refactor: Use bloc for source filtering

fulleni · fulleni · commit 7130cc7f35ef · 2025-04-14T10:07:36.000+01:00
- Implemented SourcesFilterBloc
- Handles loading, error and empty states
- Implements pagination
diff --git a/lib/headlines-feed/view/source_filter_page.dart b/lib/headlines-feed/view/source_filter_page.dart
@@ -1,20 +1,21 @@
-//
 // ignore_for_file: lines_longer_than_80_chars
 
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:go_router/go_router.dart';
+import 'package:ht_main/headlines-feed/bloc/sources_filter_bloc.dart'; // Import the BLoC
 import 'package:ht_main/l10n/l10n.dart';
 import 'package:ht_main/shared/constants/constants.dart';
 import 'package:ht_main/shared/widgets/widgets.dart'; // For loading/error widgets
 import 'package:ht_sources_client/ht_sources_client.dart';
-import 'package:ht_sources_repository/ht_sources_repository.dart';
+// Removed repository import: import 'package:ht_sources_repository/ht_sources_repository.dart';
 
 /// {@template source_filter_page}
 /// A page dedicated to selecting news sources for filtering headlines.
 ///
-/// Fetches sources paginatively, allows multiple selections, and returns
-/// the selected list via `context.pop` when the user applies the changes.
+/// Uses [SourcesFilterBloc] to fetch sources paginatively, allows multiple
+/// selections, and returns the selected list via `context.pop` when the user
+/// applies the changes.
 /// {@endtemplate}
 class SourceFilterPage extends StatefulWidget {
   /// {@macro source_filter_page}
@@ -26,32 +27,13 @@ class SourceFilterPage extends StatefulWidget {
 
 /// State for the [SourceFilterPage].
 ///
-/// Manages the local selection state ([_pageSelectedSources]), fetches
-/// sources from the [HtSourcesRepository], handles pagination using a
-/// [ScrollController], and displays loading/error/empty/loaded states.
+/// Manages the local selection state ([_pageSelectedSources]) and interacts
+/// with [SourcesFilterBloc] for data fetching and pagination.
 class _SourceFilterPageState extends State<SourceFilterPage> {
   /// Stores the sources selected by the user on this page.
   /// Initialized from the `extra` parameter passed during navigation.
   late Set<Source> _pageSelectedSources;
 
-  /// List of all sources fetched from the repository.
-  List<Source> _allSources = [];
-
-  /// Flag indicating if the initial source list is being loaded.
-  bool _isLoading = true;
-
-  /// Flag indicating if more sources are being loaded for pagination.
-  bool _isLoadingMore = false;
-
-  /// Flag indicating if more sources are available to fetch.
-  bool _hasMore = true;
-
-  /// Cursor for fetching the next page of sources.
-  String? _cursor;
-
-  /// Stores any error message that occurred during fetching.
-  String? _error;
-
   /// Scroll controller to detect when the user reaches the end of the list
   /// for pagination.
   final _scrollController = ScrollController();
@@ -63,7 +45,8 @@ class _SourceFilterPageState extends State<SourceFilterPage> {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       final initialSelection = GoRouterState.of(context).extra as List<Source>?;
       _pageSelectedSources = Set.from(initialSelection ?? []);
-      _fetchSources(); // Initial fetch
+      // Request initial sources from the BLoC
+      context.read<SourcesFilterBloc>().add(SourcesFilterRequested());
     });
     _scrollController.addListener(_onScroll);
   }
@@ -76,63 +59,20 @@ class _SourceFilterPageState extends State<SourceFilterPage> {
     super.dispose();
   }
 
-  /// Fetches sources from the [HtSourcesRepository].
-  ///
-  /// Handles both initial fetch and pagination (`loadMore = true`). Updates
-  /// loading states, fetched data ([_allSources]), pagination info
-  /// ([_cursor], [_hasMore]), and error state ([_error]).
-  Future<void> _fetchSources({bool loadMore = false}) async {
-    // Prevent unnecessary fetches
-    if (!loadMore && _isLoading) return;
-    if (loadMore && (_isLoadingMore || !_hasMore)) return;
-
-    setState(() {
-      if (loadMore) {
-        _isLoadingMore = true;
-      } else {
-        _isLoading = true;
-        _error = null;
-      }
-    });
-
-    try {
-      // Ensure HtSourcesRepository is provided higher up in the widget tree
-      final repo = context.read<HtSourcesRepository>();
-      final response = await repo.getSources(
-        limit: 20, // Adjust limit as needed
-        startAfterId: loadMore ? _cursor : null,
-      );
-
-      setState(() {
-        if (loadMore) {
-          _allSources.addAll(response.items);
-        } else {
-          _allSources = response.items;
-        }
-        _cursor = response.cursor;
-        _hasMore = response.hasMore;
-        _isLoading = false;
-        _isLoadingMore = false;
-      });
-    } catch (e) {
-      setState(() {
-        _isLoading = false;
-        _isLoadingMore = false;
-        _error = e.toString();
-      });
-    }
-  }
-
   /// Callback function for scroll events.
   ///
   /// Checks if the user has scrolled near the bottom of the list and triggers
-  /// fetching more sources if available.
+  /// fetching more sources via the BLoC if available.
   void _onScroll() {
     if (!_scrollController.hasClients) return;
     final maxScroll = _scrollController.position.maxScrollExtent;
     final currentScroll = _scrollController.offset;
-    if (currentScroll >= (maxScroll * 0.9) && _hasMore && !_isLoadingMore) {
-      _fetchSources(loadMore: true);
+    final bloc = context.read<SourcesFilterBloc>();
+    // Fetch more when nearing the bottom, if BLoC has more and isn't already loading more
+    if (currentScroll >= (maxScroll * 0.9) &&
+        bloc.state.hasMore &&
+        bloc.state.status != SourcesFilterStatus.loadingMore) {
+      bloc.add(SourcesFilterLoadMoreRequested());
     }
   }
 
