Format extension

[rbdr/junction] / extension / content_script.js

import { io } from "socket.io-client";
import Peers from "./peers";
import Media from "./media";

const internals = {
  kSocketUrl: "https://junction.tranquil.services",
  kIceServers: [{ urls: "stun:stun.l.google.com:19302" }],

  port: null,
  socket: null,
  peers: {},

  onMessage(message) {
    internals[message.action](message.data);
  },

  async joinAudioCall({ currentUrl, tada }) {
    try {
      const mediaStream = await Media.start();

      internals.socket = io(internals.kSocketUrl, {
        transports: ["websocket"],
      });

      internals.socket.on("error", function (error) {
        console.error("GENERAL ERROR", error);
      });

      internals.socket.on("connect_error", function (error) {
        console.error("CONNNECT ERROR", error);
      });

      internals.socket.on("connect", function () {
        console.log("Connected to signaling server, group: ", currentUrl);
        internals.socket.emit("join", {
          room: currentUrl,
        });
      });

      internals.socket.on("disconnect", function () {
        console.log("disconnected from signaling server");
      });

      internals.socket.on("addPeer", function ({ peerId }) {
        /**
         * Eventually the whole rtc connection logic should be moved to Peers.
         * Now it only plays tadas.
         */
        Peers.add(peerId, tada);

        const peerConnection = new RTCPeerConnection(
          { iceServers: internals.kIceServers },
          { optional: [{ DtlsSrtpKeyAgreement: true }] },
        );

        internals.peers[peerId] = peerConnection;
        mediaStream.getTracks().forEach((track) => {
          peerConnection.addTrack(track, mediaStream);
        });

        peerConnection.onicecandidate = (event) => {
          if (event.candidate) {
            internals.socket.emit("relayICECandidate", {
              peerId: peerId,
              candidate: event.candidate,
            });
          }
        };

        const remoteStream = new MediaStream();
        peerConnection.ontrack = (event) => {
          remoteStream.addTrack(event.track);
          const remoteAudioElement = new Audio();
          remoteAudioElement.srcObject = remoteStream;
          remoteAudioElement.play();
        };

        peerConnection.onnegotiationneeded = async () => {
          console.log("Creating RTC offer to ", peerId);
          const offer = await peerConnection.createOffer();
          await peerConnection.setLocalDescription(offer);

          // Emit the offer to the peer
          internals.socket.emit("relayOffer", { offer, peerId });
        };

        console.log(`There are now ${Peers.count()} participants`);
      });

      internals.socket.on("offerReceived", async ({ offer, peerId }) => {
        const peerConnection = internals.peers[peerId];

        const remoteDescription = new RTCSessionDescription(offer);
        await peerConnection.setRemoteDescription(remoteDescription);

        const answer = await peerConnection.createAnswer();
        await peerConnection.setLocalDescription(answer);

        // Send the answer to the peer
        internals.socket.emit("relayAnswer", { answer, peerId });
      });

      internals.socket.on("answerReceived", async ({ answer, peerId }) => {
        const peerConnection = internals.peers[peerId];
        const remoteDescription = new RTCSessionDescription(answer);
        await peerConnection.setRemoteDescription(remoteDescription);
      });

      internals.socket.on(
        "ICECandidateReceived",
        async ({ candidate, peerId }) => {
          const peerConnection = internals.peers[peerId];
          const iceCandidate = new RTCIceCandidate(candidate);
          await peerConnection.addIceCandidate(iceCandidate);
        },
      );

      internals.socket.on("removePeer", function ({ peerId }) {
        delete internals.peers[peerId];
        Peers.remove(peerId);
        console.log(`There are now ${Peers.count()} participants`);
      });
    } catch (err) {
      internals.port.postMessage({
        action: "error",
      });
      internals.port.disconnect();
    }
  },

  hangUp() {
    Peers.reset();
    Media.stop();
    internals.socket.close();
    internals.port.disconnect();
  },
};

internals.port = chrome.runtime.connect({ name: "content" });
internals.port.onMessage.addListener(internals.onMessage);

console.log("Content Script Loaded");

// Indicates to the background script that we executed correctly
true;