server.js

'use strict'

var os = require('os')
var nodeStatic = require('node-static')
var http = require('http')
var socketIO = require('socket.io')
var hashwords = require('hashwords')

const hasher = hashwords({salt: '~webtendo~'})

function getRoomId (seed) {
  return hasher.hashStr(seed).toLowerCase().split(' ').slice(0, 2).join('-')
}

var file = new nodeStatic.Server('./public')
var app = http.createServer(function (req, res) {
  file.serve(req, res)
}).listen(process.env.PORT || 8080)

var hosts = {}
var clients = {}
var io = socketIO.listen(app)
io.sockets.on('connection', function (socket) {
  var socketClientId
  var hostId
  var clientIP
  var socketRoom
  if (socket.request.headers['x-forwarded-for']) {
    clientIP = socket.request.headers['x-forwarded-for']
    console.log('clientIP', clientIP, 'aka', getRoomId(clientIP))
  }

  // convenience function to log server messages on the client
  function log () {
    var array = ['Message from server:']
    array.push.apply(array, arguments)
    // socket.emit('log', array);
    console.log(array)
  }

  // Message passthrough for signaling.
  socket.on('message', message => {
    log('Client said: ', message)
    if (message.recipient) {
      io.to(clients[message.recipient]).emit('message', message)
    } else {
      io.to(socketRoom).emit('message', message)
    }
  })

  socket.on('get room', () => {
    socket.emit('room', getRoomId(clientIP))
  })

  socket.on('create or join', function (room, clientId, isHost) {
    socketRoom = room || getRoomId(clientIP)
    room = socketRoom
    log('create or join room ' + room + ' from ' + clientId)
    clients[clientId] = socket.id
    socketClientId = clientId
    if (isHost) {
      socket.join(room)
      hosts[room] = clientId
      io.to(room).emit('created', room, clientId)
      return
    }
    let numClients
    if (!io.sockets.adapter.rooms[room]) {
      socket.emit('nohost', room)
      numClients = 0
    } else {
      numClients = io.sockets.adapter.rooms[room].length
    }
    log('Room ' + room + ' now has ' + numClients + ' client(s)')
    if (numClients < 30) {
      log('Client ID ' + socket.id + ' joined room ' + room)
      socket.join(room)
      hostId = hosts[room]
      if (hostId) {
        // Tell host to send an offer.
        io.to(clients[hostId]).emit('joined', room, clientId)
      }
      // Echo back to sender so they know they joined successfully.
      socket.emit('joined', room, clientId)
    } else { // max clients
      socket.emit('full', room)
    }
  })
  socket.on('disconnect', () => {
    if (!socketClientId) {
      return
    }
    console.log(socketClientId, 'disconnected from ', socketRoom)
    io.to(clients[hostId]).emit('disconnected', socketClientId)
  })

  socket.on('ipaddr', function () {
    var ifaces = os.networkInterfaces()
    for (var dev in ifaces) {
      ifaces[dev].forEach(function (details) {
        if (details.family === 'IPv4' && details.address !== '127.0.0.1') {
          socket.emit('ipaddr', details.address)
        }
      })
    }
  })

  socket.on('bye', function () {
    console.log('received bye')
  })
})