Help in restructuring a project

I have a commerce application, asp.net mvc.

I want it to be extensible in the sense others can create other payment providers, as long as they adhere to the interfaces.

/blah.core
/blah.web
/blah.Authorize.net  (Implementation of a payment provider using interfaces Ipaymentconfig and paymentdata class)

Now the problem is this:

/blah.core 
- PaymentData
/blah.core.interfaces
- IPaymentConfig

where Payment Data looks like:

using blah.core;
public class PaymentData
{
     public Order Order {get;set;}
}

IPayment data contains classes from blah.core like the Order class.

Now I want to use the actual Authorize.net implementation, so when I tried to reference it in the blah.core project I got a circular dependency error.

How could I solve this problem? Many have said to break out the interfaces into their own project, but the problem is PaymentData r开发者_运维技巧eferences entities that are found in blah.core also, so there doesn't seem to be a way around this (in my head anyhow).

How can I redesign this?

---

Breaking out the interfaces alone will not help. The provider need to know some details about the order, but probably not all of it.

I suggest you introduce a PaymentOrder which contains all information the provider need to know about an order. Break this one out to a new assembly together with the rest of the payment interfaces. Your payment assembly should not have any references to your application.

You will need to map your original Order to a PaymentOrder.

Your application will reference:

• PaymentProviderInterfaces.dll
• All payment provider implementations

While any payment provider will reference

• PaymentProviderInterfaces.dll, but nothing else from your domain