fix(backend): discover user audio session runtime dir for PipeWire support

backend/src/decktation_backend.py

@@ -33,6 +33,63 @@
         sys.path.insert(0, dependency_path)
         logger.info(f"Added dependency path: {dependency_path}")
 
+# Decky plugins run under systemd as root, which lacks the desktop user's session
+# environment. Discover and set the user's runtime directory so that PortAudio
+# and PipeWire can connect to the user session audio daemon (allowing USB, Bluetooth,
+# and dynamically selected default microphones to be captured).
+def _setup_audio_environment():
+    if os.environ.get("XDG_RUNTIME_DIR") and os.environ.get("XDG_RUNTIME_DIR") != "/run/user/0":
+        return os.environ.get("XDG_RUNTIME_DIR")
+    candidate_uids = []
+    decky_user_home = getattr(decky, "DECKY_USER_HOME", None) or os.environ.get("DECKY_USER_HOME")
+    if decky_user_home and os.path.exists(decky_user_home):
+        try:
+            candidate_uids.append(str(os.stat(decky_user_home).st_uid))
+        except Exception:
+            pass
+    if os.environ.get("SUDO_UID"):
+        candidate_uids.append(os.environ["SUDO_UID"])
+    if os.path.exists("/run/user"):
+        try:
+            for entry in sorted(os.listdir("/run/user")):
+                if entry != "0" and entry.isdigit():
+                    candidate_uids.append(entry)
+        except Exception:
+            pass
+    candidate_uids.extend(["1000", "1001", "1002"])
+
+    seen = set()
+    for uid in candidate_uids:
+        if uid in seen:
+            continue
+        seen.add(uid)
+        run_dir = f"/run/user/{uid}"
+        if os.path.exists(os.path.join(run_dir, "pipewire-0")):
+            os.environ["XDG_RUNTIME_DIR"] = run_dir
+            os.environ["PIPEWIRE_RUNTIME_DIR"] = run_dir
+            os.environ["PULSE_SERVER"] = f"unix:{run_dir}/pulse/native"
+            logger.info(f"Configured audio runtime directory: {run_dir}")
+            return run_dir
+
+
+def ensure_audio_environment():
+    """Ensure XDG_RUNTIME_DIR points to a valid PipeWire session and sounddevice is connected."""
+    current_run_dir = os.environ.get("XDG_RUNTIME_DIR")
+    pipewire_available = current_run_dir and os.path.exists(os.path.join(current_run_dir, "pipewire-0"))
+    if not pipewire_available:
+        new_dir = _setup_audio_environment()
+        if new_dir and "sounddevice" in sys.modules:
+            try:
+                import sounddevice as sd
+                sd._terminate()
+                sd._initialize()
+                logger.info(f"Reconnected sounddevice to PipeWire ({new_dir})")
+            except Exception as e:
+                logger.warning(f"Failed to reinitialize sounddevice: {e}")
+
+
+_setup_audio_environment()
+
 # sounddevice normally searches only system library paths on Linux. Store
 # builds bundle PortAudio in bin/lib so the plugin works on clean SteamOS
 # installations without modifying the read-only operating system.
@@ -880,6 +937,7 @@ async def set_active_preset(self, game: str):
     async def start_recording(self):
         """Start recording audio"""
         try:
+            ensure_audio_environment()
             if Plugin.voice_service is None:
                 logger.error("Voice service not initialized")
                 return {"success": False, "error": "Service not initialized"}

backend/src/wow_voice_chat.py

@@ -12,6 +12,53 @@
 import subprocess
 from pathlib import Path
 from faster_whisper import WhisperModel
+
+
+def _setup_audio_environment():
+    if os.environ.get("XDG_RUNTIME_DIR") and os.environ.get("XDG_RUNTIME_DIR") != "/run/user/0":
+        return os.environ.get("XDG_RUNTIME_DIR")
+    candidate_uids = []
+    if os.environ.get("SUDO_UID"):
+        candidate_uids.append(os.environ["SUDO_UID"])
+    if os.path.exists("/run/user"):
+        try:
+            for entry in sorted(os.listdir("/run/user")):
+                if entry != "0" and entry.isdigit():
+                    candidate_uids.append(entry)
+        except Exception:
+            pass
+    candidate_uids.extend(["1000", "1001", "1002"])
+
+    seen = set()
+    for uid in candidate_uids:
+        if uid in seen:
+            continue
+        seen.add(uid)
+        run_dir = f"/run/user/{uid}"
+        if os.path.exists(os.path.join(run_dir, "pipewire-0")):
+            os.environ["XDG_RUNTIME_DIR"] = run_dir
+            os.environ["PIPEWIRE_RUNTIME_DIR"] = run_dir
+            os.environ["PULSE_SERVER"] = f"unix:{run_dir}/pulse/native"
+            return run_dir
+
+
+def ensure_audio_environment():
+    """Ensure XDG_RUNTIME_DIR points to a valid PipeWire session and sounddevice is connected."""
+    current_run_dir = os.environ.get("XDG_RUNTIME_DIR")
+    pipewire_available = current_run_dir and os.path.exists(os.path.join(current_run_dir, "pipewire-0"))
+    if not pipewire_available:
+        new_dir = _setup_audio_environment()
+        if new_dir:
+            try:
+                import sounddevice as sd
+                sd._terminate()
+                sd._initialize()
+            except Exception:
+                pass
+
+
+_setup_audio_environment()
+
 import sounddevice as sd
 import numpy as np
 import wave
@@ -619,6 +666,7 @@ def run_continuous(self, duration=5, pause=1):
 
     def start_recording(self):
         """Start recording audio (for push-to-talk)"""
+        ensure_audio_environment()
         with self.recording_lock:
             if self.is_recording:
                 return