import 'package:drift/drift.dart' show Value;
import 'package:flutter/material.dart';
import '../database/database.dart' as db; // Import database with prefix 'db'
import '../utils/category_utils.dart'; // Import CategoryUtils

class AddCategoryDialog extends StatefulWidget {
  final db.AppDatabase database;

  const AddCategoryDialog({Key? key, required this.database}) : super(key: key);

  @override
  State<AddCategoryDialog> createState() => _AddCategoryDialogState();
}

class _AddCategoryDialogState extends State<AddCategoryDialog> {
  final _formKey = GlobalKey<FormState>();
  final _nameController = TextEditingController();
  // State for selected icon
  String _selectedIconName = 'label_outline'; // Default icon name (string)
  IconData _selectedIconData = Icons.label_outline; // Default icon data
  // State for selected color
  Color _selectedColor = CategoryUtils.availableColors[9]; // Default to green

  @override
  void initState() {
    super.initState();
    // Initialize icon data based on the default name
    _selectedIconData = CategoryUtils.getIconFromString(_selectedIconName);
  }

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

  // --- Function to show the icon picker dialog ---
  Future<void> _showIconPicker() async {
    final Map<String, IconData> availableIcons = CategoryUtils.getAvailableIcons();
    final List<String> iconNames = availableIcons.keys.toList();
    final List<IconData> iconDatas = availableIcons.values.toList();
    print("Number of available icons: ${availableIcons.length}"); // Debug print

    final String? chosenIconName = await showDialog<String>(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Выберите иконку'),
          contentPadding: const EdgeInsets.all(10.0), // Adjust padding
          content: SizedBox( // Constrain the size of the dialog content
            width: double.maxFinite, // Use maximum width available
            height: 300, // <--- ЗАДАЕМ ВЫСОТУ ДЛЯ ОБЛАСТИ ПРОКРУТКИ
            child: GridView.builder(
              // shrinkWrap: true, // <--- УБИРАЕМ SHRINKWRAP
              itemCount: iconNames.length,
              gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 5, // Adjust number of columns
                crossAxisSpacing: 10.0,
                mainAxisSpacing: 10.0,
              ),
              itemBuilder: (context, index) {
                final bool isSelected = _selectedIconName == iconNames[index];
                return InkWell(
                  onTap: () {
                    Navigator.pop(context, iconNames[index]); // Return the selected icon name (String)
                  },
                  borderRadius: BorderRadius.circular(8.0), // Ripple effect matches border
                  child: Container(
                    decoration: BoxDecoration(
                      border: Border.all(
                        color: isSelected
                            ? Theme.of(context).colorScheme.primary // Highlight selected
                            : Colors.grey.withOpacity(0.3), // Subtle border for all
                        width: isSelected ? 2.0 : 1.0, // Thicker border if selected
                      ),
                      borderRadius: BorderRadius.circular(8.0),
                      color: isSelected ? Theme.of(context).colorScheme.primary.withOpacity(0.1) : null,
                    ),
                    child: Icon(
                      iconDatas[index],
                      size: 30.0, // Adjust icon size
                      color: Theme.of(context).brightness == Brightness.dark
                          ? Colors.white70
                          : Colors.black87,
                    ),
                  ),
                );
              },
            ),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context, null), // Close without selection
              child: const Text('Отмена'),
            ),
          ],
        );
      },
    );

    // Update state if an icon was chosen
    if (chosenIconName != null) {
      setState(() {
        _selectedIconName = chosenIconName;
        _selectedIconData = CategoryUtils.getIconFromString(chosenIconName);
      });
    }
  }
  // --- End of Icon Picker Function ---


