/// <summary>
/// adds a dish to the menu of a restaurant
/// 'add all ingredients when dish is added'? -> dish can't be added if all ingredients it requires does not exist
/// 'recipe can only have one portion of an ingredient'
/// </summary>
/// <param name="dish">dish to be added</param>
/// <exception cref="ArgumentException">dish with a name already exists or when not all dish ingredients exist for a dish</exception>
public void AddDish(Dish dish)
{
var allDishIngredientsExist = new Func <Dish, bool>(d =>
d.IngredientIds
.Select(ingredientId => ingredientId)
.All(ingredientId => _ingredientRepository.Exists(ingredientId)));
if (!allDishIngredientsExist(dish))
{
throw new ArgumentException($"not all dish ingredients exist in a {dish}");
}
if (_dishRepository.ExistsByName(dish.Name))
{
throw new ArgumentException($"dish with name '{dish.Name}' already exists");
}
dish.IngredientIds = dish.IngredientIds.Distinct().ToList(); // 'recipe can only have one portion of an ingredient'
_dishRepository.Add(dish);
}
