import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:image_picker/image_picker.dart';
import 'package:path/path.dart' as p;
import 'package:provider/provider.dart';
import 'package:http/http.dart' as http;
import '../../providers/app_provider.dart';
import '../../widgets/fade_in_local_image.dart';
import '../../models/data_models.dart';
import '../../utils/toast_util.dart';
import '../../utils/image_path_helper.dart';
import '../../widgets/genre_selector_page.dart';
import '../../widgets/text_input_panel.dart';

/// 从多值字段列表中提取去重排序的唯一值（供 compute 使用）
List<String> _collectUnique(List<List<String>> lists) {
  final s = <String>{};
  for (final l in lists) { s.addAll(l); }
  return s.toList()..sort();
}

/// 添加/编辑书籍页面
class BookFormPage extends StatefulWidget {
  final Book? book;
  final String? initialStatus;

  const BookFormPage({super.key, this.book, this.initialStatus});

  @override
  State<BookFormPage> createState() => _BookFormPageState();
}

class _BookFormPageState extends State<BookFormPage> {
  final _formKey = GlobalKey<FormState>();
  final ImagePicker _picker = ImagePicker();

  late TextEditingController _titleController;
  late TextEditingController _publisherController;
  late TextEditingController _summaryController;
  late TextEditingController _ratingController;
  late TextEditingController _isbnController;

  List<String> _authors = [];
  List<String> _alternateTitles = [];
  List<String> _genres = [];
  String? _coverPath;
  String _status = 'want_to_read';
  DateTime? _publishDate;
  bool _isDownloading = false;

  @override
  void initState() {
    super.initState();
    _initializeData();
  }

  void _initializeData() {
    Book? book = widget.book;
    if (book != null) {
      final appProvider = context.read<AppProvider>();
      final latestBook = appProvider.books.where((b) => b.id == book!.id).firstOrNull;
      if (latestBook != null) book = latestBook;
    }

    _titleController = TextEditingController(text: book?.title ?? '');
    _publisherController = TextEditingController(text: book?.publisher ?? '');
    _summaryController = TextEditingController(text: book?.summary ?? '');
    _ratingController = TextEditingController(text: book?.rating?.toString() ?? '');
    _isbnController = TextEditingController(text: book?.isbn ?? '');

    if (book != null) {
      _authors = List.from(book.authors);
      _alternateTitles = List.from(book.alternateTitles);
      _genres = List.from(book.genres);
      _coverPath = book.coverPath;
      _status = book.status;
      _publishDate = book.publishDate;
    } else if (widget.initialStatus != null) {
      _status = widget.initialStatus!;
    }
  }

  @override
  void dispose() {
    _titleController.dispose();
    _publisherController.dispose();
    _summaryController.dispose();
    _ratingController.dispose();
    _isbnController.dispose();
    super.dispose();
  }

  Widget _buildActionButton({required IconData icon, required VoidCallback onPressed, required String tooltip}) {
    final colors = Theme.of(context).colorScheme;
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 4, vertical: 8),
      decoration: BoxDecoration(color: colors.surface.withValues(alpha: 0.9), borderRadius: BorderRadius.circular(8)),
      child: Material(
        color: Colors.transparent,
        child: InkWell(
          onTap: onPressed,
          borderRadius: BorderRadius.circular(8),
          child: Container(padding: const EdgeInsets.all(8), child: Icon(icon, color: colors.onSurface, size: 22)),
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).colorScheme;
    final isEdit = widget.book != null;

    return PopScope(
      canPop: false,
      onPopInvokedWithResult: (didPop, result) async {
        if (didPop) return;
        final shouldPop = await _confirmLeave();
        if (shouldPop && context.mounted) Navigator.pop(context);
      },
      child: Scaffold(
        backgroundColor: colors.surface,
        appBar: AppBar(
          title: Text(isEdit ? '编辑书籍' : '添加书籍'),
          actions: [
            _buildActionButton(icon: Icons.save_outlined, onPressed: _saveBook, tooltip: '保存'),
            const SizedBox(width: 8),
          ],
        ),
        body: Form(
          key: _formKey,
          child: ListView(
            padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 16),
            children: [
              // 封面
              Center(child: _buildCoverPicker()),
              const SizedBox(height: 20),

