sfu.js

var log = msg => {
    console.log(msg)
}

function uuidv4() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

const wsuri = "wss://" + location.host + "/ws";
const socket = new WebSocket(wsuri);



const config = {
  // iceServers: [{
  //   urls: 'stun:stun.l.google.com:19302'
  // }]
}

let localStream

// 0. getmedia and setLocalDescription
navigator.mediaDevices.getUserMedia({ video: true, audio: true})
    .then(stream => {
        let el = document.createElement("Video")
        el.srcObject = stream
        el.autoplay = true
        el.controls = false
        el.muted = true
        document.getElementById('local').appendChild(el)
        localStream = stream
    }).catch(log)


const pcPublish = new RTCPeerConnection(config)


pcPublish.oniceconnectionstatechange = e => log(`[rtc]ICE connection state: ${pcPublish.iceConnectionState}`)

pcPublish.ontrack = function ({ track, streams }) {
  if (track.kind === "video") {
    log("[rtc]ontrack video")
    // track.onunmute = () => {
    //   log("[rtc]onunmute")
      let el = document.createElement(track.kind)
      el.srcObject = streams[0]
      el.autoplay = true

      document.getElementById('remote').appendChild(el)
    // }
  }
}

pcPublish.onicecandidate = event => {
  log("[rtc]onicecandidate, sending trickle on ws")
  log(event.candidate)
  if (event.candidate !== null) {
    socket.send(JSON.stringify({
      method: "trickle",
      params: {
        candidate: event.candidate,
      }
    }))
  }
}



const id = uuidv4()



socket.addEventListener('message', async (event) => {
  const resp = JSON.parse(event.data)

  // Listen for server renegotiation notifications
  if (!resp.id && resp.method === "offer") {
    log(`[ws]receive offer`)
    log(resp.params)
    await pcPublish.setRemoteDescription(resp.params)
    const answer = await pcPublish.createAnswer()
    await pcPublish.setLocalDescription(answer)

    log(`[ws]Sending answer`)
    log(answer)
    socket.send(JSON.stringify({
      method: "answer",
      params: { desc: answer },
      id
    }))
  }
})





const join = async () => {
    const offer = await pcPublish.createOffer()
    await pcPublish.setLocalDescription(offer)

    log("[ws]Sending join")
    log(pcPublish.localDescription)
    socket.send(JSON.stringify({
        method: "join",
        params: { sid: "test room", offer: pcPublish.localDescription },
        id
    }))


    socket.addEventListener('message', (event) => {
        const resp = JSON.parse(event.data)
        if (resp.id === id) {
            log(`[ws]receive answer`)
            log(resp.result)

            // Hook this here so it's not called before joining
            pcPublish.onnegotiationneeded = async function () {
                log("[rtc]onnegotiationneeded")
                const offer = await pcPublish.createOffer()
                await pcPublish.setLocalDescription(offer)
                socket.send(JSON.stringify({
                    method: "offer",
                    params: { desc: offer },
                    id
                }))

                socket.addEventListener('message', (event) => {
                    const resp = JSON.parse(event.data)
                    if (resp.id === id) {
                        log(`[ws]Got renegotiation answer`)
                        pcPublish.setRemoteDescription(resp.result)
                    }
                })
            }

            log(`[rtc]setRemoteDescription`)
            // log(resp)
            pcPublish.setRemoteDescription(resp.result)
        } else if (resp.method == "trickle"){
            log("[ws]receive trickle")
            log(resp.params)
            pcPublish.addIceCandidate(resp.params)
        }
    })
}


// click pub button
window.Pub = () => {
    log("Publishing stream")

    localStream.getTracks().forEach((track) => {
        pcPublish.addTrack(track, localStream);
    });


    join()
}