feat: auto refresh of tokens in background

apps/frontend/src/app/services/auth.service.ts

@@ -23,6 +23,7 @@ export class AuthService {
   private currentUser = signal<User | null>(null);
   public readonly user = this.currentUser.asReadonly();
   private refreshing = false;
+  private refreshInterval?: ReturnType<typeof setInterval>;
 
   login(): void {
     // Redirect to API login endpoint
@@ -33,6 +34,7 @@ export class AuthService {
     return this.api.get<AuthResponse>('/auth/me').pipe(
       tap(response => {
         this.currentUser.set(response.user);
+        this.startRefreshTimer();
       }),
       catchError(error => {
         if (error.status === 401) {
@@ -40,9 +42,11 @@ export class AuthService {
             switchMap(() => this.api.get<AuthResponse>('/auth/me')),
             tap(response => {
               this.currentUser.set(response.user);
+              this.startRefreshTimer();
             }),
             catchError(() => {
               this.currentUser.set(null);
+              this.stopRefreshTimer();
               return throwError(() => error);
             })
           );
@@ -66,20 +70,45 @@ export class AuthService {
       tap(response => {
         this.currentUser.set(response.user);
         this.refreshing = false;
+        this.startRefreshTimer();
       }),
       catchError(error => {
         this.refreshing = false;
         this.currentUser.set(null);
+        this.stopRefreshTimer();
         return throwError(() => error);
       })
     );
   }
 
+  private startRefreshTimer(): void {
+    this.stopRefreshTimer();
+
+    // Refresh token every 13 minutes (before 15-minute expiry)
+    const refreshIntervalMs = 13 * 60 * 1000;
+    this.refreshInterval = setInterval(() => {
+      this.refreshToken().subscribe({
+        error: (err) => {
+          console.error('Background token refresh failed:', err);
+          this.stopRefreshTimer();
+        }
+      });
+    }, refreshIntervalMs);
+  }
+
+  private stopRefreshTimer(): void {
+    if (this.refreshInterval) {
+      clearInterval(this.refreshInterval);
+      this.refreshInterval = undefined;
+    }
+  }
+
   logout(): Observable<{ message: string }> {
     return this.api.post<{ message: string }>('/auth/logout', {}).pipe(
       tap(() => {
         this.currentUser.set(null);
         this.api.clearCsrfToken();
+        this.stopRefreshTimer();
         this.router.navigate(['/']);
       })
     );
@@ -87,6 +116,7 @@ export class AuthService {
 
   clearUser(): void {
     this.currentUser.set(null);
+    this.stopRefreshTimer();
   }
 
   isAuthenticated(): boolean {