1214: Add pois to favorites

frontend/assets/l10n/app_de.json

@@ -176,13 +176,24 @@
   "store": {
     "acceptingStore": "Akzeptanzstelle",
     "acceptingStoreNotFound": "Akzeptanzstelle nicht gefunden.",
+    "acceptingStoreNotAvailable": "Diese Akzeptanzstelle ist nicht mehr verfügbar.",
     "address": "Adresse",
     "email": "E-Mail",
     "loadingDataFailed": "Fehler beim Laden der Daten.",
     "noDescriptionAvailable": "Keine Beschreibung verfügbar",
     "phone": "Telefon",
     "showOnMap": "Auf Karte zeigen",
     "unknownCategory": "Unbekannte Kategorie",
-    "website": "Website"
+    "website": "Website",
+    "removeButtonText": "Entfernen",
+    "removeDescription": "Möchten Sie sie aus Ihren Favoriten entfernen?"
+  },
+  "favorites": {
+    "title": "Favoriten",
+    "noFavoritesFound": "Sie haben noch keine Akzeptanzstellen zu Ihren Favoriten hinzugefügt.",
+    "favoriteHasBeenAdded": "Die Akzeptanzstelle wurde zu den Favoriten hinzugefügt.",
+    "favoriteHasBeenRemoved": "Die Akzeptanzstelle wurde aus den Favoriten entfernt.",
+    "loadingFailed": "Fehler beim Laden der Favoriten.",
+    "updateFailed": "Fehler bei der Aktualisierung der Favoriten."
   }
 }

frontend/assets/l10n/app_en.json

@@ -174,15 +174,26 @@
     "title": "Search"
   },
   "store": {
-    "acceptingStore": "Acceptance points",
+    "acceptingStore": "Acceptance point",
     "acceptingStoreNotFound": "Acceptance point not found.",
+    "acceptingStoreNotAvailable": "This acceptance point is no longer available.",
     "address": "Address",
     "email": "E-Mail",
     "loadingDataFailed": "Error loading the data.",
     "noDescriptionAvailable": "No description available",
     "phone": "Phone",
     "showOnMap": "Show on map",
     "unknownCategory": "Unknown category",
-    "website": "Website"
+    "website": "Website",
+    "removeButtonText": "Remove",
+    "removeDescription": "Would you like to remove it from your favorites?"
+  },
+  "favorites": {
+    "title": "Favorites",
+    "noFavoritesFound": "You have not added any acceptance points to your favorites yet.",
+    "favoriteHasBeenAdded": "The acceptance point has been added to the favorites.",
+    "favoriteHasBeenRemoved": "The acceptance point has been removed from the favorites.",
+    "loadingFailed": "Failed to load favorites.",
+    "updateFailed": "Failed to update favorites."
   }
 }

frontend/lib/app.dart

@@ -3,6 +3,7 @@ import 'package:ehrenamtskarte/build_config/build_config.dart';
 import 'package:ehrenamtskarte/configuration/configuration.dart';
 import 'package:ehrenamtskarte/configuration/definitions.dart';
 import 'package:ehrenamtskarte/configuration/settings_model.dart';
+import 'package:ehrenamtskarte/favorites/favorites_model.dart';
 import 'package:ehrenamtskarte/graphql/configured_graphql_provider.dart';
 import 'package:ehrenamtskarte/identification/user_code_model.dart';
 import 'package:ehrenamtskarte/intro_slides/intro_screen.dart';
@@ -109,8 +110,11 @@ class App extends StatelessWidget {
       projectId: projectId,
       showDevSettings: kDebugMode,
       child: ConfiguredGraphQlProvider(
-        child: ChangeNotifierProvider(
-          create: (context) => UserCodeModel()..initialize(),
+        child: MultiProvider(
+          providers: [
+            ChangeNotifierProvider<UserCodeModel>(create: (_) => UserCodeModel()..initialize()),
+            ChangeNotifierProvider<FavoritesModel>(create: (_) => FavoritesModel()..initialize())
+          ],
           child: MaterialApp.router(
             theme: lightTheme,
             darkTheme: darkTheme,

frontend/lib/favorites/favorite_store.dart

@@ -0,0 +1,18 @@
+import 'package:ehrenamtskarte/graphql/graphql_api.graphql.dart';
+
+class FavoriteStore {
+  final int storeId;
+  final String storeName;
+  final int categoryId;
+
+  AcceptingStoreById$Query$PhysicalStore? physicalStore;
+
+  FavoriteStore(this.storeId, this.storeName, this.categoryId);
+
+  FavoriteStore.fromJson(Map<String, dynamic> json)
+      : storeId = json['storeId'] as int,
+        storeName = json['storeName'] as String,
+        categoryId = json['categoryId'] as int;
+
+  Map<String, dynamic> toJson() => {'storeId': storeId, 'storeName': storeName, 'categoryId': categoryId};
+}

