using System;

public class Program

{

    public class PushMessage<TData>

    where TData : PushMessageItem, new()

    {

        public int Version { get; }

        public string Type { get; }

        public TData Item { get; set; }

​

        public PushMessage()

        {

            var baseData = new TData();

            Version = baseData.PushMessageVersion;

            Type = baseData.PushMessageType;

        }

    }

​

    public abstract class PushMessageItem

    {

        protected internal abstract int PushMessageVersion { get; }

        protected internal abstract string PushMessageType { get; }

    }

​

    public abstract class AssetChangedDto: PushMessageItem

    {

        protected internal sealed override string PushMessageType => "AssetChanged";

    }

​

    public sealed class AssetChangedDtoV1: AssetChangedDto

    {

        protected internal override int PushMessageVersion => 1;

​

        public string Id { get; }

        public string Name { get; }

        public string Type { get; }

​

        public AssetChangedDtoV1()

        {

        }

        public AssetChangedDtoV1(string id, string name, string type)

        {

            Id = id;

            Name = name;

            Type = type;

        }

    }

​

    public sealed class AssetPositionChangedDto: PushMessageItem

    {

        protected internal override int PushMessageVersion => 1;

        protected internal override string PushMessageType => "AssetPosition";

​

        public string Id { get; }

        public double Longitude { get; }

        public double Latitude { get; }

        public int? Speed { get; }

        public int? Heading { get; }

        public DateTime RegisteredOn { get; }

​

        public AssetPositionChangedDto()

        {

        }

        public AssetPositionChangedDto(string id, double longitude, double latitude, int? speed, int? heading, DateTime registeredOn)

        {

            Id = id;

            Longitude = longitude;

            Latitude = latitude;

            Speed = speed;

            Heading = heading;

            RegisteredOn = registeredOn;

        }

    }

​

    public sealed class AssetActivityChangedDto: PushMessageItem

    {

        protected internal override int PushMessageVersion => 1;

        protected internal override string PushMessageType => "AssetActivity";

​

        public string Id { get; }

        public string Activity { get; }

        public DateTime StartedOn { get; }

​

        public AssetActivityChangedDto()

        {

        }

        public AssetActivityChangedDto(string id, string activity, DateTime startedOn)

        {

            Id = id;

            Activity = activity;

            StartedOn = startedOn;

        }

    }

​

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}