First attempt at frontend

Author: alex-deng-featurehub

admin-frontend/open_admin_app/lib/api/client_api.dart

@@ -67,8 +67,13 @@ class ManagementRepositoryClientBloc implements Bloc {
   late GroupServiceApi groupServiceApi;
   late WebhookServiceApi webhookServiceApi;
   late TrackEventsServiceApi trackEventsServiceApi;
+  late MaintenanceBannerServiceApi _maintenanceBannerApi;
   static late FHRouter router;
 
+  final _maintenanceSource = BehaviorSubject<MaintenanceInfo?>.seeded(null);
+
+  Stream<MaintenanceInfo?> get maintenanceStream => _maintenanceSource.stream;
+
   // this reflects actual requests to change the route driven externally, so a user clicks on
   // something that should cause the page to change to this route.
   final _routerSource = BehaviorSubject<RouteChange?>();
@@ -152,6 +157,33 @@ class ManagementRepositoryClientBloc implements Bloc {
     // this is for fine grained route changes, like tab changes
     _routerSource.add(route);
     prefs.saveCurrentRoute(route.toJson());
+
+    // poll maintenance banner on every navigation for already-logged-in users
+    if (personState.isLoggedIn) {
+      _checkMaintenanceBanner();
+    }
+  }
+
+  /// Temporarily hides the maintenance banner for the current session until
+  /// the next navigation event re-polls the backend.
+  void dismissMaintenanceBanner() {
+    _maintenanceSource.add(null);
+  }
+
+  Future<void> _checkMaintenanceBanner() async {
+    try {
+      final response = await _maintenanceBannerApi.apiDelegate
+          .getMaintenanceBanner();
+      if (response.statusCode == 204) {
+        _maintenanceSource.add(null);
+      } else if (response.statusCode == 200) {
+        final info = await _maintenanceBannerApi.apiDelegate
+            .getMaintenanceBanner_decode(response.body!);
+        _maintenanceSource.add(info.active ? info : null);
+      }
+    } catch (_) {
+      // silently ignore — maintenance check should never break navigation
+    }
   }
 
   void _initializeRouteStreams() {
@@ -290,6 +322,7 @@ class ManagementRepositoryClientBloc implements Bloc {
     groupServiceApi = GroupServiceApi(client);
     webhookServiceApi = WebhookServiceApi(client);
     trackEventsServiceApi = TrackEventsServiceApi(client);
+    _maintenanceBannerApi = MaintenanceBannerServiceApi(client);
     _errorSource.add(null);
     streamValley.apiClient = this;
 
@@ -342,6 +375,11 @@ class ManagementRepositoryClientBloc implements Bloc {
 
       identityProviders.identityInfo = setupResponse.providerInfo;
 
+      // Seed maintenance banner from initial load
+      _maintenanceSource.add(setupResponse.maintenanceInfo?.active == true
+          ? setupResponse.maintenanceInfo
+          : null);
+
       // yes its initialised, we may not have logged in yet
       if (bearerToken != null) {
         setBearerToken(bearerToken);
@@ -576,6 +614,7 @@ class ManagementRepositoryClientBloc implements Bloc {
     _errorSource.close();
     _overlaySource.close();
     _snackbarSource.close();
+    _maintenanceSource.close();
     personState.dispose();
   }
 

admin-frontend/open_admin_app/lib/widgets/common/fh_scaffold.dart

@@ -12,6 +12,7 @@ import 'package:open_admin_app/widgets/stepper/stepper_container.dart';
 
 import 'fh_drawer.dart';
 import 'fh_error.dart';
+import 'maintenance_banner_widget.dart';
 
 class FHScaffoldWidget extends StatefulWidget {
   final Widget body;
@@ -115,6 +116,7 @@ class _InternalFHScaffoldWidgetWidgetState extends StatelessWidget {
                 mainAxisAlignment: MainAxisAlignment.start,
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
+                  const MaintenanceBannerWidget(),
                   _mainContent(context),
                 ]),
           );

admin-frontend/open_admin_app/lib/widgets/common/maintenance_banner_widget.dart

@@ -0,0 +1,68 @@
+import 'package:bloc_provider/bloc_provider.dart';
+import 'package:flutter/material.dart';
+import 'package:mrapi/api.dart';
+import 'package:open_admin_app/api/client_api.dart';
+
+/// Shows a dismissible warning banner at the top of every page when the
+/// system is in a maintenance window.  Listens to [ManagementRepositoryClientBloc.maintenanceStream]
+/// and rebuilds automatically when the state changes.
+class MaintenanceBannerWidget extends StatelessWidget {
+  const MaintenanceBannerWidget({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final mrBloc = BlocProvider.of<ManagementRepositoryClientBloc>(context);
+    return StreamBuilder<MaintenanceInfo?>(
+      stream: mrBloc.maintenanceStream,
+      builder: (context, snapshot) {
+        final info = snapshot.data;
+        if (info == null || !info.active) return const SizedBox.shrink();
+
+        final message = (info.message != null && info.message!.isNotEmpty)
+            ? info.message!
+            : 'The system is undergoing maintenance. Some features may be unavailable.';
+
+        return Material(
+          color: Colors.transparent,
+          child: Container(
+            width: double.infinity,
+            color: Theme.of(context).colorScheme.errorContainer,
+            padding:
+                const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
+            child: Row(
+              crossAxisAlignment: CrossAxisAlignment.center,
+              children: [
+                Icon(
+                  Icons.warning_amber_rounded,
+                  color: Theme.of(context).colorScheme.onErrorContainer,
+                  size: 20,
+                ),
+                const SizedBox(width: 8),
+                Expanded(
+                  child: Text(
+                    message,
+                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                          color:
+                              Theme.of(context).colorScheme.onErrorContainer,
+                        ),
+                  ),
+                ),
+                IconButton(
+                  icon: Icon(
+                    Icons.close,
+                    size: 18,
+                    color: Theme.of(context).colorScheme.onErrorContainer,
+                  ),
+                  tooltip: 'Dismiss',
+                  padding: EdgeInsets.zero,
+                  constraints: const BoxConstraints(),
+                  onPressed: () => mrBloc.dismissMaintenanceBanner(),
+                ),
+              ],
+            ),
+          ),
+        );
+      },
+    );
+  }
+}

backend/mr-api/mr-api.yaml

@@ -2764,7 +2764,8 @@ components:
         maintenanceInfo:
           description: "If present, the system is in or near a maintenance window"
           nullable: true
-          $ref: "#/components/schemas/MaintenanceInfo"
+          allOf:
+            - $ref: "#/components/schemas/MaintenanceInfo"
     IdentityProviderInfo:
       type: object
       required: