app.js

const express = require('express');
const http = require('http');
var cors = require('cors');
const app = express();
const bodyParser = require('body-parser');
const path = require('path');
var xss = require('xss');

var server = http.createServer(app);
var io = require('socket.io')(server);

app.use(cors());
app.use(bodyParser.json());

if (process.env.NODE_ENV === 'production') {
  app.use(express.static(__dirname + '/build'));
  app.get('*', (req, res) => {
    res.sendFile(path.join(__dirname + '/build/index.html'));
  });
}
app.set('port', process.env.PORT || 3080);

let sanitizeString = (str) => {
  return xss(str);
};

let connections = {};
let messages = {};
let timeOnline = {};

io.on('connection', (socket) => {
  socket.on('join-call', (path) => {
    if (connections[path] === undefined) {
      connections[path] = [];
    }
    connections[path].push(socket.id);

    timeOnline[socket.id] = new Date();

    for (let a = 0; a < connections[path].length; ++a) {
      io.to(connections[path][a]).emit(
        'user-joined',
        socket.id,
        connections[path]
      );
    }

    if (messages[path] !== undefined) {
      for (let a = 0; a < messages[path].length; ++a) {
        io.to(socket.id).emit(
          'chat-message',
          messages[path][a]['data'],
          messages[path][a]['sender'],
          messages[path][a]['socket-id-sender']
        );
      }
    }

    console.log(path, connections[path]);
  });

  socket.on('signal', (toId, message) => {
    io.to(toId).emit('signal', socket.id, message);
  });

  socket.on('chat-message', (data, sender) => {
    data = sanitizeString(data);
    sender = sanitizeString(sender);

    var key;
    var ok = false;
    for (const [k, v] of Object.entries(connections)) {
      for (let a = 0; a < v.length; ++a) {
        if (v[a] === socket.id) {
          key = k;
          ok = true;
        }
      }
    }

    if (ok === true) {
      if (messages[key] === undefined) {
        messages[key] = [];
      }
      messages[key].push({
        sender: sender,
        data: data,
        'socket-id-sender': socket.id,
      });
      console.log('message', key, ':', sender, data);

      for (let a = 0; a < connections[key].length; ++a) {
        io.to(connections[key][a]).emit(
          'chat-message',
          data,
          sender,
          socket.id
        );
      }
    }
  });

  socket.on('disconnect', () => {
    var diffTime = Math.abs(timeOnline[socket.id] - new Date());
    var key;
    for (const [k, v] of JSON.parse(
      JSON.stringify(Object.entries(connections))
    )) {
      for (let a = 0; a < v.length; ++a) {
        if (v[a] === socket.id) {
          key = k;

          for (let a = 0; a < connections[key].length; ++a) {
            io.to(connections[key][a]).emit('user-left', socket.id);
          }

          var index = connections[key].indexOf(socket.id);
          connections[key].splice(index, 1);

          console.log(key, socket.id, Math.ceil(diffTime / 1000));

          if (connections[key].length === 0) {
            delete connections[key];
          }
        }
      }
    }
  });
});

server.listen(app.get('port'), () => {
  console.log('listening on', app.get('port'));
});