using System;

namespace EntityServiceDispatchThing
{
   public interface ISubmitOrder
   {
      void Submit(IOrderSubmissionProcessor processor);
   }

   public class Order : ISubmitOrder
   {
      private bool _submitted;

      void ISubmitOrder.Submit(IOrderSubmissionProcessor processor)
      {
         if (_submitted) return; // or throw
         _submitted = true;
         Console.WriteLine("Order state has changed to submitted!");

         processor.IssueFulfillmentRequestFor(this);
         // or we could go with PostProcessOrder in the case of multiple dependencies
         // or anti-corruption layers. point is this solution is for COMPLEX behavior
      }
   }

   public interface IOrderSubmissionProcessor
   {
      void Submit(ISubmitOrder order);
      void IssueFulfillmentRequestFor(Order order);
   }

   public class OrderSubmissionProcessor : IOrderSubmissionProcessor
   {
      private readonly IFulfillmentAntiCorruptionLayer _fulfillment;

      public OrderSubmissionProcessor() : this(new FulfillmentAntiCorruptionLayer()) { }

      public OrderSubmissionProcessor(IFulfillmentAntiCorruptionLayer fulfillment)
      {
         _fulfillment = fulfillment;
      }

      public void Submit(ISubmitOrder order)
      {
         order.Submit(this);
      }

      void IOrderSubmissionProcessor.IssueFulfillmentRequestFor(Order order)
      {
         var request = ConvertOrderToFulfillmentRequest(order);
         _fulfillment.Send(request);
      }

      private FulfillmentRequest ConvertOrderToFulfillmentRequest(Order order)
      {
         // map the order to a fulfillment request
         // if the order changes or the fulfillment request changes
         // it'd be desirable for code to break here
         // we might even forward the mapping to our ACL eventually
         Console.WriteLine("Converting the order to a fulfillment request");

         return new FulfillmentRequest();
      }
   }

   public class FulfillmentRequest {}

   public interface IFulfillmentAntiCorruptionLayer
   {
      void Send(FulfillmentRequest request);
   }

   public class FulfillmentAntiCorruptionLayer : IFulfillmentAntiCorruptionLayer
   {
      public void Send(FulfillmentRequest request)
      {
         Console.WriteLine("fulfillment request sent to the legacy fulfillment system");
      }
   }

   public class OrdersRepository
   {
      public Order FindBy(int id)
      {
         return new Order();
      }
   }

   internal class Program
   {
      private static readonly OrdersRepository _orders = new OrdersRepository();
      private static readonly OrderSubmissionProcessor submissionProcessor = new OrderSubmissionProcessor();

      private static void Main(string[] args)
      {
         var order = _orders.FindBy(42);
         submissionProcessor.Submit(order);
         Console.ReadLine();
      }
   }
}