import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../theme/app_theme.dart';

class AppearanceSettingsScreen extends StatefulWidget {
  const AppearanceSettingsScreen({super.key});

  @override
  State<AppearanceSettingsScreen> createState() => _AppearanceSettingsScreenState();
}

class _AppearanceSettingsScreenState extends State<AppearanceSettingsScreen> {
  ThemeMode _themeMode = ThemeMode.system;
  double _fontSize = 1.0; // 1.0 = 正常，0.8 = 小，1.2 = 大

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

  Future<void> _loadSettings() async {
    final prefs = await SharedPreferences.getInstance();
    final themeModeIndex = prefs.getInt('theme_mode') ?? 0;
    setState(() {
      _themeMode = ThemeMode.values[themeModeIndex];
      _fontSize = prefs.getDouble('font_size') ?? 1.0;
    });
  }

  Future<void> _saveSettings() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt('theme_mode', _themeMode.index);
    await prefs.setDouble('font_size', _fontSize);
  }

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

    return Scaffold(
      appBar: AppBar(
        title: const Text('外观设置'),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 主题模式
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Icon(Icons.palette, color: AppTheme.primaryColor),
                        const SizedBox(width: 8),
                        Text(
                          '主题模式',
                          style: theme.textTheme.titleMedium?.copyWith(
                            fontWeight: FontWeight.w600,
                          ),
                        ),
                      ],
                    ),
                    const SizedBox(height: 16),
                    RadioListTile<ThemeMode>(
                      title: const Text('跟随系统'),
                      subtitle: const Text('根据系统设置自动切换'),
                      value: ThemeMode.system,
                      groupValue: _themeMode,
                      onChanged: (value) {
                        if (value != null) {
                          setState(() {
                            _themeMode = value;
                          });
                          _saveSettings();
                          // 通知应用更新主题
                          // 注意：这需要重启应用或使用 Provider 来管理主题
                        }
                      },
                    ),
                    RadioListTile<ThemeMode>(
                      title: const Text('浅色模式'),
                      subtitle: const Text('始终使用浅色主题'),
                      value: ThemeMode.light,
                      groupValue: _themeMode,
                      onChanged: (value) {
                        if (value != null) {
                          setState(() {
                            _themeMode = value;
                          });
                          _saveSettings();
                        }
                      },
                    ),
                    RadioListTile<ThemeMode>(
                      title: const Text('深色模式'),
                      subtitle: const Text('始终使用深色主题'),
                      value: ThemeMode.dark,
                      groupValue: _themeMode,
                      onChanged: (value) {
                        if (value != null) {
                          setState(() {
                            _themeMode = value;
                          });
                          _saveSettings();
                        }
                      },
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),

            // 字体大小
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Icon(Icons.text_fields, color: AppTheme.primaryColor),
                        const SizedBox(width: 8),
                        Text(
                          '字体大小',
                          style: theme.textTheme.titleMedium?.copyWith(
                            fontWeight: FontWeight.w600,
                          ),
                        ),
                      ],
                    ),
                    const SizedBox(height: 16),
                    Text(
                      '当前大小: ${_getFontSizeLabel(_fontSize)}',
                      style: theme.textTheme.bodyMedium,
                    ),
                    const SizedBox(height: 16),
                    Slider(
                      value: _fontSize,
                      min: 0.8,
                      max: 1.2,
                      divisions: 4,
                      label: _getFontSizeLabel(_fontSize),
                      onChanged: (value) {
                        setState(() {
                          _fontSize = value;
                        });
                        _saveSettings();
                      },
                    ),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Text(
                          '小',
                          style: theme.textTheme.bodySmall?.copyWith(
                            fontSize: 12 * _fontSize,
                          ),
                        ),
                        Text(
                          '正常',
                          style: theme.textTheme.bodyMedium?.copyWith(
                            fontSize: 14 * _fontSize,
                          ),
                        ),
                        Text(
                          '大',
                          style: theme.textTheme.bodyLarge?.copyWith(
                            fontSize: 16 * _fontSize,
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),

            // 图表样式（占位，未来功能）
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Icon(Icons.bar_chart, color: AppTheme.primaryColor),
                        const SizedBox(width: 8),
                        Text(
                          '图表样式',
                          style: theme.textTheme.titleMedium?.copyWith(
                            fontWeight: FontWeight.w600,
                          ),
                        ),
                      ],
                    ),
                    const SizedBox(height: 16),
                    ListTile(
                      title: const Text('图表颜色主题'),
                      subtitle: const Text('默认主题'),
                      trailing: const Icon(Icons.chevron_right),
                      onTap: () {
                        ScaffoldMessenger.of(context).showSnackBar(
                          const SnackBar(
                            content: Text('此功能正在开发中'),
                          ),
                        );
                      },
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 24),

            // 说明
            Card(
              color: AppTheme.infoColor.withOpacity(0.1),
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Icon(Icons.info_outline, color: AppTheme.infoColor),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Text(
                        '主题模式更改需要重启应用才能生效。字体大小更改会立即生效。',
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: theme.colorScheme.onSurface.withOpacity(0.7),
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  String _getFontSizeLabel(double size) {
    if (size <= 0.9) {
      return '小';
    } else if (size <= 1.1) {
      return '正常';
    } else {
      return '大';
    }
  }
}