using System;

public class Program

{

    public static void Main()

    {

​

        var emailService = new OrderEmailService();

        var orderService = new OrderService(emailService);

        var handler = new CompleteOrderHandler(orderService);

        handler.Invoke(new Order());

    }

}

​

public class CompleteOrderHandler

{

    private readonly IOrderService _orderService;

    public CompleteOrderHandler(IOrderService orderService)

    {

        _orderService = orderService;

    }

    public void Invoke(Order order)

    {

        _orderService.CreateOrder(order);

    }

}

​

public class OrderService : IOrderService

{

    private readonly IOrderEmailService _emailService;

​

    public OrderService(IOrderEmailService emailService)

    {

        _emailService = emailService;

    }

    public void CreateOrder(Order order)

    {

        // Create order code.

        _emailService.SendConfirmation(order);

    }

}

​

public interface IOrderEmailService

{

    void SendConfirmation(Order order);

}

​

public interface IOrderService

{

    void CreateOrder(Order order);

}

​

public class OrderEmailService : IOrderEmailService

{

    public void SendConfirmation(Order order)

    {

        Console.WriteLine("Email sent.");

    }

}

​

public class Order;