Move seeking support into the engine.

src/camera/engine.ts

@@ -77,4 +77,11 @@ export interface CameraManagerEngine {
     queries: MediaQueries,
     results: MediaQueriesResults,
   ): boolean;
+
+  getMediaSeekTime(
+    hass: HomeAssistant,
+    cameras: Map<string, CameraConfig>,
+    media: ViewMedia,
+    target: Date,
+  ): Promise<number | null>;
 }

src/camera/frigate/engine-frigate.ts

@@ -392,6 +392,32 @@ export class FrigateCameraManagerEngine implements CameraManagerEngine {
     );
   }
 
+  public async getMediaSeekTime(
+    hass: HomeAssistant,
+    cameras: Map<string, CameraConfig>,
+    media: ViewMedia,
+    target: Date,
+  ): Promise<number | null> {
+    const start = media.getStartTime();
+    const end = media.getEndTime();
+    if (!start || !end || target < start || target > end) {
+      return null;
+    }
+
+    const query: RecordingSegmentsQuery = {
+      cameraID: media.getCameraID(),
+      start: start,
+      end: end,
+      type: QueryType.RecordingSegments,
+    };
+
+    const segments = await this.getRecordingSegments(hass, cameras, query);
+    const out = segments
+      ? this._getSeekTimeInSegments(start, target, segments.segments)
+      : null;
+    return out;
+  }
+
   protected _getQueryableCameraConfig(
     cameras: Map<string, CameraConfig>,
     cameraID: string,
@@ -466,4 +492,36 @@ export class FrigateCameraManagerEngine implements CameraManagerEngine {
         `Released ${segmentsStart - countSegments()} segment(s)`,
     );
   }
+
+  /**
+   * Get the number of seconds to seek into a video stream consisting of the
+   * provided segments to reach the target time provided.
+   * @param startTime The earliest allowable time to seek from.
+   * @param targetTime Target time.
+   * @param segments An array of segments dataset items. Must be sorted from oldest to youngest.
+   * @returns
+   */
+  protected _getSeekTimeInSegments(
+    startTime: Date,
+    targetTime: Date,
+    segments: RecordingSegment[],
+  ): number | null {
+    if (!segments.length) {
+      return null;
+    }
+    let seekMilliseconds = 0;
+
+    // Inspired by: https://github.com/blakeblackshear/frigate/blob/release-0.11.0/web/src/routes/Recording.jsx#L27
+    for (const segment of segments) {
+      const segmentStart = fromUnixTime(segment.start_time);
+      if (segmentStart > targetTime) {
+        break;
+      }
+      const segmentEnd = fromUnixTime(segment.end_time);
+      const start = segmentStart < startTime ? startTime : segmentStart;
+      const end = segmentEnd > targetTime ? targetTime : segmentEnd;
+      seekMilliseconds += end.getTime() - start.getTime();
+    }
+    return seekMilliseconds / 1000;
+  }
 }

src/camera/frigate/requests.ts

@@ -26,6 +26,7 @@ export const getRecordingsSummary = async (
       type: 'frigate/recordings/summary',
       instance_id: client_id,
       camera: camera_name,
+      timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
     },
     true,
   );

src/camera/manager.ts

@@ -278,6 +278,28 @@ export class CameraManager {
     return true;
   }
 
+  public async getMediaSeekTime(
+    hass: HomeAssistant,
+    media: ViewMedia,
+    target: Date,
+  ): Promise<number | null> {
+    const startTime = media.getStartTime();
+    const endTime = media.getEndTime();
+    const cameraConfig = this._cameras.get(media.getCameraID());
+    if (
+      !cameraConfig ||
+      !startTime ||
+      !endTime ||
+      target < startTime ||
+      target > endTime
+    ) {
+      return null;
+    }
+
+    const engine = this._engineFactory.getEngineForCamera(cameraConfig);
+    return (await engine?.getMediaSeekTime(hass, this._cameras, media, target)) ?? null;
+  }
+
   protected async _handleQuery<QT extends DataQuery>(
     hass: HomeAssistant,
     query: QT | QT[],