Add SWR for system health and command palette search fetching

Replace manual fetch/useState/useEffect patterns with SWR hooks in
system health section and command palette search, gaining automatic
caching, request deduplication, and stale-while-revalidate.

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

app/(pages)/settings/_components/system-health-section.tsx

@@ -9,7 +9,7 @@ import {
   IconPlayerPlay,
   IconRefresh,
 } from "@tabler/icons-react";
-import { useCallback, useEffect, useState } from "react";
+import { useEffect, useState } from "react";
 import { toast } from "sonner";
 import { StatusDot } from "@/components/status-dot";
 import { Button } from "@/components/ui/button";
@@ -34,6 +34,7 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
+import { useSystemHealth } from "@/hooks/use-system-health";
 import { useTimeAgo } from "@/hooks/use-time-ago";
 import type { SystemHealthData } from "@/lib/services/system-health";
 
@@ -129,30 +130,15 @@ function LiveTimeAgo({
 
 /** Renders 3 separate cards: System status, Background jobs, Storage */
 export function SystemHealthCards() {
-  const [data, setData] = useState<SystemHealthData | null>(null);
-  const [loading, setLoading] = useState(true);
-  const [refreshing, setRefreshing] = useState(false);
-
-  const fetchHealth = useCallback(async (isRefresh = false) => {
-    if (isRefresh) setRefreshing(true);
-    try {
-      const res = await fetch("/api/admin/system-health");
-      if (!res.ok) throw new Error("Failed to fetch");
-      const health: SystemHealthData = await res.json();
-      setData(health);
-    } catch {
-      if (isRefresh) toast.error("Failed to refresh system health");
-    } finally {
-      setLoading(false);
-      setRefreshing(false);
-    }
-  }, []);
+  const { data, error, isLoading, isValidating, refresh } = useSystemHealth();
 
   useEffect(() => {
-    fetchHealth();
-  }, [fetchHealth]);
+    if (error && !isLoading) {
+      toast.error("Failed to refresh system health");
+    }
+  }, [error, isLoading]);
 
-  if (loading) return <SkeletonCards />;
+  if (isLoading) return <SkeletonCards />;
   if (!data) return null;
 
   return (
@@ -178,12 +164,12 @@ export function SystemHealthCards() {
                   <Button
                     variant="ghost"
                     size="icon"
-                    onClick={() => fetchHealth(true)}
-                    disabled={refreshing}
+                    onClick={() => refresh()}
+                    disabled={isValidating}
                   />
                 }
               >
-                {refreshing ? <Spinner /> : <IconRefresh />}
+                {isValidating ? <Spinner /> : <IconRefresh />}
               </TooltipTrigger>
               <TooltipContent>Refresh</TooltipContent>
             </Tooltip>
@@ -277,10 +263,7 @@ export function SystemHealthCards() {
       </Card>
 
       {/* ── Card 2: Background Jobs ── */}
-      <BackgroundJobsCard
-        jobs={data.jobs}
-        onRefresh={() => fetchHealth(true)}
-      />
+      <BackgroundJobsCard jobs={data.jobs} onRefresh={refresh} />
 
       {/* ── Card 3: Storage ── */}
       <Card className="border-l-2 border-l-primary/30">

bun.lock

@@ -29,6 +29,7 @@
         "recharts": "3.7.0",
         "shadcn": "3.8.5",
         "sonner": "2.0.7",
+        "swr": "2.4.1",
         "tailwind-merge": "3.5.0",
         "tw-animate-css": "1.4.0",
         "vaul": "1.1.2",
@@ -759,6 +760,8 @@
 
     "depd": ["depd@2.0.0", "", {}, "sha512-g7nH6P6dyDioJogAAGprGpCtVImJhpPk/roCzdb3fIh61/s/nPsfR6onyMwkCAR/OlC3yBC0lESvUoQEAssIrw=="],
 
