server.js

import {Server} from 'socket.io';
import express from 'express';
import { createServer }  from 'http';

import  Connection from './database/db.js';

import { getDocument, updateDocument } from './controller/document-controller.js'

const PORT =process.env.PORT || 9000;

const URL = process.env.MONGODB_URI || `mongodb://atul786:test@cluster0-shard-00-00.baisg.mongodb.net:27017,cluster0-shard-00-01.baisg.mongodb.net:27017,cluster0-shard-00-02.baisg.mongodb.net:27017/google-docs?ssl=true&replicaSet=atlas-6leq5p-shard-0&authSource=admin&retryWrites=true&w=majority`;

Connection(URL);

const app=express();

if(process.env.NODE_ENV==='production'){
    app.use(express.static('client/build'));
    //app.use(express.static(path.join(__dirname,"client","build")))
}

const httpServer=createServer(app);
httpServer.listen(PORT);

const io=new Server(httpServer);

io.on('connection', socket => {
    socket.on('get-document', async documentId => {
        const document  = await getDocument(documentId);
        socket.join(documentId);
        socket.emit('load-document', document.data);

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

        socket.on('save-document', async data => {
            await updateDocument(documentId,data);
        })
    })
    
});