frontend/lib/favorites/favorites_loader.dart

@@ -0,0 +1,204 @@
+import 'dart:math';
+
+import 'package:flutter/material.dart';
+import 'package:graphql_flutter/graphql_flutter.dart';
+import 'package:infinite_scroll_pagination/infinite_scroll_pagination.dart';
+
+import 'package:ehrenamtskarte/graphql/graphql_api.graphql.dart';
+import 'package:ehrenamtskarte/home/home_page.dart';
+import 'package:ehrenamtskarte/favorites/favorites_model.dart';
+import 'package:ehrenamtskarte/favorites/favorite_store.dart';
+import 'package:ehrenamtskarte/map/preview/models.dart';
+import 'package:ehrenamtskarte/store_widgets/accepting_store_summary.dart';
+import 'package:ehrenamtskarte/store_widgets/removed_store_summary.dart';
+import 'package:ehrenamtskarte/configuration/configuration.dart';
+import 'package:ehrenamtskarte/l10n/translations.g.dart';
+import 'package:provider/provider.dart';
+
+class FavoritesLoader extends StatefulWidget {
+  const FavoritesLoader({super.key});
+
+  @override
+  State<StatefulWidget> createState() => FavoritesLoaderState();
+}
+
+class FavoritesLoaderState extends State<FavoritesLoader> {
+  static const _pageSize = 20;
+
+  GraphQLClient? _client;
+
+  late FavoritesModel _favoritesModel;
+
+  final PagingController<int, FavoriteStore> _pagingController = PagingController(firstPageKey: 0);
+
+  @override
+  void initState() {
+    super.initState();
+    _pagingController.addPageRequestListener(_fetchPage);
+    _favoritesModel = Provider.of<FavoritesModel>(context, listen: false);
+    _favoritesModel.addListener(() {
+      _pagingController.refresh();
+    });
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final client = GraphQLProvider.of(context).value;
+    if (client != _client) {
+      _client = client;
+    }
+  }
+
+  @override
+  void didUpdateWidget(FavoritesLoader oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    _pagingController.refresh();
+  }
+
+  Future<void> _fetchPage(int pageKey) async {
+    try {
+      final favoritesModel = _favoritesModel;
+      if (!favoritesModel.isInitialized) {
+        throw Exception('Failed to load favorites');
+      }
+
+      final favorites = favoritesModel.getFavoriteIds();
+
+      if (favorites.isEmpty || pageKey >= favorites.length) {
+        _pagingController.appendLastPage(List.empty());
+        return;
+      }
+
+      final fetchIds = favorites.getRange(pageKey, min(pageKey + _pageSize, favorites.length)).toList();
+
+      final newItems = await Future.wait(fetchIds
+          .map((id) async => favoritesModel.getFavoriteStore(id)..physicalStore = await _fetchPhysicalStore(id)));
+
+      final isLastPage = newItems.length < _pageSize;
+      if (isLastPage) {
+        _pagingController.appendLastPage(newItems);
+      } else {
+        final nextPageKey = pageKey + newItems.length;
+        _pagingController.appendPage(newItems, nextPageKey);
+      }
+    } catch (error) {
+      _pagingController.error = error;
+    }
+  }
+
+  Future<AcceptingStoreById$Query$PhysicalStore?> _fetchPhysicalStore(int storeId) async {
+    final projectId = Configuration.of(context).projectId;
+
+    final query = AcceptingStoreByIdQuery(variables: AcceptingStoreByIdArguments(project: projectId, ids: [storeId]));
+
+    final client = _client;
+    if (client == null) {
+      throw Exception('GraphQL client is not yet initialized!');
+    }
+
+    final result = await client.query(QueryOptions(document: query.document, variables: query.getVariablesMap()));
+    final exception = result.exception;
+    if (result.hasException && exception != null) {
+      throw exception;
+    }
+
+    final data = result.data;
+    if (data == null) {
+      throw Exception('Fetched data is null');
+    }
+    return query.parse(data).physicalStoresByIdInProject.firstOrNull;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return PagedSliverList<int, FavoriteStore>.separated(
+      pagingController: _pagingController,
+      builderDelegate: PagedChildBuilderDelegate<FavoriteStore>(
+        itemBuilder: _buildItem,
+        noItemsFoundIndicatorBuilder: _buildNoItemsFoundIndicator,
+        firstPageErrorIndicatorBuilder: _buildErrorWithRetry,
+        newPageErrorIndicatorBuilder: _buildErrorWithRetry,
+        firstPageProgressIndicatorBuilder: _buildProgressIndicator,
+        newPageProgressIndicatorBuilder: _buildProgressIndicator,
+      ),
+      separatorBuilder: (context, index) => const Divider(height: 0),
+    );
+  }
+
+  Widget _buildItem(BuildContext context, FavoriteStore item, index) {
+    final physicalStore = item.physicalStore;
+    if (physicalStore != null) {
+      return IntrinsicHeight(
+        child: AcceptingStoreSummary(
+          key: ValueKey(physicalStore.id),
+          store: AcceptingStoreSummaryModel(
+            physicalStore.id,
+            physicalStore.store.name,
+            physicalStore.store.description,
+            physicalStore.store.category.id,
+            null,
+            null,
+          ),
+          showOnMap: (it) => HomePageData.of(context)?.navigateToMapTab(it),
+        ),
+      );
+    } else {
+      return IntrinsicHeight(
+        child: RemovedStoreSummary(
+          storeId: item.storeId,
+          storeName: item.storeName,
+          categoryId: item.categoryId,
+        ),
+      );
+    }
+  }
+
+  Widget _buildProgressIndicator(BuildContext context) =>
+      const Center(child: Padding(padding: EdgeInsets.all(5), child: CircularProgressIndicator()));
+
+  Widget _buildErrorWithRetry(BuildContext context) {
+    final t = context.t;
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          const Icon(Icons.warning, size: 60, color: Colors.orange),
+          Text(t.favorites.loadingFailed),
+          OutlinedButton(
+            onPressed: _pagingController.retryLastFailedRequest,
+            child: Text(t.common.tryAgain),
+          )
+        ],
+      ),
+    );
+  }
+
+  Widget _buildNoItemsFoundIndicator(BuildContext context) {
+    final t = context.t;
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(Icons.search_off, size: 60, color: Theme.of(context).disabledColor),
+          Padding(
+            padding: const EdgeInsets.all(8.0),
+            child: Text(
+              t.favorites.noFavoritesFound,
+              textAlign: TextAlign.center,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  @override
+  void dispose() {
+    _favoritesModel.removeListener(() {
+      _pagingController.refresh();
+    });
+    _pagingController.dispose();
+    super.dispose();
+  }
+}

