public static void RentGates(Airport airport, Airline airline, int gates)
        {
            AirportContract contract = new AirportContract(airline, airport, GameObject.GetInstance().GameTime, gates, 20, GetYearlyContractPayment(airport, gates, 20));

            airport.addAirlineContract(contract);
        }
        //reallocate all gates and facilities from one airport to another - gates, facilities and routes
        public static void ReallocateAirport(Airport oldAirport, Airport newAirport, Airline airline)
        {

            //contract
            List<AirportContract> oldContracts = oldAirport.getAirlineContracts(airline);

            foreach (AirportContract oldContract in oldContracts)
            {

                oldAirport.removeAirlineContract(oldContract);

                oldContract.Airport = newAirport;

                newAirport.addAirlineContract(oldContract);


            }
            //routes
            var obsoleteRoutes = (from r in airline.Routes where r.Destination1 == oldAirport || r.Destination2 == oldAirport select r);

            foreach (Route route in obsoleteRoutes)
            {
                if (route.Destination1 == oldAirport) route.Destination1 = newAirport;
                if (route.Destination2 == oldAirport) route.Destination2 = newAirport;


                var entries = route.TimeTable.Entries.FindAll(e => e.Destination.Airport == oldAirport);

                foreach (RouteTimeTableEntry entry in entries)
                    entry.Destination.Airport = newAirport;

                foreach (FleetAirliner airliner in route.getAirliners())
                {
                    if (airliner.Homebase == oldAirport)
                        airliner.Homebase = newAirport;
                }
            }

            //facilities
            foreach (AirportFacility facility in oldAirport.getCurrentAirportFacilities(airline))
            {
                newAirport.addAirportFacility(airline, facility, GameObject.GetInstance().GameTime);
            }

            oldAirport.clearFacilities(airline);

            foreach (AirportFacility.FacilityType type in Enum.GetValues(typeof(AirportFacility.FacilityType)))
            {

                AirportFacility noneFacility = AirportFacilities.GetFacilities(type).Find((delegate(AirportFacility facility) { return facility.TypeLevel == 0; }));

                oldAirport.addAirportFacility(airline, noneFacility, GameObject.GetInstance().GameTime);
            }
        }
 public static void CreateAirportContract(Airport airport, Airline airline, int gates, int length, double yearlypayment)
 {
     AirportContract contract = new AirportContract(airline, airport, GameObject.GetInstance().GameTime, gates, length, yearlypayment);
     airport.addAirlineContract(contract);
 }
        public static void RentGates(Airport airport, Airline airline, int gates)
        {
            int currentgates = airport.AirlineContracts.Where(a => a.Airline == airline).Sum(c => c.NumberOfGates);
            AirportContract contract = new AirportContract(airline, airport, GameObject.GetInstance().GameTime, gates, 20, GetYearlyContractPayment(airport, gates, 20));

            if (currentgates == 0)
            {
                airport.addAirlineContract(contract);
            }
            else
            {
                foreach (AirportContract c in airport.AirlineContracts.Where(a => a.Airline == airline))
                {
                c.NumberOfGates += gates;
                }
            }
        }