public void CreatePresetPizza(string name, int orderId)
        {
            PresetPizzaModel preset = _db.PresetPizzas
                                      .Where(p => p.Name == name)
                                      .Include(p => p.Crust)
                                      .Include(p => p.Size)
                                      .Include(p => p.PresetToppings).ThenInclude(pt => pt.Topping)
                                      .SingleOrDefault();

            PizzaModel pizza = new PizzaModel()
            {
                Crust = preset.Crust,
                Size  = preset.Size,
                Order = _db.Orders.SingleOrDefault(o => o.Id == orderId),
                Name  = preset.Name
            };

            foreach (var pt in preset.PresetToppings)
            {
                PizzaToppingModel pizzaTopping = new PizzaToppingModel()
                {
                    Pizza   = pizza,
                    Topping = pt.Topping
                };
                _db.PizzaToppings.Add(pizzaTopping);
                _db.SaveChanges();
            }
        }
        public void CreateCustomPizza(string crust, string size, List <string> toppings, int orderId)
        {
            //Create new Pizza
            PizzaModel pizza = new PizzaModel()
            {
                Crust = _db.Crusts.SingleOrDefault(c => c.Name == crust),
                Size  = _db.Sizes.SingleOrDefault(s => s.Name == size),
                Order = _db.Orders.SingleOrDefault(o => o.Id == orderId),
                Name  = "Custom"
            };

            //Create corresponding PizzaToppings
            foreach (var topping in toppings)
            {
                PizzaToppingModel pizzaTopping = new PizzaToppingModel()
                {
                    Pizza   = pizza,
                    Topping = _db.Toppings.SingleOrDefault(t => t.Name == topping)
                };
                _db.PizzaToppings.Add(pizzaTopping);
                _db.SaveChanges();
            }
        }