tm_app/lib/view_models/auth_view_model.dart

import 'package:flutter/material.dart';
import '../core/utils/result.dart';
import '../data/models/user_model.dart';
import '../data/repositories/auth_repository.dart';

class AuthViewModel with ChangeNotifier {
  final AuthRepository _authRepository;

  AuthViewModel({required AuthRepository authRepository})
      : _authRepository = authRepository {
    usernameController.addListener(_onTextChanged);
    passwordController.addListener(_onTextChanged);
    usernameFocus.addListener(_onTextChanged);
    passwordFocus.addListener(_onTextChanged);
  }

  final TextEditingController usernameController = TextEditingController();
  final TextEditingController passwordController = TextEditingController();
  final FocusNode usernameFocus = FocusNode();
  final FocusNode passwordFocus = FocusNode();

  bool _obscurePassword = true;
  bool get obscurePassword => _obscurePassword;
  bool get isLoginEnabled =>
      usernameController.text.isNotEmpty &&
      passwordController.text.isNotEmpty;

  // Auth state
  bool _isLoading = false;
  String? _errorMessage;
  UserModel? _loggedInUser;

  bool get isLoading => _isLoading;
  String? get errorMessage => _errorMessage;
  UserModel? get loggedInUser => _loggedInUser;

  void togglePasswordVisibility() {
    _obscurePassword = !_obscurePassword;
    notifyListeners();
  }

  void _onTextChanged() {
    notifyListeners();
  }

  Future<void> login() async {
    _isLoading = true;
    _errorMessage = null;
    notifyListeners();

    final result = await _authRepository.login(
      usernameController.text.trim(),
      passwordController.text.trim(),
    );

    switch (result) {
      case Ok<UserModel>():
        _loggedInUser = result.value;
        break;
      case Error<UserModel>():
        _errorMessage = result.error.toString();
        break;
    }

    _isLoading = false;
    notifyListeners();
  }

  @override
  void dispose() {
    usernameController.dispose();
    passwordController.dispose();
    usernameFocus.dispose();
    passwordFocus.dispose();
    super.dispose();
  }
}