server.js

require('dotenv').config({ path: '.env' });
const express = require('express');
const fetch = require('node-fetch');
const cors = require('cors');
const app = express();
const server = require('http').Server(app);
const PORT = process.env.PORT || 3002;
const FRONTEND_ORIGIN = process.env.FRONTEND_ORIGIN
const MONGOOSE_URL = process.env.MONGOOSE_URL
const { PeerServer } = require('peer');
app.use(cors())
app.use(express.urlencoded())
app.use(express.json())

app.get('/', (req, res) => {
    res.send("CodeColab Backend!")
});

const io = require('socket.io')(server, {
    cors: {
        origin: FRONTEND_ORIGIN,
    }
});

const peerServer = PeerServer({ port: 9002, path: '/' }, (exp) => {
    console.log("Peerjs Server Running: " + exp.address().port);
});

peerServer.on('connection', (client) => { console.log("Client Connected: ", client.id); });

const mongoose = require('mongoose');
const Doc = require('./models/Doc');




mongoose.connect(MONGOOSE_URL, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
    useFindAndModify: false,
    useCreateIndex: true
})
    .then(() => console.log('connected to mongodb'))
    .catch((error) => console.error(error));

app.get('/runcode', (req, res) => {
    var url = req.query.url;
    const headers = {
        'Content-Type': 'application/json',
        'client-secret': process.env.REACT_APP_HACKEREARTH_SECRET
    }
    fetch(url, {
        method: 'get',
        headers,
    })
        .then(res => res.json())
        .then(json => {
            res.send(json)
        }).catch((err) => {
            res.send(err)
        });
});

app.post('/runcode', (req, res) => {
    // get post data from request

    var data = req.body;

    const url = "https://api.hackerearth.com/v4/partner/code-evaluation/submissions/";
    fetch(url, {
        method: 'post',
        body: JSON.stringify(data),
        headers: {
            'Content-Type': 'application/json',
            'client-secret': process.env.REACT_APP_HACKEREARTH_SECRET
        },
    })
        .then(res => res.json())
        .then(json => {
            res.send(json);
        }).catch((err) => {
            res.send(err)
        });
});


io.on('connection', (socket) => {
    console.log(`Connected to frontend!`);
    socket.on('get-document', async (DocId) => {
        const doc = await findOrCreateDocument(DocId);

        socket.join(DocId);


        socket.emit('load-document', doc)        ;


        socket.on('changes', delta => {
            
            socket.broadcast.to(DocId).emit("receive-changes", delta);
        });

        socket.on('drawing', (data) => {
            socket.broadcast.emit('drawing', data)
        });

        socket.on('save-document', async (data) => {
            Doc.findByIdAndUpdate({ '_id': DocId }, { 'html': data.html, 'css': data.css, 'js': data.js, 'pascal': data.pascal, 'perl': data.perl, 'php': data.php, 'ruby': data.ruby, 'python': data.python, 'cpp': data.cpp, 'java': data.java, 'input': data.input, 'output': data.output }).then((d) => {
            })
                .catch(err => {
                    console.error(err);
                })
        })

        socket.on('pencil-color-change', color => {
            console.log(color);
            socket.broadcast.to(DocId).emit("pencil-color-change", color);
        })
    });


    socket.on('join-room', (roomId, userId, userName) => {
        socket.join(roomId)
        socket.to(roomId).emit('user-connected', userId)

        socket.on('toggled', (userId, video, audio) => {
            socket.to(roomId).emit('received-toggled-events', userId, video, audio);
        });

        socket.on('disconnect', () => {
            socket.to(roomId).emit('user-disconnected', userId)
        });
    });
});



var findOrCreateDocument = async (id) => {
    if (id === null) {
        return;
    }
    const document = await Doc.findById(id);
    if (document) return document;
    return await Doc.create({ _id: id, html: "", css: "", js: "", python: "", java: "", cpp: "", input: "", output: "", pascal: "", perl: "", php: "", ruby: "" });
};

server.listen(PORT, () => {
    console.log(`Express Server Listening to ${PORT}`);
    console.log(`Socket Listening to ${FRONTEND_ORIGIN}`);
})