From b03fad914b05c681b7843d6b9f1cc860069118c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20=C5=A0ediv=C3=BD?= <sedivy.miro@gmail.com>
Date: Sun, 28 Nov 2021 18:36:36 +0100
Subject: [PATCH] SDP add remote answer.

---
 src/component/internal/messages.ts | 30 ++++++++++++++++++++++++------
 src/component/internal/webrtc.ts   | 18 ++++++++++++------
 2 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/src/component/internal/messages.ts b/src/component/internal/messages.ts
index d4ab2de6..de24b28f 100644
--- a/src/component/internal/messages.ts
+++ b/src/component/internal/messages.ts
@@ -141,27 +141,45 @@ export class NekoMessages extends EventEmitter<NekoEvents> {
 
   protected async [EVENT.SIGNAL_PROVIDE]({ sdp, video, iceservers }: message.SignalProvide) {
     this._localLog.debug(`EVENT.SIGNAL_PROVIDE`)
-    this.emit('connection.webrtc.sdp', 'remote', sdp)
 
-    await this._connection.webrtc.connect(sdp, iceservers)
+    // create WebRTC connection
+    await this._connection.webrtc.connect(iceservers)
+
+    // set remote offer
+    await this._connection.webrtc.setOffer(sdp)
+
+    this.emit('connection.webrtc.sdp', 'remote', sdp)
     Vue.set(this._state.connection.webrtc, 'video', video)
   }
 
   protected async [EVENT.SIGNAL_OFFER]({ sdp }: message.SignalDescription) {
     this._localLog.debug(`EVENT.SIGNAL_OFFER`)
-    this.emit('connection.webrtc.sdp', 'remote', sdp)
 
+    // set remote offer
     await this._connection.webrtc.setOffer(sdp)
+
+    this.emit('connection.webrtc.sdp', 'remote', sdp)
   }
 
-  // Todo: Use offer event intead.
+  protected async [EVENT.SIGNAL_ANSWER]({ sdp }: message.SignalDescription) {
+    this._localLog.debug(`EVENT.SIGNAL_ANSWER`)
+    this.emit('connection.webrtc.sdp', 'remote', sdp)
+
+    // set remote answer
+    await this._connection.webrtc.setAnswer(sdp)
+  }
+
+  // TODO: Use offer event intead.
   protected async [EVENT.SIGNAL_RESTART]({ sdp }: message.SignalDescription) {
     this[EVENT.SIGNAL_OFFER]({ sdp })
   }
 
-  protected [EVENT.SIGNAL_CANDIDATE](candidate: message.SignalCandidate) {
+  protected async [EVENT.SIGNAL_CANDIDATE](candidate: message.SignalCandidate) {
     this._localLog.debug(`EVENT.SIGNAL_CANDIDATE`)
-    this._connection.webrtc.setCandidate(candidate)
+
+    // set remote candidate
+    await this._connection.webrtc.setCandidate(candidate)
+
     this.emit('connection.webrtc.sdp.candidate', 'remote', candidate)
   }
 
diff --git a/src/component/internal/webrtc.ts b/src/component/internal/webrtc.ts
index 1708a344..827aecc7 100644
--- a/src/component/internal/webrtc.ts
+++ b/src/component/internal/webrtc.ts
@@ -63,11 +63,11 @@ export class NekoWebRTC extends EventEmitter<NekoWebRTCEvents> {
       return
     }
 
-    this._peer.addIceCandidate(candidate)
+    await this._peer.addIceCandidate(candidate)
     this._log.debug(`adding remote ICE candidate`, { candidate })
   }
 
-  public async connect(sdp: string, iceServers: ICEServer[]) {
+  public async connect(iceServers: ICEServer[]) {
     if (!this.supported) {
       throw new Error('browser does not support webrtc')
     }
@@ -170,8 +170,6 @@ export class NekoWebRTC extends EventEmitter<NekoWebRTCEvents> {
 
     this._peer.ontrack = this.onTrack.bind(this)
     this._peer.ondatachannel = this.onDataChannel.bind(this)
-
-    await this.setOffer(sdp)
   }
 
   public async setOffer(sdp: string) {
@@ -183,7 +181,7 @@ export class NekoWebRTC extends EventEmitter<NekoWebRTCEvents> {
 
     if (this._candidates.length > 0) {
       for (const candidate of this._candidates) {
-        this._peer.addIceCandidate(candidate)
+        await this._peer.addIceCandidate(candidate)
       }
 
       this._log.debug(`added ${this._candidates.length} remote ICE candidates`, { candidates: this._candidates })
@@ -191,7 +189,7 @@ export class NekoWebRTC extends EventEmitter<NekoWebRTCEvents> {
     }
 
     const answer = await this._peer.createAnswer()
-    this._peer!.setLocalDescription(answer)
+    this._peer.setLocalDescription(answer)
 
     if (answer) {
       this.emit('negotiation', answer)
@@ -200,6 +198,14 @@ export class NekoWebRTC extends EventEmitter<NekoWebRTCEvents> {
     }
   }
 
+  public async setAnswer(sdp: string) {
+    if (!this._peer) {
+      throw new Error('attempting to set answer for nonexistent peer')
+    }
+
+    this._peer.setRemoteDescription({ type: 'answer', sdp })
+  }
+
   public addTrack(track: MediaStreamTrack, ...streams: MediaStream[]): RTCRtpSender {
     if (!this._peer) {
       throw new Error('attempting to add track for nonexistent peer')