fix: use listener port (no auth) for server library fetch and track downloads

Previously, fetch_server_library() and populate_server_library() used
get_server_base_url() which resolves to the DJ panel port (5000). When
dj_panel_password is set, ALL routes on port 5000 require an authenticated
session cookie. The Qt client had no cookie, so every library.json request
was redirected to /login (HTML), json.loads() failed, and the server list
stayed empty.

Fix:
- Add get_listener_base_url() that derives the listener port (DJ port + 1,
  default 5001) from the configured stream_server_url
- fetch_server_library() now fetches /library.json from the listener port
- Track download URLs built in populate_server_library() now point to the
  listener port's /music_proxy/ route — both are auth-free on the listener
  server (port 5001)
- upload_track() still correctly POSTs to the DJ port (5000) since the
  listener server blocks /upload; it now also authenticates with the DJ
  panel cookie before uploading so uploads work with a password too

techdj_qt.py

@@ -9,6 +9,7 @@ import shutil
 import requests
 import re
 import socketio
+from urllib.parse import urlparse
 import subprocess
 import atexit
 from pathlib import Path
@@ -250,6 +251,50 @@ def get_audio_capture_source():
     return 'default.monitor'
 
 
+def _route_qt_audio_to_virtual_sink():
+    """Move any PulseAudio/PipeWire sink-inputs from this process to the
+    virtual techdj_stream sink.
+
+    Needed because Qt6 may output audio via the PipeWire-native backend
+    instead of the PulseAudio compatibility layer, which means PULSE_SINK
+    has no effect and the monitor source used by the streaming ffmpeg would
+    capture silence instead of the DJ's music.  Calling pactl move-sink-input
+    works regardless of whether the client originally used PulseAudio or
+    PipeWire-native, as PipeWire exposes a PulseAudio-compatible socket.
+    """
+    if not _audio_isolated:
+        return
+    pid_str = str(os.getpid())
+    try:
+        result = subprocess.run(
+            ['pactl', 'list', 'sink-inputs'],
+            capture_output=True, text=True, timeout=3,
+        )
+        current_id = None
+        current_app_pid = None
+        for line in result.stdout.splitlines():
+            stripped = line.strip()
+            if stripped.startswith('Sink Input #'):
+                # Flush previous block
+                if current_id and current_app_pid == pid_str:
+                    subprocess.run(
+                        ['pactl', 'move-sink-input', current_id, _AUDIO_SINK_NAME],
+                        capture_output=True, timeout=3,
+                    )
+                current_id = stripped.split('#')[1].strip()
+                current_app_pid = None
+            elif 'application.process.id' in stripped and '"' in stripped:
+                current_app_pid = stripped.split('"')[1]
+        # Handle last block
+        if current_id and current_app_pid == pid_str:
+            subprocess.run(
+                ['pactl', 'move-sink-input', current_id, _AUDIO_SINK_NAME],
+                capture_output=True, timeout=3,
+            )
+    except Exception:
+        pass
+
+
 atexit.register(_teardown_audio_isolation)
 
 
@@ -583,8 +628,26 @@ class SettingsDialog(QDialog):
             }
         """)
 
+        pw_label = QLabel("DJ Panel Password (leave blank if none):")
+        self.dj_password_input = QLineEdit()
+        self.dj_password_input.setEchoMode(QLineEdit.EchoMode.Password)
+        self.dj_password_input.setPlaceholderText("Leave blank if no password is set")
+        self.dj_password_input.setText(self.audio_settings.get("dj_panel_password", ""))
+        self.dj_password_input.setStyleSheet("""
+            QLineEdit {
+                background: #1a1a1a;
+                border: 1px solid #333;
+                padding: 8px;
+                color: #fff;
+                border-radius: 4px;
+            }
+        """)
+
         layout.addWidget(stream_url_label)
         layout.addWidget(self.stream_url_input)
+        layout.addSpacing(8)
+        layout.addWidget(pw_label)
+        layout.addWidget(self.dj_password_input)
         layout.addSpacing(20)
         
