import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../theme/app_theme.dart';
import '../services/category_service.dart';
import '../database/app_usage_dao.dart';
import '../widgets/empty_state_widget.dart';
import '../widgets/error_state_widget.dart';

class CategoryManagementScreen extends ConsumerStatefulWidget {
  const CategoryManagementScreen({super.key});

  @override
  ConsumerState<CategoryManagementScreen> createState() => _CategoryManagementScreenState();
}

class _CategoryManagementScreenState extends ConsumerState<CategoryManagementScreen> {
  final CategoryService _categoryService = CategoryService();
  final AppUsageDao _appUsageDao = AppUsageDao();
  final TextEditingController _searchController = TextEditingController();
  String _searchQuery = '';

  // 可用分类列表
  final List<String> _availableCategories = ['work', 'study', 'entertainment', 'social', 'tool', 'other'];

  @override
  void dispose() {
    _searchController.dispose();
    super.dispose();
  }

  Future<List<AppCategoryItem>> _loadAppCategories() async {
    // 获取所有应用使用记录（最近使用的）
    // 如果数据库为空，返回空列表（Web 平台会返回空列表）
    final now = DateTime.now();
    final startOfWeek = now.subtract(const Duration(days: 7));
    final appUsages = await _appUsageDao.getAppUsages(
      startTime: startOfWeek,
      endTime: now,
    );
    
    // 如果没有数据，返回空列表
    if (appUsages.isEmpty) {
      return [];
    }

    // 获取自定义分类
    final customCategories = await _categoryService.getAllCustomCategories();

    // 去重并创建列表
    final packageMap = <String, AppCategoryItem>{};
    for (final usage in appUsages) {
      if (!packageMap.containsKey(usage.packageName)) {
        final currentCategory = customCategories[usage.packageName] ??
            CategoryService.defaultCategories[usage.packageName] ??
            'other';
        
        packageMap[usage.packageName] = AppCategoryItem(
          packageName: usage.packageName,
          appName: usage.appName,
          category: currentCategory,
          isCustom: customCategories.containsKey(usage.packageName),
        );
      }
    }

    return packageMap.values.toList()
      ..sort((a, b) => a.appName.compareTo(b.appName));
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Scaffold(
      appBar: AppBar(
        title: const Text('应用分类'),
      ),
      body: Column(
        children: [
          // 搜索框
          Padding(
            padding: const EdgeInsets.all(16),
            child: TextField(
              controller: _searchController,
              decoration: InputDecoration(
                hintText: '搜索应用...',
                prefixIcon: const Icon(Icons.search),
                suffixIcon: _searchQuery.isNotEmpty
                    ? IconButton(
                        icon: const Icon(Icons.clear),
                        onPressed: () {
                          _searchController.clear();
                          setState(() {
                            _searchQuery = '';
                          });
                        },
                      )
                    : null,
                border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(12),
                ),
              ),
              onChanged: (value) {
                setState(() {
                  _searchQuery = value;
                });
              },
            ),
          ),

          // 应用列表
          Expanded(
            child: FutureBuilder<List<AppCategoryItem>>(
              future: _loadAppCategories(),
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return const Center(child: CircularProgressIndicator());
                }

                if (snapshot.hasError) {
                  return ErrorStateWidget.dataLoad(
                    message: _getErrorMessage(snapshot.error!),
                    onRetry: () {
                      setState(() {});
                    },
                  );
                }

                final items = snapshot.data ?? [];
                final filteredItems = _searchQuery.isEmpty
                    ? items
                    : items.where((item) {
                        return item.appName.toLowerCase().contains(_searchQuery.toLowerCase()) ||
                               item.packageName.toLowerCase().contains(_searchQuery.toLowerCase());
                      }).toList();

                if (filteredItems.isEmpty) {
                  if (_searchQuery.isEmpty) {
                    return EmptyStateWidget.noApps(
                      onAction: () {
                        setState(() {});
                      },
                    );
                  } else {
                    return EmptyStateWidget.noSearchResults(query: _searchQuery);
                  }
                }

                return ListView.builder(
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  itemCount: filteredItems.length,
                  itemBuilder: (context, index) {
                    final item = filteredItems[index];
                    return _buildAppCategoryItem(context, theme, item);
                  },
                );
              },
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildAppCategoryItem(
    BuildContext context,
    ThemeData theme,
    AppCategoryItem item,
  ) {
    return Card(
      margin: const EdgeInsets.only(bottom: 8),
      child: ListTile(
        leading: Container(
          width: 40,
          height: 40,
          decoration: BoxDecoration(
            color: AppTheme.getCategoryColor(item.category).withOpacity(0.1),
            borderRadius: BorderRadius.circular(8),
          ),
          child: Icon(
            Icons.phone_android,
            color: AppTheme.getCategoryColor(item.category),
          ),
        ),
        title: Text(
          item.appName,
          style: theme.textTheme.bodyLarge?.copyWith(
            fontWeight: FontWeight.w500,
          ),
        ),
        subtitle: Text(
          item.packageName,
          style: theme.textTheme.bodySmall?.copyWith(
            color: theme.colorScheme.onSurface.withOpacity(0.6),
          ),
        ),
        trailing: PopupMenuButton<String>(
          icon: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Container(
                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                decoration: BoxDecoration(
                  color: AppTheme.getCategoryColor(item.category).withOpacity(0.1),
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Text(
                  AppTheme.getCategoryName(item.category),
                  style: TextStyle(
                    color: AppTheme.getCategoryColor(item.category),
                    fontSize: 12,
                    fontWeight: FontWeight.w500,
                  ),
                ),
              ),
              const SizedBox(width: 8),
              const Icon(Icons.arrow_drop_down),
            ],
          ),
          onSelected: (String category) async {
            await _categoryService.setCategory(item.packageName, category);
            setState(() {});
            
            if (context.mounted) {
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(
                  content: Text('已将 ${item.appName} 分类为 ${AppTheme.getCategoryName(category)}'),
                  duration: const Duration(seconds: 2),
                ),
              );
            }
          },
          itemBuilder: (BuildContext context) {
            return _availableCategories.map((category) {
              return PopupMenuItem<String>(
                value: category,
                child: Row(
                  children: [
                    if (item.category == category)
                      const Icon(Icons.check, size: 20, color: AppTheme.primaryColor)
                    else
                      const SizedBox(width: 20),
                    const SizedBox(width: 8),
                    Container(
                      width: 12,
                      height: 12,
                      decoration: BoxDecoration(
                        color: AppTheme.getCategoryColor(category),
                        shape: BoxShape.circle,
                      ),
                    ),
                    const SizedBox(width: 8),
                    Text(AppTheme.getCategoryName(category)),
                  ],
                ),
              );
            }).toList();
          },
        ),
      ),
    );
  }

  String _getErrorMessage(Object error) {
    final errorString = error.toString().toLowerCase();
    if (errorString.contains('permission') || errorString.contains('权限')) {
      return '需要授予应用使用权限';
    } else if (errorString.contains('network') || errorString.contains('网络')) {
      return '网络连接失败，请检查网络';
    } else if (errorString.contains('database') || errorString.contains('数据库')) {
      return '数据库操作失败';
    }
    return '加载失败，请稍后重试';
  }
}

class AppCategoryItem {
  final String packageName;
  final String appName;
  final String category;
  final bool isCustom;

  AppCategoryItem({
    required this.packageName,
    required this.appName,
    required this.category,
    required this.isCustom,
  });
}