hack9-nft.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.11;


import "@openzeppelin/contracts@4.4.2/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts@4.4.2/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts@4.4.2/access/Ownable.sol";
import "@openzeppelin/contracts@4.4.2/utils/Counters.sol";

contract amaziNgFreakingarT is ERC721, ERC721URIStorage, Ownable {
    using Counters for Counters.Counter;

    Counters.Counter private _tokenIdCounter;

    constructor() ERC721("amaziNgFreakingarT", "ART") {}

    function safeMint(address to, string memory uri) public onlyOwner {
        uint256 tokenId = _tokenIdCounter.current();
        _tokenIdCounter.increment();
        _safeMint(to, tokenId);
        _setTokenURI(tokenId, uri);
    }

    // The following functions are overrides required by Solidity.

    function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
        super._burn(tokenId);
    }

    function tokenURI(uint256 tokenId)
        public
        view
        override(ERC721, ERC721URIStorage)
        returns (string memory)
    {
        return super.tokenURI(tokenId);
    }
}




contract ArtsyNFTSales {
    // hardcode the "gallery" address
    address public constant GALLERY_ADDR = 0xbC19Bd22fefcbC9a62d8DF37a7eBdC1f3510c9df;
    address public constant NFT_CONTRACT = 0xF7e5d002E621626F66882413754b80a57461BD99;

    ////// add a boolean for sale or not

    uint public tokenID;
    uint public price;


    modifier onlyBy(address account) {
        require(account == msg.sender, "Only the gallery can do that.");
        _;
    }


    event TokenForSale(uint tokenID, uint price);
    event TokenRemovedFromSale(uint tokenID);


    receive() external payable {
        if (msg.value != price) {
            revert("Wrong price!");
        }
        
        // whatever money comes to the contract, it goes to the gallery
        (bool success,) = payable(GALLERY_ADDR).call{value: msg.value}("");
        require(success);


        amaziNgFreakingarT nftcontract = amaziNgFreakingarT(NFT_CONTRACT);
        nftcontract.safeTransferFrom(GALLERY_ADDR, msg.sender, tokenID);

        _removeFromSale(tokenID);
    }

    // Stores a new value in the contract
    function putForSale(uint _tokenID, uint256 _price) public onlyBy(GALLERY_ADDR) {
        price = _price;
        tokenID = _tokenID;

        // amaziNgFreakingarT nftcontract = amaziNgFreakingarT(NFT_CONTRACT);
        // nftcontract.approve(address(this), _tokenID);
    
        emit TokenForSale(_tokenID, _price);
    }

    function removeFromSale(uint _tokenID) public onlyBy(GALLERY_ADDR) {
        _removeFromSale(_tokenID);
    }

    function isForSale() public view returns(bool) {
        return price != 0;
    }

    function priceFor() public view returns(uint256) {
        return price;
    }


    // INTERNAL FUNCS

    function _removeFromSale(uint _tokenID) private {
        price = 0;
        emit TokenRemovedFromSale(_tokenID);
    }
}