(mintStarted == true, "NFT: Mint not started yet!");
        require(msg.value >= mintPrice * amount, "NFT: Insufficient mint fees!");
        require(amount <= maxNFT, "NFT: Max NFT limit exceeded!");
        for (uint256 i = 0; i < amount; i++) {
            internalMint(msg.sender);
        }
    }   
    
    // ------------------------------------------------------------------------
    // Function to Withdraw Coins sent by mistake to the Token Contract Address.
    // Only the Contract owner can withdraw the Coins.
    // ------------------------------------------------------------------------
    function withdrawCoins() public onlyOwner {
        payable(msg.sender).transfer(address(this).balance);
    }

    // ------------------------------------------------------------------------
    // Function to Withdraw Tokens sent by mistake to the Token Contract Address.
    // Only the Contract owner can withdraw the Tokens.
    // ------------------------------------------------------------------------
    function withdrawTokens(address tokenAddress, uint256 tokenAmount) public virtual onlyOwner {
        IST20(tokenAddress).transfer(owner(), tokenAmount);
    }
}