workouttest_app/lib/model/auth.dart

import 'package:aitrainer_app/model/customer.dart';
import 'package:aitrainer_app/model/exercise_tree.dart';
import 'package:aitrainer_app/service/exercise_tree_service.dart';
import 'package:aitrainer_app/service/exercisetype_service.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:aitrainer_app/model/exercise_type.dart';

enum SharePrefsChange {
  login,
  registration,
  logout,
}
/*
  Auth flow of the app
  1. During the login screen the authentication will be executed
    - if not successful: message: Network error, try again later
    - if successful
      - get the stored shared preferences and customer id
        - if customer_id not present -> registration page
        - if present, check if the expiration_date > 10 days -> login page
        - else get the API customer by the stored customer_id
      - After registration / login store the preferences:
        - AuthToken
        - customer_id
        - last_store_date
        - is_registered
        - is_logged_in
 */

class Auth {
  static final Auth _singleton = Auth._internal();

  // Keys to store and fetch data from SharedPreferences
  static final String authTokenKey = 'auth_token';
  static final String customerIdKey = 'customer_id';
  static final String lastStoreDateKey = 'last_date';
  static final String isRegisteredKey = 'is_registered';
  static final String isLoggedInKey = 'is_logged_in';

  static final String baseUrl = 'http://aitrainer.info:8888/api/';
  static final String mediaUrl = 'https://aitrainer.info:4343/media/';
  static final String username = 'bosi';
  static final String password = 'andio2009';

  String authToken = "";
  Customer userLoggedIn;
  bool firstLoad = true;
  List<ExerciseType> _exerciseTypes;
  List<ExerciseTree> _exerciseTree;
  List deviceLanguages;
  String startPage;

  factory Auth() {
    return _singleton;
  }

  Auth._internal();

  String getAuthToken() {
    return this.authToken;
  }

  static String getToken(SharedPreferences prefs) {
    return prefs.getString(authTokenKey);
  }

  static String getBaseUrl() {
    return baseUrl;
  }

  static String getMediaUrl() {
    return mediaUrl;
  }

  afterRegistration(Customer customer) {
    Future<SharedPreferences> prefs = SharedPreferences.getInstance();

    userLoggedIn = customer;
    setPreferences(prefs, SharePrefsChange.registration, customer.customerId);
  }

  afterLogin(Customer customer) async {
    Future<SharedPreferences> prefs = SharedPreferences.getInstance();

    userLoggedIn = customer;
    await setPreferences(prefs, SharePrefsChange.login, customer.customerId);
  }

  logout() async {
    userLoggedIn = null;
    authToken = "";
    //firstLoad = true;
    Future<SharedPreferences> prefs = SharedPreferences.getInstance();
    await setPreferences(prefs, SharePrefsChange.logout, 0);
  }

  setPreferences(Future<SharedPreferences> prefs,
                SharePrefsChange type,
                int customerId) async {
    SharedPreferences sharedPreferences;
    sharedPreferences = await prefs;

    DateTime now = DateTime.now();
    sharedPreferences.setString(Auth.lastStoreDateKey, now.toString());
    if ( type == SharePrefsChange.registration ) {
      Auth().startPage = "home";
      sharedPreferences.setInt(Auth.customerIdKey, customerId);
      sharedPreferences.setBool(Auth.isRegisteredKey, true);
      sharedPreferences.setBool(Auth.isLoggedInKey, true);
      await ExerciseTypeApi().getExerciseTypes();
      await ExerciseTreeApi().getExerciseTree();
    } else if ( type == SharePrefsChange.login ) {
      Auth().startPage = "home";
      sharedPreferences.setInt(Auth.customerIdKey, customerId);
      sharedPreferences.setBool(Auth.isLoggedInKey, true);
      await ExerciseTypeApi().getExerciseTypes();
      await ExerciseTreeApi().getExerciseTree();
    } else if ( type == SharePrefsChange.logout ) {
      sharedPreferences.setBool(Auth.isLoggedInKey, false);
      sharedPreferences.setInt(Auth.customerIdKey, 0);
      sharedPreferences.setString(authTokenKey, "");
    }
  }

  void setExerciseTypes( List<ExerciseType> exerciseTypes) {
    this._exerciseTypes = exerciseTypes;
  }

  void setExerciseTree( List<ExerciseTree> exerciseTree) {
    this._exerciseTree = exerciseTree;
  }

  List<ExerciseType> getExerciseTypes() {
    return this._exerciseTypes;
  }

  List<ExerciseTree> getExerciseTree() {
    return this._exerciseTree;
  }
}