public async Task <DomainValidationResult <Promotion> > CreatePromotionAsync(
string promotionalCode,
Currency currency,
TimeSpan duration,
DateTime expiredAt
)
{
var result = new DomainValidationResult <Promotion>();
if (!await _promotionRepository.IsPromotionalCodeAvailableAsync(promotionalCode))
{
result.AddFailedPreconditionError("The promotional code isn't available");
}
if (result.IsValid)
{
var promotion = new Promotion(
promotionalCode,
currency,
duration,
new DateTimeProvider(expiredAt));
_promotionRepository.Create(promotion);
await _promotionRepository.CommitAsync();
return(promotion);
}
return(result);
}