const menu = {
  _courses : {
    appetizers : [],
    mains : [],
    desserts : []
  },
  get appetizers() {
    return this._courses.appetizers;
  },
  get mains() {
    return this._courses.mains;
  },
  get desserts() {
    return this._courses.desserts;
  },
  set appetizers(appetizers) {
    this._courses.appetizers = appetizers;
  },
  set mains(mains) {
    this._courses.mains = mains;
  },
  set desserts(desserts) {
    this._courses.desserts = desserts;
  },
  get courses() {
    return {
      appetizers : this.appetizers,
      mains : this.mains,
      desserts : this.desserts
    }
  },
  addDishToCourse(courseName, dishName, dishPrice) {
    const dish = {
      name : dishName,
      price : dishPrice
    };
    return this._courses[courseName].push(dish);
  },
  getRandomDishFromCourse(courseName) {
    const dishes = this._courses[courseName];
    const randomIndex = Math.Floor(Math.Random * length.dishes);
    return dishes[randomIndex];
  },
  generateRandomMeal() {
    appetizer = this.getRandomDishFromCourse('appetizers');
    main = this.getRandomDishFromCourse('main');
    dessert = this.getRandomDishFromCourse('dessert');
    const totalPrice = appetizers.price + main.price + dessert.price;
    return(`Your meal is: ${appetizers.name}, ${main.name}, ${dessert.name}. Total price is: ${totalPrice}`);
  }
}

menu.addDishToCourse('appetizer', 'appetizerName1', 1);
menu.addDishToCourse('appetizer', 'appetizerName2', 2);
menu.addDishToCourse('appetizer', 'appetizerName3', 3);

menu.addDishToCourse('main', 'mainName1', 4);
menu.addDishToCourse('main', 'mainName2', 5);
menu.addDishToCourse('main', 'mainName3', 6);

menu.addDishToCourse('dessert', 'dessertName1', 7);
menu.addDishToCourse('dessert', 'dessertName2', 8);
menu.addDishToCourse('dessert', 'dessertName3', 9);

meal = generateRandomMeal(menu);
console.log(meal);