[ENG-7471] Have a display of some form when the OSF is down for planned maintenance [FE] (#969)

- Ticket: https://openscience.atlassian.net/browse/ENG-7471
- Feature flag: n/a

## Summary of Changes
1. Added logic for maintenance.

Author: nsemets

src/app/core/components/layout/layout.component.html

@@ -19,6 +19,13 @@
 
     <osf-footer></osf-footer>
   </div>
+
+  @if (isMaintenanceMode()) {
+    <section class="maintenance-overlay font-bold text-xl flex flex-column align-items-center justify-content-center">
+      <p>{{ 'maintenance.title' | translate }}</p>
+      <p>{{ 'maintenance.message' | translate }}</p>
+    </section>
+  }
 </main>
 
 <p-confirm-dialog

src/app/core/components/layout/layout.component.scss

@@ -84,3 +84,10 @@
     }
   }
 }
+
+.maintenance-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 2000;
+  background: var(--white);
+}

src/app/core/components/layout/layout.component.spec.ts

@@ -1,15 +1,16 @@
 import { MockComponents, MockProvider } from 'ng-mocks';
 
-import { ConfirmationService } from 'primeng/api';
 import { ConfirmDialog } from 'primeng/confirmdialog';
 
 import { BehaviorSubject } from 'rxjs';
 
 import { ComponentFixture, TestBed } from '@angular/core/testing';
 
+import { MaintenanceModeService } from '@core/services/maintenance-mode.service';
 import { IS_MEDIUM, IS_WEB } from '@osf/shared/helpers/breakpoints.tokens';
 
 import { provideOSFCore } from '@testing/osf.testing.provider';
+import { MaintenanceModeServiceMock } from '@testing/providers/maintenance-mode.service.mock';
 
 import { BreadcrumbComponent } from '../breadcrumb/breadcrumb.component';
 import { FooterComponent } from '../footer/footer.component';
@@ -47,7 +48,7 @@ describe('LayoutComponent', () => {
         provideOSFCore(),
         MockProvider(IS_WEB, isWebSubject),
         MockProvider(IS_MEDIUM, isMediumSubject),
-        MockProvider(ConfirmationService),
+        MockProvider(MaintenanceModeService, MaintenanceModeServiceMock.simple()),
       ],
     });
 

src/app/core/components/layout/layout.component.ts

@@ -6,6 +6,7 @@ import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
 import { toSignal } from '@angular/core/rxjs-interop';
 import { RouterOutlet } from '@angular/router';
 
+import { MaintenanceModeService } from '@core/services/maintenance-mode.service';
 import { ScrollTopOnRouteChangeDirective } from '@osf/shared/directives/scroll-top.directive';
 import { IS_MEDIUM, IS_WEB } from '@osf/shared/helpers/breakpoints.tokens';
 
@@ -35,6 +36,9 @@ import { TopnavComponent } from '../topnav/topnav.component';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class LayoutComponent {
+  private readonly maintenanceModeService = inject(MaintenanceModeService);
+
   isWeb = toSignal(inject(IS_WEB));
   isMedium = toSignal(inject(IS_MEDIUM));
+  isMaintenanceMode = this.maintenanceModeService.isActive;
 }

src/app/core/components/osf-banners/maintenance-banner/maintenance-banner.component.html

@@ -4,9 +4,9 @@
     styleClass="w-full"
     icon="pi pi-info-circle"
     [severity]="maintenance()?.severity"
-    [text]="maintenance()?.message"
     [closable]="true"
     (onClose)="dismiss()"
   >
+    {{ maintenance()?.message }}
   </p-message>
 }

src/app/core/interceptors/error.interceptor.spec.ts

@@ -9,12 +9,17 @@ import { Router } from '@angular/router';
 
 import { SENTRY_TOKEN } from '@core/provider/sentry.provider';
 import { AuthService } from '@core/services/auth.service';
+import { MaintenanceModeService } from '@core/services/maintenance-mode.service';
 import { ToastService } from '@osf/shared/services/toast.service';
 import { ViewOnlyLinkHelperService } from '@osf/shared/services/view-only-link-helper.service';
 
