using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public class Flight

    {

        public IList<Segment> Segments { get; set; }

    }

​

    public class Segment

    {

        public DateTime DepartureDate { get; set; }

        public DateTime ArrivalDate { get; set; }

    }

    public class FlightBuilder

    {

        private DateTime _threeDaysFromNow;

​

        public FlightBuilder()

        {

            _threeDaysFromNow = DateTime.Now.AddDays(3);

        }

​

        public IList<Flight> GetFlights()

        {

            return new List<Flight>

                       {

                           //A normal flight with two hour duration

                           CreateFlight(_threeDaysFromNow, _threeDaysFromNow.AddHours(2)),

​

                           //A normal multi segment flight

                           CreateFlight(_threeDaysFromNow, _threeDaysFromNow.AddHours(2), _threeDaysFromNow.AddHours(3), _threeDaysFromNow.AddHours(5)),

                           //A flight departing in the past

                           CreateFlight(_threeDaysFromNow.AddDays(-6), _threeDaysFromNow),

​

                           //A flight that departs before it arrives

                           CreateFlight(_threeDaysFromNow, _threeDaysFromNow.AddHours(-6)),

​

                           //A flight with more than two hours ground time

                           CreateFlight(_threeDaysFromNow, _threeDaysFromNow.AddHours(2), _threeDaysFromNow.AddHours(5), _threeDaysFromNow.AddHours(6)),

​

                            //Another flight with more than two hours ground time

                           CreateFlight(_threeDaysFromNow, _threeDaysFromNow.AddHours(2), _threeDaysFromNow.AddHours(3), _threeDaysFromNow.AddHours(4), _threeDaysFromNow.AddHours(6), _threeDaysFromNow.AddHours(7))

                       };

        }

​

        private static Flight CreateFlight(params DateTime[] dates)

        {

            if (dates.Length % 2 != 0) throw new ArgumentException("You must pass an even number of dates,", "dates");

​

            var departureDates = dates.Where((date, index) => index % 2 == 0);

            var arrivalDates = dates.Where((date, index) => index % 2 == 1);

​

            var segments = departureDates.Zip(arrivalDates,

                                              (departureDate, arrivalDate) =>

                                              new Segment { DepartureDate = departureDate, ArrivalDate = arrivalDate }).ToList();

​

            return new Flight { Segments = segments };

        }

    }

​

/*Invoke the GetFlights method and given the flights returned from the FlightBuilder class filter out those that;

1. Depart before the current date/time.

2. Have a segment with an arrival date before the departure date.

3. Spend more than 2 hours on the ground. i.e those with a total gap of over two hours between the arrival

date of one segment and the departure date of the next.*/

    public static void Main()

    {

        Console.WriteLine("Hey");

    }

}