using System;

using System.Linq;

public class Program

{

    static Random random = new Random();

    static string[] cities = new string[] { "Amsterdam", "Barcelona", "Paris", "Prague", "London", "Rome", "Oslo", "Moscow" };

    public static void Main()

    {

        // Tady se generuji nahodna data. Parametry si muzes zmenit podle uvazeni. 

        // Pokud si chces prohlednout vygenerovana data pro kontrolu prikladu, vypis si je cyklem.

        var flights = GenerateTestData(10, new DateTime(2018, 1, 1), DateTime.Today, 12, 90);

        foreach(var item in flights)

        {

            Console.WriteLine(item);

        }

        // 1. Spocitej vsechny lety CSA.    

        Console.WriteLine(flights.Count(f => f.Carrier == Carrier.CSA));

        // 2. Najdi vsechny chybne lety (stejne misto odletu a priletu).

        foreach(var item in flights.Where(f => f.Origin == f.Destination).Select(f => f.Carrier + " " + f.Origin + " " + f.Destination))

        {

            Console.WriteLine(item.ToString());

        }

        // 3. Zjisti kody vsech letu, ktere nemeli spozdeni.

        foreach(var item in flights.Where(f => f.ScheduledArrival >= f.Arrived).Select(f => f.Carrier + " " + f.Code))

        {

            Console.WriteLine(item.ToString());

        }

        //https://dotnetfiddle.net/ 4. Najdi prvni (podle odletu) a posledni let (podle priletu) z intervalu.

        Console.WriteLine(flights.OrderBy(f => f.Departed).First().ToString());

        Console.WriteLine(flights.OrderBy(f => f.Arrived).Last().ToString());

        // 5. Zjisti, jestli se letelo z Prahy do Barcelony behem unora.

        foreach(var item in flights.Where(f => f.Origin == "Prague" && f.Destination == "Barcelona").Where(f => f.ScheduledDeparture.Month == 2 || f.ScheduledArrival.Month == 2).Select(f => f.Carrier + " " + f.Code))

        {

            Console.WriteLine(item.ToString());

        }

        // 6. Spocitej prumerne spozdeni.

        Console.WriteLine(flights.Average(f => (f.Arrived - f.ScheduledArrival).Minutes));

        // 7. Zjisti, kolik casu stravila ve vzduchu vsechna letadla.

        Console.WriteLine(flights.Select(f => (f.Arrived - f.Departed).TotalHours).Sum());

        // 8. Zjisti, kolikrat se odkud kam letelo a seznam serad podle mista odletu.

        foreach(var item in flights.OrderBy(f => f.Origin).GroupBy(f => f.Origin + " to " + f.Destination).ToDictionary(f => f.Key))

        {

            Console.WriteLine(item.Key + " " + string.Join(", ", item.Value.Select(z => z.Code)) + ", počet letů: " + item.Value.Count());

        }

        // 9. Zjisti, jesti je mesto, do ktereho nic nikdy neletelo.

        var destinations = flights.Select(f => f.Destination).ToList();

        foreach(string city in cities)

        {

            if(!destinations.Contains(city))

            {

                Console.WriteLine("{0} is not a destination", city);

            }

        }

        // 10. Najdi nejdelsi lety.     

        double max = flights.Max(f => (f.Arrived - f.Departed).Hours);

        Console.WriteLine(max);

        foreach(var item in flights.Where(f => (f.Arrived - f.Departed).Hours == max))

        {

            Console.WriteLine(item.ToString());

        }

    }

    static Flight[] GenerateTestData(int numberOfFlights, DateTime flightsFromDate, DateTime flightsToDate, int flightMaxHours, int maxDelayMinutes)

    {

        if (numberOfFlights < 1)

            throw new ArgumentException("Number of flights has to be more than 0.");

        if (flightMaxHours < 1)

            throw new ArgumentException("Flight has to take at least one hour.");

        if (maxDelayMinutes < 0)

            throw new ArgumentException("Max delay has to be positive.");

        if (flightsToDate.AddHours(flightMaxHours) < flightsFromDate)

            throw new ArgumentException("Date of the flight arrival has to be after the date of its departure including flight max hours.");

        var flights = new Flight[numberOfFlights];

        int daysInRange = (flightsToDate - flightsFromDate).Days;

        var carriers = (Carrier[]) Enum.GetValues(typeof(Carrier));

        for (int i = 0; i < numberOfFlights; i++)

        {

            var flightDuration = random.Next(1, flightMaxHours + 1);

            var randomDayOffset = random.Next(0, daysInRange);

            var randomHour = random.Next(0, 23);

            var randomDelay = random.Next(0, maxDelayMinutes);

            var randomCarrierNumber = random.Next(0, carriers.Length);

            var carrier = carriers[randomCarrierNumber];

            var randomOrigin = cities[i % cities.Length];

            var randomDestination = cities[random.Next(0, cities.Length)];

            var randomDepartureDate = flightsFromDate.AddDays(randomDayOffset).AddHours(randomHour);

            var departed = randomDepartureDate.AddMinutes(randomDelay);

            var randomArrivalDate = randomDepartureDate.AddHours(flightDuration);

            var arrived = randomArrivalDate.AddMinutes(randomDelay);

            flights[i] = new Flight(carrier, randomOrigin, randomDestination, carrier.ToString()[0] + i.ToString(), randomDepartureDate, departed, randomArrivalDate, arrived);

        }

        return flights;

    }

}

​

class Flight

{

    public Carrier Carrier { get; set; }

    public string Origin { get; set; }

    public string Destination { get; set; }

    public string Code { get; set; }

    public DateTime ScheduledDeparture { get; set; }

    public DateTime Departed { get; set; }

    public DateTime ScheduledArrival { get; set; }

    public DateTime Arrived { get; set; }

    public Flight(Carrier carrier, string origin, string destination, string code, DateTime scheduledDeparture, DateTime departed, DateTime scheduledArrival, DateTime arrived)

    {

        Carrier = carrier;

        Origin = origin;

        Destination = destination;

        Code = code;

        ScheduledDeparture = scheduledDeparture;

        Departed = departed;

        ScheduledArrival = scheduledArrival;

        Arrived = arrived;

    }

    public override string ToString()

    {

        return string.Format("{0} {1} {2} {3} {4} {5} {6} {7}", Carrier, Origin, Destination, Code, ScheduledDeparture, Departed, ScheduledArrival, Arrived);

    }

}

​

enum Carrier

{

    AirNewZealand,

    BritishAirways,

    CSA,

    Emirates,

    Norwegian

}