import 'dart:developer';

import 'package:flutter/foundation.dart';

import '../../api/errors/auth_exception.dart';
import '../../api/errors/error_mapper.dart';
import '../../api/marianumconnect/auth/device_token_name.dart';
import '../../api/marianumconnect/auth/token_storage.dart';
import '../../api/marianumconnect/queries/auth_login/auth_login.dart';
import '../../model/account_data.dart';
import '../../widget_data/widget_sync.dart';

/// Owns the login flow's transient state (loading, last error) so it can be
/// driven from a thin Stateful view and unit-tested without a widget tree.
class LoginController extends ChangeNotifier {
  bool _loading = false;
  String? _errorMessage;
  String? _errorDetails;

  bool get loading => _loading;
  String? get errorMessage => _errorMessage;
  String? get errorDetails => _errorDetails;

  /// Returns `true` when the credential probe succeeded. The view should
  /// then transition the AccountBloc to `loggedIn`.
  Future<bool> submit(String username, String password) async {
    if (_loading) return false;
    _loading = true;
    _errorMessage = null;
    _errorDetails = null;
    notifyListeners();

    final user = username.trim().toLowerCase();
    try {
      await AccountData().removeData();
      // Vorherigen Token revoken bevor wir einen neuen anfordern — ein altes
      // Account hätte sonst noch einen aktiven Token in api_tokens.
      await const MarianumConnectTokenStorage().clear();
      // Widget-Snapshot löschen, sonst blitzt nach Account-Wechsel kurz der
      // Stundenplan des vorigen Users auf dem Home-Bildschirm.
      await WidgetSync.clear();
      await WidgetSync.triggerUpdate();
      // AuthLogin = Credential-Probe + Token-Create in einem Call.
      // 401 hier heißt: falsches Passwort.
      await AuthLogin().run(
        username: user,
        password: password,
        tokenName: await DeviceTokenName.resolve(),
      );
      await AccountData().setData(user, password);
      _loading = false;
      notifyListeners();
      return true;
    } catch (e) {
      log(e.toString());
      await AccountData().removeData();
      await const MarianumConnectTokenStorage().clear();
      final isWrongCredentials = e is AuthException && e.statusCode == 401;
      _errorMessage = isWrongCredentials
          ? 'Benutzername oder Passwort falsch.'
          : errorToUserMessage(e);
      _errorDetails = errorToTechnicalDetails(e);
      _loading = false;
      notifyListeners();
      return false;
    }
  }
}