@@ -153,61 +93,95 @@ class _SourceFilterPageState extends State<SourceFilterPage> {
           ),
         ],
       ),
-      body: _buildBody(context),
+      // Use BlocBuilder to react to state changes from SourcesFilterBloc
+      body: BlocBuilder<SourcesFilterBloc, SourcesFilterState>(
+        builder: (context, state) {
+          return _buildBody(context, state);
+        },
+      ),
     );
   }
 
-  /// Builds the main content body based on the current loading/error/data state.
-  Widget _buildBody(BuildContext context) {
+  /// Builds the main content body based on the current [SourcesFilterState].
+  Widget _buildBody(BuildContext context, SourcesFilterState state) {
     final l10n = context.l10n;
-    if (_isLoading) {
-      // Show initial loading indicator
+
+    // Handle initial loading state
+    if (state.status == SourcesFilterStatus.loading) {
       return LoadingStateWidget(
         icon: Icons.source_outlined,
         headline: l10n.sourceFilterLoadingHeadline,
         subheadline: l10n.sourceFilterLoadingSubheadline,
       );
     }
 
-    if (_error != null) {
-      return FailureStateWidget(message: _error!, onRetry: _fetchSources);
+    // Handle failure state (show error and retry button)
+    if (state.status == SourcesFilterStatus.failure && state.sources.isEmpty) {
+      return FailureStateWidget(
+        message: state.error?.toString() ?? l10n.unknownError, // Assumes unknownError exists
+        onRetry: () =>
+            context.read<SourcesFilterBloc>().add(SourcesFilterRequested()),
+      );
     }
 
-    if (_allSources.isEmpty) {
+    // Handle empty state (after successful load but no sources found)
+    if (state.status == SourcesFilterStatus.success && state.sources.isEmpty) {
       return InitialStateWidget(
         icon: Icons.search_off,
         headline: l10n.sourceFilterEmptyHeadline,
         subheadline: l10n.sourceFilterEmptySubheadline,
       );
     }
 
+    // Handle loaded state (success or loading more)
     return ListView.builder(
       controller: _scrollController,
       padding: const EdgeInsets.only(bottom: AppSpacing.xxl),
-      itemCount: _allSources.length + (_hasMore ? 1 : 0),
+      itemCount: state.sources.length +
+          ((state.status == SourcesFilterStatus.loadingMore ||
+                  (state.status == SourcesFilterStatus.failure &&
+                      state.sources.isNotEmpty))
+              ? 1
+              : 0),
       itemBuilder: (context, index) {
-        if (index >= _allSources.length) {
-          return _isLoadingMore
-              ? const Padding(
-                padding: EdgeInsets.symmetric(vertical: AppSpacing.lg),
-                child: Center(child: CircularProgressIndicator()),
-              )
-              : const SizedBox.shrink();
+        if (index >= state.sources.length) {
+          if (state.status == SourcesFilterStatus.loadingMore) {
+            return const Padding(
+              padding: EdgeInsets.symmetric(vertical: AppSpacing.lg),
+              child: Center(child: CircularProgressIndicator()),
+            );
+          } else if (state.status == SourcesFilterStatus.failure) {
+            return Padding(
+              padding: const EdgeInsets.symmetric(
+                vertical: AppSpacing.md,
+                horizontal: AppSpacing.lg,
+              ),
+              child: Center(
+                child: Text(
+                  l10n.loadMoreError, // Assumes loadMoreError exists
+                  style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                        color: Theme.of(context).colorScheme.error,
+                      ),
+                ),
+              ),
+            );
+          } else {
+            return const SizedBox.shrink();
+          }
         }
 
-        final source = _allSources[index];
+        final source = state.sources[index];
         final isSelected = _pageSelectedSources.contains(source);
 
-        // Sources don't have icons in the model, so just use text
         return CheckboxListTile(
           title: Text(source.name),
           subtitle:
               source.description != null && source.description!.isNotEmpty
                   ? Text(
-                    source.description!,
-                    maxLines: 1,
-                    overflow: TextOverflow.ellipsis,
-                  )
+                      source.description!,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                    )
                   : null,
           value: isSelected,
           onChanged: (bool? value) {
