feat(analytics): detections continue on the single-camera page

src/OpenIPC.Viewer.Analytics/ObjectDetectionEngine.cs

@@ -119,6 +119,8 @@ public void Detach(CameraId cameraId)
             reg.Dispose();
     }
 
+    public bool IsAttached(CameraId cameraId) => _cameras.ContainsKey(cameraId);
+
     private void OnFrame(CameraId cameraId, CameraRegistration reg, in VideoFrame frame)
     {
         var settings = reg.Settings();

src/OpenIPC.Viewer.App/Services/SingleCameraPageFactory.cs

@@ -26,6 +26,8 @@ public sealed class SingleCameraPageFactory
     private readonly OpenIPC.Viewer.Core.Platform.IAudioInput _audioInput;
     private readonly IAudioBackchannelClient _backchannel;
     private readonly IReachabilityProbe _reachability;
+    private readonly OpenIPC.Viewer.Core.Analytics.IAnalyticsEngine _analytics;
+    private readonly AnalyticsBootstrap _analyticsBootstrap;
     private readonly ILoggerFactory _loggerFactory;
 
     public SingleCameraPageFactory(
@@ -43,6 +45,8 @@ public SingleCameraPageFactory(
         OpenIPC.Viewer.Core.Platform.IAudioInput audioInput,
         IAudioBackchannelClient backchannel,
         IReachabilityProbe reachability,
+        OpenIPC.Viewer.Core.Analytics.IAnalyticsEngine analytics,
+        AnalyticsBootstrap analyticsBootstrap,
         ILoggerFactory loggerFactory)
     {
         _coordinator = coordinator;
@@ -59,12 +63,16 @@ public SingleCameraPageFactory(
         _audioInput = audioInput;
         _backchannel = backchannel;
         _reachability = reachability;
+        _analytics = analytics;
+        _analyticsBootstrap = analyticsBootstrap;
         _loggerFactory = loggerFactory;
     }
 
     public SingleCameraPageViewModel Create(Camera camera) =>
         new(camera, _coordinator, _directory, _onvif, _majestic, _schema, _majesticSsh, _recordings, _userSettings, _dialogs, _snapshots, _audio,
             new PushToTalkController(_audioInput, _backchannel),
             _reachability,
+            _analytics,
+            _analyticsBootstrap,
             _loggerFactory.CreateLogger<SingleCameraPageViewModel>());
 }

src/OpenIPC.Viewer.App/ViewModels/SingleCameraPageViewModel.cs

@@ -3,6 +3,7 @@
 using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
+using System.Reactive.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Globalization;
@@ -13,6 +14,7 @@
 using OpenIPC.Viewer.App.Messages;
 using OpenIPC.Viewer.App.Services;
 using OpenIPC.Viewer.App.ViewModels.Majestic;
+using OpenIPC.Viewer.Core.Analytics;
 using OpenIPC.Viewer.Core.Entities;
 using OpenIPC.Viewer.Core.Majestic;
 using OpenIPC.Viewer.Core.Onvif;
@@ -40,10 +42,19 @@ public sealed partial class SingleCameraPageViewModel : ViewModelBase, IAsyncDis
     private readonly AudioMonitor _audio;
     private readonly PushToTalkController _talk;
     private readonly IReachabilityProbe _reachability;
+    private readonly IAnalyticsEngine _analytics;
+    private readonly AnalyticsBootstrap _analyticsBootstrap;
     private readonly ILogger<SingleCameraPageViewModel> _logger;
     private Camera _camera;
     private DispatcherTimer? _recTimer;
 
+    private IDisposable? _detectionsSub;
+    // True when WE attached this camera's frames to the analytics engine (the
+    // fallback path — normally the grid tile's feed is still running and we
+    // only mirror its results). Guards the detach so closing this page never
+    // strips a live tile registration.
+    private bool _analyticsAttachedHere;
+
     // On a stream fault, TCP-probe the camera so we can tell a wedged-but-alive
     // camera (Attention) from one that's truly gone (Offline). Short timeout.
     private static readonly TimeSpan ReachabilityProbeTimeout = TimeSpan.FromSeconds(2);
@@ -92,9 +103,23 @@ public sealed partial class SingleCameraPageViewModel : ViewModelBase, IAsyncDis
     public string StatusHeading => Localizer.Instance[
         Status == CameraStatus.Attention ? "Stream.Interrupted" : "Stream.Disconnected"];
 
-    [ObservableProperty] private SessionTelemetry? _telemetry;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(SourceAspect))]
+    private SessionTelemetry? _telemetry;
     [ObservableProperty] private string? _errorMessage;
 
+    // AI detections (Phase 15) continue onto this page: boxes computed by the
+    // engine (usually still fed by the grid tile's substream) are normalized
+    // 0..1, so they land correctly on the mainstream picture here too.
+    [ObservableProperty] private IReadOnlyList<Detection> _detections = Array.Empty<Detection>();
+
+    public bool AnalyticsEnabled => _camera.AnalyticsOrDefault.Enabled;
+
+    // Source frame aspect (width/height) so DetectionOverlay maps boxes into
+    // the letterboxed video rect; 0 until telemetry → overlay uses full bounds.
+    public double SourceAspect =>
+        Telemetry is { Width: > 0, Height: > 0 } t ? (double)t.Width / t.Height : 0;
+
     // Visible while the session is mid-connect (or backing off a reconnect). Gated
     // on Session != null so the empty pre-activate window doesn't show a spinner
     // out of nowhere. State changes flip both flags via NotifyPropertyChangedFor.
@@ -215,6 +240,8 @@ public SingleCameraPageViewModel(
         AudioMonitor audio,
         PushToTalkController talk,
         IReachabilityProbe reachability,
+        IAnalyticsEngine analytics,
+        AnalyticsBootstrap analyticsBootstrap,
         ILogger<SingleCameraPageViewModel> logger)
     {
         _camera = camera;
@@ -231,8 +258,16 @@ public SingleCameraPageViewModel(
         _audio = audio;
         _talk = talk;
         _reachability = reachability;
+        _analytics = analytics;
+        _analyticsBootstrap = analyticsBootstrap;
         _logger = logger;
 
