FavoritesBloc

import 'dart:async';
import 'dart:convert';
import 'package:e_commerce_bloc/bloc/icons_bloc.dart';
import 'package:rxdart/rxdart.dart';

import 'package:e_commerce_bloc/models/product.dart';
import 'package:shared_preferences/shared_preferences.dart';

class FavoritesBloc {
  Map<String, Product> _favorites = {};
  IconsBloc _iconsBloc;

  final _favoritesController = BehaviorSubject<Map<String, Product>>.seeded({});
  Stream<Map<String, Product>> get outFav => _favoritesController.stream;

  FavoritesBloc(){
    _iconsBloc = IconsBloc();
    SharedPreferences.getInstance().then((prefs){
      if(prefs.getKeys().contains('favorites')){
        _favorites = json.decode(prefs.getString('favorites')).map((k, v){
          return MapEntry(k, Product.fromJson(v));
        }).cast<String, Product>();
        _favoritesController.add(_favorites);
      }
    });
  }

  void toggleFavorites(Product product){
    if(_favorites.containsKey(product.id)) {
      _favorites.remove(product.id);
      _favoritesController.add(_favorites);
      _iconsBloc.notifyFavoriteIcon(true);
      print(_favorites.length);
    } else {
      _favorites[product.id] = product;
      print(_favorites.length);
    }

    _favoritesController.sink.add(_favorites);

    _saveFav();
  }

  void removeFav(Product product){
    _favorites.remove(product.id);
    _favoritesController.add(_favorites);
    _iconsBloc.notifyFavoriteIcon(true);
    _saveFav();
  }

  void _saveFav(){
     SharedPreferences.getInstance().then((prefs){
       prefs.setString('favorites', json.encode(_favorites));
     });
  }


  void dispose(){
    _favoritesController.close();
  }
}