 import { provideOSFCore } from '@testing/osf.testing.provider';
 import { AuthServiceMock, AuthServiceMockType } from '@testing/providers/auth-service.mock';
 import { LoaderServiceMock, provideLoaderServiceMock } from '@testing/providers/loader-service.mock';
+import {
+  MaintenanceModeServiceMock,
+  MaintenanceModeServiceMockType,
+} from '@testing/providers/maintenance-mode.service.mock';
 import { RouterMockBuilder, RouterMockType } from '@testing/providers/router-provider.mock';
 import { SentryMock, SentryMockType } from '@testing/providers/sentry-provider.mock';
 import { ToastServiceMock, ToastServiceMockType } from '@testing/providers/toast-provider.mock';
@@ -28,6 +33,7 @@ describe('errorInterceptor', () => {
   let toastServiceMock: ToastServiceMockType;
   let loaderServiceMock: LoaderServiceMock;
   let authServiceMock: AuthServiceMockType;
+  let maintenanceModeServiceMock: MaintenanceModeServiceMockType;
   let viewOnlyHelperMock: ViewOnlyLinkHelperMockType;
   let sentryMock: SentryMockType;
 
@@ -36,6 +42,7 @@ describe('errorInterceptor', () => {
     toastServiceMock = ToastServiceMock.simple();
     loaderServiceMock = new LoaderServiceMock();
     authServiceMock = AuthServiceMock.simple();
+    maintenanceModeServiceMock = MaintenanceModeServiceMock.simple();
     viewOnlyHelperMock = ViewOnlyLinkHelperMock.simple(viewOnly);
     sentryMock = SentryMock.simple();
 
@@ -46,6 +53,7 @@ describe('errorInterceptor', () => {
         MockProvider(Router, router),
         MockProvider(ToastService, toastServiceMock),
         MockProvider(AuthService, authServiceMock),
+        MockProvider(MaintenanceModeService, maintenanceModeServiceMock),
         MockProvider(ViewOnlyLinkHelperService, viewOnlyHelperMock),
         MockProvider(PLATFORM_ID, platformId),
         { provide: SENTRY_TOKEN, useValue: sentryMock },
@@ -156,4 +164,21 @@ describe('errorInterceptor', () => {
     expect(loaderServiceMock.hide).toHaveBeenCalled();
     expect(toastServiceMock.showError).not.toHaveBeenCalled();
   });
+
+  it('should activate maintenance mode on 503 maintenance response', async () => {
+    setup('browser', false);
+    const request = createRequest('/api/v2/');
+    const error = new HttpErrorResponse({
+      status: 503,
+      error: { meta: { maintenance_mode: true } },
+      url: request.url,
+    });
+
+    const caught = await runInterceptor(request, error);
+
+    expect(caught?.status).toBe(503);
+    expect(maintenanceModeServiceMock.activate).toHaveBeenCalled();
+    expect(loaderServiceMock.hide).toHaveBeenCalled();
+    expect(toastServiceMock.showError).not.toHaveBeenCalled();
+  });
 });

src/app/core/interceptors/error.interceptor.ts

@@ -7,8 +7,10 @@ import { inject, PLATFORM_ID } from '@angular/core';
 import { Router } from '@angular/router';
 
 import { ERROR_MESSAGES } from '@core/constants/error-messages';
+import { MaintenanceResponse } from '@core/models/maintenance-response.model';
 import { SENTRY_TOKEN } from '@core/provider/sentry.provider';
 import { AuthService } from '@core/services/auth.service';
+import { MaintenanceModeService } from '@core/services/maintenance-mode.service';
 import { LoaderService } from '@osf/shared/services/loader.service';
 import { ToastService } from '@osf/shared/services/toast.service';
 import { ViewOnlyLinkHelperService } from '@osf/shared/services/view-only-link-helper.service';
@@ -20,6 +22,7 @@ export const errorInterceptor: HttpInterceptorFn = (req, next) => {
   const loaderService = inject(LoaderService);
   const router = inject(Router);
   const authService = inject(AuthService);
+  const maintenanceModeService = inject(MaintenanceModeService);
   const sentry = inject(SENTRY_TOKEN);
   const platformId = inject(PLATFORM_ID);
   const viewOnlyHelper = inject(ViewOnlyLinkHelperService);
@@ -43,6 +46,17 @@ export const errorInterceptor: HttpInterceptorFn = (req, next) => {
       }
 
