Direct order creation?

[d0ublezer0]

I have only one shipment and one payment variants. For real i won't use them, because i sell digital products by subscription.

I want to develop direct order creation for my products.

My logic:
If user is logged in, it already has a subscription. So, when it click buy button, i want to create order without going to cart.

Send product to cart, use default shipment and payment, without completing user fields (they already filled in user section and really not important) and confirm order in only one click.

Click - Order Done.
User get email with order description and can see this order in his user section.

How to do this?

I understand, how to send product to cart session with ajax, i see it in vmprices.js
But what to do after that? How to submit order?