WIP: Phase 3B playback engine handoff

server/src/app.js

@@ -6,6 +6,8 @@ const {
 const { createAssetRouter } = require("./assets/routes");
 const { createMediaRouter } = require("./assets/media-routes");
 const { createAssetService } = require("./assets/service");
+const { createPlaybackService } = require("./playback");
+const { createPlaybackRouter } = require("./playback/routes");
 const {
   createPlaylistRouter,
   createPlaylistService,
@@ -13,10 +15,10 @@ const {
 const { createSettingsRouter } = require("./settings/routes");
 const { createSettingsService } = require("./settings/service");
 
-function safeNotifier(notifier, logger) {
+function safeNotifier(notifier, logger, failureMessage) {
   const warn = (error) => {
     try {
-      logger?.warn?.("Playlist invalidation notification failed", error);
+      logger?.warn?.(failureMessage, error);
     } catch {
       // A best-effort notification or warning must not undo a database commit.
     }
@@ -40,10 +42,35 @@ function createApp({
   migrations,
   now = Date.now,
   onPlaylistsChanged = () => {},
+  playbackService: suppliedPlaybackService,
   storage,
 }) {
   const app = express();
-  const notifyPlaylistsChanged = safeNotifier(onPlaylistsChanged, logger);
+  const notifyPlaylistsChanged = safeNotifier(
+    onPlaylistsChanged,
+    logger,
+    "Playlist invalidation notification failed",
+  );
+  const playbackService =
+    suppliedPlaybackService ||
+    createPlaybackService({
+      database,
+      now,
+      onActivationChanged: notifyPlaylistsChanged,
+    });
+  if (!suppliedPlaybackService) {
+    playbackService.initialize();
+  }
+  const reconcilePlaybackDomain = (change) =>
+    playbackService.domainChanged(change);
+  const reconcileBeforeDomainChange = () =>
+    playbackService.reconcile("before_domain_change");
+  const notifyPlaylistMutation = (change) => {
+    reconcilePlaybackDomain(change);
+    const publicChange = { ...change };
+    delete publicChange.invalidBoundaryChanged;
+    notifyPlaylistsChanged(publicChange);
+  };
   const settingsService = createSettingsService(database);
   const assetService = createAssetService({
     database,
@@ -53,8 +80,10 @@ function createApp({
   const playlistService = createPlaylistService({
     database,
     now,
-    onChanged: notifyPlaylistsChanged,
+    onBeforeChange: reconcileBeforeDomainChange,
+    onChanged: notifyPlaylistMutation,
   });
+  app.locals.playbackService = playbackService;
 
   app.disable("x-powered-by");
   app.set("trust proxy", config.trustProxy);
@@ -85,18 +114,28 @@ function createApp({
   app.use(
     "/api/settings",
     createSettingsRouter(settingsService, {
+      onBeforePlaybackDomainChange: reconcileBeforeDomainChange,
       onPlaylistsChanged: notifyPlaylistsChanged,
+      onPlaybackDomainChanged: reconcilePlaybackDomain,
     }),
   );
   app.use(
     "/api/assets",
     createAssetRouter({
       assetService,
+      onBeforePlaybackDomainChange: reconcileBeforeDomainChange,
       onPlaylistsChanged: notifyPlaylistsChanged,
+      onPlaybackDomainChanged: reconcilePlaybackDomain,
       processingConfig: config.processing,
     }),
   );
-  app.use("/api/playlists", createPlaylistRouter(playlistService));
+  app.use(
+    "/api/playlists",
+    createPlaylistRouter(playlistService, {
+      playbackService,
+    }),
+  );
+  app.use("/api/playback", createPlaybackRouter(playbackService));
   app.use("/media", createMediaRouter(assetService));
 
   app.use((request, response) => {