       const serverErrorRegex = /5\d{2}/;
+      const maintenanceResponse = error.error as MaintenanceResponse | null;
+
+      const maintenanceMode = error.status === 503 && maintenanceResponse?.meta?.maintenance_mode === true;
+
+      if (maintenanceMode) {
+        loaderService.hide();
+        if (isPlatformBrowser(platformId)) {
+          maintenanceModeService.activate();
+        }
+        return throwError(() => error);
+      }
 
       if (serverErrorRegex.test(error.status.toString())) {
         errorMessage = error.error.message || 'common.errorMessages.serverError';

src/app/core/models/maintenance-response.model.ts

@@ -0,0 +1,5 @@
+export interface MaintenanceResponse {
+  meta?: {
+    maintenance_mode?: boolean;
+  };
+}

src/app/core/services/maintenance-mode.service.ts

@@ -0,0 +1,66 @@
+import { catchError, map, Observable, of, Subscription, switchMap, timer } from 'rxjs';
+
+import { HttpClient, HttpContext } from '@angular/common/http';
+import { inject, Injectable, OnDestroy, signal } from '@angular/core';
+
+import { MaintenanceResponse } from '@core/models/maintenance-response.model';
+import { ENVIRONMENT } from '@core/provider/environment.provider';
+
+import { BYPASS_ERROR_INTERCEPTOR } from '../interceptors/error-interceptor.tokens';
+
+@Injectable({
+  providedIn: 'root',
+})
+export class MaintenanceModeService implements OnDestroy {
+  private readonly http = inject(HttpClient);
+  private readonly environment = inject(ENVIRONMENT);
+
+  private readonly POLL_INTERVAL_MS = 5 * 60 * 1_000;
+  private readonly _isActive = signal(false);
+  private readonly bypassContext = new HttpContext().set(BYPASS_ERROR_INTERCEPTOR, true);
+
+  private pollingSubscription: Subscription | null = null;
+
+  readonly isActive = this._isActive.asReadonly();
+
+  activate(): void {
+    this._isActive.set(true);
+    if (this.pollingSubscription) {
+      return;
+    }
+    this.startPolling();
+  }
+
+  deactivate(): void {
+    this._isActive.set(false);
+    this.stopPolling();
+  }
+
+  ngOnDestroy(): void {
+    this.stopPolling();
+  }
+
+  private startPolling(): void {
+    this.pollingSubscription = timer(0, this.POLL_INTERVAL_MS)
+      .pipe(switchMap(() => this.checkMaintenanceStatus()))
+      .subscribe((isMaintenance) => {
+        if (!isMaintenance) {
+          this.deactivate();
+        }
+      });
+  }
+
+  private stopPolling(): void {
+    this.pollingSubscription?.unsubscribe();
+    this.pollingSubscription = null;
+  }
+
+  private checkMaintenanceStatus(): Observable<boolean> {
+    return this.http
+      .get<MaintenanceResponse>(`${this.environment.apiDomainUrl}/v2/`, { context: this.bypassContext })
+      .pipe(
+        map((response) => response.meta?.maintenance_mode === true),
+        catchError(() => of(true))
+      );
+  }
+}

src/assets/i18n/en.json

@@ -2824,6 +2824,10 @@
       }
     }
   },
+  "maintenance": {
+    "message": "Please come back later.",
+    "title": "The OSF is currently down for scheduled maintenance."
+  },
   "shared": {
     "affiliatedInstitutions": {
       "description": "This is a service provided by the OSF and is automatically applied to your registration. If you are not sure if your institution has signed up for this service, you can look for their name in this list."