using System;
using System.Threading;

namespace events
{
    public class AirCraftParameters : EventArgs
    {
        public  AirCraftParameters(int alt, int speed)
        {
            Altitude = alt;
            Speed = speed;
        }

        public readonly int Altitude;
        public readonly int Speed;
    }
    public class Ground
    {
        public static void GroundHandler(object obj, AirCraftParameters e)
        {
            Console.WriteLine(obj.ToString()+", it's the Ground, your parameters: alt="+e.Altitude+", speed="+e.Speed);
        }
    }

    public class B737
    {
        public void b737Handler(object obj, AirCraftParameters e)
        {
            Console.WriteLine(obj.ToString() + ", it's Boeing737, all OK!");
        }
    }

    public class A300
    {
        public void a300Handler(object obj, AirCraftParameters e)
        {
            Console.WriteLine(obj.ToString() + ", it's AirbusA300, everything's perfect!");
        }
    }
    //public delegate void AircraftEventHandler(object sender, AirCraftParameters e);
    public class B787
    {
        public override string ToString()
        {
            return "Boeing787";
        }

        public event EventHandler<AirCraftParameters> TheSituationEvent;

        public void CheckTheSituation()
        {
            int times = 1;
            Console.WriteLine("Checking...");
            for (int i = 0; i < times; i++)
            {
                TheSituationEvent?.Invoke(this,new AirCraftParameters(35000, 260));
                System.Threading.Thread.Sleep(1000);
            }

            Console.WriteLine("Connection successfully disrupted");
        }
    }
    internal class Program
    {
        public static void Main(string[] args)
        {
            B787 b787 = new B787();
            B737 b737 = new B737();
            A300 a300 = new A300();

            b787.TheSituationEvent += Ground.GroundHandler;
            b787.TheSituationEvent += b737.b737Handler;
            b787.TheSituationEvent += a300.a300Handler;

            b787.CheckTheSituation();
            b787.TheSituationEvent -= Ground.GroundHandler;
            Console.WriteLine("*** communication with the earth is lost");
            b787.CheckTheSituation();
            b787.TheSituationEvent -= b737.b737Handler;
            b787.TheSituationEvent -= a300.a300Handler;
            Console.WriteLine("*** communication with other aircrafts is lost");
            b787.CheckTheSituation();

        }
    }
}