feat: simplify graphql subscriptions

Author: olivertgwalton

src/lib/services/riven-live-updates.ts

@@ -1,29 +1,18 @@
 import { gqlSubscribeClient } from "$lib/graphql-client";
-import {
-    MOVIE_REQUESTED_SUBSCRIPTION,
-    SHOW_INDEXED_SUBSCRIPTION,
-    SHOW_REQUESTED_SUBSCRIPTION,
-    SHOW_REQUEST_UPDATED_SUBSCRIPTION
-} from "$lib/services/riven-media";
 
-const MEDIA_EVENT_SUBSCRIPTIONS = [
-    MOVIE_REQUESTED_SUBSCRIPTION,
-    SHOW_REQUESTED_SUBSCRIPTION,
-    SHOW_REQUEST_UPDATED_SUBSCRIPTION,
-    SHOW_INDEXED_SUBSCRIPTION,
-    `subscription RivenItemScraped {
-        itemScraped
-    }`,
-    `subscription RivenItemDownloaded {
-        itemDownloaded
-    }`,
-    `subscription RivenItemFailed {
-        itemFailed
-    }`,
-    `subscription RivenItemsDeleted {
-        itemsDeleted
-    }`
-];
+/// Unified backend subscription that fans every relevant media-state event
+/// (movie/show requested, show indexed, item scraped/downloaded/failed,
+/// items deleted) onto a single multipart stream. One connection replaces
+/// eight individual subscriptions, which keeps the home/library/dashboard
+/// pages under the per-origin connection cap on HTTP/1.1 deployments and
+/// cuts subscription-side server work by ~8x on every transport.
+const MEDIA_EVENTS_SUBSCRIPTION = `subscription RivenMediaEvents {
+    mediaEvents { kind itemId }
+}`;
+
+type MediaEventPayload = {
+    mediaEvents: { kind: string; itemId: number | null };
+};
 
 export function subscribeToRivenMediaEvents(
     refresh: () => void | Promise<void>,
@@ -40,21 +29,21 @@ export function subscribeToRivenMediaEvents(
         }, debounceMs);
     }
 
-    const unsubscribers = MEDIA_EVENT_SUBSCRIPTIONS.map((subscription) =>
-        gqlSubscribeClient<Record<string, unknown>>(subscription, undefined, {
+    const unsubscribe = gqlSubscribeClient<MediaEventPayload>(
+        MEDIA_EVENTS_SUBSCRIPTION,
+        undefined,
+        {
             onData: refreshSoon,
             onError: () => {
                 // Callers keep their last successful data snapshot. The shared GraphQL
                 // subscription client owns transport-level retry behaviour where needed.
             }
-        })
+        }
     );
 
     return () => {
         active = false;
         clearTimeout(refreshTimer);
-        for (const unsubscribe of unsubscribers) {
-            unsubscribe();
-        }
+        unsubscribe();
     };
 }