public void BuyAlbum(int credentialId, int albumId, short price) { //Load the profile Profile profile = GetById(credentialId); //Validate sum if (profile.GetSum() < price) { throw new NotEnoughFundsException("Du har ikke nok penge", profile.GetSum(), price); } if (profile.Purchases.Any(x => x.AlbumId == albumId)) { throw new AlreadyPurchasedException("Du har allerede købt produktet", albumId); } ProfileRepository.AddAlbumPurchase(profile.ProfileId, albumId, price, DateTime.Now); }