feat(app): 搜索改为调用后端并渲染卡片结果

lib/pages/discover/discover_logic.dart

@@ -1,20 +1,29 @@
 // Author: fruit.com.cn
 
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 
 import '../../core/data/models/drama.dart';
 import '../../core/data/models/watch_progress.dart';
+import '../../core/data/remote/api_exception.dart';
+import '../../core/data/repositories/search_repository.dart';
 import '../../core/data/repositories/watch_history_repository.dart';
 import '../../l10n/app_localizations.dart';
 
 enum DiscoverPageAction { home, my, watchlist, detail, resume }
 
 class DiscoverLogic extends ChangeNotifier {
-  DiscoverLogic({required this.history, required this.drama}) {
+  DiscoverLogic({
+    required this.history,
+    required this.drama,
+    this.searchRepository,
+  }) {
     refreshPosition();
   }
 
   final WatchHistoryRepository history;
+  final SearchRepository? searchRepository;
   Drama drama;
   late Future<Duration?> position;
   WatchProgress? resumeRecord;
@@ -22,6 +31,17 @@ class DiscoverLogic extends ChangeNotifier {
   final FocusNode searchFocus = FocusNode();
   final ScrollController scroll = ScrollController();
   bool searchOpen = false;
+
+  /// 搜索防抖与分页口径：与后端 `/app/search` 一致。
+  Duration searchDebounce = const Duration(milliseconds: 350);
+  static const int searchPageSize = 20;
+  List<Drama> searchResults = const [];
+  int searchTotal = 0;
+  bool searchLoading = false;
+  String? searchError;
+  Timer? _searchTimer;
+  String _lastRequestedQuery = '';
+  int _searchRequest = 0;
   bool _disposed = false;
 
   void notify() {
@@ -51,20 +71,89 @@ class DiscoverLogic extends ChangeNotifier {
     notify();
   }
 
-  void onSearchChanged() => notify();
+  bool get hasSearchQuery => search.text.trim().isNotEmpty;
 
-  List<Drama> filtered(List<Drama> dramas) {
-    final query = search.text.trim().toLowerCase();
-    if (query.isEmpty) return dramas;
-    return dramas.where((drama) {
-      final haystack = [
-        drama.title,
-        drama.genre,
-        drama.category,
-        drama.synopsis,
-      ].join(' ').toLowerCase();
-      return haystack.contains(query);
-    }).toList();
+  /// 输入变化只触发后端查询；本地不再做标题/简介匹配。
+  void onSearchChanged() {
+    final query = search.text.trim();
+    if (query.isEmpty) {
+      _resetSearch();
+      notify();
+      return;
+    }
+    notify();
+    _scheduleSearch(query);
+  }
+
+  /// 搜索态展示后端结果，非搜索态展示剧场自身的可见短剧。
+  List<Drama> visibleDramas(List<Drama> fallback) {
+    if (!hasSearchQuery) return fallback;
+    return searchResults;
+  }
+
+  Future<void> retrySearch() async {
+    final query = search.text.trim();
+    if (query.isEmpty) return;
+    await _runSearch(query);
+  }
+
+  void _resetSearch() {
+    _searchTimer?.cancel();
+    _searchRequest++;
+    searchResults = const [];
+    searchTotal = 0;
+    searchLoading = false;
+    searchError = null;
+    _lastRequestedQuery = '';
+  }
+
+  void _scheduleSearch(String query) {
+    final alreadyRequested = query == _lastRequestedQuery;
+    if (alreadyRequested && (searchLoading || searchResults.isNotEmpty || searchError != null)) {
+      return;
+    }
+    _lastRequestedQuery = query;
+    _searchTimer?.cancel();
+    if (searchDebounce == Duration.zero) {
+      unawaited(_runSearch(query));
+      return;
+    }
+    _searchTimer = Timer(searchDebounce, () => unawaited(_runSearch(query)));
+  }
+
+  Future<void> _runSearch(String query) async {
+    final repository = searchRepository;
+    if (repository == null) return;
+    final request = ++_searchRequest;
+    searchLoading = true;
+    searchError = null;
+    notify();
+    try {
+      final result = await repository.search(
+        query,
+        pageIndex: 1,
+        pageSize: searchPageSize,
+      );
+      if (request != _searchRequest) return;
+      searchResults = result.list;
+      searchTotal = result.total;
+    } on ApiException catch (exception) {
+      _applySearchError(request, exception.message);
+    } catch (_) {
+      _applySearchError(request, 'searchFailed');
+    } finally {
+      if (request == _searchRequest) {
+        searchLoading = false;
+        notify();
+      }
+    }
+  }
+
+  void _applySearchError(int request, String message) {
+    if (request != _searchRequest) return;
+    searchError = message;
+    searchResults = const [];
+    searchTotal = 0;
   }
 
   Drama? resumeDrama(List<Drama> dramas) {
@@ -165,6 +254,7 @@ class DiscoverLogic extends ChangeNotifier {
   @override
   void dispose() {
     _disposed = true;
+    _searchTimer?.cancel();
     search.dispose();
     searchFocus.dispose();
     scroll.dispose();