Support sale operation by Magento payment provider gateway

[viktym]

Design for task "Support sale operation out of the box" from Payment Improvements organization scope.

https://app.zenhub.com/workspace/o/magento/payment-improvements/issues/11

[vkublytskyi]

Please describe this interface with methods signatures. For sure it would be similar to canAuthorize/authorize, canCapture/capture methods but it's better to document this explicitly

[viktym]

These methods are visible on diagrams https://github.com/magento-mpi/architecture/blob/b8380eee4248d17be578696f8a6d5af086888a37/design-documents/Sale_Payment_Operation.md, but I will add them in text content also

[vkublytskyi]

On the diagram, there are no full methods signatures (input and output types)

[viktym]

Done

[paliarush]

1. On the order_payment_current diagram PaymentAdapter does not have order method defined, but it is invoked by OrderOperation::order if I'm not mistaken
2. On the order_payment_new diagram PaymentAdapter does not have order and authorize methods defined, but they are invoked by other classes
3. It looks like it would be cleaner if we split MethodInterface into smaller ones, like SaleOperationInterface. At least in 2.3+, which still allows breaking changes. In this case we should deprecate the MethodInterface and redirect all calls to the new interfaces

[paliarush]

These methods will have implementation as far as I understand, if so - this will be minor change, otherwise it will be a major change.

[joni-jones]

The base implementation of sale() and canSale() will be in Magento\Payment\Model\Method\Adapter as it is the main extension point for payment integrations.

[viktym]

Yes, they will

[joni-jones]

Hi, @paliarush.
1-2.The PaymentAdapter on the diagram it is \Magento\Payment\Model\Method\Adapter but not the \Magento\Sales\Model\Order\PaymentAdapter (it does not implement \Magento\Payment\Model\MethodInterface). All methods like authorize, capture, sale, order are present in \Magento\Payment\Model\MethodInterface.
3. This is not a part of this task. Decomposition of MethodInterface requires deep refactoring of \Magento\Payment\Model\Method\Adapter which now is the main extension point for all payments integrations. Such changes will require rework of all payment integrations based on Payment Adapter. Changing only interfaces won't get a practical profit.

[viktym]

Hi Alex
As @joni-jones already mentioned, PaymentAdapter is actually \Magento\Payment\Model\Method\Adapter. For compactness, I used short class names on diagrams and it caused some misunderstanding. Diagrams have been corrected.
MethodInterface splitting requires serious changes and should be investigated. We must evaluate the benefits of such a separation against risks and complexity. I suppose it can be done in the separate scope.