Implement Phase 3A playlist management

server/src/app.js

@@ -6,24 +6,55 @@ const {
 const { createAssetRouter } = require("./assets/routes");
 const { createMediaRouter } = require("./assets/media-routes");
 const { createAssetService } = require("./assets/service");
+const {
+  createPlaylistRouter,
+  createPlaylistService,
+} = require("./playlists");
 const { createSettingsRouter } = require("./settings/routes");
 const { createSettingsService } = require("./settings/service");
 
+function safeNotifier(notifier, logger) {
+  const warn = (error) => {
+    try {
+      logger?.warn?.("Playlist invalidation notification failed", error);
+    } catch {
+      // A best-effort notification or warning must not undo a database commit.
+    }
+  };
+  return (event) => {
+    try {
+      const result = notifier(event);
+      result?.catch?.(warn);
+    } catch (error) {
+      warn(error);
+    }
+  };
+}
+
 function createApp({
   config,
   database,
   imageProcessor,
   lifecycle,
+  logger = console,
   migrations,
+  now = Date.now,
+  onPlaylistsChanged = () => {},
   storage,
 }) {
   const app = express();
+  const notifyPlaylistsChanged = safeNotifier(onPlaylistsChanged, logger);
   const settingsService = createSettingsService(database);
   const assetService = createAssetService({
     database,
     imageProcessor,
     storage,
   });
+  const playlistService = createPlaylistService({
+    database,
+    now,
+    onChanged: notifyPlaylistsChanged,
+  });
 
   app.disable("x-powered-by");
   app.set("trust proxy", config.trustProxy);
@@ -51,11 +82,21 @@ function createApp({
     "/api/status",
     createDetailedHealthRouter(detailedHealthRouterOptions),
   );
-  app.use("/api/settings", createSettingsRouter(settingsService));
+  app.use(
+    "/api/settings",
+    createSettingsRouter(settingsService, {
+      onPlaylistsChanged: notifyPlaylistsChanged,
+    }),
+  );
   app.use(
     "/api/assets",
-    createAssetRouter({ assetService, processingConfig: config.processing }),
+    createAssetRouter({
+      assetService,
+      onPlaylistsChanged: notifyPlaylistsChanged,
+      processingConfig: config.processing,
+    }),
   );
+  app.use("/api/playlists", createPlaylistRouter(playlistService));
   app.use("/media", createMediaRouter(assetService));
 
   app.use((request, response) => {