public async Task <string> CreateShortenerAsync(string sourceLink, string appUrl)
{
if (!LinkHelper.IsLinkValid(sourceLink) || sourceLink == null)
{
throw new BusinessRuleValidationException("Неправильный URL.");
}
string backHalf;
do
{
backHalf = LinkHelper.GenerateBackHalf(sourceLink);
}while ((await _shortenerRepository.GetByBackHalf(backHalf)) != null);
var shortener = Shortener.Create(sourceLink, appUrl, backHalf);
await _shortenerRepository
.CreateShortenerAsync(shortener);
return(shortener.ShortLink);
}
