adrift/client/RTCTransport.ts

import Transport from "./Transport";
import Connection from "./Connection";

const rtcConf = {
  iceServers: [
    {
      urls: "stun:stun.l.google.com:19302"
    }
  ]
}


type Offer = { offer: any, localCandidates: any };
interface RTCOptions {

  onconnectionstatechange?,
  onsignalingstatechange?,
  oniceconnectionstatechange?,
  onicegatheringstatechange?,
  onopen?,
  onclose?,
  onmessage?
}

export class RTCTransport extends Transport {
  peer: RTCPeerConnection;

  dataChannel: RTCDataChannel;
  constructor(onopen, onclose,
    public onconnectionstatechange: () => void,
    public onsignalingstatechange: () => void,
    public onicegatheringstatechange: () => void,
  ) {
    super(onopen, onclose);
    this.peer = new RTCPeerConnection(rtcConf);
    this.peer.onconnectionstatechange = onconnectionstatechange;

    this.peer.onsignalingstatechange = onsignalingstatechange;

    this.peer.oniceconnectionstatechange =
      (event) => {
        console.log('ICE connection state:', this.peer.iceConnectionState);
        if (this.peer.iceConnectionState == "disconnected" || this.peer.iceConnectionState == "failed") {
          console.log("disconnected");
          onclose();
        }
      };
    this.peer.onicegatheringstatechange = onicegatheringstatechange;
    this.dataChannel = this.peer.createDataChannel('host-server');
    this.dataChannel.onopen = onopen;

    this.dataChannel.onclose = onclose;
    this.dataChannel.onmessage = (event) => {
      this.ondata(event.data)
    };
  }

  send(data: ArrayBuffer) {
    this.dataChannel.send(data);
  }



  async createOffer(): Promise<Promise<Offer>> {

    const localCandidates: RTCIceCandidate[] = [];


    let readyPromise: Promise<Offer> = new Promise((resolve, reject) => {

      this.peer.onicecandidate = async (event) => {
        if (event.candidate) {
          localCandidates.push(event.candidate);
          return;
        }

        resolve({ offer, localCandidates });
      };
    });



    const offer = await this.peer.createOffer();
    await this.peer.setLocalDescription(offer);
    return readyPromise;
  }

  async answer(answer: any, candidates: any) {
    await this.peer.setRemoteDescription(answer);
    for (let candidate of candidates) {
      await this.peer.addIceCandidate(candidate);
    }
  }
}