/// <summary>
/// Updates an existing food item in the database.
/// Updates the total calories for the diary entry the food item belongs to.
/// </summary>
/// <param name="id"></param>
/// <param name="foodItem"></param>
/// <returns>
/// Unsuccessful FoodItemResponse if food item does not exist;
/// Unsuccessful FoodItemResponse if there was an issue updating the food item in the database;
/// Successful FoodItemResponse with the food item
/// </returns>
public async Task <FoodItemResponse> UpdateFoodItemAsync(int id, FoodItem foodItem)
{
// check if the food item exists
var existingFoodItem = await _foodItemRepository.GetAsync(id);
if (existingFoodItem == null)
{
return(new FoodItemResponse($"Food item {id} not found"));
}
// remove the old calories from the total calories
existingFoodItem.DiaryEntry.TotalCalories -= existingFoodItem.Calories;
// add the new calories to the total calories
existingFoodItem.DiaryEntry.TotalCalories += foodItem.Calories;
// update the name and calories of the old food item
existingFoodItem.Name = foodItem.Name;
existingFoodItem.Calories = foodItem.Calories;
// save the changes
try
{
_foodItemRepository.Update(existingFoodItem);
await _unitOfWork.CompleteAsync();
}
catch (Exception e)
{
return(new FoodItemResponse($"An error occurred when updating food item {id}: {e}"));
}
return(new FoodItemResponse(existingFoodItem));
}
