server.js

const express = require("express");
const app = express();
const webrtc = require("wrtc");
fs = require("fs");
require("dotenv").config();
var port = process.env.PORT || 3000;
let senderStream = [];
let peerUser = [];

app.use(express.static("public"));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

app.use(function (req, res, next) {
  const allowedOrigins = [
    "http://127.0.0.1:3000",
    "http://localhost:3000",
    "http://localhost:8000",
    "http://127.0.0.1:8080",
    "http://localhost:9000",
    "https://webrct-sfu-demo.herokuapp.com/",
  ];
  const origin = req.headers.origin;
  // Website you wish to allow to connect
  if (allowedOrigins.includes(origin)) {
    res.setHeader("Access-Control-Allow-Origin", origin);
  }

  // Request methods you wish to allow
  res.setHeader(
    "Access-Control-Allow-Methods",
    "GET, POST, OPTIONS, PUT, PATCH, DELETE"
  );

  // Request headers you wish to allow
  res.setHeader(
    "Access-Control-Allow-Headers",
    "Origin, X-Requested-With, Content-Type, Accept,x-socket-id,x-csrf-token"
  );

  // Set to true if you need the website to include cookies in the requests sent
  // to the API (e.g. in case you use sessions)
  res.setHeader("Access-Control-Allow-Credentials", true);

  // Pass to next layer of middleware
  next();
});

app.post("/consumer/:roomID/:userID", async (req, res) => {
  if (req.params.roomID === "null")
    return res.status(401).json({ error: "no room id" });
  if (req.params.userID === "null")
    return res.status(401).json({ error: "no user id" });
  var roomID = parseInt(req.params.roomID);
  var userID = parseInt(req.params.userID);
  if (typeof senderStream[roomID] === "undefined")
    return res.status(401).json({ error: "sender not found" });
  if (peerUser[userID]) await peerUser[userID].close();
  peerUser[userID] = new webrtc.RTCPeerConnection({
    iceServers: [
      {
        urls: process.env.STUN_URL,
      },
    ],
  });
  const desc = new webrtc.RTCSessionDescription(req.body.sdp);
  await peerUser[userID].setRemoteDescription(desc);
  senderStream[roomID]
    .getTracks()
    .forEach((track) => peerUser[userID].addTrack(track, senderStream[roomID]));
  const answer = await peerUser[userID].createAnswer();
  await peerUser[userID].setLocalDescription(answer);
  const payload = {
    sdp: peerUser[userID].localDescription,
  };
  res.json(payload);
});
app.post("/disconnect/:roomID/:userID", async (req, res) => {
  if (req.params.roomID === "null")
    return res.status(401).json({ error: "no room id" });
  if (req.params.userID === "null")
    return res.status(401).json({ error: "no user id" });
  var roomID = parseInt(req.params.roomID);
  var userID = parseInt(req.params.userID);
  if (typeof peerUser[userID] === "undefined")
    return res.status(401).json({ error: "peer not found" });
  peerUser[userID].close();
  delete peerUser[userID];
  return res.json({ success: "clear peer succees" });
});

app.post("/broadcast/:roomID/:userID", async (req, res) => {
  if (req.params.roomID === "null")
    return res.status(401).json({ error: "no room id" });
  if (req.params.userID === "null")
    return res.status(401).json({ error: "no user id" });
  if (peerUser[userID]) return res.json({ error: "user already exist" });
  var roomID = parseInt(req.params.roomID);
  var userID = parseInt(req.params.userID);
  peerUser[userID] = new webrtc.RTCPeerConnection({
    iceServers: [
      {
        urls: process.env.STUN_URL,
      },
    ],
  });
  peerUser[userID].ontrack = (e) =>
    handleTrackEvent(e, peerUser[userID], roomID);
  const desc = new webrtc.RTCSessionDescription(req.body.sdp);
  await peerUser[userID].setRemoteDescription(desc);
  const answer = await peerUser[userID].createAnswer();
  await peerUser[userID].setLocalDescription(answer);
  const payload = {
    sdp: peerUser[userID].localDescription,
  };
  return res.json(payload);
});

function handleTrackEvent(e, peer, roomID) {
  senderStream[roomID] = e.streams[0];
}

app.listen(port, () => console.log("server started : " + port));