feat: add HTML providers for Realbooru and Paheal, hidden posts screen, and UI/search enhancements

lib/features/viewed/presentation/viewed_controller.dart

@@ -4,11 +4,13 @@ import '../../../backend/backend.dart';
 import '../../../core/utils/result.dart';
 
 final viewedControllerProvider =
-    AsyncNotifierProvider<ViewedController, List<Post>>(ViewedController.new);
+    AsyncNotifierProvider<ViewedController, List<ViewedTimelineGroup>>(
+  ViewedController.new,
+);
 
-class ViewedController extends AsyncNotifier<List<Post>> {
+class ViewedController extends AsyncNotifier<List<ViewedTimelineGroup>> {
   @override
-  Future<List<Post>> build() => _load();
+  Future<List<ViewedTimelineGroup>> build() => _load();
 
   Future<void> refresh() async {
     state = AsyncData(await _load());
@@ -20,9 +22,44 @@ class ViewedController extends AsyncNotifier<List<Post>> {
     state = const AsyncData([]);
   }
 
-  Future<List<Post>> _load() async {
+  Future<List<ViewedTimelineGroup>> _load() async {
     final result =
-        await ref.read(viewedHistoryServiceProvider).getViewedPosts();
-    return result is Success<List<Post>> ? result.data : const [];
+        await ref.read(viewedHistoryServiceProvider).getViewedPostEntries();
+    if (result is! Success<List<ViewedPostEntry>>) return const [];
+    return groupViewedTimeline(result.data);
   }
 }
+
+class ViewedTimelineGroup {
+  const ViewedTimelineGroup({required this.label, required this.items});
+
+  final String label;
+  final List<ViewedPostEntry> items;
+}
+
+List<ViewedTimelineGroup> groupViewedTimeline(
+  List<ViewedPostEntry> entries, {
+  DateTime? now,
+}) {
+  final today = DateTime(now?.year ?? DateTime.now().year,
+      now?.month ?? DateTime.now().month, now?.day ?? DateTime.now().day);
+  final buckets = <String, List<ViewedPostEntry>>{};
+  for (final entry in entries) {
+    final date =
+        DateTime(entry.viewedAt.year, entry.viewedAt.month, entry.viewedAt.day);
+    final days = today.difference(date).inDays;
+    final label = switch (days) {
+      0 => 'Today',
+      1 => 'Yesterday',
+      _ => _dateLabel(date),
+    };
+    buckets.putIfAbsent(label, () => []).add(entry);
+  }
+  return [
+    for (final entry in buckets.entries)
+      ViewedTimelineGroup(label: entry.key, items: entry.value),
+  ];
+}
+
+String _dateLabel(DateTime date) =>
+    '${date.year.toString().padLeft(4, '0')}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';