public FlightDetail PurchaseTicket(int flightId)
        {
            var flight   = _flightRepository.Get().FirstOrDefault(x => x.Id == flightId);
            int soldSeat = flight.SoldSeats;

            if (flight.SoldSeats <= flight.Seats)
            {
                flight.SoldSeats = soldSeat + 1;
            }

            var            ticketoffice  = _ticketOfficeRepository.Get().FirstOrDefault(x => x.FlightID == flightId);
            PromotionSales promotionsale = new PromotionSales(ticketoffice);
            var            ticket        = GetFlightDetail(flightId).FirstOrDefault();

            ticket.Cost = promotionsale.CheckDiscounts();

            return(ticket);
        }
        public FlightDetail PurchaseTicket(int flightId)
        {
            var flight = _flightRepository.Get().FirstOrDefault(x => x.Id == flightId);
            int soldSeat = flight.SoldSeats;
            if (flight.SoldSeats <= flight.Seats )
            {
                flight.SoldSeats = soldSeat + 1;
            }

            var ticketoffice = _ticketOfficeRepository.Get().FirstOrDefault(x => x.FlightID == flightId);
            PromotionSales promotionsale = new PromotionSales(ticketoffice);
            var ticket = GetFlightDetail(flightId).FirstOrDefault();
            ticket.Cost = promotionsale.CheckDiscounts();

            return ticket;
        }