         # Recording section
@@ -684,6 +747,7 @@ class SettingsDialog(QDialog):
                 "recording_sample_rate": self.sample_rate_combo.currentData(),
                 "recording_format": self.format_combo.currentData(),
                 "stream_server_url": self.stream_url_input.text(),
+                "dj_panel_password": self.dj_password_input.text(),
             },
             "ui": {
                 "neon_mode": self.neon_combo.currentData(),
@@ -810,6 +874,8 @@ class StreamingWorker(QThread):
         super().__init__(parent)
         self.sio = None
         self.stream_url = ""
+        self.dj_password = ""
+        self.glow_intensity = 30  # mirrors the UI slider; sent to listeners on connect
         self.is_running = False
         self.ffmpeg_proc = None
         self._broadcast_started = False
@@ -819,11 +885,14 @@ class StreamingWorker(QThread):
         if not self._broadcast_started:
             self._broadcast_started = True
             self.sio.emit('start_broadcast', {'format': 'mp3', 'bitrate': '128k'})
+            # Push current glow intensity to all listeners as soon as we connect
+            self.sio.emit('listener_glow', {'intensity': self.glow_intensity})
             self.streaming_started.emit()
         else:
-            # Reconnected mid-stream - server handles resume gracefully
+            # Reconnected mid-stream — server handles resume gracefully
             print("[SOCKET] Reconnected - resuming existing broadcast")
             self.sio.emit('start_broadcast', {'format': 'mp3', 'bitrate': '128k'})
+            self.sio.emit('listener_glow', {'intensity': self.glow_intensity})
 
     def on_disconnect(self):
         print("[SOCKET] Disconnected from DJ server")
@@ -834,6 +903,42 @@ class StreamingWorker(QThread):
     def on_listener_count(self, data):
         self.listener_count.emit(data.get('count', 0))
 
+    @staticmethod
+    def _get_auth_cookie(base_url, password):
+        """POST the DJ panel password to /login and return the session cookie string.
+
+        The server sets a Flask session cookie on success.  We forward that
+        cookie as an HTTP header on the Socket.IO upgrade request so the
+        socket handler sees an authenticated session.
+        """
+        try:
+            resp = requests.post(
+                f"{base_url}/login",
+                data={"password": password},
+                allow_redirects=False,
+                timeout=5,
+            )
+            # Server responds with 302 + Set-Cookie on success
+            if resp.cookies:
+                return "; ".join(f"{k}={v}" for k, v in resp.cookies.items())
+            print(f"[AUTH] Login response {resp.status_code} — no session cookie returned")
+            return None
+        except Exception as e:
+            print(f"[AUTH] Login request failed: {e}")
+            return None
+
+    @staticmethod
+    def _drain_stderr(proc):
+        """Read ffmpeg's stderr in a daemon thread so the OS pipe buffer never
+        fills up and deadlocks the stdout read loop."""
+        try:
+            for raw_line in iter(proc.stderr.readline, b''):
+                line = raw_line.decode('utf-8', errors='ignore').strip()
+                if line:
+                    print(f"[STREAM FFMPEG] {line}")
+        except Exception:
+            pass
+
     def run(self):
         try:
             # Create a fresh Socket.IO client for each session
@@ -843,7 +948,25 @@ class StreamingWorker(QThread):
             self.sio.on('listener_count', self.on_listener_count)
             self.sio.on('connect_error', self.on_connect_error)
 