frontend/lib/favorites/favorites_model.dart

@@ -0,0 +1,65 @@
+import 'dart:developer';
+
+import 'package:flutter/cupertino.dart';
+
+import 'package:ehrenamtskarte/favorites/favorites_storage.dart';
+import 'package:ehrenamtskarte/favorites/favorite_store.dart';
+
+class FavoritesModel extends ChangeNotifier {
+  List<FavoriteStore> _favoriteStores = [];
+  bool _isInitialized = false;
+
+  Future<void> initialize() async {
+    if (_isInitialized) {
+      return;
+    }
+    try {
+      _favoriteStores = await FavoritesStorage().readFavorites();
+      _isInitialized = true;
+    } catch (error) {
+      log('Failed to load favorites from secure storage', error: error);
+    } finally {
+      notifyListeners();
+    }
+  }
+
+  bool get isInitialized {
+    return _isInitialized;
+  }
+
+  List<FavoriteStore> get favoriteStores {
+    return _favoriteStores;
+  }
+
+  List<int> getFavoriteIds() {
+    return _favoriteStores.map((item) => item.storeId).toList();
+  }
+
+  FavoriteStore getFavoriteStore(int storeId) {
+    return _favoriteStores.where((item) => item.storeId == storeId).first;
+  }
+
+  bool isFavorite(int storeId) {
+    return getFavoriteIds().contains(storeId);
+  }
+
+  Future<void> saveFavorite(FavoriteStore newFavoriteStore) async {
+    if (isFavorite(newFavoriteStore.storeId)) {
+      return;
+    }
+    final favoriteStores = [..._favoriteStores, newFavoriteStore];
+    await FavoritesStorage().writeFavorites(favoriteStores);
+    _favoriteStores = favoriteStores;
+    notifyListeners();
+  }
+
+  Future<void> removeFavorite(int storeId) async {
+    if (!isFavorite(storeId)) {
+      return;
+    }
+    final favoriteStores = [..._favoriteStores]..removeWhere((item) => item.storeId == storeId);
+    await FavoritesStorage().writeFavorites(favoriteStores);
+    _favoriteStores = favoriteStores;
+    notifyListeners();
+  }
+}

frontend/lib/favorites/favorites_page.dart

@@ -0,0 +1,30 @@
+import 'package:ehrenamtskarte/favorites/favorites_loader.dart';
+import 'package:ehrenamtskarte/l10n/translations.g.dart';
+import 'package:flutter/material.dart';
+
+class FavoritesPage extends StatefulWidget {
+  const FavoritesPage({super.key});
+
+  @override
+  State<StatefulWidget> createState() => _FavoritesPageState();
+}
+
+class _FavoritesPageState extends State<FavoritesPage> {
+  @override
+  Widget build(BuildContext context) {
+    final t = context.t;
+
+    return Stack(
+      children: [
+        CustomScrollView(
+          slivers: [
+            SliverAppBar(
+              title: Text(t.favorites.title),
+            ),
+            FavoritesLoader()
+          ],
+        ),
+      ],
+    );
+  }
+}