Add OS notification listener for Windows toast capture

Polls Windows notifications via winsdk UserNotificationListener API
and fires matching notification CSS streams with os_listener=True.
Includes history API endpoint for tracking captured notifications.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/core/processing/os_notification_listener.py

@@ -0,0 +1,181 @@
+"""OS-level notification listener for Windows.
+
+Polls Windows toast notifications via the UserNotificationListener API
+(winsdk) and fires matching NotificationColorStripStream instances when
+new notifications appear.  Sources with os_listener=True are monitored.
+
+Runs in a background thread with ~500ms polling interval.
+"""
+
+import asyncio
+import collections
+import platform
+import threading
+import time
+from typing import Dict, List, Optional, Set
+
+from wled_controller.utils import get_logger
+
+logger = get_logger(__name__)
+
+_POLL_INTERVAL = 0.5  # seconds between polls
+
+# Module-level singleton for dependency access
+_instance: Optional["OsNotificationListener"] = None
+
+
+def get_os_notification_listener() -> Optional["OsNotificationListener"]:
+    """Return the global OsNotificationListener instance (or None)."""
+    return _instance
+
+
+class OsNotificationListener:
+    """Monitors OS notifications and fires notification CSS streams."""
+
+    def __init__(self, color_strip_store, color_strip_stream_manager):
+        self._css_store = color_strip_store
+        self._css_stream_manager = color_strip_stream_manager
+        self._running = False
+        self._thread: Optional[threading.Thread] = None
+        self._seen_ids: Set[int] = set()
+        self._available = False
+        # Recent notification history (thread-safe deque, newest first)
+        self._history: collections.deque = collections.deque(maxlen=50)
+
+    def start(self) -> None:
+        global _instance
+        _instance = self
+        if self._running:
+            return
+        if platform.system() != "Windows":
+            logger.info("OS notification listener: skipped (not Windows)")
+            return
+
+        # Check winsdk availability
+        try:
+            from winsdk.windows.ui.notifications.management import (
+                UserNotificationListener,
+                UserNotificationListenerAccessStatus,
+            )
+            listener = UserNotificationListener.current
+            status = listener.get_access_status()
+            if status != UserNotificationListenerAccessStatus.ALLOWED:
+                logger.warning(
+                    f"OS notification listener: access denied (status={status}). "
+                    "Enable notification access in Windows Settings > Privacy > Notifications."
+                )
+                return
+            self._available = True
+        except ImportError:
+            logger.info("OS notification listener: winsdk not installed, skipping")
+            return
+        except Exception as e:
+            logger.warning(f"OS notification listener: init error: {e}")
+            return
+
+        self._running = True
+        self._thread = threading.Thread(
+            target=self._poll_loop,
+            name="os-notif-listener",
+            daemon=True,
+        )
+        self._thread.start()
+        logger.info("OS notification listener started")
+
+    def stop(self) -> None:
+        self._running = False
+        if self._thread:
+            self._thread.join(timeout=3.0)
+            self._thread = None
+        logger.info("OS notification listener stopped")
+
+    def _poll_loop(self) -> None:
+        """Background polling loop."""
+        from winsdk.windows.ui.notifications.management import UserNotificationListener
+        from winsdk.windows.ui.notifications import NotificationKinds
+
+        listener = UserNotificationListener.current
+        loop = asyncio.new_event_loop()
+
+        async def _get_notifications():
+            return await listener.get_notifications_async(NotificationKinds.TOAST)
+
+        # Seed with current notifications so we don't fire on startup
+        try:
+            initial = loop.run_until_complete(_get_notifications())
+            for n in initial:
+                self._seen_ids.add(n.id)
+            logger.debug(f"OS notification listener: seeded {len(self._seen_ids)} existing notifications")
+        except Exception as e:
+            logger.warning(f"OS notification listener: seed error: {e}")
+
+        try:
+            while self._running:
+                try:
+                    notifications = loop.run_until_complete(_get_notifications())
+                    current_ids = set()
+                    for n in notifications:
+                        current_ids.add(n.id)
+                        if n.id not in self._seen_ids:
+                            self._seen_ids.add(n.id)
+                            self._on_new_notification(n)
+
+                    # Prune seen IDs that are no longer in the notification center
+                    self._seen_ids &= current_ids
+
+                except Exception as e:
+                    logger.debug(f"OS notification listener poll error: {e}")
+
+                time.sleep(_POLL_INTERVAL)
+        finally:
+            loop.close()
+            self._running = False
+
+    @property
+    def recent_history(self) -> List[Dict]:
+        """Return recent notification history (newest first)."""
+        return list(self._history)
+
+    def _on_new_notification(self, notification) -> None:
+        """Handle a new OS notification — fire matching streams."""
+        try:
+            app_name = notification.app_info.display_info.display_name
+        except (OSError, AttributeError):
+            try:
+                app_name = notification.app_info.app_user_model_id
+            except (OSError, AttributeError):
+                app_name = None
+
+        # Find all notification sources with os_listener=True
+        from wled_controller.storage.color_strip_source import NotificationColorStripSource
+
+        fired = 0
+        filtered = 0
+        try:
+            sources = self._css_store.get_all_sources()
+        except Exception:
+            sources = []
+
+        for source in sources:
+            if not isinstance(source, NotificationColorStripSource):
+                continue
+            if not source.os_listener:
+                continue
+
+            streams = self._css_stream_manager.get_streams_by_source_id(source.id)
+            for stream in streams:
+                if hasattr(stream, "fire"):
+                    if stream.fire(app_name=app_name):
+                        fired += 1
+                    else:
+                        filtered += 1
+
+        entry = {
+            "app": app_name,
+            "time": time.time(),
+            "fired": fired,
+            "filtered": filtered,
+        }
+        self._history.appendleft(entry)
+
+        logger.info(f"OS notification captured: app={app_name!r}, fired={fired}, filtered={filtered}")