-            self.sio.connect(self.stream_url)
+            # If the DJ panel has a password set, authenticate via HTTP first to
+            # obtain a Flask session cookie, then forward it on the WS upgrade
+            # request so the socket handler sees an authenticated session.
+            connect_headers = {}
+            if self.dj_password:
+                print("[AUTH] DJ panel password configured — authenticating...")
+                cookie = self._get_auth_cookie(self.stream_url, self.dj_password)
+                if cookie:
+                    connect_headers['Cookie'] = cookie
+                    print("[AUTH] Authenticated — session cookie obtained")
+                else:
+                    self.streaming_error.emit(
+                        "Authentication failed.\n"
+                        "Check the DJ panel password in Settings → Audio."
+                    )
+                    return
+
+            # wait_timeout: how long to wait for the server to respond during connect
+            self.sio.connect(self.stream_url, wait_timeout=10, headers=connect_headers)
 
             source = get_audio_capture_source()
             print(f"[STREAM] Capturing from: {source}")
@@ -863,46 +986,83 @@ class StreamingWorker(QThread):
                 # Flush every packet — critical for low-latency pipe streaming
                 "-flush_packets", "1",
                 "-f", "mp3",
-                "pipe:1"
+                "pipe:1",
             ]
             self.ffmpeg_proc = subprocess.Popen(
                 cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=0
             )
 
+            # Drain stderr in a real daemon thread so the OS pipe buffer never
+            # fills up and blocks stdout (classic Python subprocess deadlock).
+            import threading as _threading
+            stderr_thread = _threading.Thread(
+                target=self._drain_stderr, args=(self.ffmpeg_proc,), daemon=True
+            )
+            stderr_thread.start()
+
             while self.is_running and self.ffmpeg_proc.poll() is None:
-                # 4096 bytes ≈ 10 MP3 frames ≈ ~260ms at 128kbps — low-latency chunks
+                # 4096 bytes ≈ 10 MP3 frames ≈ ~260 ms at 128 kbps — low-latency chunks
                 chunk = self.ffmpeg_proc.stdout.read(4096)
                 if not chunk:
                     break
-                sio = self.sio  # Local ref to avoid race with stop_streaming()
+                sio = self.sio  # local ref guards against stop_streaming() race
                 if sio and sio.connected:
                     sio.emit('audio_chunk', chunk)
 
+            # Detect unexpected ffmpeg exit during an active stream
+            if self.is_running:
+                ret = self.ffmpeg_proc.poll() if self.ffmpeg_proc else None
+                if ret is not None and ret != 0:
+                    self.streaming_error.emit(
+                        f"FFmpeg exited with code {ret}.\n"
+                        "Check that PulseAudio / PipeWire is running and the "
+                        "virtual audio sink was created successfully."
+                    )
+
         except Exception as e:
-            self.streaming_error.emit(f"Streaming thread error: {e}")
+            self.streaming_error.emit(f"Streaming error: {e}")
         finally:
             self.stop_streaming()
 
-    def start_streaming(self, base_url, bitrate=128):
+    def start_streaming(self, base_url, bitrate=128, password=""):
         self.stream_url = base_url
+        self.dj_password = password
         self.is_running = True
         self.start()
         return True
 
+    def emit_if_connected(self, event, data=None):
+        """Thread-safe emit from any thread — no-op if socket is not connected."""
+        sio = self.sio
+        if sio and sio.connected:
+            try:
+                sio.emit(event, data)
+            except Exception as e:
+                print(f"[SOCKET] emit_if_connected error: {e}")
+
     def stop_streaming(self):
+        """Thread-safe stop: capture refs locally before clearing to avoid TOCTOU."""
         self.is_running = False
         self._broadcast_started = False
-        if self.ffmpeg_proc:
+
-            try: self.ffmpeg_proc.terminate()
+        proc = self.ffmpeg_proc
-            except: pass
+        self.ffmpeg_proc = None
-            self.ffmpeg_proc = None
+        sio = self.sio
-        if self.sio and self.sio.connected:
+        self.sio = None
+
+        if proc:
             try:
-                self.sio.emit('stop_broadcast')
+                proc.terminate()
-                self.sio.disconnect()
+            except Exception:
+                pass
+
+        if sio:
+            try:
+                if sio.connected:
+                    sio.emit('stop_broadcast')
+                sio.disconnect()
             except Exception:
                 pass
-            self.sio = None
     