+    "dequal": ["dequal@2.0.3", "", {}, "sha512-0je+qPKHEMohvfRTCEo3CrPG6cAzAYgmzKyxRiYSSDkS6eGJdyVJm7WaYA5ECaAD9wLB2T4EEeymA5aFVcYXCA=="],
+
     "destr": ["destr@2.0.5", "", {}, "sha512-ugFTXCtDZunbzasqBxrK93Ik/DRYsO6S/fedkWEMKqt04xZ4csmnmwGDBAb07QWNaGMAmnTIemsYZCksjATwsA=="],
 
     "detect-libc": ["detect-libc@2.1.2", "", {}, "sha512-Btj2BOOO83o3WyH59e8MgXsxEQVcarkUOpEYrubB0urwnN10yQ364rsiByU11nZlqWYZm05i/of7io4mzihBtQ=="],
@@ -1381,6 +1384,8 @@
 
     "styled-jsx": ["styled-jsx@5.1.6", "", { "dependencies": { "client-only": "0.0.1" }, "peerDependencies": { "react": ">= 16.8.0 || 17.x.x || ^18.0.0-0 || ^19.0.0-0" } }, "sha512-qSVyDTeMotdvQYoHWLNGwRFJHC+i+ZvdBRYosOFgC+Wg1vx4frN2/RG/NA7SYqqvKNLf39P2LSRA2pu6n0XYZA=="],
 
+    "swr": ["swr@2.4.1", "", { "dependencies": { "dequal": "^2.0.3", "use-sync-external-store": "^1.6.0" }, "peerDependencies": { "react": "^16.11.0 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-2CC6CiKQtEwaEeNiqWTAw9PGykW8SR5zZX8MZk6TeAvEAnVS7Visz8WzphqgtQ8v2xz/4Q5K+j+SeMaKXeeQIA=="],
+
     "tabbable": ["tabbable@6.4.0", "", {}, "sha512-05PUHKSNE8ou2dwIxTngl4EzcnsCDZGJ/iCLtDflR/SHB/ny14rXc+qU5P4mG9JkusiV7EivzY9Mhm55AzAvCg=="],
 
     "tagged-tag": ["tagged-tag@1.0.0", "", {}, "sha512-yEFYrVhod+hdNyx7g5Bnkkb0G6si8HJurOoOEgC8B/O0uXLHlaey/65KRv6cuWBNhBgHKAROVpc7QyYqE5gFng=="],

components/command-palette.tsx

@@ -33,6 +33,7 @@ import {
 import { Kbd } from "@/components/ui/kbd";
 import { Skeleton } from "@/components/ui/skeleton";
 import { useDebounce } from "@/hooks/use-debounce";
+import { useSearch } from "@/hooks/use-search";
 import {
   commandPaletteOpenAtom,
   helpOpenAtom,
@@ -41,14 +42,7 @@ import {
 } from "@/lib/atoms/command-palette";
 import { SHORTCUT_DESCRIPTIONS } from "@/lib/constants/shortcuts";
 
-interface SearchResult {
-  tmdbId: number;
-  type: "movie" | "tv";
-  title: string;
-  posterPath: string | null;
-  releaseDate: string | null;
-  voteAverage: number;
-}
+type SearchResult = ReturnType<typeof useSearch>["results"][number];
 
 export function CommandPalette() {
   const router = useRouter();
@@ -58,9 +52,8 @@ export function CommandPalette() {
   const [helpOpen, setHelpOpen] = useAtom(helpOpenAtom);
   const [recentSearches, setRecentSearches] = useAtom(recentSearchesAtom);
   const [query, setQuery] = useState("");
-  const [results, setResults] = useState<SearchResult[]>([]);
-  const [loading, setLoading] = useState(false);
   const debouncedQuery = useDebounce(query, 300);
+  const { results, isLoading: loading } = useSearch(debouncedQuery);
   const enabled = !commandPaletteOpen;
 
   useHotkey("Mod+K", () => setCommandPaletteOpen((prev) => !prev));
@@ -75,41 +68,23 @@ export function CommandPalette() {
     timeout: 500,
   });
 
