public async Task <ActionResult> Delete([FromBody] CompleteReservationDto completeReservation)
{
var reservationIds = await _showingsService.GetUserReservations(completeReservation.ShowingId, completeReservation.UserId);
await _reservationsService.DeleteReservations(reservationIds);
var seats = await _showingsService.GetTakenSeats(completeReservation.ShowingId);
await _hubContext.Clients.All.SendAsync("OnSeatsChanged", seats);
return(Ok());
}