 # --- WIDGETS ---
 
@@ -1144,6 +1304,7 @@ class DeckWidget(QGroupBox):
         self.loop_end = 0
         self.loop_btns = []
         self.xf_vol = 100
+        self.current_title = ""
 
         self.loop_timer = QTimer(self)
         self.loop_timer.setInterval(LOOP_CHECK_INTERVAL)
@@ -1379,6 +1540,7 @@ class DeckWidget(QGroupBox):
         
         try:
             self.player.setSource(QUrl.fromLocalFile(str(p.absolute())))
+            self.current_title = p.stem
             self.lbl_tr.setText(p.stem.upper())
             self.vinyl.set_speed(0)
             self.vinyl.angle = 0
@@ -1428,13 +1590,31 @@ class DeckWidget(QGroupBox):
                 # Stop mode or no queue items
                 self.stop()
 
+    def _emit_playing_state(self, is_playing):
+        """Emit deck_glow and now_playing events to the listener page."""
+        mw = self.window()
+        if not hasattr(mw, 'streaming_worker') or not hasattr(mw, 'deck_a') or not hasattr(mw, 'deck_b'):
+            return
+        other = mw.deck_b if self.deck_id == 'A' else mw.deck_a
+        other_playing = (other.player.playbackState() == QMediaPlayer.PlaybackState.PlayingState)
+        a_playing = is_playing if self.deck_id == 'A' else other_playing
+        b_playing = is_playing if self.deck_id == 'B' else other_playing
+        mw.streaming_worker.emit_if_connected('deck_glow', {'A': a_playing, 'B': b_playing})
+        if is_playing and self.current_title:
+            mw.streaming_worker.emit_if_connected('now_playing', {
+                'title': self.current_title,
+                'deck': self.deck_id,
+            })
+
     def play(self):
         self.player.play()
         self.vinyl.start_spin()
+        self._emit_playing_state(True)
     
     def pause(self):
         self.player.pause()
         self.vinyl.stop_spin()
+        self._emit_playing_state(False)
     
     def stop(self):
         self.player.stop()
@@ -1442,6 +1622,7 @@ class DeckWidget(QGroupBox):
         self.vinyl.angle = 0
         self.vinyl.update()
         self.clear_loop()
+        self._emit_playing_state(False)
     
     def on_position_changed(self, pos):
         self.wave.set_position(pos)
@@ -1532,6 +1713,15 @@ class DJApp(QMainWindow):
         self.streaming_worker.listener_count.connect(self.update_listener_count)
         self.is_streaming = False
 
+        # Periodically ensure Qt's audio sink-inputs are routed to the virtual
+        # sink.  Qt6 may use the PipeWire-native audio backend which ignores
+        # PULSE_SINK, causing the streaming ffmpeg to capture silence instead
+        # of the DJ's music.  pactl move-sink-input fixes this regardless of
+        # which Qt audio backend is active.
+        self._audio_route_timer = QTimer()
+        self._audio_route_timer.timeout.connect(_route_qt_audio_to_virtual_sink)
+        self._audio_route_timer.start(2000)  # run every 2 s
+        
         # Server library state
         self.server_url = "http://localhost:5000"
         self.library_mode = "local" # "local" or "server"
@@ -1726,6 +1916,56 @@ class DJApp(QMainWindow):
         stream_info.addWidget(self.stream_status_label)
         stream_info.addWidget(self.listener_count_label)
 