              // 状态 + 评分
              _buildStatusRatingRow(),
              const SizedBox(height: 24),

              // 信息卡片网格
              Wrap(
                spacing: 12,
                runSpacing: 12,
                children: [
                  // 书名 + 别名
                  _halfCard('书名', _titleController.text, Icons.book_outlined, required: true,
                    onTap: () async {
                      final r = await TextInputPanel.show(context: context, title: '书名', initialValue: _titleController.text, hint: '请输入书名');
                      if (r != null) setState(() => _titleController.text = r);
                    },
                  ),
                  _halfCard('别名', _alternateTitles.isEmpty ? '' : '${_alternateTitles.length}个：${_alternateTitles.join('、')}', Icons.alternate_email_outlined,
                    onTap: () async {
                      final r = await GenreSelectorPage.show(context: context, title: '添加别名', existingTags: [], initialSelected: _alternateTitles, hint: '输入别名');
                      if (r != null) setState(() => _alternateTitles = r);
                    },
                  ),

                  // 作者 + 出版社
                  _halfCard('作者', _authors.isEmpty ? '' : '${_authors.length}人：${_authors.join('、')}', Icons.person_outline,
                    onTap: () async {
                      final provider = context.read<AppProvider>();
                      final data = provider.books.map((b) => b.authors).toList();
                      final r = await GenreSelectorPage.show(context: context, title: '选择作者', existingTagsFuture: compute(_collectUnique, data), initialSelected: _authors, hint: '如：余华、莫言');
                      if (r != null) setState(() => _authors = r);
                    },
                  ),
                  _halfCard('出版社', _publisherController.text, Icons.business_outlined,
                    onTap: () async {
                      final r = await TextInputPanel.show(context: context, title: '出版社', initialValue: _publisherController.text, hint: '请输入出版社');
                      if (r != null) setState(() => _publisherController.text = r);
                    },
                  ),

                  // 类型 + ISBN
                  _halfCard('类型', _genres.isEmpty ? '' : '${_genres.length}个：${_genres.join('、')}', Icons.category_outlined,
                    onTap: () async {
                      final provider = context.read<AppProvider>();
                      final tags = await provider.getTags('book_genre', excludeHidden: true);
                      if (!mounted) return;
                      final r = await GenreSelectorPage.show(context: context, title: '选择类型', existingTags: tags.map((t) => t['name'] as String).toList(), initialSelected: _genres, hint: '如：小说、历史、传记');
                      if (r != null) setState(() => _genres = r);
                    },
                  ),
                  _halfCard('ISBN', _isbnController.text, Icons.qr_code_outlined,
                    onTap: () async {
                      final r = await TextInputPanel.show(context: context, title: 'ISBN', initialValue: _isbnController.text, hint: '请输入ISBN编号');
                      if (r != null) setState(() => _isbnController.text = r);
                    },
                  ),

                  // 出版时间
                  SizedBox(
                    width: double.infinity, height: 90,
                    child: _buildInfoCard(
                      label: '出版时间',
                      value: _publishDate != null ? '${_publishDate!.year}.${_publishDate!.month.toString().padLeft(2, '0')}.${_publishDate!.day.toString().padLeft(2, '0')}' : '',
                      icon: Icons.date_range_outlined,
                      trailing: _publishDate != null
                          ? GestureDetector(onTap: () => setState(() => _publishDate = null), child: Icon(Icons.close, size: 16, color: colors.onSurface.withValues(alpha: 0.35)))
                          : null,
                      onTap: () => _selectPublishDate(),
                    ),
                  ),

                  // 书籍简介
                  SizedBox(
                    width: double.infinity,
                    child: _buildInfoCard(label: '书籍简介', value: _summaryController.text, icon: Icons.description_outlined, height: 160, scrollable: true, onTap: () => _editSummary()),
                  ),
                ],
              ),
              const SizedBox(height: 48),
            ],
          ),
        ),
      ),
    );
  }

