backend

2026-05-26 11:25:49 +00:00 · 2025-07-25 11:10:44 +05:30
parent 4455b39267
commit 7e6f0d0b1e
32 changed files with 2093 additions and 15 deletions
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.19;
+
+import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/utils/Counters.sol";
+
+contract CertificateNFT is ERC721, ERC721URIStorage, Ownable {
+    using Counters for Counters.Counter;
+    Counters.Counter private _tokenIds;
+    
+    struct Certificate {
+        string subject;
+        string studentName;
+        uint256 score;
+        uint256 timestamp;
+        bool verified;
+    }
+    
+    mapping(uint256 => Certificate) public certificates;
+    mapping(address => uint256[]) public userCertificates;
+    
+    event CertificateMinted(
+        uint256 indexed tokenId,
+        address indexed student,
+        string subject,
+        uint256 score,
+        string tokenURI
+    );
+    
+    constructor() ERC721("OpenLearnX Certificate", "OLXC") {}
+    
+    function mintCertificate(
+        address to,
+        string memory _tokenURI
+    ) public onlyOwner returns (uint256) {
+        _tokenIds.increment();
+        uint256 newTokenId = _tokenIds.current();
+        
+        _mint(to, newTokenId);
+        _setTokenURI(newTokenId, _tokenURI);
+        
+        certificates[newTokenId] = Certificate({
+            subject: "General",
+            studentName: "",
+            score: 100,
+            timestamp: block.timestamp,
+            verified: true
+        });
+        
+        userCertificates[to].push(newTokenId);
+        
+        emit CertificateMinted(newTokenId, to, "General", 100, _tokenURI);
+        
+        return newTokenId;
+    }
+    
+    function mintCertificateWithDetails(
+        address to,
+        string memory _tokenURI,
+        string memory subject,
+        string memory studentName,
+        uint256 score
+    ) public onlyOwner returns (uint256) {
+        _tokenIds.increment();
+        uint256 newTokenId = _tokenIds.current();
+        
+        _mint(to, newTokenId);
+        _setTokenURI(newTokenId, _tokenURI);
+        
+        certificates[newTokenId] = Certificate({
+            subject: subject,
+            studentName: studentName,
+            score: score,
+            timestamp: block.timestamp,
+            verified: true
+        });
+        
+        userCertificates[to].push(newTokenId);
+        
+        emit CertificateMinted(newTokenId, to, subject, score, _tokenURI);
+        
+        return newTokenId;
+    }
+    
+    function getCertificate(uint256 tokenId) 
+        public 
+        view 
+        returns (Certificate memory) 
+    {
+        require(_exists(tokenId), "Certificate does not exist");
+        return certificates[tokenId];
+    }
+    
+    function getUserCertificates(address user) 
+        public 
+        view 
+        returns (uint256[] memory) 
+    {
+        return userCertificates[user];
+    }
+    
+    function verifyCertificate(uint256 tokenId) 
+        public 
+        view 
+        returns (bool) 
+    {
+        require(_exists(tokenId), "Certificate does not exist");
+        return certificates[tokenId].verified;
+    }
+    
+    function totalSupply() public view returns (uint256) {
+        return _tokenIds.current();
+    }
+    
+    // Override required functions
+    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);
+    }
+    
+    function supportsInterface(bytes4 interfaceId)
+        public
+        view
+        override(ERC721, ERC721URIStorage)
+        returns (bool)
+    {
+        return super.supportsInterface(interfaceId);
+    }
+}