feat(spotify): library caching

src/lib/stores/spotify.ts

@@ -23,6 +23,7 @@ export interface SpotifyAuthState {
   // User data
   user: SpotifyUser | null;
   loggedIn: boolean;
+  cacheTimestamp: number | null; // Unix timestamp in seconds
 }
 
 // Initialize the store with spotify.json
@@ -36,7 +37,8 @@ const defaultState: SpotifyAuthState = {
   refreshToken: null,
   expiresAt: null,
   user: null,
-  loggedIn: false
+  loggedIn: false,
+  cacheTimestamp: null
 };
 
 // Create a writable store for reactive UI updates
@@ -50,6 +52,7 @@ export async function loadSpotifyAuth(): Promise<void> {
   const refreshToken = await store.get<string>('refreshToken');
   const expiresAt = await store.get<number>('expiresAt');
   const user = await store.get<SpotifyUser>('user');
+  const cacheTimestamp = await store.get<number>('cacheTimestamp');
 
   spotifyAuth.set({
     clientId: clientId ?? null,
@@ -58,7 +61,8 @@ export async function loadSpotifyAuth(): Promise<void> {
     refreshToken: refreshToken ?? null,
     expiresAt: expiresAt ?? null,
     user: user ?? null,
-    loggedIn: !!(accessToken && user)
+    loggedIn: !!(accessToken && user),
+    cacheTimestamp: cacheTimestamp ?? null
   });
 }
 
@@ -129,5 +133,16 @@ export function isTokenExpired(expiresAt: number | null): boolean {
   return Date.now() >= (expiresAt - bufferTime);
 }
 
+// Save cache timestamp
+export async function saveCacheTimestamp(timestamp: number): Promise<void> {
+  await store.set('cacheTimestamp', timestamp);
+  await store.save();
+
+  spotifyAuth.update(s => ({
+    ...s,
+    cacheTimestamp: timestamp
+  }));
+}
+
 // Initialize on module load
 loadSpotifyAuth();