  /// 半宽卡片快捷方法
  Widget _halfCard(String label, String value, IconData icon, {bool required = false, VoidCallback? onTap}) {
    return SizedBox(
      width: (MediaQuery.of(context).size.width - 52) / 2,
      height: 90,
      child: _buildInfoCard(label: label, value: value, icon: icon, required: required, onTap: onTap ?? () {}),
    );
  }

  // ─── 状态 + 评分合并行 ───

  Widget _buildStatusRatingRow() {
    final colors = Theme.of(context).colorScheme;
    final currentRating = double.tryParse(_ratingController.text) ?? 0;
    final starRating = currentRating / 2;
    final hasRating = _ratingController.text.isNotEmpty;
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      decoration: BoxDecoration(color: colors.surface, borderRadius: BorderRadius.circular(12), border: Border.all(color: colors.outlineVariant, width: 0.5)),
      child: Column(children: [
        // 状态
        Row(children: [
          Text('状态', style: TextStyle(fontSize: 12, color: colors.onSurface.withValues(alpha: 0.4))),
          const SizedBox(width: 12),
          Container(
            padding: const EdgeInsets.all(2),
            decoration: BoxDecoration(color: colors.surfaceContainerHighest, borderRadius: BorderRadius.circular(6)),
            child: Row(mainAxisSize: MainAxisSize.min, children: [
              _buildStatusOption('想读', 'want_to_read'),
              _buildStatusOption('在读', 'reading'),
              _buildStatusOption('已读', 'read'),
            ]),
          ),
        ]),
        const SizedBox(height: 12),
        // 评分
        Row(children: [
          Text('评分', style: TextStyle(fontSize: 12, color: colors.onSurface.withValues(alpha: 0.4))),
          const SizedBox(width: 12),
          ...List.generate(5, (i) {
            final sv = i + 1;
            final filled = sv <= starRating;
            final half = sv == starRating.ceil() && starRating % 1 != 0;
            return GestureDetector(
              onTap: () => setState(() => _ratingController.text = (sv * 2).toString()),
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 1),
                child: Icon(half ? Icons.star_half : (filled ? Icons.star : Icons.star_border), size: 22, color: (filled || half) ? const Color(0xFFFFB800) : colors.outline),
              ),
            );
          }),
          const SizedBox(width: 8),
          Container(
            width: 48, height: 28,
            decoration: BoxDecoration(color: colors.surfaceContainerHighest, borderRadius: BorderRadius.circular(6)),
            child: TextFormField(
              controller: _ratingController,
              keyboardType: const TextInputType.numberWithOptions(decimal: true),
              textAlign: TextAlign.center,
              inputFormatters: [_RatingInputFormatter()],
              style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: colors.onSurface),
              decoration: InputDecoration(hintText: '0-10', hintStyle: TextStyle(fontSize: 11, color: colors.onSurface.withValues(alpha: 0.25)), border: InputBorder.none, contentPadding: const EdgeInsets.symmetric(vertical: 6), isDense: true),
              onChanged: (_) => setState(() {}),
            ),
          ),
          if (hasRating) ...[
            const SizedBox(width: 6),
            GestureDetector(onTap: () => setState(() => _ratingController.clear()), child: Icon(Icons.close, size: 14, color: colors.onSurface.withValues(alpha: 0.3))),
          ],
        ]),
      ]),
    );
  }

  Widget _buildStatusOption(String label, String value) {
    final isSelected = _status == value;
    final colors = Theme.of(context).colorScheme;
    return GestureDetector(
      onTap: () => setState(() => _status = value),
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 200),
        padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 8),
        decoration: BoxDecoration(
          color: isSelected ? colors.surface : Colors.transparent,
          borderRadius: BorderRadius.circular(6),
          boxShadow: isSelected ? [BoxShadow(color: colors.onSurface.withValues(alpha: 0.03), blurRadius: 4, offset: const Offset(0, 2))] : null,
        ),
        child: Text(label, style: TextStyle(fontSize: 14, fontWeight: isSelected ? FontWeight.w500 : FontWeight.normal, color: isSelected ? colors.onSurface : colors.onSurface.withValues(alpha: 0.4))),
      ),
    );
  }

