public IActionResult CheckIn(int id)
        {
            var reservation = _reservationRepo.Get(id);

            if (reservation == null)
            {
                return(BadRequest("reservation not exist"));
            }
            if (reservation.Status != ReservationStatus.Booked.ToString())
            {
                return(BadRequest("unvalid reservation status"));
            }

            var result = _reservationRepo.CheckIn(reservation);

            return(Ok(result));
        }