import 'package:flutter/material.dart';

import '../../../../l10n/app_localizations.dart';
import '../../../../shared/theme/design_tokens.dart';
import '../../data/models/profile_settings.dart';
import '../widgets/settings_section_widgets.dart';
import 'language_settings_screen.dart';

class GeneralSettingsScreen extends StatefulWidget {
  const GeneralSettingsScreen({
    super.key,
    required this.settings,
    required this.onSettingsChanged,
  });

  final ProfileSettingsV1 settings;
  final Future<void> Function(ProfileSettingsV1 settings) onSettingsChanged;

  @override
  State<GeneralSettingsScreen> createState() => _GeneralSettingsScreenState();
}

class _GeneralSettingsScreenState extends State<GeneralSettingsScreen> {
  late ProfileSettingsV1 _settings;

  @override
  void initState() {
    super.initState();
    _settings = widget.settings;
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final colors = Theme.of(context).colorScheme;

    return PopScope<ProfileSettingsV1>(
      canPop: false,
      onPopInvokedWithResult: (didPop, result) {
        if (didPop) {
          return;
        }
        Navigator.of(context).pop(_settings);
      },
      child: Scaffold(
        backgroundColor: colors.surfaceContainerLow,
        appBar: AppBar(
          leading: IconButton(
            onPressed: () => Navigator.of(context).pop(_settings),
            icon: const Icon(Icons.arrow_back_ios_new_rounded),
          ),
          title: Text(l10n.settingsGeneralTitle),
          centerTitle: true,
          backgroundColor: colors.surfaceContainerLow,
          surfaceTintColor: colors.surfaceContainerLow,
        ),
        body: ListView(
          padding: const EdgeInsets.all(AppSpacing.lg),
          children: [
            SectionLabel(text: l10n.settingsSectionGeneral),
            SettingsGroupCard(
              children: [
                SettingsMenuTile(
                  icon: Icons.language_rounded,
                  title: l10n.settingsInterfaceLanguage,
                  subtitle: displayLanguageLabel(
                    l10n,
                    _settings.preferences.interfaceLanguage,
                  ),
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  onTap: () => _selectLanguage(
                    _settings.preferences.interfaceLanguage,
                    (lang) => setState(() {
                      _settings = _settings.copyWith(
                        preferences: _settings.preferences.copyWith(
                          interfaceLanguage: lang,
                        ),
                      );
                    }),
                  ),
                ),
                SettingsMenuTile(
                  icon: Icons.smart_toy_rounded,
                  title: l10n.settingsAiLanguage,
                  subtitle: displayLanguageLabel(
                    l10n,
                    _settings.preferences.aiLanguage,
                  ),
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: true,
                  onTap: () => _selectLanguage(
                    _settings.preferences.aiLanguage,
                    (lang) => setState(() {
                      _settings = _settings.copyWith(
                        preferences: _settings.preferences.copyWith(
                          aiLanguage: lang,
                        ),
                      );
                    }),
                  ),
                ),
                SettingsMenuTile(
                  icon: Icons.access_time_rounded,
                  title: l10n.settingsTimezone,
                  subtitle: _settings.preferences.timezone,
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: true,
                  onTap: () => _selectTimezone(context),
                ),
                SettingsMenuTile(
                  icon: Icons.public_rounded,
                  title: l10n.settingsCountry,
                  subtitle: _settings.preferences.country,
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: false,
                  onTap: () => _selectCountry(context),
                ),
              ],
            ),
            const SizedBox(height: AppSpacing.lg),
            SectionLabel(text: l10n.settingsSectionNotification),
            SettingsGroupCard(
              children: [
                SettingsSwitchTile(
                  icon: Icons.notifications_rounded,
                  title: l10n.settingsNotificationAllow,
                  value: _settings.notification.allowNotifications,
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  onChanged: (value) =>
                      _updateNotification(allowNotifications: value),
                ),
                SettingsSwitchTile(
                  icon: Icons.vibration_rounded,
                  title: l10n.settingsNotificationVibration,
                  value: _settings.notification.allowVibration,
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: false,
                  onChanged: (value) =>
                      _updateNotification(allowVibration: value),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _selectLanguage(
    String currentLanguage,
    void Function(String) onChanged,
  ) async {
    final result = await Navigator.of(context).push<String>(
      MaterialPageRoute<String>(
        builder: (_) =>
            LanguageSettingsScreen(selectedLanguageTag: currentLanguage),
      ),
    );
    if (result == null || result == currentLanguage) {
      return;
    }
    onChanged(result);
    await widget.onSettingsChanged(_settings);
  }

