//returns if an airline wants to have code sharing with another airline
public static Boolean AcceptCodesharing(Airline airline, Airline asker, CodeshareAgreement.CodeshareType type)
{
double coeff = type == CodeshareAgreement.CodeshareType.One_Way ? 0.25 : 0.40;
IEnumerable<Country> sameCountries = asker.Airports.Select(a => a.Profile.Country).Distinct().Intersect(airline.Airports.Select(a => a.Profile.Country).Distinct());
IEnumerable<Airport> sameDestinations = asker.Airports.Distinct().Intersect(airline.Airports);
IEnumerable<Country> sameCodesharingCountries = airline.getCodesharingAirlines().SelectMany(a => a.Airports).Select(a => a.Profile.Country).Distinct().Intersect(airline.Airports.Select(a => a.Profile.Country).Distinct());
double airlineDestinations = airline.Airports.Count;
double airlineRoutes = airline.Routes.Count;
double airlineCountries = airline.Airports.Select(a => a.Profile.Country).Distinct().Count();
double airlineCodesharings = airline.Codeshares.Count;
double airlineAlliances = airline.Alliances.Count;
//declines if asker is much smaller than the invited airline
if (airlineRoutes > 3 * asker.Routes.Count)
return false;
//declines if there is a match for x% of the airlines
if (sameDestinations.Count() >= airlineDestinations * coeff)
return false;
//declines if there is a match for 75% of the airlines
if (sameCountries.Count() >= airlineCountries * 0.75)
return false;
//declines if the airline already has a code sharing or alliance in that area
if (sameCodesharingCountries.Count() >= airlineCountries * coeff)
return false;
return true;
}