git.r.bdr.sh - rbdr/junction/blob - extension/peers.js

   1 const internals = {
   2   peers: {},
   3
   4   createAudioElement(source) {
   5     const audioElement = document.createElement("audio");
   6     audioElement.setAttribute("class", "junction-call-audio");
   7     audioElement.autoplay = "autoplay";
   8     audioElement.srcObject = source;
   9
  10     document.querySelector("body").appendChild(audioElement);
  11
  12     return audioElement;
  13   },
  14 };
  15
  16 export function addPeer({ peerId, shouldCreateOffer, mediaStream, onOffer, socket }) {
  17   const peerConnection = new RTCPeerConnection(
  18     { iceServers: internals.kIceServers },
  19     { optional: [{ DtlsSrtpKeyAgreement: true }] },
  20   );
  21
  22   internals.peers[peerId] = peerConnection;
  23   mediaStream.getTracks().forEach((track) => {
  24     peerConnection.addTrack(track, mediaStream);
  25   });
  26
  27   peerConnection.onicecandidate = (event) => {
  28     if (event.candidate) {
  29       socket.emit("relayICECandidate", {
  30         peerId: peerId,
  31         candidate: event.candidate,
  32       });
  33     }
  34   };
  35
  36   const remoteStream = new MediaStream();
  37   peerConnection.ontrack = (event) => {
  38     remoteStream.addTrack(event.track);
  39     const remoteAudioElement = new Audio();
  40     remoteAudioElement.srcObject = remoteStream;
  41     remoteAudioElement.play();
  42   };
  43
  44   peerConnection.onnegotiationneeded = async () => {
  45     if (shouldCreateOffer) {
  46       console.debug("Creating RTC offer to ", peerId);
  47       const offer = await peerConnection.createOffer();
  48       await peerConnection.setLocalDescription(offer);
  49
  50       onOffer({ peerId, offer });
  51     }
  52   };
  53
  54   console.info(`There are now ${countPeers()} participants`);
  55 }
  56
  57 export function removePeer({ peerId }) {
  58   delete internals.peers[peerId];
  59   console.info(`There are now ${countPeers()} participants`);
  60 }
  61
  62 export async function answerPeerOffer({ peerId, offer }) {
  63   console.info(`Answering peer ${peerId}`);
  64   const peerConnection = internals.peers[peerId];
  65
  66   const remoteDescription = new RTCSessionDescription(offer);
  67   await peerConnection.setRemoteDescription(remoteDescription);
  68
  69   const answer = await peerConnection.createAnswer();
  70   await peerConnection.setLocalDescription(answer);
  71
  72   return { peerId, answer };
  73 }
  74
  75 export async function processPeerAnswer({ peerId, answer }) {
  76   console.info(`Processing answer for peer ${peerId}`);
  77   const peerConnection = internals.peers[peerId];
  78   const remoteDescription = new RTCSessionDescription(answer);
  79   await peerConnection.setRemoteDescription(remoteDescription);
  80 }
  81
  82 export async function addIceCandidate({ peerId, candidate }) {
  83   console.info(`Adding ICE candidate for peer ${peerId}`);
  84   const peerConnection = internals.peers[peerId];
  85   console.info(peerConnection.signalingState);
  86   const iceCandidate = new RTCIceCandidate(candidate);
  87   await peerConnection.addIceCandidate(iceCandidate);
  88 }
  89
  90 export function countPeers() {
  91   return Object.keys(internals.peers).length;
  92 }
  93
  94 export function resetPeers() {
  95   internals.peers = {};
  96   document
  97     .querySelectorAll(".junction-call-audio")
  98     .forEach((audioElement) => audioElement.remove());
  99 }