public async Task <IActionResult> CreateAsync(DeckCreateModel deckCreateModel)
{
var userId = HttpContext.User.GetUserId();
var newCards = await Task.WhenAll(deckCreateModel.Cards
.Select(newCard => cardsService.CreateAsync(userId, newCard.Question, newCard.Answer)));
var newDeck = await decksService.CreateAsync(userId, deckCreateModel.Name, newCards);
return(CreatedAtAction(nameof(FindAsync), new { id = newDeck.Id }, new DeckModel
{
Id = newDeck.Id,
Name = newDeck.Name,
Cards = newCards
.ToList()
}));
}