/// Gear that opens the settings sheet.
library;

import 'package:flutter/material.dart';

import '../services/app_settings.dart';
import '../services/backup_service.dart';
import '../supermarkets_screen.dart';

class SettingsButton extends StatelessWidget {
  const SettingsButton({super.key});

  @override
  Widget build(BuildContext context) {
    return IconButton(
      tooltip: 'Settings',
      onPressed: () => showSettingsSheet(context),
      icon: const Icon(Icons.settings_outlined),
    );
  }
}

Future<void> showSettingsSheet(BuildContext context) {
  return showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    showDragHandle: true,
    builder: (context) {
      return const _SettingsSheet();
    },
  );
}

class _SettingsSheet extends StatefulWidget {
  const _SettingsSheet();

  @override
  State<_SettingsSheet> createState() => _SettingsSheetState();
}

class _SettingsSheetState extends State<_SettingsSheet> {
  bool _busy = false;

  Future<void> _export(AppSettings settings) async {
    setState(() => _busy = true);
    try {
      final shared = await BackupService(settings.repository).exportBackup();
      if (!mounted) return;
      if (shared) {
        ScaffoldMessenger.of(context)
            .showSnackBar(const SnackBar(content: Text('Backup ready.')));
      }
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Could not export the backup.')),
      );
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  Future<void> _import(AppSettings settings) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) {
        return AlertDialog(
          title: const Text('Import backup?'),
          content: const Text(
            'This replaces all products, shopping trips, photos, and settings on this device.',
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context, false),
              child: const Text('Cancel'),
            ),
            FilledButton(
              onPressed: () => Navigator.pop(context, true),
              child: const Text('Import'),
            ),
          ],
        );
      },
    );
    if (confirmed != true || !mounted) return;

    setState(() => _busy = true);
    try {
      final imported = await BackupService(settings.repository).importBackup();
      if (!mounted) return;
      if (imported) {
        await settings.reload();
        if (!mounted) return;
        ScaffoldMessenger.of(context)
            .showSnackBar(const SnackBar(content: Text('Backup imported.')));
      }
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Could not import this backup.')),
      );
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  void _openSupermarkets(BuildContext context, AppSettings settings) {
    Navigator.of(context)
      ..pop()
      ..push(
        MaterialPageRoute(
          builder: (_) => SupermarketsScreen(repository: settings.repository),
        ),
      );
  }

  @override
  Widget build(BuildContext context) {
    final settings = SettingsScope.of(context);
    final bottom = MediaQuery.viewInsetsOf(context).bottom;

    return ListenableBuilder(
      listenable: settings,
      builder: (context, _) {
        return Padding(
          padding: EdgeInsets.fromLTRB(16, 0, 16, 16 + bottom),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Text('Settings', style: Theme.of(context).textTheme.titleLarge),
              const SizedBox(height: 8),
              SwitchListTile(
                contentPadding: EdgeInsets.zero,
                title: const Text('Dark mode'),
                value: settings.darkMode,
                onChanged: _busy ? null : settings.setDarkMode,
              ),
              ListTile(
                contentPadding: EdgeInsets.zero,
                leading: const Icon(Icons.store_outlined),
                title: const Text('Supermarkets'),
                subtitle: Text(
                  settings.supermarkets.isEmpty
                      ? 'Names, colors, and bonus cards'
                      : '${settings.supermarkets.length} stores',
                ),
                trailing: const Icon(Icons.chevron_right),
                onTap: _busy
                    ? null
                    : () => _openSupermarkets(context, settings),
              ),
              const SizedBox(height: 16),
              Text('Backup', style: Theme.of(context).textTheme.titleMedium),
              Text(
                'Save everything to a JSON file, or replace this device from a backup.',
                style: Theme.of(context).textTheme.bodyMedium,
              ),
              const SizedBox(height: 8),
              Row(
                children: [
                  Expanded(
                    child: OutlinedButton.icon(
                      onPressed: _busy ? null : () => _export(settings),
                      icon: const Icon(Icons.file_upload_outlined),
                      label: const Text('Export'),
                    ),
                  ),
                  const SizedBox(width: 8),
                  Expanded(
                    child: OutlinedButton.icon(
                      onPressed: _busy ? null : () => _import(settings),
                      icon: const Icon(Icons.file_download_outlined),
                      label: const Text('Import'),
                    ),
                  ),
                ],
              ),
              if (_busy) ...[
                const SizedBox(height: 8),
                const LinearProgressIndicator(),
              ],
            ],
          ),
        );
      },
    );
  }
}