/// <summary>
/// Saves email addresses of recipients to the database.
/// And returns his ids that stored in DB.
/// </summary>
/// <param name="recipientMails">Email addresses of recipients</param>
/// <returns>List recipients with id and mail</returns>
private async Task <IEnumerable <Recipient> > SaveRecipients(IEnumerable <string> recipientMails)
{
var recipients = new List <Recipient>();
bool isNewAdded = false;
foreach (string recipientMail in recipientMails)
{
Recipient recipient = await _recipientRepository.GetByEmail(recipientMail);
if (recipient == null)
{
recipient = _recipientRepository.Add(new Recipient {
Email = recipientMail
});
isNewAdded = true;
}
recipients.Add(recipient);
}
if (isNewAdded)
{
await _recipientRepository.UnitOfWork.SaveChangesAsync();
}
return(recipients);
}