From 8a86ff3fe5bb37f25652492297df097920e67294 Mon Sep 17 00:00:00 2001
From: Maxim Dolgolyov <maxim.dolgolyov@gmail.com>
Date: Wed, 15 Apr 2026 13:45:07 +0300
Subject: [PATCH] debug: add RTC diagnostic logs (ICE state, ontrack,
 sendOffer, signal flow)

---
 frontend/js/classroom-rtc.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/frontend/js/classroom-rtc.js b/frontend/js/classroom-rtc.js
index 7023615..80f60b9 100644
--- a/frontend/js/classroom-rtc.js
+++ b/frontend/js/classroom-rtc.js
@@ -44,8 +44,10 @@ class ClassroomRTC {
       this._localStream = await navigator.mediaDevices.getUserMedia({ audio: true, video: false });
       this._localStream.getAudioTracks().forEach(t => { t.enabled = !this._muted; });
       this._startVAD(this._uid, this._localStream);
+      console.log('[RTC] startAudio OK, tracks:', this._localStream.getAudioTracks().map(t => `${t.label} enabled=${t.enabled}`));
       return true;
-    } catch {
+    } catch (e) {
+      console.warn('[RTC] startAudio FAILED', e);
       return false;
     }
   }
@@ -182,6 +184,7 @@ class ClassroomRTC {
 
   async handleSignal(fromUid, payload) {
     const { kind } = payload;
+    console.log(`[RTC] signal ← ${kind} from uid=${fromUid}`, 'myUid=', this._uid);
     try {
       if (kind === 'offer')          await this._handleOffer(fromUid, payload);
       else if (kind === 'answer')    await this._handleAnswer(fromUid, payload);
@@ -249,6 +252,7 @@ class ClassroomRTC {
 
   async _sendOffer(targetUid) {
     const peer = this._getOrCreate(targetUid);
+    console.log(`[RTC] _sendOffer → uid=${targetUid} localStream=${!!this._localStream}`);
     if (this._localStream) {
       const existing = peer.pc.getSenders().map(s => s.track);
       this._localStream.getAudioTracks().forEach(t => {
@@ -287,6 +291,13 @@ class ClassroomRTC {
       if (e.candidate) this._onSignal(uid, { kind: 'candidate', candidate: e.candidate.toJSON() });
     };
 
+    pc.oniceconnectionstatechange = () => {
+      console.log(`[RTC] ICE uid=${uid} → ${pc.iceConnectionState}`);
+    };
+    pc.onconnectionstatechange = () => {
+      console.log(`[RTC] conn uid=${uid} → ${pc.connectionState}`);
+    };
+
     /* Renegotiation: fires when tracks are added/removed (e.g. screen share) */
     pc.onnegotiationneeded = async () => {
       if (peer.negotiating || !peer.remoteSet || pc.signalingState !== 'stable') return;
@@ -302,6 +313,7 @@ class ClassroomRTC {
     pc.ontrack = e => {
       const track  = e.track;
       const stream = e.streams[0] || new MediaStream([track]);
+      console.log(`[RTC] ontrack uid=${uid} kind=${track.kind} readyState=${track.readyState} streams=${e.streams.length}`);
 
       if (track.kind === 'audio') {
         if (!peer.audioEl) {
@@ -311,7 +323,9 @@ class ClassroomRTC {
           document.body.appendChild(peer.audioEl);
         }
         peer.audioEl.srcObject = stream;
-        peer.audioEl.play().catch(() => {});
+        peer.audioEl.play()
+          .then(() => console.log(`[RTC] audio play() OK uid=${uid}`))
+          .catch(err => console.warn(`[RTC] audio play() BLOCKED uid=${uid}`, err));
         this._startVAD(uid, stream);
       } else if (track.kind === 'video') {
         if (this._onScreen) this._onScreen(stream);