+        # --- Listener Glow Controls ---
+        glow_title = QLabel("LISTENER GLOW")
+        glow_title.setStyleSheet(
+            "color: #bc13fe; font-size: 10px; font-weight: bold; "
+            "font-family: 'Courier New'; letter-spacing: 1px;"
+        )
+        glow_title.setAlignment(Qt.AlignmentFlag.AlignCenter)
+
+        self.glow_slider = QSlider(Qt.Orientation.Horizontal)
+        self.glow_slider.setRange(0, 100)
+        self.glow_slider.setValue(30)
+        self.glow_slider.setFixedWidth(130)
+        self.glow_slider.setToolTip(
+            "Listener page glow intensity\n"
+            "0 = off  |  100 = max\n"
+            "Sends to all listeners in real-time while streaming"
+        )
+        self.glow_slider.setStyleSheet("""
+            QSlider::groove:horizontal {
+                border: 1px solid #550088;
+                height: 6px;
+                background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
+                    stop:0 #1a0026, stop:1 #bc13fe);
+                border-radius: 3px;
+            }
+            QSlider::handle:horizontal {
+                background: #bc13fe;
+                border: 2px solid #e040fb;
+                width: 14px;
+                height: 14px;
+                margin: -5px 0;
+                border-radius: 7px;
+            }
+            QSlider::handle:horizontal:hover {
+                background: #e040fb;
+                border-color: #fff;
+            }
+        """)
+        self.glow_slider.valueChanged.connect(self.on_glow_slider_changed)
+
+        self.glow_value_label = QLabel("30")
+        self.glow_value_label.setStyleSheet("color: #bc13fe; font-size: 10px;")
+        self.glow_value_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
+
+        glow_vbox = QVBoxLayout()
+        glow_vbox.setSpacing(2)
+        glow_vbox.addWidget(glow_title)
+        glow_vbox.addWidget(self.glow_slider)
+        glow_vbox.addWidget(self.glow_value_label)
+
         rec_layout.addStretch()
         rec_layout.addWidget(self.record_button)
         rec_layout.addSpacing(20)
@@ -1734,6 +1974,8 @@ class DJApp(QMainWindow):
         rec_layout.addWidget(self.stream_button)
         rec_layout.addSpacing(20)
         rec_layout.addLayout(stream_info)
+        rec_layout.addSpacing(40)
+        rec_layout.addLayout(glow_vbox)
         rec_layout.addStretch()
         
         layout.addLayout(rec_layout, 3)
@@ -2001,11 +2243,15 @@ class DJApp(QMainWindow):
         self.library_list.clear()
         self.library_list.addItem("Fetching server library...")
 
-        base_url = self.get_server_base_url()
+        # Use the listener port (no auth required) for library / track data.
-        self.server_url = base_url 
+        # The DJ port requires a password session which the Qt client doesn't hold.
+        listener_url = self.get_listener_base_url()
+        self.server_url = self.get_server_base_url()  # kept for socket/streaming
 
-        self.fetcher = ServerLibraryFetcher(f"{base_url}/library.json")
+        self.fetcher = ServerLibraryFetcher(f"{listener_url}/library.json")
-        self.fetcher.finished.connect(lambda tracks, err, success: self.on_server_library_fetched(tracks, base_url, err, success))
+        self.fetcher.finished.connect(
+            lambda tracks, err, success: self.on_server_library_fetched(tracks, listener_url, err, success)
+        )
         self.fetcher.start()
 
     def on_server_library_fetched(self, tracks, base_url, err, success):
@@ -2136,10 +2382,24 @@ class DJApp(QMainWindow):
             try:
                 self.status_label.setText("Uploading to server...")
                 base_url = self.get_server_base_url()
+                password = self.all_settings.get("audio", {}).get("dj_panel_password", "")
+
+                # Authenticate if a password is configured (same approach as StreamingWorker)
+                session_cookie = None
+                if password:
+                    session_cookie = StreamingWorker._get_auth_cookie(base_url, password)
+                    if not session_cookie:
+                        QMessageBox.warning(self, "Upload Error", "DJ panel authentication failed.\nCheck the password in Settings → Audio.")
+                        self.status_label.setText("Upload failed")
+                        return
+
+                headers = {}
+                if session_cookie:
+                    headers['Cookie'] = session_cookie
 
                 with open(file_path, 'rb') as f:
                     files = {'file': f}
-                    response = requests.post(f"{base_url}/upload", files=files, timeout=60)
+                    response = requests.post(f"{base_url}/upload", files=files, headers=headers, timeout=60)
                 
                 if response.status_code == 200:
                     self.status_label.setText("Upload successful!")
@@ -2255,12 +2515,13 @@ class DJApp(QMainWindow):
     def toggle_streaming(self):
         """Toggle live streaming on/off"""
         if not self.is_streaming:
-            # Get base URL from settings
+            # Get base URL and credentials from settings
             base_url = self.get_server_base_url()
             bitrate = self.all_settings.get("audio", {}).get("bitrate", 128)
+            password = self.all_settings.get("audio", {}).get("dj_panel_password", "")
 
