import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:login_vault_app/auth_service.dart';
import 'package:login_vault_app/theme_provider.dart';

/// Settings: change app password, switch theme (dark/system), and Exit.
class SettingsScreen extends StatefulWidget {
  final AuthService auth;
  final ThemeProvider theme;
  const SettingsScreen({super.key, required this.auth, required this.theme});

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  final _oldCtrl = TextEditingController();
  final _newCtrl = TextEditingController();
  String? _msg;

  Future<void> _changePassword() async {
    final oldP = _oldCtrl.text;
    final newP = _newCtrl.text;
    if (newP.isEmpty) {
      setState(() => _msg = 'Password baru wajib diisi');
      return;
    }
    final stored = await widget.auth.getAppPassword();
    if (stored != null && stored != '__google__' && stored != oldP) {
      setState(() => _msg = 'Password lama salah');
      return;
    }
    await widget.auth.changePassword(newP);
    setState(() => _msg = 'Password aplikasi berhasil diubah');
    _oldCtrl.clear();
    _newCtrl.clear();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Pengaturan')),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          const Text('Tema',
              style: TextStyle(fontWeight: FontWeight.bold)),
          ListTile(
            title: const Text('Gelap (Dark)'),
            leading: const Icon(Icons.dark_mode),
            trailing: Radio<ThemeMode>(
              value: ThemeMode.dark,
              groupValue: widget.theme.mode,
              onChanged: (m) => widget.theme.setMode(m!),
            ),
            onTap: () => widget.theme.setMode(ThemeMode.dark),
          ),
          ListTile(
            title: const Text('Sistem (System)'),
            leading: const Icon(Icons.brightness_auto),
            trailing: Radio<ThemeMode>(
              value: ThemeMode.system,
              groupValue: widget.theme.mode,
              onChanged: (m) => widget.theme.setMode(m!),
            ),
            onTap: () => widget.theme.setMode(ThemeMode.system),
          ),
          const Divider(),
          const Text('Ubah Password Aplikasi',
              style: TextStyle(fontWeight: FontWeight.bold)),
          TextField(
            controller: _oldCtrl,
            obscureText: true,
            decoration: const InputDecoration(labelText: 'Password lama'),
          ),
          TextField(
            controller: _newCtrl,
            obscureText: true,
            decoration: const InputDecoration(labelText: 'Password baru'),
          ),
          const SizedBox(height: 8),
          ElevatedButton(
            onPressed: _changePassword,
            child: const Text('Simpan Password'),
          ),
          if (_msg != null)
            Padding(
              padding: const EdgeInsets.only(top: 8),
              child: Text(_msg!,
                  style: const TextStyle(color: Colors.green)),
            ),
          const Divider(),
          ListTile(
            leading: const Icon(Icons.exit_to_app),
            title: const Text('Keluar (Exit)'),
            onTap: () {
              // On Android, pop the whole stack then ask the system to close.
              Navigator.of(context).popUntil((r) => r.isFirst);
              if (Platform.isAndroid) {
                SystemNavigator.pop();
              } else {
                exit(0);
              }
            },
          ),
        ],
      ),
    );
  }
}