Merge pull request #6 from headlines-toolkit/feature_dashboard_summary_api_handling

Feature dashboard summary api handling

Author: fulleni

lib/src/registry/model_registry.dart

@@ -313,6 +313,27 @@ final modelRegistry = <String, ModelConfig<dynamic>>{
       type: RequiredPermissionType.adminOnly, // Only administrators can delete
     ),
   ),
+  'dashboard_summary': ModelConfig<DashboardSummary>(
+    fromJson: DashboardSummary.fromJson,
+    getId: (summary) => summary.id,
+    getOwnerId: null, // Not a user-owned resource
+    // Permissions: Read-only for admins, all other actions unsupported.
+    getCollectionPermission: const ModelActionPermission(
+      type: RequiredPermissionType.unsupported,
+    ),
+    getItemPermission: const ModelActionPermission(
+      type: RequiredPermissionType.adminOnly,
+    ),
+    postPermission: const ModelActionPermission(
+      type: RequiredPermissionType.unsupported,
+    ),
+    putPermission: const ModelActionPermission(
+      type: RequiredPermissionType.unsupported,
+    ),
+    deletePermission: const ModelActionPermission(
+      type: RequiredPermissionType.unsupported,
+    ),
+  ),
 };
 
 /// Type alias for the ModelRegistry map for easier provider usage.

lib/src/services/dashboard_summary_service.dart

@@ -0,0 +1,48 @@
+import 'package:ht_data_repository/ht_data_repository.dart';
+import 'package:ht_shared/ht_shared.dart';
+
+/// {@template dashboard_summary_service}
+/// A service responsible for calculating the dashboard summary data on demand.
+///
+/// This service aggregates data from various repositories to provide a
+/// real-time overview of key metrics in the system.
+/// {@endtemplate}
+class DashboardSummaryService {
+  /// {@macro dashboard_summary_service}
+  const DashboardSummaryService({
+    required HtDataRepository<Headline> headlineRepository,
+    required HtDataRepository<Category> categoryRepository,
+    required HtDataRepository<Source> sourceRepository,
+  })  : _headlineRepository = headlineRepository,
+        _categoryRepository = categoryRepository,
+        _sourceRepository = sourceRepository;
+
+  final HtDataRepository<Headline> _headlineRepository;
+  final HtDataRepository<Category> _categoryRepository;
+  final HtDataRepository<Source> _sourceRepository;
+
+  /// Calculates and returns the current dashboard summary.
+  ///
+  /// This method fetches all items from the required repositories to count them
+  /// and constructs a [DashboardSummary] object.
+  Future<DashboardSummary> getSummary() async {
+    // Use Future.wait to fetch all counts in parallel for efficiency.
+    final results = await Future.wait([
+      _headlineRepository.readAll(),
+      _categoryRepository.readAll(),
+      _sourceRepository.readAll(),
+    ]);
+
+    // The results are PaginatedResponse objects.
+    final headlineResponse = results[0] as PaginatedResponse<Headline>;
+    final categoryResponse = results[1] as PaginatedResponse<Category>;
+    final sourceResponse = results[2] as PaginatedResponse<Source>;
+
+    return DashboardSummary(
+      id: 'dashboard_summary', // Fixed ID for the singleton summary
+      headlineCount: headlineResponse.items.length,
+      categoryCount: categoryResponse.items.length,
+      sourceCount: sourceResponse.items.length,
+    );
+  }
+}

routes/_middleware.dart

@@ -5,6 +5,7 @@ import 'package:ht_api/src/registry/model_registry.dart';
 import 'package:ht_api/src/services/auth_service.dart';
 import 'package:ht_api/src/services/auth_token_service.dart';
 import 'package:ht_api/src/services/default_user_preference_limit_service.dart';
+import 'package:ht_api/src/services/dashboard_summary_service.dart';
 import 'package:ht_api/src/services/jwt_auth_token_service.dart';
 import 'package:ht_api/src/services/token_blacklist_service.dart';
 import 'package:ht_api/src/services/user_preference_limit_service.dart';
@@ -175,6 +176,14 @@ Handler middleware(Handler handler) {
       _createUserContentPreferencesRepository();
   final appConfigRepository = _createAppConfigRepository();
 
+  // Instantiate the new DashboardSummaryService with its dependencies
+  final dashboardSummaryService = DashboardSummaryService(
+    headlineRepository: headlineRepository,
+    categoryRepository: categoryRepository,
+    sourceRepository: sourceRepository,
+  );
+  print('[MiddlewareSetup] DashboardSummaryService instantiated.');
+
   const uuid = Uuid();
 
   // --- Auth Dependencies ---
@@ -308,6 +317,7 @@ Handler middleware(Handler handler) {
       .use(
         provider<AuthService>((_) => authService),
       ) // Reads other services/repos
+      .use(provider<DashboardSummaryService>((_) => dashboardSummaryService))
       // --- 5. RBAC Service Provider ---
       // PURPOSE: Provides the PermissionService for authorization checks.
       // ORDER:   Must be provided before any middleware or handlers that use it

routes/api/v1/data/[id].dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:dart_frog/dart_frog.dart';
 import 'package:ht_api/src/rbac/permission_service.dart';
 import 'package:ht_api/src/registry/model_registry.dart';
+import 'package:ht_api/src/services/dashboard_summary_service.dart';
 import 'package:ht_api/src/services/user_preference_limit_service.dart'; // Import UserPreferenceLimitService
 import 'package:ht_data_repository/ht_data_repository.dart';
 import 'package:ht_shared/ht_shared.dart';
@@ -122,6 +123,9 @@ Future<Response> _handleGet(
         id: id,
         userId: userIdForRepoCall,
       ); // userId should be null for AppConfig
+    case 'dashboard_summary':
+      final service = context.read<DashboardSummaryService>();
+      item = await service.getSummary();
     default:
       // This case should ideally be caught by middleware, but added for safety
       // Throw an exception to be caught by the errorHandler