  // ─── 封面选择器 ───

  Widget _buildCoverPicker() {
    final hasCover = _coverPath != null && _coverPath!.isNotEmpty;
    final colors = Theme.of(context).colorScheme;
    return Column(mainAxisSize: MainAxisSize.min, children: [
      GestureDetector(
        onTap: _pickCover,
        child: Container(
          width: 120, height: 170,
          decoration: BoxDecoration(color: colors.surfaceContainerHighest, borderRadius: BorderRadius.circular(8)),
          clipBehavior: Clip.antiAlias,
          child: Stack(alignment: Alignment.center, children: [
            if (hasCover) FadeInLocalImage(path: _coverPath, fit: BoxFit.cover) else _buildCoverPlaceholder(),
            if (_isDownloading) Container(color: Colors.black.withValues(alpha: 0.4), child: const CircularProgressIndicator(strokeWidth: 2, color: Colors.white)),
          ]),
        ),
      ),
      if (hasCover)
        Padding(
          padding: const EdgeInsets.only(top: 10),
          child: GestureDetector(
            onTap: () => setState(() => _coverPath = null),
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
              decoration: BoxDecoration(color: colors.surfaceContainerHighest, borderRadius: BorderRadius.circular(16)),
              child: Row(mainAxisSize: MainAxisSize.min, children: [
                Icon(Icons.delete_outline, size: 14, color: colors.onSurface.withValues(alpha: 0.6)),
                const SizedBox(width: 4),
                Text('移除封面', style: TextStyle(fontSize: 12, color: colors.onSurface.withValues(alpha: 0.6))),
              ]),
            ),
          ),
        ),
    ]);
  }

  Widget _buildCoverPlaceholder() {
    final colors = Theme.of(context).colorScheme;
    return Column(mainAxisAlignment: MainAxisAlignment.center, children: [
      Icon(Icons.image_outlined, size: 32, color: colors.onSurface.withValues(alpha: 0.25)),
      const SizedBox(height: 8),
      Text('封面', style: TextStyle(fontSize: 12, color: colors.onSurface.withValues(alpha: 0.35))),
    ]);
  }

  Future<void> _pickCover() async {
    final colors = Theme.of(context).colorScheme;
    await showModalBottomSheet(
      context: context,
      backgroundColor: colors.surface,
      shape: const RoundedRectangleBorder(borderRadius: BorderRadius.vertical(top: Radius.circular(16))),
      builder: (ctx) {
        final c = Theme.of(ctx).colorScheme;
        return SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 12),
            child: Column(mainAxisSize: MainAxisSize.min, children: [
              Container(width: 36, height: 4, decoration: BoxDecoration(color: c.onSurface.withValues(alpha: 0.15), borderRadius: BorderRadius.circular(2))),
              const SizedBox(height: 16),
              Align(alignment: Alignment.centerLeft, child: Padding(padding: const EdgeInsets.symmetric(horizontal: 20), child: Text('添加封面', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: c.onSurface)))),
              const SizedBox(height: 8),
              ListTile(
                leading: Container(width: 36, height: 36, decoration: BoxDecoration(color: c.surfaceContainerHighest, borderRadius: BorderRadius.circular(10)), child: Icon(Icons.photo_library_outlined, size: 20, color: c.onSurface.withValues(alpha: 0.6))),
                title: Text('从相册选择', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: c.onSurface)),
                trailing: Icon(Icons.chevron_right, color: c.onSurface.withValues(alpha: 0.25)),
                onTap: () { Navigator.pop(ctx); _pickCoverFromGallery(); },
              ),
              Divider(height: 0.5, color: c.outlineVariant),
              ListTile(
                leading: Container(width: 36, height: 36, decoration: BoxDecoration(color: c.surfaceContainerHighest, borderRadius: BorderRadius.circular(10)), child: Icon(Icons.link_outlined, size: 20, color: c.onSurface.withValues(alpha: 0.6))),
                title: Text('网络链接', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: c.onSurface)),
                trailing: Icon(Icons.chevron_right, color: c.onSurface.withValues(alpha: 0.25)),
                onTap: () { Navigator.pop(ctx); _pickCoverFromUrl(); },
              ),
            ]),
          ),
        );
      },
    );
  }