-            # Start streaming
+            # Start streaming (password handled inside StreamingWorker)
-            if self.streaming_worker.start_streaming(base_url, bitrate):
+            if self.streaming_worker.start_streaming(base_url, bitrate, password=password):
                 self.is_streaming = True
                 self.stream_button.setText("STOP")
                 self.stream_button.setStyleSheet("""
@@ -2315,21 +2576,62 @@ class DJApp(QMainWindow):
     def update_listener_count(self, count):
         self.listener_count_label.setText(f"{count} listeners")
 
+    def on_glow_slider_changed(self, val):
+        """Send listener glow intensity to all connected listeners in real-time."""
+        self.glow_value_label.setText(str(val))
+        # Keep the worker's glow_intensity in sync so it's sent on reconnect too
+        self.streaming_worker.glow_intensity = val
+        self.streaming_worker.emit_if_connected('listener_glow', {'intensity': val})
+
+    def get_listener_base_url(self):
+        """Return the listener server base URL (no auth required).
+
+        The listener server runs on DJ_port + 1 by convention (default 5001).
+        Library JSON and music_proxy routes are available there without any
+        password, so we use this for all library / track-download requests.
+        """
+        audio_settings = self.all_settings.get("audio", {})
+        raw = audio_settings.get("stream_server_url", "http://localhost:5000").strip()
+
+        if not raw.startswith(("http://", "https://", "ws://", "wss://")):
+            raw = "http://" + raw
+
+        parsed = urlparse(raw)
+        host = parsed.hostname or "localhost"
+        dj_port = parsed.port or 5000
+
+        # Normalise: if the configured port IS the listener port, keep it;
+        # otherwise derive listener port as DJ port + 1.
+        if dj_port == 5001:
+            listener_port = 5001
+        else:
+            # Remap any reverse-proxy or listener port back to DJ port first,
+            # then add 1 to get the listener port.
+            if dj_port == 8080:
+                dj_port = 5000
+            listener_port = dj_port + 1
+
+        return f"http://{host}:{listener_port}"
+
     def get_server_base_url(self):
         audio_settings = self.all_settings.get("audio", {})
-        server_url = audio_settings.get("stream_server_url", "http://localhost:5000")
+        raw = audio_settings.get("stream_server_url", "http://localhost:5000").strip()
 
-        # Normal techdj server runs on 5000 (DJ) and 5001 (Listener)
+        # Ensure scheme is present so urlparse parses host/port correctly
-        # If the URL is for the listener or stream, switch to 5000
+        if not raw.startswith(("http://", "https://", "ws://", "wss://")):
-        if ":5001" in server_url:
+            raw = "http://" + raw
-            return server_url.split(":5001")[0] + ":5000"
-        elif ":8080" in server_url:
-            return server_url.split(":8080")[0] + ":5000"
-        elif "/api/stream" in server_url:
-            return server_url.split("/api/stream")[0].rstrip("/")
 
-        if server_url.endswith("/"): server_url = server_url[:-1]
+        parsed = urlparse(raw)
-        return server_url
+        host = parsed.hostname or "localhost"
+        port = parsed.port or 5000
+
+        # Remap listener port and common reverse-proxy port to the DJ server port
+        if port in (5001, 8080):
+            port = 5000
+
+        # Always use plain HTTP — the server never terminates TLS directly.
+        # Any path component (e.g. /stream.mp3, /api/stream) is intentionally stripped.
+        return f"http://{host}:{port}"
 
     def resizeEvent(self, event):
         """Update glow frame size when window is resized"""