fix: adjust handling of backend errors

src/app/components/login/login.component.ts

@@ -79,7 +79,6 @@ export class LoginComponent {
       this.loginData.email = this.loginData.email.toLowerCase();
       try {
         await this.authService.login(this.loginData, this.checkboxRememberMe);
-        this.router.navigate(['/summary']);
         this.buttonStateService.enableButton();
       } catch (error) {
         this.buttonStateService.enableButton();

src/app/interceptors/auth-interceptor.ts

@@ -53,6 +53,11 @@ export class AuthInterceptor implements HttpInterceptor {
 
     return next.handle(clonedReq).pipe(
       catchError((error: HttpErrorResponse) => {
+        if (error.status === 0 && !this.isNavigatingToLogin) {
+          this.tokenService.deleteAuthToken();
+          this.tokenService.deleteUserId();
+          this.router.navigate(['/login']);
+        }
         if (error.status === 401 && !this.isNavigatingToLogin) {
           this.toast.showSessionExpiredToast();
           this.router.navigate(['/login']);

src/app/services/auth.service.ts

@@ -41,6 +41,7 @@ export class AuthService {
       this.tokenService.storeUserId(userId, storage);
       this.currentUserIdSubject.next(userId);
       this.toastNotificationService.loginSuccessToast();
+      this.router.navigate(['/summary']);
     } catch (error) {
       console.error('Login failed:', error);
     }
@@ -65,8 +66,8 @@ export class AuthService {
       await lastValueFrom(
         this.apiService.request('POST', `/auth/register/`, credentials)
       );
-      this.router.navigate(['/login']);
       this.toastNotificationService.registerSuccessToast();
+      this.router.navigate(['/login']);
     } catch (error: any) {
       console.error('Registration failed:', error);
       throw new Error(error?.error?.error);

src/app/services/error-notification.service.ts

@@ -7,8 +7,13 @@ import { ToastrService } from 'ngx-toastr';
 })
 export class ErrorNotificationService {
   constructor(private toastr: ToastrService) {}
+  private isToastVisible = false;
 
   handleHttpError(error: unknown): void {
+    if (this.isToastVisible) {
+      return;
+    }
+
     let errorMessage = 'An unknown error occurred.';
 
     if (error instanceof HttpErrorResponse) {
@@ -22,8 +27,19 @@ export class ErrorNotificationService {
             'The request could not be processed due to invalid input. Please check your entries and try again.';
           break;
         case 401:
-          errorMessage =
-            'The login credentials are incorrect. Please check your email and password.';
+          console.log(error);
+
+          if (
+            error.error.detail &&
+            (error.error.detail.includes('Token') ||
+              error.error.detail.includes('token'))
+          ) {
+            errorMessage =
+              'The authentication token is invalid or expired. Please log in again.';
+          } else {
+            errorMessage =
+              'The login credentials are incorrect. Please check your email and password.';
+          }
           break;
         case 403:
           errorMessage =
@@ -59,10 +75,16 @@ export class ErrorNotificationService {
       errorMessage = `Network error: ${error.message || error.toString()}`;
     }
 
+    this.isToastVisible = true;
+
     this.toastr.error(errorMessage, 'Error', {
       timeOut: 3000,
       positionClass: 'toast-top-right',
       progressBar: true,
     });
+
+    setTimeout(() => {
+      this.isToastVisible = false;
+    }, 3000);
   }
 }