  Future<void> _pickCoverFromGallery() async {
    try {
      final picked = await _picker.pickImage(source: ImageSource.gallery, maxWidth: 800, maxHeight: 1200, imageQuality: 85);
      if (picked != null) {
        final fileName = 'cover_${DateTime.now().millisecondsSinceEpoch}.jpg';
        final bookId = widget.book?.id ?? DateTime.now().millisecondsSinceEpoch.toString();
        final targetPath = await ImagePathHelper.instance.getBookCoverPath(bookId, fileName);
        await ImagePathHelper.instance.ensureDirExists(p.dirname(targetPath));
        await File(picked.path).copy(targetPath);
        setState(() => _coverPath = targetPath);
      }
    } catch (e) {
      if (mounted) ToastUtil.show(context, '选择封面失败: $e');
    }
  }

  Future<void> _pickCoverFromUrl() async {
    final urlController = TextEditingController();
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) {
        final c = Theme.of(ctx).colorScheme;
        return AlertDialog(
          backgroundColor: c.surface, elevation: 0,
          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
          title: Text('添加网络图片', style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: c.onSurface)),
          content: Column(mainAxisSize: MainAxisSize.min, crossAxisAlignment: CrossAxisAlignment.start, children: [
            Text('请输入图片链接地址', style: TextStyle(fontSize: 14, color: c.onSurface.withValues(alpha: 0.6))),
            const SizedBox(height: 12),
            TextField(
              controller: urlController, keyboardType: TextInputType.url,
              style: TextStyle(fontSize: 14, color: c.onSurface),
              decoration: InputDecoration(
                hintText: 'https://example.com/image.jpg',
                hintStyle: TextStyle(color: c.onSurface.withValues(alpha: 0.25)),
                filled: true, fillColor: c.surfaceContainerHigh,
                contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
                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(color: c.primary, width: 1)),
              ),
            ),
          ]),
          actions: [
            TextButton(onPressed: () => Navigator.pop(ctx, false), child: Text('取消', style: TextStyle(color: c.onSurface.withValues(alpha: 0.6)))),
            ElevatedButton(
              onPressed: () => Navigator.pop(ctx, true),
              style: ElevatedButton.styleFrom(backgroundColor: c.primary, foregroundColor: c.onPrimary, elevation: 0, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)), padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8)),
              child: const Text('确定'),
            ),
          ],
        );
      },
    );

    final url = urlController.text.trim();
    urlController.dispose();
    if (confirmed != true || url.isEmpty) return;

    setState(() => _isDownloading = true);
    try {
      final response = await http.get(Uri.parse(url), headers: {
        'User-Agent': 'Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Mobile/15E148 Safari/604.1',
        'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8',
        'Referer': Uri.parse(url).replace(path: '/').toString(),
      });
      if (response.statusCode != 200) throw Exception('下载失败: HTTP ${response.statusCode}');
      final ct = response.headers['content-type'];
      if (ct != null && !ct.startsWith('image/')) throw Exception('链接返回的不是图片');
      if (response.bodyBytes.length > 10 * 1024 * 1024) throw Exception('图片太大');

      final fileName = 'cover_${DateTime.now().millisecondsSinceEpoch}.jpg';
      final bookId = widget.book?.id ?? DateTime.now().millisecondsSinceEpoch.toString();
      final targetPath = await ImagePathHelper.instance.getBookCoverPath(bookId, fileName);
      await ImagePathHelper.instance.ensureDirExists(p.dirname(targetPath));
      await File(targetPath).writeAsBytes(response.bodyBytes);
      setState(() => _coverPath = targetPath);
    } catch (e) {
      debugPrint('封面下载失败: $e');
      if (mounted) ToastUtil.show(context, '下载失败: $e');
    } finally {
      if (mounted) setState(() => _isDownloading = false);
    }
  }

  // ─── Info Card ───

  Widget _buildInfoCard({
    required String label,
    required String value,
    required VoidCallback onTap,
    bool required = false,
    IconData? icon,
    Widget? trailing,
    double? height,
    bool scrollable = false,
  }) {
    final hasValue = value.isNotEmpty;
    final colors = Theme.of(context).colorScheme;

