server.ts

import express from "express";
import { RTCPeerConnection } from "werift";
import * as yargs from "yargs";
import https from "https";
import { readFileSync } from "fs";

const args = yargs
  .option("host", {
    description: "Host for HTTP server (default: 0.0.0.0)",
    default: "0.0.0.0",
  })
  .option("port", {
    description: "Port for HTTP server (default: 8080)",
    default: 8080,
  })
  .option("cert-file", { description: "SSL certificate file (for HTTPS)" })
  .option("key-file", { description: "SSL key file (for HTTPS)" })
  .option("static", {})
  .help().argv;

console.log(args);

const app = express();
app.use(express.json());
if (args["cert-file"] && args["key-file"]) {
  https
    .createServer(
      {
        cert: readFileSync(args["cert-file"] as string),
        key: readFileSync(args["key-file"] as string),
      },
      app
    )
    .listen(args.port, args.host);
} else {
  app.listen(args.port, args.host);
}
app.use(express.static((args.static as string) || "../html"));

app.post("/offer", async (req, res) => {
  const offer = req.body;
  console.log("offer", offer);

  const pc = new RTCPeerConnection({
    iceServers: [{ urls: "stun:stun.l.google.com:19302" }],
  });
  pc.onRemoteTransceiverAdded.subscribe(async (transceiver) => {
    const [track] = await transceiver.onTrack.asPromise();
    pc.addTrack(track);
  });
  pc.onDataChannel.subscribe((dc) => {
    dc.message.subscribe((msg) => {
      console.log("datachannel incoming message", msg);
      dc.send(msg);
    });
  });

  await pc.setRemoteDescription(offer);
  const answer = await pc.setLocalDescription(await pc.createAnswer());
  res.send(answer);
});