server.js

require("dotenv").config();
var sslRedirect = require("heroku-ssl-redirect");

// Twillio config
var twillioAuthToken =
	process.env.HEROKU_AUTH_TOKEN || process.env.LOCAL_AUTH_TOKEN;
var twillioAccountSID =
	process.env.HEROKU_TWILLIO_SID || process.env.LOCAL_TWILLIO_SID;
var twilio = require("twilio")(twillioAccountSID, twillioAuthToken);
var express = require("express");
var path = require("path");
const app = express();

// Live reload for development
if (process.env.NODE_ENV === "development") {
	const livereload = require("livereload");
	const connectLivereload = require("connect-livereload");

	// open livereload high port and start to watch public directory for changes
	const liveReloadServer = livereload.createServer();
	liveReloadServer.watch(path.join(__dirname, "public"));

	// ping browser on Express boot, once browser has reconnected and handshaken
	liveReloadServer.server.once("connection", () => {
		setTimeout(() => {
			liveReloadServer.refresh("/");
		}, 100);
	});

	// monkey patch every served HTML so they know of changes
	app.use(connectLivereload());
}

var http = require("http").createServer(app);
var io = require("socket.io")(http);
const chalk = require("chalk");

app.use(sslRedirect());

// BEGIN SOCKETIO COMMUNICATION FOR WEBRTC
// When a socket connects, set up the specific listeners we will use.
io.on("connection", function (socket) {
	// When a client tries to join a room, only allow them if they are first or
	// second in the room. Otherwise it is full.
	socket.on("join", function (room, acknowledgement) {
		console.log("Client joining: ", room);
		acknowledgement();

		var clients = io.sockets.adapter.rooms[room];
		var numClients = typeof clients !== "undefined" ? clients.length : 0;
		if (numClients === 0) {
			socket.join(room);
		} else if (numClients < 15) {
			socket.join(room);
			// When the client is not the first to join the room, all clients are ready.
			console.log("Ready message broadcasted to: ", room);
			socket.broadcast.to(room).emit("willInitiateCall", socket.id, room);
		} else {
			console.log(
				room,
				" already full with ",
				numClients,
				"clients in the room."
			);
			socket.emit("full", room);
		}
	});

	// Client is disconnecting from the server
	socket.on("disconnecting", () => {
		var room = Object.keys(socket.rooms).filter(item => item != socket.id); // Socket joins a room of itself, remove that
		console.log("Client disconnected from: ", room);
		socket.broadcast.to(room).emit("leave", socket.id);
	});

	// When receiving the token message, use the Twilio REST API to request an
	// token to get ephemeral credentials to use the TURN server.
	socket.on("token", function (room, uuid) {
		console.log("Received token request to:", room);
		twilio.tokens.create(function (err, response) {
			if (err) {
				console.log(err, "for", room);
			} else {
				console.log(
					room + ": Token generated. Returning it to the browser client"
				);
				socket.emit("token", response, uuid);
			}
		});
	});

	// Relay candidate messages
	socket.on("candidate", function (candidate, room, uuid) {
		console.log("Received candidate. Broadcasting...", room);
		io.to(uuid).emit("candidate", candidate, socket.id);
	});

	// Relay offers
	socket.on("offer", function (offer, room, uuid) {
		console.log(
			"Offer from " + socket.id + "... emitting to " + uuid + "in room: ",
			room
		);
		io.to(uuid).emit("offer", offer, socket.id);
	});

	// Relay answers
	socket.on("answer", function (answer, room, uuid) {
		console.log(
			"Answer from " + socket.id + "... emitting to " + uuid + "in room: ",
			room
		);
		io.to(uuid).emit("answer", answer, socket.id);
	});
});

var port = process.env.PORT || 3000;
http.listen(port, function () {
	if (process.env.NODE_ENV === "development") {
		console.warn(chalk`📙: When running in development mode, connections to the server will not be over HTTPS. 
      If you want to connect to a call from an address {green.bold besides localhost or from another computer},
      you must use a service like ngrok or localtunnel.`);
	}

	console.log(
		chalk.green(
			"Running Catalyst server on  ",
			chalk.underline.bgWhite.black.bold(`http://localhost:${port}`)
		)
	);
});