    Widget buildContent() {
      if (scrollable && height != null) {
        return Flexible(
          child: SingleChildScrollView(physics: const BouncingScrollPhysics(),
            child: Text(hasValue ? value : '点击填写', style: TextStyle(fontSize: 15, color: hasValue ? colors.onSurface : colors.onSurface.withValues(alpha: 0.25), fontWeight: hasValue ? FontWeight.w500 : FontWeight.normal))),
        );
      }
      return Text(hasValue ? value : '点击填写', style: TextStyle(fontSize: 15, color: hasValue ? colors.onSurface : colors.onSurface.withValues(alpha: 0.25), fontWeight: hasValue ? FontWeight.w500 : FontWeight.normal), maxLines: 1, overflow: TextOverflow.ellipsis);
    }

    return GestureDetector(
      onTap: onTap,
      child: Container(
        height: height,
        padding: const EdgeInsets.all(16),
        decoration: BoxDecoration(
          color: colors.surface, borderRadius: BorderRadius.circular(12), border: Border.all(color: colors.outline),
          boxShadow: [BoxShadow(color: colors.onSurface.withValues(alpha: 0.018), blurRadius: 8, offset: const Offset(0, 2))],
        ),
        child: Column(crossAxisAlignment: CrossAxisAlignment.start, mainAxisSize: height != null ? MainAxisSize.max : MainAxisSize.min, children: [
          Row(children: [
            if (icon != null) ...[Icon(icon, size: 14, color: colors.onSurface.withValues(alpha: 0.4)), const SizedBox(width: 6)],
            Text(required ? '$label *' : label, style: TextStyle(fontSize: 12, color: required ? colors.onSurface : colors.onSurface.withValues(alpha: 0.4), fontWeight: required ? FontWeight.w500 : FontWeight.normal)),
            if (trailing != null) ...[const Spacer(), trailing],
          ]),
          const SizedBox(height: 8),
          buildContent(),
        ]),
      ),
    );
  }

  // ─── 数据操作 ───

  Future<void> _selectPublishDate() async {
    final picked = await showDatePicker(context: context, initialDate: _publishDate ?? DateTime.now(), firstDate: DateTime(1900), lastDate: DateTime.now().add(const Duration(days: 365 * 5)));
    if (picked != null) setState(() => _publishDate = picked);
  }

  Future<void> _editSummary() async {
    final result = await Navigator.push<String>(context, MaterialPageRoute(builder: (_) => _SummaryEditorPage(initialText: _summaryController.text)));
    if (result != null) setState(() => _summaryController.text = result);
  }

  bool _hasContent() {
    if (widget.book != null) return true;
    if (_titleController.text.trim().isNotEmpty) return true;
    if (_summaryController.text.trim().isNotEmpty) return true;
    if (_ratingController.text.trim().isNotEmpty) return true;
    if (_isbnController.text.trim().isNotEmpty) return true;
    if (_publisherController.text.trim().isNotEmpty) return true;
    if (_coverPath != null) return true;
    if (_authors.isNotEmpty || _alternateTitles.isNotEmpty || _genres.isNotEmpty) return true;
    if (_publishDate != null) return true;
    return false;
  }

  Future<bool> _confirmLeave() async {
    if (!_hasContent()) return true;
    final colors = Theme.of(context).colorScheme;
    final result = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: colors.surface, elevation: 0, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
        title: Text('未保存', style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: colors.onSurface)),
        content: Text('当前内容未保存，确定要离开吗？', style: TextStyle(fontSize: 14, color: colors.onSurface.withValues(alpha: 0.6), height: 1.5)),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: Text('取消', style: TextStyle(color: colors.onSurface.withValues(alpha: 0.6)))),
          ElevatedButton(onPressed: () => Navigator.pop(ctx, true),
            style: ElevatedButton.styleFrom(backgroundColor: colors.error, foregroundColor: colors.onError, elevation: 0, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)), padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8)),
            child: const Text('离开'),
          ),
        ],
        actionsPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      ),
    );
    return result ?? false;
  }

