public async Task <StatisticsResult> GetByPeriodAsync(DateTime startDate, DateTime endDate)
{
if (startDate >= endDate)
{
throw new InvalidOperationException($"{nameof(startDate)} must be earlier than {nameof(endDate)}");
}
var periodCountTask = _customerProfileRepository.GetByPeriodAsync(startDate, endDate);
var totalCountTask = _customerProfileRepository.GetTotalByDateAsync(endDate);
await Task.WhenAll(periodCountTask, totalCountTask);
return(new StatisticsResult
{
RegistrationsCount = periodCountTask.Result,
TotalCount = totalCountTask.Result,
});
}