import 'dart:convert'; import 'package:flutter/material.dart'; import 'package:xml/xml.dart'; import '../../services/epub/epub_stream_service.dart'; import 'book_session.dart'; class SearchSheet extends StatefulWidget { final BookSession bookSession; final EpubStreamService streamService; final void Function(int spineIndex, String keyword, double scrollRatio) onNavigate; const SearchSheet({ super.key, required this.bookSession, required this.streamService, required this.onNavigate, }); @override State createState() => _SearchSheetState(); } class _SearchSheetState extends State { final TextEditingController _controller = TextEditingController(); final ScrollController _scrollController = ScrollController(); List<_SearchResult> _allResults = []; List<_SearchResult> _displayResults = []; bool _searching = false; bool _searched = false; bool _loadingMore = false; String _currentQuery = ''; static const int _pageSize = 20; @override void initState() { super.initState(); _scrollController.addListener(_onScroll); } @override void dispose() { _controller.dispose(); _scrollController.dispose(); super.dispose(); } void _onScroll() { if (_scrollController.position.pixels >= _scrollController.position.maxScrollExtent - 50 && !_loadingMore && _displayResults.length < _allResults.length) { _loadMore(); } } void _loadMore() { if (_loadingMore) return; setState(() => _loadingMore = true); Future.delayed(const Duration(milliseconds: 100), () { if (!mounted) return; final nextBatch = _allResults .skip(_displayResults.length) .take(_pageSize) .toList(); setState(() { _displayResults.addAll(nextBatch); _loadingMore = false; }); }); } Future _performSearch(String query) async { if (query.trim().isEmpty) return; // 收起键盘 FocusScope.of(context).unfocus(); setState(() { _searching = true; _searched = true; _currentQuery = query; }); final results = <_SearchResult>[]; final spine = widget.bookSession.spine; for (int i = 0; i < spine.length; i++) { final href = spine[i].href; try { final bytes = await widget.streamService.readFileFromEpub( targetFilePath: href, ); if (bytes == null) continue; final text = _extractBodyText(bytes); if (text.isEmpty) continue; final lowerText = text.toLowerCase(); final lowerQuery = query.toLowerCase(); int startIndex = 0; while (true) { final idx = lowerText.indexOf(lowerQuery, startIndex); if (idx == -1) break; final start = (idx - 40).clamp(0, text.length); final end = (idx + query.length + 40).clamp(0, text.length); final contextStr = text.substring(start, end); results.add(_SearchResult( chapterIndex: i, chapterTitle: _getChapterTitle(i), context: contextStr, matchIndex: idx, scrollRatio: idx / text.length, )); startIndex = idx + query.length; } } catch (_) {} } if (mounted) { setState(() { _allResults = results; _displayResults = results.take(_pageSize).toList(); _searching = false; }); } } String _extractBodyText(List bytes) { try { final content = utf8.decode(bytes, allowMalformed: true); final doc = XmlDocument.parse(content); // 只提取内容 final body = doc.findAllElements('body').firstOrNull; if (body == null) return ''; final buffer = StringBuffer(); _extractTextFromBody(body, buffer); return buffer.toString().replaceAll(RegExp(r'\s+'), ' ').trim(); } catch (_) { return ''; } } void _extractTextFromBody(XmlNode node, StringBuffer buffer) { // 跳过 script、style、svg 等非内容标签 if (node is XmlElement) { final name = node.name.local.toLowerCase(); if (name == 'script' || name == 'style' || name == 'svg' || name == 'head' || name == 'nav') { return; } } if (node is XmlText) { buffer.write(node.value); } for (final child in node.children) { _extractTextFromBody(child, buffer); } } String _getChapterTitle(int index) { final toc = widget.bookSession.toc; for (final entry in toc) { if (entry.spineIndex == index) return entry.label; } return '第${index + 1}章'; } List _buildHighlightedText(String text, String query, ColorScheme colors) { if (query.isEmpty) { return [TextSpan(text: text, style: TextStyle(fontSize: 13, color: colors.onSurface.withValues(alpha: 0.7)))]; } final spans = []; final lowerText = text.toLowerCase(); final lowerQuery = query.toLowerCase(); int lastEnd = 0; int idx = lowerText.indexOf(lowerQuery); while (idx != -1) { if (idx > lastEnd) { spans.add(TextSpan( text: text.substring(lastEnd, idx), style: TextStyle(fontSize: 13, color: colors.onSurface.withValues(alpha: 0.7)), )); } spans.add(TextSpan( text: text.substring(idx, idx + query.length), style: TextStyle( fontSize: 13, color: colors.error, fontWeight: FontWeight.w600, ), )); lastEnd = idx + query.length; idx = lowerText.indexOf(lowerQuery, lastEnd); } if (lastEnd < text.length) { spans.add(TextSpan( text: text.substring(lastEnd), style: TextStyle(fontSize: 13, color: colors.onSurface.withValues(alpha: 0.7)), )); } return spans; } @override Widget build(BuildContext context) { final colors = Theme.of(context).colorScheme; final bottomPadding = MediaQuery.of(context).padding.bottom; return Container( height: MediaQuery.of(context).size.height * 0.75, decoration: BoxDecoration( color: colors.surface, borderRadius: const BorderRadius.vertical(top: Radius.circular(16)), ), child: Column( children: [ // 拖拽条 Container( width: 36, height: 4, margin: const EdgeInsets.only(top: 12, bottom: 8), decoration: BoxDecoration( color: colors.onSurface.withValues(alpha: 0.15), borderRadius: BorderRadius.circular(2), ), ), // 搜索框 Padding( padding: const EdgeInsets.fromLTRB(16, 8, 16, 8), child: Row( children: [ Expanded( child: TextField( controller: _controller, autofocus: true, textInputAction: TextInputAction.search, onSubmitted: _performSearch, decoration: InputDecoration( hintText: '搜索书籍内容...', hintStyle: TextStyle( fontSize: 14, color: colors.onSurface.withValues(alpha: 0.35), ), prefixIcon: Icon(Icons.search, size: 20, color: colors.onSurface.withValues(alpha: 0.4)), filled: true, fillColor: colors.surfaceContainerHighest, contentPadding: const EdgeInsets.symmetric( horizontal: 12, vertical: 10), border: OutlineInputBorder( borderRadius: BorderRadius.circular(10), borderSide: BorderSide.none, ), enabledBorder: OutlineInputBorder( borderRadius: BorderRadius.circular(10), borderSide: BorderSide.none, ), focusedBorder: OutlineInputBorder( borderRadius: BorderRadius.circular(10), borderSide: BorderSide.none, ), ), style: TextStyle(fontSize: 14, color: colors.onSurface), ), ), const SizedBox(width: 8), GestureDetector( onTap: () => _performSearch(_controller.text), child: Text('搜索', style: TextStyle( fontSize: 14, color: colors.primary, fontWeight: FontWeight.w500)), ), ], ), ), Divider(height: 0.5, thickness: 0.5, color: colors.outline), // 结果统计 if (_searched && !_searching && _allResults.isNotEmpty) Padding( padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8), child: Align( alignment: Alignment.centerLeft, child: Text('共找到 ${_allResults.length} 条结果', style: TextStyle(fontSize: 12, color: colors.onSurface.withValues(alpha: 0.4))), ), ), // 结果列表 Expanded( child: _searching ? Center( child: Column( mainAxisSize: MainAxisSize.min, children: [ CircularProgressIndicator(strokeWidth: 2, color: colors.primary), const SizedBox(height: 12), Text('搜索中...', style: TextStyle(fontSize: 13, color: colors.onSurface.withValues(alpha: 0.5))), ], ), ) : !_searched ? Center( child: Text('输入关键词搜索书籍内容', style: TextStyle( fontSize: 13, color: colors.onSurface.withValues(alpha: 0.35)))) : _allResults.isEmpty ? Center( child: Text('未找到相关内容', style: TextStyle( fontSize: 13, color: colors.onSurface.withValues(alpha: 0.35)))) : ListView.separated( controller: _scrollController, padding: EdgeInsets.only(bottom: bottomPadding + 16), itemCount: _displayResults.length + (_loadingMore ? 1 : 0), separatorBuilder: (_, __) => Divider(height: 0.5, indent: 16, endIndent: 16, color: colors.outline), itemBuilder: (context, index) { if (index >= _displayResults.length) { return const Padding( padding: EdgeInsets.all(16), child: Center( child: SizedBox(width: 20, height: 20, child: CircularProgressIndicator(strokeWidth: 2)), ), ); } final r = _displayResults[index]; return ListTile( contentPadding: const EdgeInsets.symmetric(horizontal: 16), title: Text(r.chapterTitle, maxLines: 1, overflow: TextOverflow.ellipsis, style: TextStyle( fontSize: 12, color: colors.primary, fontWeight: FontWeight.w500)), subtitle: RichText( maxLines: 2, overflow: TextOverflow.ellipsis, text: TextSpan( children: _buildHighlightedText( '...${r.context}...', _currentQuery, colors), ), ), onTap: () => widget.onNavigate( r.chapterIndex, _currentQuery, r.scrollRatio), ); }, ), ), ], ), ); } } class _SearchResult { final int chapterIndex; final String chapterTitle; final String context; final int matchIndex; final double scrollRatio; // 匹配位置在章节中的比例 (0.0~1.0) _SearchResult({ required this.chapterIndex, required this.chapterTitle, required this.context, required this.matchIndex, required this.scrollRatio, }); }