public bool PayForDelivery(string userName, long billId)
{
Bill bill = _billRepository.FindByIdAndIsDeliveryPaidFalse(billId);
if (bill == null)
{
throw new DeliveryAlreadyPaidException();
}
User user = _userRepository.FindByIdAndUserMoneyInCentsGreaterThanEqual(userName, bill.CostInCents);
if (user == null)
{
throw new NotEnoughMoneyException();
}
user.UserMoneyInCents = (user.UserMoneyInCents - bill.CostInCents);
bill.IsDeliveryPaid = true;
bill.DateOfPay = DateTime.Now;
_userRepository.Save();
_billRepository.Save();
return(true);
}