  Future<void> _saveBook() async {
    if (!_formKey.currentState!.validate()) return;

    try {
      final rating = _ratingController.text.isNotEmpty ? double.tryParse(_ratingController.text) : null;
      final now = DateTime.now();

      if (widget.book == null) {
        final newBookId = now.millisecondsSinceEpoch.toString();
        String? finalCoverPath;
        if (_coverPath != null && _coverPath!.isNotEmpty) {
          finalCoverPath = await _moveCoverToNewId(_coverPath!, newBookId);
        }
        final newBook = Book(
          id: newBookId, title: _titleController.text.trim(), coverPath: finalCoverPath,
          authors: _authors, alternateTitles: _alternateTitles, publisher: _publisherController.text.trim(),
          genres: _genres, summary: _summaryController.text.trim(), rating: rating, status: _status,
          isbn: _isbnController.text.trim().isNotEmpty ? _isbnController.text.trim() : null,
          publishDate: _publishDate, createdAt: now, updatedAt: now,
        );
        await context.read<AppProvider>().addBook(newBook);
      } else {
        final updatedBook = widget.book!.copyWith(
          title: _titleController.text.trim(), coverPath: _coverPath,
          authors: _authors, alternateTitles: _alternateTitles, publisher: _publisherController.text.trim(),
          genres: _genres, summary: _summaryController.text.trim(), rating: rating, status: _status,
          isbn: _isbnController.text.trim().isNotEmpty ? _isbnController.text.trim() : null,
          publishDate: _publishDate, updatedAt: now,
        );
        await context.read<AppProvider>().updateBook(updatedBook);
      }

      if (!mounted) return;
      ToastUtil.show(context, widget.book == null ? '添加成功' : '更新成功');
      Navigator.pop(context);
    } catch (e) {
      if (!mounted) return;
      ToastUtil.show(context, '保存失败: $e');
    }
  }

  Future<String?> _moveCoverToNewId(String currentPath, String newBookId) async {
    final normalizedPath = currentPath.replaceAll('\\', '/');
    if (normalizedPath.contains('/books/$newBookId/')) return currentPath;
    final fileName = p.basename(currentPath);
    final newPath = await ImagePathHelper.instance.getBookCoverPath(newBookId, fileName);
    await ImagePathHelper.instance.ensureDirExists(p.dirname(newPath));
    final currentFile = File(currentPath);
    if (await currentFile.exists()) {
      await currentFile.rename(newPath);
      try { await Directory(p.dirname(currentPath)).delete(recursive: true); } catch (_) {}
      return newPath;
    }
    return null;
  }
}

/// 书籍简介编辑页
class _SummaryEditorPage extends StatefulWidget {
  final String initialText;
  const _SummaryEditorPage({required this.initialText});
  @override
  State<_SummaryEditorPage> createState() => _SummaryEditorPageState();
}

class _SummaryEditorPageState extends State<_SummaryEditorPage> {
  late final TextEditingController _controller;
  @override
  void initState() { super.initState(); _controller = TextEditingController(text: widget.initialText); }
  @override
  void dispose() { _controller.dispose(); super.dispose(); }
  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).colorScheme;
    return Scaffold(
      backgroundColor: colors.surface,
      appBar: AppBar(title: const Text('书籍简介'), actions: [
        TextButton(onPressed: () => Navigator.pop(context, _controller.text.trim()), child: Text('完成', style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: colors.primary))),
        const SizedBox(width: 8),
      ]),
      body: TextField(controller: _controller, maxLines: null, expands: true, textAlignVertical: TextAlignVertical.top,
        style: TextStyle(fontSize: 15, color: colors.onSurface, height: 1.6),
        decoration: InputDecoration(hintText: '写下书籍简介...', hintStyle: TextStyle(color: colors.onSurface.withValues(alpha: 0.3)), contentPadding: const EdgeInsets.all(20), border: InputBorder.none),
      ),
    );
  }
}

/// 评分输入格式化器：只允许 0-10，最多1位小数
class _RatingInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
    final text = newValue.text;
    if (text.isEmpty) return newValue;
    if (!RegExp(r'^\d{0,2}\.?\d{0,1}$').hasMatch(text)) return oldValue;
    final n = double.tryParse(text);
    if (n != null && n > 10) return oldValue;
    return newValue;
  }
}