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contracts...ERC721.sol

//SPDX-License-Identifier: Unlicense

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "hardhat/console.sol";

contract Ticket is ERC721URIStorage {
    uint256 private tokenId;

    event TicketCreated(uint256 tokenId, address visitor);

    constructor(
        string memory eventName,
        string memory shortName
    ) ERC721(eventName, shortName) {
        // initializes the NFT storage
    }

    function createTicket(address visitor, string memory tokenURI) external {
        tokenId++;

        // mint the NFT and assign to the visitor address
        _mint(visitor, tokenId);

        // set the token JSON file link that was uploaded to the IPFS
        _setTokenURI(tokenId, tokenURI);

        console.log(tokenId);
        emit TicketCreated(tokenId, visitor);
    }
}