-  // Reset ephemeral state when palette opens
+  // Reset query when palette opens
   useEffect(() => {
     if (commandPaletteOpen) {
       setQuery("");
-      setResults([]);
     }
   }, [commandPaletteOpen]);
 
-  // Search TMDB
+  // Save to recent searches when results arrive
   useEffect(() => {
-    if (!debouncedQuery.trim()) {
-      setResults([]);
-      return;
-    }
-    let cancelled = false;
-    setLoading(true);
-    fetch(`/api/search?query=${encodeURIComponent(debouncedQuery)}`)
-      .then((r) => r.json())
-      .then((data) => {
-        if (!cancelled) {
-          setResults((data.results ?? []).slice(0, 8));
-          const trimmed = debouncedQuery.trim();
-          setRecentSearches((prev) => {
-            const filtered = prev.filter((q) => q !== trimmed);
-            return [trimmed, ...filtered].slice(0, MAX_RECENT);
-          });
-        }
-      })
-      .finally(() => {
-        if (!cancelled) setLoading(false);
+    const trimmed = debouncedQuery.trim();
+    if (trimmed && results.length > 0) {
+      setRecentSearches((prev) => {
+        const filtered = prev.filter((q) => q !== trimmed);
+        return [trimmed, ...filtered].slice(0, MAX_RECENT);
       });
-    return () => {
-      cancelled = true;
-    };
-  }, [debouncedQuery, setRecentSearches]);
+    }
+  }, [debouncedQuery, results, setRecentSearches]);
 
   const handleSelect = useCallback(
     (result: SearchResult) => {

hooks/use-search.ts

@@ -0,0 +1,30 @@
+import useSWR from "swr";
+import { fetcher } from "@/lib/swr/fetcher";
+
+interface SearchResponse {
+  results: {
+    tmdbId: number;
+    type: "movie" | "tv";
+    title: string;
+    posterPath: string | null;
+    releaseDate: string | null;
+    voteAverage: number;
+  }[];
+}
+
+export function useSearch(debouncedQuery: string) {
+  const trimmed = debouncedQuery.trim();
+  const { data, isLoading } = useSWR<SearchResponse>(
+    trimmed ? `/api/search?query=${encodeURIComponent(trimmed)}` : null,
+    fetcher,
+    {
+      revalidateOnFocus: false,
+      dedupingInterval: 2_000,
+    },
+  );
+
+  return {
+    results: data?.results?.slice(0, 8) ?? [],
+    isLoading,
+  };
+}

hooks/use-system-health.ts

@@ -0,0 +1,19 @@
+import useSWR from "swr";
+import type { SystemHealthData } from "@/lib/services/system-health";
+import { fetcher } from "@/lib/swr/fetcher";
+
+export function useSystemHealth() {
+  const { data, error, isLoading, isValidating, mutate } =
+    useSWR<SystemHealthData>("/api/admin/system-health", fetcher, {
+      revalidateOnFocus: true,
+      dedupingInterval: 10_000,
+    });
+
+  return {
+    data: data ?? null,
+    error,
+    isLoading,
+    isValidating,
+    refresh: () => mutate(),
+  };
+}

lib/swr/fetcher.ts

@@ -0,0 +1,8 @@
+export async function fetcher<T>(url: string): Promise<T> {
+  const res = await fetch(url);
+  if (!res.ok) {
+    const body = await res.json().catch(() => ({}));
+    throw new Error(body.error || `Request failed (${res.status})`);
+  }
+  return res.json();
+}

package.json

@@ -39,6 +39,7 @@
     "recharts": "3.7.0",
     "shadcn": "3.8.5",
     "sonner": "2.0.7",
+    "swr": "2.4.1",
     "tailwind-merge": "3.5.0",
     "tw-animate-css": "1.4.0",
     "vaul": "1.1.2",