Web RTC example

index.js

const webrtc = require('wrtc');
const lzString = require('lz-string');
const readline = require('readline');

const dataChannelSettings = {
  reliable: {
    ordered: true,
    maxRetransmits: 1
  }
}

const pcSettings = [
  {
    iceServers: [{ url: 'stun:stun.l.google.com:19302'}]
  },
  {
    optional: [{ DtlsSrtpKeyAgreement: false }]
  }
]

let pc
const pendingDataChannels = {}
const dataChannels = {}

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
})

if (process.argv[2] === 'create') {
  makeOffer()
} else {
  rl.question('Offer:\n', offer => {
    getOffer(offer)
  })
}

function makeOffer() {
  pc = new webrtc.RTCPeerConnection(pcSettings)
  makeDataChannel()
  pc.createOffer(desc => pc.setLocalDescription(desc, () => {}, err => {}),
    err => console.log("Error ", err))

  pc.onicecandidate = candidate => {
    if (candidate.candidate == null) {
      console.log("Your offer is:")
      console.log(JSON.stringify(pc.localDescription))
      const answer = new webrtc.RTCSessionDescription(pc.localDescription);
      answer.type = 'offer'
      pc.setRemoteDescription(answer);
    }
  }
}

function makeDataChannel() {
  const channel = pc.createDataChannel('test', { reliable:true })
  channel.onopen = () => {
    console.log("\nConnected!");
    inputLoop(channel);
  }
  channel.onmessage = evt => {
    { message } = JSON.parse(evt.data)
    console.log(message)
    inputLoop(channel)
  };
}

function inputLoop(channel) {
  rl.question("> ", text => {
    channel.send(JSON.stringify({ message: text }));
    inputLoop(channel);
  });
}