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Peer-to-Peer Interview Feature for DSA Problem-Solving Platform

This guide provides step-by-step instructions to implement the Peer-to-Peer Interview feature with a DSA Problem-Solving Compiler on your e-learning platform. The feature enables peer-to-peer interaction, real-time code collaboration, and video/audio calls, allowing users to solve DSA problems together.

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Table of Contents

1. Introduction
2. Technologies Used
3. Project Setup
4. Backend Implementation
   • Real-Time Communication
   • Compiler API Integration
5. Frontend Implementation
   • Real-Time Code Collaboration with Monaco Editor
   • Video/Audio Calling with WebRTC
   • Problem Solving Interface
6. Testing and Deployment
7. Additional Enhancements

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Introduction

This implementation enables a peer-to-peer interview platform where users can solve DSA problems together. It includes real-time code collaboration, a video/audio calling feature for interviews, and the integration of a code compiler for immediate feedback.

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Technologies Used

• Frontend: React, Monaco Editor, WebRTC (or Twilio/Agora for video calls)
• Backend: Node.js, Express, Socket.IO, Judge0 API (for code compilation)
• Real-Time Communication: Socket.IO
• Video/Audio Calls: WebRTC (or Twilio/Agora)
• Code Editor: Monaco Editor
• Code Compilation: Judge0 API

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Project Setup

Frontend Setup

1. Create a React project:

   npx create-react-app peer-to-peer-interview
   cd peer-to-peer-interview

Install dependencies:

bash Copy code npm install socket.io-client monaco-editor react-webcam twilio-video Backend Setup Create a Node.js project:

bash Copy code mkdir backend cd backend npm init -y npm install express socket.io axios mongoose Install Judge0 API for code compilation:

bash Copy code npm install axios Backend Implementation Real-Time Communication with Socket.IO In backend/index.js, create the server and handle real-time communication using Socket.IO:

js Copy code const express = require('express'); const http = require('http'); const socketIo = require('socket.io'); const axios = require('axios'); const app = express(); const server = http.createServer(app); const io = socketIo(server);

app.use(express.json());

// Real-time Socket.IO connection io.on('connection', (socket) => { console.log('New peer connected: ', socket.id);

// Listen for joining room
socket.on('joinRoom', (roomId) => {
    socket.join(roomId);
    console.log(`${socket.id} joined room ${roomId}`);
});

// Send code changes to all peers in the room
socket.on('codeChange', (data) => {
    socket.to(data.roomId).emit('receiveCodeChange', data);
});

// Handle chat messages
socket.on('sendMessage', (data) => {
    io.to(data.roomId).emit('receiveMessage', data);
});

socket.on('disconnect', () => {
    console.log('Peer disconnected:', socket.id);
});

});

// Run server server.listen(5000, () => { console.log('Server running on port 5000'); }); Compiler API Integration (Judge0 API) Add a /compile endpoint to compile code using the Judge0 API:

js Copy code const compileCode = async (code, languageId) => { const response = await axios.post('https://api.judge0.com/submissions', { source_code: code, language_id: languageId, });

const submissionId = response.data.token;

// Wait for code execution result
const result = await axios.get(`https://api.judge0.com/submissions/${submissionId}`);
return result.data;

};

// Endpoint to compile user code app.post('/compile', async (req, res) => { const { code, languageId } = req.body; try { const result = await compileCode(code, languageId); res.json(result); } catch (error) { res.status(500).send('Error compiling code'); } }); Frontend Implementation Real-Time Code Collaboration with Monaco Editor In frontend/src/CodeEditor.js, set up Monaco Editor and Socket.IO to sync code in real-time:

js Copy code import React, { useEffect, useRef } from 'react'; import MonacoEditor from 'react-monaco-editor'; import { io } from 'socket.io-client';

const CodeEditor = ({ roomId }) => { const editorRef = useRef(null); const socket = useRef(io('http://localhost:5000'));

useEffect(() => {
    socket.current.emit('joinRoom', roomId);

    socket.current.on('receiveCodeChange', (data) => {
        if (editorRef.current) {
            editorRef.current.setValue(data.code);
        }
    });

    return () => {
        socket.current.disconnect();
    };
}, [roomId]);

const handleCodeChange = (newCode) => {
    socket.current.emit('codeChange', { roomId, code: newCode });
};

return (
    <MonacoEditor
        ref={editorRef}
        height="600px"
        language="javascript"
        theme="vs-dark"
        value=""
        onChange={handleCodeChange}
    />
);

};

export default CodeEditor; Video/Audio Calling with WebRTC For WebRTC-based video/audio calling, create a component frontend/src/VideoCall.js:

js Copy code import React, { useEffect, useRef } from 'react';

const VideoCall = ({ roomId }) => { const localVideoRef = useRef(null); const remoteVideoRef = useRef(null);

useEffect(() => {
    const peerConnection = new RTCPeerConnection();

    // Get local video stream
    navigator.mediaDevices.getUserMedia({ video: true, audio: true })
        .then((stream) => {
            localVideoRef.current.srcObject = stream;
            stream.getTracks().forEach((track) => peerConnection.addTrack(track, stream));
        });

    // Set up ICE candidate handling, connection, and remote video rendering here

    return () => {
        peerConnection.close();
    };
}, [roomId]);

return (
    <div>
        <video ref={localVideoRef} autoPlay muted />
        <video ref={remoteVideoRef} autoPlay />
    </div>
);

};

export default VideoCall; Problem Solving Interface In frontend/src/ProblemPage.js, display the problem and handle code compilation:

js Copy code import React, { useState } from 'react'; import axios from 'axios';

const ProblemPage = ({ problemId }) => { const [code, setCode] = useState(''); const [output, setOutput] = useState('');

const handleCompile = async () => {
    try {
        const response = await axios.post('http://localhost:5000/compile', { code, languageId: 63 }); // Example for JavaScript
        setOutput(response.data.stdout || response.data.stderr);
    } catch (error) {
        setOutput('Error compiling code.');
    }
};

return (
    <div>
        <h1>Problem: {problemId}</h1>
        <textarea value={code} onChange={(e) => setCode(e.target.value)} />
        <button onClick={handleCompile}>Run Code</button>
        <pre>{output}</pre>
    </div>
);

};

export default ProblemPage; Testing and Deployment Frontend: Test the video call, code collaboration, and problem-solving interfaces. Backend: Test the API for code compilation and real-time communication. Deployment: Frontend: Use platforms like Vercel or Netlify. Backend: Use Heroku or Render to deploy your Express server. Additional Enhancements Session Recording: Use RecordRTC or the MediaRecorder API to record video/audio. Feedback System: Allow users to rate and give feedback after each interview. Analytics: Track session durations, problems solved, and user performance. Peer Matching: Match peers based on skill level, preferred language, or problem type. With these instructions and code snippets, you can successfully integrate a peer-to-peer interview system with a collaborative code editor and compiler into your e-learning platform.

yaml Copy code

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This README.md file contains all the necessary implementation details, code, and explanations for building a peer-to-peer interview system with a code compiler for your platform. You can use this as documentation in your project repository.