using System;
using Microsoft.Extensions.DependencyInjection;

namespace ConsoleApp12
{
    public interface ICommand { }
    public interface IPipeline<in T> where T : ICommand
    {
        void Run(T aCommand);
    }
    public interface IDispatcher
    {
        public void Execute<TRequest>(TRequest aCommand) where TRequest : ICommand;
    }
    public class CommandA : ICommand { }
    public class CommandB : CommandA { }
    public class CommandC : CommandA { }
    public class CommandD : CommandA { }
    public class Pipeline<T> : IPipeline<T> where T : ICommand
    {
        public void Run(T aCommand)
        {
            Console.WriteLine(aCommand.ToString());
        }
    }
    public class Dispatcher : IDispatcher
    {
        private readonly IServiceProvider _provider;

        public Dispatcher(IServiceProvider aProvider)
        {
            _provider = aProvider;
        }

        public void Execute<TRequest>(TRequest aCommand) where TRequest : ICommand
        {
            var p = typeof(TRequest);
            Console.WriteLine(p.Name);

            var pipeline = _provider.GetService<IPipeline<TRequest>>();
            pipeline.Run(aCommand);
        }

    }


    class Program
    {
        static void Main(string[] args)
        {
            var sc = new ServiceCollection();

            sc.AddScoped<IPipeline<CommandB>, Pipeline<CommandB>>();
            sc.AddScoped<IPipeline<CommandC>, Pipeline<CommandC>>();
            sc.AddScoped<IPipeline<CommandD>, Pipeline<CommandD>>();

            var p = sc.BuildServiceProvider();
            IDispatcher d = new Dispatcher(p);

            CommandA cB = new CommandB();
            d.Execute(cB);
        }
    }
}