/// <summary>
/// Delete a food item from the database.
/// Updates the total calories for the diary entry the food item belongs to.
/// </summary>
/// <param name="id"></param>
/// <returns>
/// Unsuccessful FoodItemResponse if the food item does not exist;
/// Unsuccessful FoodItemResponse if there was an issue removing the food item from the database;
/// Successful FoodItemResponse with the food item
/// </returns>
public async Task <FoodItemResponse> DeleteFoodItemAsync(int id)
{
// check if the food item exists
var existingFoodItem = await _foodItemRepository.GetAsync(id);
if (existingFoodItem == null)
{
return(new FoodItemResponse($"Food item {id} not found"));
}
var diaryEntry = existingFoodItem.DiaryEntry;
// remove the calories from the total calories
diaryEntry.TotalCalories -= existingFoodItem.Calories;
// check if this food item is the last one in the diary entry
var foodItems = existingFoodItem.DiaryEntry.FoodItems;
bool deleteDiaryEntry = false;
if (foodItems.Count == 1 && foodItems[0].Id == existingFoodItem.Id)
{
deleteDiaryEntry = true; // mark the diary entry for deletion
}
// remove the food item from the database and save the changes to the diary entry
try
{
_foodItemRepository.Remove(existingFoodItem);
await _unitOfWork.CompleteAsync();
}
catch (Exception e)
{
return(new FoodItemResponse($"An error occurred when deleting diary entry {id}: {e}"));
}
// wait until after the food item is deleted, as the food item is a child of the diary
if (deleteDiaryEntry)
{
var deleteResult = await _diaryEntryService.DeleteDiaryEntryAsync(diaryEntry.Id);
if (!deleteResult.Success)
{
return(new FoodItemResponse($"Failed to delete diary entry: {deleteResult}"));
}
}
return(new FoodItemResponse(existingFoodItem));
}
