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

/// Settings: change app password, switch theme (dark/system), session timeout,
/// fingerprint toggle, 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;
  Color _msgColor = Colors.grey;
  bool _biometricOn = false;
  bool _biometricAvailable = false;
  int _timeout = 3;

  final List<int> _timeoutOptions = [3, 5, 10, 15, 30, 60, 0];

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

  Future<void> _loadSettings() async {
    final on = await widget.auth.isBiometricEnabled();
    final avail = await widget.auth.canUseBiometrics();
    final t = await widget.auth.getTimeoutMinutes();
    if (mounted) {
      setState(() {
        _biometricOn = on && avail;
        _biometricAvailable = avail;
        _timeout = t;
      });
    }
  }

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

  Future<void> _backup() async {
    try {
      final path = await BackupService.exportEncrypted(widget.auth);
      if (mounted) {
        setState(() {
          _msg = 'Backup tersimpan: $path';
          _msgColor = Colors.green;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _msg = 'Backup gagal: $e';
          _msgColor = Colors.red;
        });
      }
    }
  }

  Future<void> _restore() async {
    try {
      final backups = await BackupService.listBackups();
      if (backups.isEmpty) {
        if (mounted) {
          setState(() {
            _msg = 'Tidak ada file backup di folder Download/loginvault';
            _msgColor = Colors.red;
          });
        }
        return;
      }
      if (!mounted) return;
      final chosen = await showDialog<String>(
        context: context,
        builder: (ctx) => AlertDialog(
          title: const Text('Pilih file backup'),
          content: SizedBox(
            width: double.maxFinite,
            child: ListView.builder(
              shrinkWrap: true,
              itemCount: backups.length,
              itemBuilder: (_, i) => ListTile(
                title: Text(backups[i].path.split('/').last),
                onTap: () => Navigator.of(ctx).pop(backups[i].path),
              ),
            ),
          ),
        ),
      );
      if (chosen == null) return;
      final count = await BackupService.importEncrypted(widget.auth, chosen);
      if (mounted) {
        setState(() {
          _msg = 'Restore berhasil: $count entri';
          _msgColor = Colors.green;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _msg = 'Restore gagal: $e';
          _msgColor = Colors.red;
        });
      }
    }
  }

  Future<void> _toggleBiometric(bool value) async {
    if (value && !_biometricAvailable) {
      setState(() {
        _msg = 'Perangkat tidak mendukung biometrik';
        _msgColor = Colors.red;
      });
      return;
    }
    // When turning ON, ask for confirmation first. If cancelled, keep OFF.
    if (value) {
      final confirmed = await showDialog<bool>(
        context: context,
        builder: (ctx) => AlertDialog(
          title: const Text('Aktifkan Sidik Jari?'),
          content: const Text(
              'Saat login, Anda akan diminta verifikasi sidik jari '
              'untuk masuk tanpa mengisi email & password.'),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(ctx).pop(false),
              child: const Text('Batal'),
            ),
            TextButton(
              onPressed: () => Navigator.of(ctx).pop(true),
              child: const Text('Aktifkan'),
            ),
          ],
        ),
      );
      if (confirmed != true) {
        // cancelled -> revert switch to OFF
        if (mounted) setState(() => _biometricOn = false);
        return;
      }
    }
    // Settings only sets the flag; actual biometric prompt happens at login.
    await widget.auth.setBiometricEnabled(value);
    if (mounted) {
      setState(() {
        _biometricOn = value;
        _msg = value
            ? 'Sidik jari aktif. Akan diminta saat login.'
            : 'Sidik jari nonaktif.';
        _msgColor = value ? Colors.green : Colors.grey;
      });
    }
  }

  Future<void> _setTimeout(int? value) async {
    if (value == null) return;
    await widget.auth.setTimeoutMinutes(value);
    if (mounted) setState(() => _timeout = value);
    widget.auth.openSession(); // activity
  }

  String _timeoutLabel(int m) => m == 0 ? 'Selamanya' : '$m menit';

  @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('Session', style: TextStyle(fontWeight: FontWeight.bold)),
          ListTile(
            title: const Text('Timeout (tanpa aktivitas)'),
            subtitle: Text('Logout otomatis setelah: ${_timeoutLabel(_timeout)}'),
            trailing: PopupMenuButton<int>(
              initialValue: _timeoutOptions.contains(_timeout) ? _timeout : _timeoutOptions.first,
              onSelected: _setTimeout,
              itemBuilder: (ctx) => _timeoutOptions
                  .map((m) => PopupMenuItem(value: m, child: Text(_timeoutLabel(m))))
                  .toList(),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text(_timeoutLabel(_timeout)),
                  const Icon(Icons.arrow_drop_down),
                ],
              ),
            ),
          ),
          SwitchListTile(
            title: const Text('Login dengan sidik jari'),
            subtitle: Text(_biometricAvailable
                ? 'Gunakan fingerprint untuk membuka app'
                : 'Perangkat tidak mendukung biometrik'),
            value: _biometricOn,
            onChanged: _toggleBiometric,
          ),
          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: TextStyle(color: _msgColor)),
            ),
          const Divider(),
          const Text('Backup & Restore',
              style: TextStyle(fontWeight: FontWeight.bold)),
          ListTile(
            leading: const Icon(Icons.backup),
            title: const Text('Backup ke file (lokal)'),
            subtitle: const Text(
                'Simpan vault terenkripsi ke folder Download. Bisa dipindah ke Drive manual.'),
            onTap: _backup,
          ),
          ListTile(
            leading: const Icon(Icons.restore),
            title: const Text('Restore dari file'),
            subtitle: const Text('Pilih file backup .enc untuk dikembalikan.'),
            onTap: _restore,
          ),
          const Divider(),
          ListTile(
            leading: const Icon(Icons.exit_to_app),
            title: const Text('Keluar (Exit)'),
            onTap: () async {
              await widget.auth.closeSession();
              // restart to a fresh AuthScreen (re-evaluates registered +
              // session state) instead of just popping back to Dashboard.
              if (!mounted) return;
              Navigator.of(context).pushAndRemoveUntil(
                MaterialPageRoute(
                  builder: (_) => AuthScreen(auth: widget.auth),
                ),
                (r) => false,
              );
            },
          ),
        ],
      ),
    );
  }
}