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Forked from dabit3/marketplace.sol
Created March 4, 2022 15:38
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NFT Marketplace Smart Contract (V2)
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "hardhat/console.sol";
contract NFTMarketplace is ERC721URIStorage {
using Counters for Counters.Counter;
Counters.Counter private _tokenIds;
Counters.Counter private _itemsSold;
uint256 listingPrice = 0.025 ether;
address payable owner;
mapping(uint256 => MarketItem) private idToMarketItem;
struct MarketItem {
uint256 tokenId;
address payable seller;
address payable owner;
uint256 price;
bool sold;
}
event MarketItemCreated (
uint256 indexed tokenId,
address seller,
address owner,
uint256 price,
bool sold
);
constructor() ERC721("Metaverse Tokens", "METT") {
owner = payable(msg.sender);
}
/* Updates the listing price of the contract */
function updateListingPrice(uint _listingPrice) public payable {
require(owner == msg.sender, "Only marketplace owner can update listing price.");
listingPrice = _listingPrice;
}
/* Returns the listing price of the contract */
function getListingPrice() public view returns (uint256) {
return listingPrice;
}
/* Mints a token and lists it in the marketplace */
function createToken(string memory tokenURI, uint256 price) public payable returns (uint) {
_tokenIds.increment();
uint256 newTokenId = _tokenIds.current();
_mint(msg.sender, newTokenId);
_setTokenURI(newTokenId, tokenURI);
createMarketItem(newTokenId, price);
return newTokenId;
}
function createMarketItem(
uint256 tokenId,
uint256 price
) private {
require(price > 0, "Price must be at least 1 wei");
require(msg.value == listingPrice, "Price must be equal to listing price");
idToMarketItem[tokenId] = MarketItem(
tokenId,
payable(msg.sender),
payable(address(this)),
price,
false
);
_transfer(msg.sender, address(this), tokenId);
emit MarketItemCreated(
tokenId,
msg.sender,
address(this),
price,
false
);
}
/* allows someone to resell a token they have purchased */
function resellToken(uint256 tokenId, uint256 price) public payable {
require(idToMarketItem[tokenId].owner == msg.sender, "Only item owner can perform this operation");
require(msg.value == listingPrice, "Price must be equal to listing price");
idToMarketItem[tokenId].sold = false;
idToMarketItem[tokenId].price = price;
idToMarketItem[tokenId].seller = payable(msg.sender);
idToMarketItem[tokenId].owner = payable(address(this));
_itemsSold.decrement();
_transfer(msg.sender, address(this), tokenId);
}
/* Creates the sale of a marketplace item */
/* Transfers ownership of the item, as well as funds between parties */
function createMarketSale(
uint256 tokenId
) public payable {
uint price = idToMarketItem[tokenId].price;
address seller = idToMarketItem[tokenId].seller;
require(msg.value == price, "Please submit the asking price in order to complete the purchase");
idToMarketItem[tokenId].owner = payable(msg.sender);
idToMarketItem[tokenId].sold = true;
idToMarketItem[tokenId].seller = payable(address(0));
_itemsSold.increment();
_transfer(address(this), msg.sender, tokenId);
payable(owner).transfer(listingPrice);
payable(seller).transfer(msg.value);
}
/* Returns all unsold market items */
function fetchMarketItems() public view returns (MarketItem[] memory) {
uint itemCount = _tokenIds.current();
uint unsoldItemCount = _tokenIds.current() - _itemsSold.current();
uint currentIndex = 0;
MarketItem[] memory items = new MarketItem[](unsoldItemCount);
for (uint i = 0; i < itemCount; i++) {
if (idToMarketItem[i + 1].owner == address(this)) {
uint currentId = i + 1;
MarketItem storage currentItem = idToMarketItem[currentId];
items[currentIndex] = currentItem;
currentIndex += 1;
}
}
return items;
}
/* Returns only items that a user has purchased */
function fetchMyNFTs() public view returns (MarketItem[] memory) {
uint totalItemCount = _tokenIds.current();
uint itemCount = 0;
uint currentIndex = 0;
for (uint i = 0; i < totalItemCount; i++) {
if (idToMarketItem[i + 1].owner == msg.sender) {
itemCount += 1;
}
}
MarketItem[] memory items = new MarketItem[](itemCount);
for (uint i = 0; i < totalItemCount; i++) {
if (idToMarketItem[i + 1].owner == msg.sender) {
uint currentId = i + 1;
MarketItem storage currentItem = idToMarketItem[currentId];
items[currentIndex] = currentItem;
currentIndex += 1;
}
}
return items;
}
/* Returns only items a user has listed */
function fetchItemsListed() public view returns (MarketItem[] memory) {
uint totalItemCount = _tokenIds.current();
uint itemCount = 0;
uint currentIndex = 0;
for (uint i = 0; i < totalItemCount; i++) {
if (idToMarketItem[i + 1].seller == msg.sender) {
itemCount += 1;
}
}
MarketItem[] memory items = new MarketItem[](itemCount);
for (uint i = 0; i < totalItemCount; i++) {
if (idToMarketItem[i + 1].seller == msg.sender) {
uint currentId = i + 1;
MarketItem storage currentItem = idToMarketItem[currentId];
items[currentIndex] = currentItem;
currentIndex += 1;
}
}
return items;
}
}
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