+        // Mirror this camera's detection results (whoever feeds the engine —
+        // usually the still-running grid tile) onto the page overlay.
+        _detectionsSub = _analytics.Results
+            .Where(r => r.CameraId == _camera.Id)
+            .Subscribe(r => Dispatcher.UIThread.Post(() => Detections = r.Detections));
+
         // Hydrate the shared monitor from the persisted prefs and reflect any
         // later change (incl. from another page) back into the speaker UI.
         _audio.Muted = _userSettings.Current.AudioMuted;
@@ -633,6 +668,8 @@ public async Task ActivateAsync(CancellationToken ct)
                 // only plays once unmuted; default is muted.
                 if (_audio.IsAvailable)
                     _audio.Attach(session, _camera.Id);
+
+                AttachAnalyticsFallback(session);
             }
             catch (Exception ex)
             {
@@ -815,6 +852,7 @@ private async Task ReloadStreamAsync()
         _stateSub?.Dispose();
         _telemetrySub?.Dispose();
         _audioPresenceSub?.Dispose();
+        DetachAnalyticsFallback();
         // Re-detect on the fresh session — a swapped camera may not have audio.
         HasAudio = false;
         if (Session is not null)
@@ -1300,6 +1338,33 @@ private async Task SaveSnapshotAsAsync()
         }
     }
 
+    // Fallback feed for the analytics engine: only when NOBODY is already
+    // feeding this camera (no grid tile — opened from the library, tile dropped
+    // by the session cap, stills mode, …). When a tile feed exists we only
+    // mirror its results; attaching over it would steal the registration and
+    // orphan the tile's detections when this page closes.
+    private void AttachAnalyticsFallback(IVideoSession session)
+    {
+        if (!_camera.AnalyticsOrDefault.Enabled || _analytics.IsAttached(_camera.Id))
+            return;
+        _ = _analyticsBootstrap.EnsureStartedAsync();
+        _analytics.Attach(
+            _camera.Id,
+            session.Frames,
+            () => _camera.AnalyticsOrDefault,
+            () => !_disposed && State == SessionState.Playing);
+        _analyticsAttachedHere = true;
+    }
+
+    private void DetachAnalyticsFallback()
+    {
+        if (!_analyticsAttachedHere)
+            return;
+        _analyticsAttachedHere = false;
+        _analytics.Detach(_camera.Id);
+        Detections = Array.Empty<Detection>();
+    }
+
     [RelayCommand]
     private void Back() =>
         WeakReferenceMessenger.Default.Send(new GoBackToLibraryMessage());
@@ -1317,6 +1382,8 @@ public async ValueTask DisposeAsync()
         _stateSub?.Dispose();
         _telemetrySub?.Dispose();
         _audioPresenceSub?.Dispose();
+        _detectionsSub?.Dispose();
+        DetachAnalyticsFallback();
         _recordings.StateChanged -= OnRecordingsStateChanged;
         _userSettings.Changed -= OnUserSettingsChanged;
         _coordinator.Invalidated -= OnCoordinatorInvalidated;

src/OpenIPC.Viewer.App/Views/Pages/SingleCameraPage.axaml

@@ -57,6 +57,20 @@
         </controls:RtspVideoView.GestureRecognizers>
       </controls:RtspVideoView>
 
+      <!-- AI detection boxes (Phase 15.5) — detection started on the grid tile
+           continues here; boxes are normalized so the substream-fed results
+           map onto the mainstream picture. Mirrors the video's zoom transform
+           so boxes stay glued to objects under digital zoom. -->
+      <controls:DetectionOverlay Detections="{Binding Detections}"
+                                 ShowBoxes="{Binding AnalyticsEnabled}"
+                                 SourceAspect="{Binding SourceAspect}"
+                                 RenderTransformOrigin="0.5,0.5"
+                                 IsHitTestVisible="False">
+        <controls:DetectionOverlay.RenderTransform>
+          <ScaleTransform ScaleX="{Binding ZoomLevel}" ScaleY="{Binding ZoomLevel}" />
+        </controls:DetectionOverlay.RenderTransform>
+      </controls:DetectionOverlay>
+
       <!-- Top-left LIVE badge -->
       <Border HorizontalAlignment="Left" VerticalAlignment="Top" Margin="12"
               Background="{StaticResource DangerBrush}"

src/OpenIPC.Viewer.Core/Analytics/IAnalyticsEngine.cs

@@ -31,4 +31,10 @@ void Attach(CameraId cameraId, IObservable<VideoFrame> frames,
         Func<AnalyticsSettings> settings, Func<bool> isActive);
 
     void Detach(CameraId cameraId);
+
+    // Whether some frame source currently feeds this camera. Lets a second
+    // view (single-camera page) attach its own session ONLY as a fallback —
+    // Attach replaces the existing registration, so blindly re-attaching
+    // would steal the grid tile's feed and orphan it on detach.
+    bool IsAttached(CameraId cameraId);
 }