Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.8.0+commit.c7dfd78e.js&optimize=true&runs=100000&gist=

CheckInterface.sol

// SPDX-License-Identifier: Unlicensed

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";

/// @title Contract to check that a given address is an NFT
/// @notice Returns integer type representing the position of the returned value from the tokenType enum

library CheckInterface {
    using ERC165Checker for address;

    enum tokenTypes {
        NULL,
        ERC1155,
        ERC721
    }

    ///
    bytes4 constant Interface_ERC721 = type(IERC721).interfaceId;
    bytes4 constant Interface_ERC1155 = type(IERC1155).interfaceId;

    /// @notice Check token type
    /// @dev Takes the token address and checks the type using the ERC165 refelection standards
    /// @param _token The address of the NFT
    /// @return _tokenType Specifies the type of token
    function checkTokenType(address _token)
        external
        view
        returns (uint8 _tokenType)
    {
        if (_token.supportsInterface(Interface_ERC1155)) {
            return uint8(tokenTypes.ERC1155);
        } else if (_token.supportsInterface(Interface_ERC721)) {
            return uint8(tokenTypes.ERC721);
        } else {
            return uint8(tokenTypes.NULL);
        }
    }
}