feat(views): added view handling for diets, recipes, plans and posts

lib/features/feed/presentation/pages/feed_screen.dart

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:easy_debounce/easy_debounce.dart';
 import 'package:eatvio_app/core/const.dart';
 import 'package:eatvio_app/core/widgets/add_item_button.dart';
@@ -60,18 +62,19 @@ class _FeedScreenContentState extends State<FeedScreenContent> {
   final consultantsController = TextEditingController();
 
   late final List<String> chipsLabelList;
+  late final AppLifecycleListener _listener;
   int _selectedChipIndex = 0;
   final blogPostsScrollController = ScrollController();
   final recipesScrollController = ScrollController();
   final dietsScrollController = ScrollController();
   final plansScrollController = ScrollController();
   final consultantsScrollController = ScrollController();
-
+  final _feedCubit = sl<FeedCubit>();
   @override
   void initState() {
     // Initialize chipsLabelList based on hidePlans setting
     chipsLabelList = hidePlans ? ['Все', 'Рецепты', 'Диеты', 'Консультанты'] : ['Все', 'Рецепты', 'Диеты', 'Планы питания', 'Консультанты'];
-
+    _listener = AppLifecycleListener(onDetach: _sendViews);
     consultantsScrollController.addListener(_onScrollConsultants);
     super.initState();
   }
@@ -80,6 +83,21 @@ class _FeedScreenContentState extends State<FeedScreenContent> {
     if (consultantsScrollController.offset >= consultantsScrollController.position.maxScrollExtent && !consultantsScrollController.position.outOfRange) {}
   }
 
+  void _sendViews() {
+    if (postsIds.isNotEmpty) {
+      _feedCubit.viewContent(type: ViewableContentType.posts, ids: postsIds.toList());
+    }
+    if (plansIds.isNotEmpty) {
+      _feedCubit.viewContent(type: ViewableContentType.plans, ids: plansIds.toList());
+    }
+    if (dietsIds.isNotEmpty) {
+      _feedCubit.viewContent(type: ViewableContentType.diets, ids: dietsIds.toList());
+    }
+    if (recipesIds.isNotEmpty) {
+      _feedCubit.viewContent(type: ViewableContentType.recipes, ids: recipesIds.toList());
+    }
+  }
+
   @override
   void dispose() {
     blogPostsScrollController.dispose();
@@ -87,9 +105,64 @@ class _FeedScreenContentState extends State<FeedScreenContent> {
     dietsScrollController.dispose();
     plansScrollController.dispose();
     consultantsScrollController.dispose();
+    for (final map in _visibilityTimers.values) {
+      for (final t in map.values) {
+        t.cancel();
+      }
+      map.clear();
+    }
+    _listener.dispose();
+    _sendViews();
     super.dispose();
   }
 
+  final Set<int> postsIds = <int>{};
+  final Set<int> plansIds = <int>{};
+  final Set<int> dietsIds = <int>{};
+  final Set<int> recipesIds = <int>{};
+
+  final Map<ViewableContentType, Map<int, Timer>> _visibilityTimers = {
+    ViewableContentType.posts: <int, Timer>{},
+    ViewableContentType.plans: <int, Timer>{},
+    ViewableContentType.diets: <int, Timer>{},
+    ViewableContentType.recipes: <int, Timer>{},
+  };
+
+  Set<int> _idsForType(ViewableContentType type) {
+    switch (type) {
+      case ViewableContentType.posts:
+        return postsIds;
+      case ViewableContentType.plans:
+        return plansIds;
+      case ViewableContentType.diets:
+        return dietsIds;
+      case ViewableContentType.recipes:
+        return recipesIds;
+    }
+  }
+
+  void _handleVisibility({required double visibleFraction, required int id, required ViewableContentType type}) {
+    final timers = _visibilityTimers[type]!;
+    final ids = _idsForType(type);
+
+    if (ids.contains(id)) {
+      timers[id]?.cancel();
+      timers.remove(id);
+      return;
+    }
+
+    if (visibleFraction >= 0.5) {
+      if (timers.containsKey(id)) return;
+      timers[id] = Timer(const Duration(seconds: 1), () {
+        ids.add(id);
+        timers.remove(id);
+      });
+    } else {
+      timers[id]?.cancel();
+      timers.remove(id);
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     FlutterNativeSplash.remove();
@@ -228,10 +301,10 @@ class _FeedScreenContentState extends State<FeedScreenContent> {
           ];
         },
         body: switch (_selectedChipIndex) {
-          0 => const BlogPosts(),
-          1 => const Recipes(),
-          2 => const Diets(),
-          3 when !hidePlans => const Plans(),
+          0 => BlogPosts(handleVisibility: _handleVisibility),
+          1 => Recipes(handleVisibility: _handleVisibility),
+          2 => Diets(handleVisibility: _handleVisibility),
+          3 when !hidePlans => Plans(handleVisibility: _handleVisibility),
           3 when hidePlans => const Consultants(),
           4 when !hidePlans => const Consultants(),
           _ => Center(child: Text(chipsLabelList[_selectedChipIndex])),
@@ -240,3 +313,20 @@ class _FeedScreenContentState extends State<FeedScreenContent> {
     );
   }
 }
+
+enum ViewableContentType {
+  plans,
+  posts,
+  diets,
+  recipes;
+
+  String getStringifiedVersion() => switch (this) {
+    ViewableContentType.plans => 'plans',
+
+    ViewableContentType.posts => 'blog_posts',
+
+    ViewableContentType.diets => 'diets',
+
+    ViewableContentType.recipes => 'recipes',
+  };
+}