server.js

const express = require('express')
const app = express();
const http = require('http')
const path =require('path')
const { Server } = require('socket.io');
const ACTIONS = require('./src/Actions');


const server=http.createServer(app)

const io=new Server(server);

app.use(express.static('build'));

app.use((req, res, next) => {
    res.sendFile(path.join(__dirname, 'build', 'index.html'));
});

const userSocketMap={}

function getAllConnectedUsers(nestID){
    //Map 
    
    return Array.from(io.sockets.adapter.rooms.get(nestID) || []).map(
        (socketId)=>{
      return {
          socketId,
          username:userSocketMap[socketId],
      }  
    });
}

io.on('connection',(socket)=>{
    console.log('socket connected',socket.id);
    socket.on(ACTIONS.JOIN,({nestID,username})=>{
       
        userSocketMap[socket.id]=username;
        socket.join(nestID);
        
        const clients=getAllConnectedUsers(nestID);
        
        clients.forEach(({socketId})=>{
            io.to(socketId).emit(ACTIONS.JOINED,{
                clients,
                username,
                socketId:socket.id,
            })
        })

    });

    socket.on(ACTIONS.CODE_CHANGE, ({ nestID, code }) => {
        socket.in(nestID).emit(ACTIONS.CODE_CHANGE, { code });
    });


    
    socket.on(ACTIONS.SYNC_CODE, ({ socketId, code }) => {
        io.to(socketId).emit(ACTIONS.CODE_CHANGE, { code });
    });



    socket.on('disconnecting', () => {
        const rooms = [...socket.rooms];
        rooms.forEach((nestID) => {
            socket.in(nestID).emit(ACTIONS.DISCONNECTED, {
                socketId: socket.id,
                username: userSocketMap[socket.id],
            });
        });
        delete userSocketMap[socket.id];
        socket.leave();
    });   
});



const PORT = process.env.PORT || 5000
server.listen(PORT,()=>console.log(`Listening on port ${PORT}`));