  Future<void> _selectTimezone(BuildContext context) async {
    final result = await Navigator.of(context).push<String>(
      MaterialPageRoute<String>(
        builder: (_) => TimezoneSettingsScreen(
          selectedTimezone: _settings.preferences.timezone,
        ),
      ),
    );
    if (result == null || result == _settings.preferences.timezone) {
      return;
    }
    setState(() {
      _settings = _settings.copyWith(
        preferences: _settings.preferences.copyWith(timezone: result),
      );
    });
    await widget.onSettingsChanged(_settings);
  }

  Future<void> _selectCountry(BuildContext context) async {
    final result = await Navigator.of(context).push<String>(
      MaterialPageRoute<String>(
        builder: (_) => CountrySettingsScreen(
          selectedCountry: _settings.preferences.country,
        ),
      ),
    );
    if (result == null || result == _settings.preferences.country) {
      return;
    }
    setState(() {
      _settings = _settings.copyWith(
        preferences: _settings.preferences.copyWith(country: result),
      );
    });
    await widget.onSettingsChanged(_settings);
  }

  void _updateNotification({bool? allowNotifications, bool? allowVibration}) {
    final newNotification = _settings.notification.copyWith(
      allowNotifications: allowNotifications,
      allowVibration: allowVibration,
    );
    final newSettings = _settings.copyWith(notification: newNotification);
    setState(() {
      _settings = newSettings;
    });
    widget.onSettingsChanged(newSettings);
  }
}

class TimezoneSettingsScreen extends StatelessWidget {
  const TimezoneSettingsScreen({super.key, required this.selectedTimezone});

  final String selectedTimezone;

  static const _timezones = [
    'Asia/Shanghai',
    'Asia/Hong_Kong',
    'Asia/Tokyo',
    'America/New_York',
    'America/Los_Angeles',
    'Europe/London',
    'Europe/Paris',
  ];

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final colors = Theme.of(context).colorScheme;

    return Scaffold(
      backgroundColor: colors.surfaceContainerLow,
      appBar: AppBar(
        title: Text(l10n.settingsTimezone),
        centerTitle: true,
        backgroundColor: colors.surfaceContainerLow,
        surfaceTintColor: colors.surfaceContainerLow,
      ),
      body: ListView(
        padding: const EdgeInsets.all(AppSpacing.lg),
        children: [
          SettingsGroupCard(
            children: [
              for (int i = 0; i < _timezones.length; i++)
                SettingsMenuTile(
                  icon: Icons.access_time_rounded,
                  title: _timezones[i],
                  subtitle: '',
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: i != _timezones.length - 1,
                  showChevron: false,
                  trailing: selectedTimezone == _timezones[i]
                      ? Icon(Icons.check_rounded, color: colors.primary)
                      : null,
                  onTap: () => Navigator.of(context).pop(_timezones[i]),
                ),
            ],
          ),
        ],
      ),
    );
  }
}

class CountrySettingsScreen extends StatelessWidget {
  const CountrySettingsScreen({super.key, required this.selectedCountry});

  final String selectedCountry;

  static const _countries = ['CN', 'HK', 'TW', 'US', 'JP', 'GB', 'FR'];
  static const _labels = [
    'China',
    'Hong Kong',
    'Taiwan',
    'USA',
    'Japan',
    'UK',
    'France',
  ];

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final colors = Theme.of(context).colorScheme;

    return Scaffold(
      backgroundColor: colors.surfaceContainerLow,
      appBar: AppBar(
        title: Text(l10n.settingsCountry),
        centerTitle: true,
        backgroundColor: colors.surfaceContainerLow,
        surfaceTintColor: colors.surfaceContainerLow,
      ),
      body: ListView(
        padding: const EdgeInsets.all(AppSpacing.lg),
        children: [
          SettingsGroupCard(
            children: [
              for (int i = 0; i < _countries.length; i++)
                SettingsMenuTile(
                  icon: Icons.public_rounded,
                  title: _labels[i],
                  subtitle: _countries[i],
                  tint: colors.primary,
                  background: colors.surfaceContainerHighest,
                  showDivider: i != _countries.length - 1,
                  showChevron: false,
                  trailing: selectedCountry == _countries[i]
                      ? Icon(Icons.check_rounded, color: colors.primary)
                      : null,
                  onTap: () => Navigator.of(context).pop(_countries[i]),
                ),
            ],
          ),
        ],
      ),
    );
  }
}