using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var ea = new EventAggregator();

        var client = new SomeClient(ea);

        var actor = new SomeActor(ea);

        actor.DoSomething();

    }

// Event Aggregator

//-------------------

    public interface IHandle {}

    public interface IHandle<TEvent> : IHandle 

    {

        void Handle(TEvent e);

    }

    public class EventAggregator 

    {

        // todo: Use concurrency safe collection, and implement addition and iteration in safe manner

        private List<IHandle> _subscribers = new List<IHandle>();

        public void Subscribe<TSubscriber>(TSubscriber s) where TSubscriber : IHandle

        {

            if (!_subscribers.Contains(s))

                _subscribers.Add(s);

        }

        // todo: Implement Unsubscribe

        public void Publish<TEvent>(TEvent e) 

        {

            var eventSubsribers = _subscribers.OfType<IHandle<TEvent>>().ToArray();

            foreach (var s in eventSubsribers)

                s.Handle(e); // todo: Wrap in try catch?

        }

    }

// Test

//--------------

    public class SomeEvent {}

    public class SomeClient : IHandle<SomeEvent>

    {

        public SomeClient(EventAggregator ea) 

        {

            ea.Subscribe(this);

        }

        public void Handle(SomeEvent e) 

        {

            Console.WriteLine("Catched " + e);

        }

    }

    public class SomeActor 

    {

        private readonly EventAggregator _ea;

        public SomeActor(EventAggregator ea) 

        {

            _ea = ea;

        }

        public void DoSomething() 

        {

            var e = new SomeEvent();

            Console.WriteLine("Fired " + e);

            _ea.Publish(e);

        }

    }

}