marktvogt.de/app/lib/features/user/presentation/security_screen.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../../shared/widgets/alert_banner.dart';
import '../../../shared/widgets/app_button.dart';
import '../../auth/domain/auth_provider.dart';
import '../../auth/domain/models/totp_setup_data.dart';

class SecurityScreen extends ConsumerStatefulWidget {
  const SecurityScreen({super.key});

  @override
  ConsumerState<SecurityScreen> createState() => _SecurityScreenState();
}

class _SecurityScreenState extends ConsumerState<SecurityScreen> {
  TotpSetupData? _setupData;
  bool _settingUp = false;
  bool _disabling = false;
  String? _error;
  String? _success;
  final _codeController = TextEditingController();

  @override
  void dispose() {
    _codeController.dispose();
    super.dispose();
  }

  Future<void> _startSetup() async {
    setState(() {
      _settingUp = true;
      _error = null;
    });
    try {
      final data = await ref.read(authRepositoryProvider).setupTotp();
      setState(() {
        _setupData = data;
        _settingUp = false;
      });
    } catch (e) {
      setState(() {
        _error = 'Fehler beim Starten der 2FA-Einrichtung.';
        _settingUp = false;
      });
    }
  }

  Future<void> _verifyCode() async {
    final code = _codeController.text.trim();
    if (code.length != 6) return;

    setState(() {
      _settingUp = true;
      _error = null;
    });
    try {
      await ref.read(authRepositoryProvider).verifyTotp(code);
      setState(() {
        _setupData = null;
        _settingUp = false;
        _success = '2FA wurde erfolgreich aktiviert.';
      });
      _codeController.clear();
    } catch (e) {
      setState(() {
        _error = 'Ungültiger Code. Bitte versuche es erneut.';
        _settingUp = false;
      });
    }
  }

  Future<void> _disableTotp() async {
    final code = _codeController.text.trim();
    if (code.length != 6) return;

    setState(() {
      _disabling = true;
      _error = null;
    });
    try {
      await ref.read(authRepositoryProvider).disableTotp(code);
      setState(() {
        _disabling = false;
        _success = '2FA wurde deaktiviert.';
      });
      _codeController.clear();
    } catch (e) {
      setState(() {
        _error = 'Ungültiger Code. Bitte versuche es erneut.';
        _disabling = false;
      });
    }
  }

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

    return Scaffold(
      appBar: AppBar(title: const Text('Sicherheit')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Center(
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 500),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text('Zwei-Faktor-Authentifizierung',
                    style: theme.textTheme.headlineMedium),
                const SizedBox(height: 16),

                if (_success != null) ...[
                  AlertBanner(
                    message: _success!,
                    type: AlertType.success,
                    onDismiss: () => setState(() => _success = null),
                  ),
                  const SizedBox(height: 16),
                ],

                if (_error != null) ...[
                  AlertBanner(
                    message: _error!,
                    type: AlertType.error,
                    onDismiss: () => setState(() => _error = null),
                  ),
                  const SizedBox(height: 16),
                ],

                // Setup flow
                if (_setupData != null) ...[
                  _buildSetupFlow(theme),
                ] else ...[
                  _buildActions(theme),
                ],
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildSetupFlow(ThemeData theme) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('2FA einrichten', style: theme.textTheme.titleLarge),
            const SizedBox(height: 12),
            Text(
              'Scanne diesen QR-Code mit deiner Authenticator-App:',
              style: theme.textTheme.bodyMedium,
            ),
            const SizedBox(height: 16),

            // QR code URL display (user would use the URL in their auth app)
            Container(
              width: double.infinity,
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(
                color: theme.colorScheme.surfaceContainerHighest,
                borderRadius: BorderRadius.circular(8),
              ),
              child: Column(
                children: [
                  Icon(Icons.qr_code_2, size: 120, color: theme.colorScheme.onSurface),
                  const SizedBox(height: 8),
                  SelectableText(
                    _setupData!.secret,
                    style: theme.textTheme.bodySmall?.copyWith(
                      fontFamily: 'monospace',
                      fontSize: 12,
                    ),
                    textAlign: TextAlign.center,
                  ),
                ],
              ),
            ),
            const SizedBox(height: 16),

            TextField(
              controller: _codeController,
              decoration: const InputDecoration(
                labelText: 'Bestätigungscode',
                hintText: '6-stelliger Code',
                prefixIcon: Icon(Icons.pin),
              ),
              keyboardType: TextInputType.number,
              maxLength: 6,
              textInputAction: TextInputAction.done,
              onSubmitted: (_) => _verifyCode(),
            ),
            const SizedBox(height: 12),
            Row(
              children: [
                Expanded(
                  child: OutlinedButton(
                    onPressed: () => setState(() => _setupData = null),
                    child: const Text('Abbrechen'),
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: AppButton(
                    label: 'Bestätigen',
                    isLoading: _settingUp,
                    onPressed: _verifyCode,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildActions(ThemeData theme) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Row(
              children: [
                Icon(Icons.security, color: theme.colorScheme.primary),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text('2FA-Status', style: theme.textTheme.titleMedium),
                      const SizedBox(height: 4),
                      Text(
                        'Schütze dein Konto mit einem zweiten Faktor.',
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: theme.colorScheme.outline,
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),

            // Enable 2FA
            AppButton(
              label: '2FA aktivieren',
              icon: Icons.shield,
              isLoading: _settingUp,
              onPressed: _startSetup,
              fullWidth: true,
            ),

            const SizedBox(height: 16),
            const Divider(),
            const SizedBox(height: 16),

            // Disable 2FA section
            Text('2FA deaktivieren', style: theme.textTheme.titleMedium),
            const SizedBox(height: 8),
            TextField(
              controller: _codeController,
              decoration: const InputDecoration(
                labelText: 'Aktueller 2FA-Code',
                hintText: '6-stelliger Code',
                prefixIcon: Icon(Icons.pin),
              ),
              keyboardType: TextInputType.number,
              maxLength: 6,
            ),
            const SizedBox(height: 8),
            AppButton(
              label: '2FA deaktivieren',
              variant: AppButtonVariant.danger,
              isLoading: _disabling,
              onPressed: _disableTotp,
              fullWidth: true,
            ),
          ],
        ),
      ),
    );
  }
}