Simplify preview refreshing with custom hook (#11293)

web/src/components/card/AnimatedEventCard.tsx

@@ -7,12 +7,12 @@ import { REVIEW_PADDING, ReviewSegment } from "@/types/review";
 import { useNavigate } from "react-router-dom";
 import { RecordingStartingPoint } from "@/types/record";
 import axios from "axios";
-import { Preview } from "@/types/preview";
 import {
   InProgressPreview,
   VideoPreview,
 } from "../player/PreviewThumbnailPlayer";
 import { isCurrentHour } from "@/utils/dateUtil";
+import { useCameraPreviews } from "@/hooks/use-camera-previews";
 
 type AnimatedEventCardProps = {
   event: ReviewSegment;
@@ -24,10 +24,15 @@ export function AnimatedEventCard({ event }: AnimatedEventCardProps) {
 
   // preview
 
-  const { data: previews } = useSWR<Preview[]>(
-    currentHour
-      ? null
-      : `/preview/${event.camera}/start/${Math.round(event.start_time)}/end/${Math.round(event.end_time || event.start_time + 20)}`,
+  const previews = useCameraPreviews(
+    {
+      after: Math.round(event.start_time),
+      before: Math.round(event.end_time || event.start_time + 20),
+    },
+    {
+      camera: event.camera,
+      fetchPreviews: !currentHour,
+    },
   );
 
   // interaction

web/src/hooks/use-camera-previews.ts

@@ -0,0 +1,57 @@
+import { Preview } from "@/types/preview";
+import { TimeRange } from "@/types/timeline";
+import { useEffect, useState } from "react";
+import useSWR from "swr";
+
+type OptionalCameraPreviewProps = {
+  camera?: string;
+  autoRefresh?: boolean;
+  fetchPreviews?: boolean;
+};
+
+export function useCameraPreviews(
+  initialTimeRange: TimeRange,
+  {
+    camera = "all",
+    autoRefresh = true,
+    fetchPreviews = true,
+  }: OptionalCameraPreviewProps,
+) {
+  const [timeRange, setTimeRange] = useState(initialTimeRange);
+
+  useEffect(() => {
+    setTimeRange(initialTimeRange);
+  }, [initialTimeRange]);
+
+  const { data: allPreviews } = useSWR<Preview[]>(
+    fetchPreviews
+      ? `preview/${camera}/start/${timeRange.after}/end/${timeRange.before}`
+      : null,
+    { revalidateOnFocus: false, revalidateOnReconnect: false },
+  );
+
+  // Set a timeout to update previews on the hour
+  useEffect(() => {
+    if (!autoRefresh || !fetchPreviews || !allPreviews) {
+      return;
+    }
+
+    const callback = () => {
+      const nextPreviewStart = new Date(
+        allPreviews[allPreviews.length - 1].end * 1000,
+      );
+      nextPreviewStart.setHours(nextPreviewStart.getHours() + 1);
+
+      if (Date.now() > nextPreviewStart.getTime()) {
+        setTimeRange({ after: timeRange.after, before: Date.now() / 1000 });
+      }
+    };
+    document.addEventListener("focusin", callback);
+
+    return () => {
+      document.removeEventListener("focusin", callback);
+    };
+  }, [allPreviews, autoRefresh, fetchPreviews, timeRange]);
+
+  return allPreviews;
+}

web/src/pages/Events.tsx

@@ -1,9 +1,9 @@
 import ActivityIndicator from "@/components/indicators/activity-indicator";
 import useApiFilter from "@/hooks/use-api-filter";
+import { useCameraPreviews } from "@/hooks/use-camera-previews";
 import { useTimezone } from "@/hooks/use-date-utils";
 import { useOverlayState, useSearchEffect } from "@/hooks/use-overlay-state";
 import { FrigateConfig } from "@/types/frigateConfig";
-import { Preview } from "@/types/preview";
 import { RecordingStartingPoint } from "@/types/record";
 import {
   ReviewFilter,
@@ -161,7 +161,6 @@ export default function Events() {
   }, [updateSummary]);
 
   // preview videos
-  const [previewKey, setPreviewKey] = useState(0);
   const previewTimes = useMemo(() => {
     if (!reviews || reviews.length == 0) {
       return undefined;
@@ -170,50 +169,22 @@ export default function Events() {
     const startDate = new Date();
     startDate.setMinutes(0, 0, 0);
 
-    let endDate;
-    if (previewKey == 0) {
-      endDate = new Date(reviews.at(-1)?.end_time || 0);
+    const endDate = new Date(reviews.at(-1)?.end_time || 0);
     endDate.setHours(0, 0, 0, 0);
-    } else {
-      endDate = new Date();
-      endDate.setMilliseconds(0);
-    }
 
     return {
-      start: startDate.getTime() / 1000,
-      end: endDate.getTime() / 1000,
+      after: startDate.getTime() / 1000,
+      before: endDate.getTime() / 1000,
     };
-  }, [reviews, previewKey]);
-  const { data: allPreviews } = useSWR<Preview[]>(
-    previewTimes
-      ? `preview/all/start/${previewTimes.start}/end/${previewTimes.end}`
-      : null,
-    { revalidateOnFocus: false, revalidateOnReconnect: false },
+  }, [reviews]);
+
+  const allPreviews = useCameraPreviews(
+    previewTimes ?? { after: 0, before: 0 },
+    {
+      fetchPreviews: previewTimes != undefined,
+    },
   );
 
-  // Set a timeout to update previews on the hour
-  useEffect(() => {
-    if (!allPreviews || allPreviews.length == 0) {
-      return;
-    }
-
-    const callback = () => {
-      const nextPreviewStart = new Date(
-        allPreviews[allPreviews.length - 1].end * 1000,
-      );
-      nextPreviewStart.setHours(nextPreviewStart.getHours() + 1);
-
-      if (Date.now() > nextPreviewStart.getTime()) {
-        setPreviewKey(10 * Math.random());
-      }
-    };
-    document.addEventListener("focusin", callback);
-
-    return () => {
-      document.removeEventListener("focusin", callback);
-    };
-  }, [allPreviews]);
-
   // review status
 
   const markAllItemsAsReviewed = useCallback(