  Future<void> _saveCategory() async {
    if (_formKey.currentState!.validate()) {
      final name = _nameController.text;
      // Use the selected icon name
      final icon = _selectedIconName;
      // Use the selected color value
      final color = _selectedColor.value;

      final newCategoryCompanion = db.CategoriesCompanion(
        name: Value(name),
        icon: Value(icon), // Use selected icon name
        color: Value(color),     // Use selected color value
      );

      try {
        // TODO: Add check for duplicate category name before inserting (more robustly)
        final newCategoryId = await widget.database.addCategory(newCategoryCompanion);
        final newCategory = await widget.database.getCategoryById(newCategoryId);
        if (mounted) {
          Navigator.pop(context, newCategory); // Return the newly created CategoryDb object
        }
      } catch (e) {
        print('Error adding category: $e');
        // Handle potential duplicate name error from database (depends on DB constraints)
        String errorMessage = 'Произошла ошибка при добавлении категории.';
        if (e.toString().toLowerCase().contains('unique constraint failed')) {
           errorMessage = 'Категория с таким именем уже существует.';
        }
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text(errorMessage),
              backgroundColor: Colors.red,
            ),
          );
        }
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    // Determine icon color based on the selected background color's brightness
    final iconColor = ThemeData.estimateBrightnessForColor(_selectedColor) == Brightness.dark
        ? Colors.white70
        : Colors.black87;

    return AlertDialog(
      title: const Text('Создать категорию'),
      content: Form(
        key: _formKey,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start, // Align children to the start
          children: [
            // --- Icon and Name Row ---
            Row(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                // --- Icon Picker ---
                Padding(
                  padding: const EdgeInsets.only(right: 16.0, bottom: 10.0), // Add padding
                  child: InkWell(
                    onTap: _showIconPicker, // Show picker on tap
                    customBorder: const CircleBorder(), // Make ripple circular
                    child: CircleAvatar(
                      radius: 24,
                      backgroundColor: _selectedColor, // Use selected color for background
                      child: Icon(
                        _selectedIconData, // Display selected icon
                        color: iconColor, // Adjust icon color based on background
                        size: 26,
                      ),
                    ),
                  ),
                ),
                // --- Name Field ---
                Expanded(
                  child: TextFormField(
                    controller: _nameController,
                    decoration: const InputDecoration(
                      labelText: 'Название категории',
                    ),
                    validator: (value) {
                      if (value == null || value.isEmpty) {
                        return 'Пожалуйста, введите название';
                      }
                      // Basic length check
                      if (value.length > 50) {
                         return 'Название слишком длинное';
                      }
                      return null;
                    },
                    textCapitalization: TextCapitalization.sentences,
                  ),
                ),
              ],
            ),
            const SizedBox(height: 20), // Space before color picker

            // --- Color Picker ---
            const Text('Выберите цвет:', style: TextStyle(fontSize: 16)),
            const SizedBox(height: 8),
            Wrap( // Use Wrap for horizontal layout with wrapping
              spacing: 8.0, // Horizontal space between circles
              runSpacing: 8.0, // Vertical space between rows
              children: CategoryUtils.availableColors.map((color) {
                final bool isSelected = _selectedColor == color;
                return InkWell(
                  onTap: () {
                    setState(() {
                      _selectedColor = color; // Update selected color on tap
                    });
                  },
                  customBorder: const CircleBorder(),
                  child: Container(
                    width: 32, // Size of the color circle
                    height: 32,
                    decoration: BoxDecoration(
                      color: color,
                      shape: BoxShape.circle,
                      border: Border.all(
                        color: isSelected
                            ? theme.colorScheme.onSurface // Highlight selected
                            : theme.dividerColor, // Border for others
                        width: isSelected ? 3.0 : 1.0,
                      ),
                      boxShadow: isSelected ? [
                         BoxShadow(
                           color: Colors.black.withOpacity(0.3),
                           blurRadius: 3,
                           offset: const Offset(0, 1),
                         )
                      ] : null,
                    ),
                  ),
                );
              }).toList(),
            ),
            const SizedBox(height: 16), // Add some space at the bottom
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(context, null), // Return null if cancelled
          child: const Text('Отмена'),
        ),
        ElevatedButton(
          onPressed: _saveCategory,
          child: const Text('Сохранить'),
        ),
      ],
    );
  }
}