feat: 逻辑与页面布局分离

lib/pages/discover/discover_logic.dart

@@ -2,8 +2,11 @@ import 'package:flutter/material.dart';
 
 import '../../core/data/models/drama.dart';
 import '../../core/data/repositories/watch_history_repository.dart';
+import '../../l10n/app_localizations.dart';
 
-class DiscoverLogic {
+enum DiscoverPageAction { home, my, watchlist, detail, resume }
+
+class DiscoverLogic extends ChangeNotifier {
   DiscoverLogic({required this.history, required this.drama}) {
     refreshPosition();
   }
@@ -15,6 +18,11 @@ class DiscoverLogic {
   final FocusNode searchFocus = FocusNode();
   final ScrollController scroll = ScrollController();
   int category = 0;
+  bool _disposed = false;
+
+  void notify() {
+    if (!_disposed) notifyListeners();
+  }
 
   void refreshPosition() {
     position = history.positionFor(
@@ -24,9 +32,125 @@ class DiscoverLogic {
     );
   }
 
+  void selectCategory(int index) {
+    category = index;
+    notify();
+  }
+
+  void onSearchChanged() => notify();
+
+  void syncDrama({
+    required bool active,
+    required bool wasActive,
+    required Drama nextDrama,
+    required bool dramaChanged,
+    required int searchRequest,
+    required int previousSearchRequest,
+    required bool Function() isActive,
+  }) {
+    if (active && (!wasActive || dramaChanged)) {
+      drama = nextDrama;
+      refreshPosition();
+      notify();
+    }
+    if (active && searchRequest != previousSearchRequest) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (isActive()) searchFocus.requestFocus();
+      });
+    }
+  }
+
+  void act(
+    BuildContext context,
+    DiscoverPageAction action, {
+    required bool embedded,
+    ValueChanged<DiscoverPageAction>? onAction,
+  }) {
+    if (embedded) {
+      onAction?.call(action);
+    } else {
+      Navigator.pop(context, action);
+    }
+  }
+
+  Drama? dramaFor(String? dramaId, List<Drama> dramas) {
+    for (final item in dramas) {
+      if (item.id == dramaId) return item;
+    }
+    return null;
+  }
+
+  void openCard(
+    BuildContext context,
+    Drama? selected, {
+    required bool embedded,
+    ValueChanged<Drama>? onDramaSelected,
+    ValueChanged<DiscoverPageAction>? onAction,
+  }) {
+    if (selected == null) {
+      unavailable(context);
+    } else if (embedded && onDramaSelected != null) {
+      onDramaSelected(selected);
+    } else {
+      act(context, DiscoverPageAction.detail, embedded: embedded, onAction: onAction);
+    }
+  }
+
+  void unavailable(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(l10n.artworkOnlyNotice)));
+  }
+
+  void catalogInfo(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(l10n.demoCatalogNotice)));
+  }
+
+  void showFilters(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    final labels = [
+      l10n.featured,
+      l10n.suspense,
+      l10n.romance,
+      l10n.actionGenre,
+    ];
+    showModalBottomSheet<void>(
+      context: context,
+      backgroundColor: const Color(0xFF202126),
+      showDragHandle: true,
+      builder: (sheetContext) => SafeArea(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            ListTile(title: Text(l10n.filter)),
+            for (var index = 0; index < labels.length; index++)
+              ListTile(
+                title: Text(labels[index]),
+                trailing: index == category
+                    ? const Icon(Icons.check_rounded, color: Color(0xFFFF5B3D))
+                    : null,
+                onTap: () {
+                  selectCategory(index);
+                  Navigator.pop(sheetContext);
+                },
+              ),
+            const SizedBox(height: 8),
+          ],
+        ),
+      ),
+    );
+  }
+
+  @override
   void dispose() {
+    _disposed = true;
     search.dispose();
     searchFocus.dispose();
     scroll.dispose();
+    super.dispose();
   }
 }