Limit the specific product amount per user account

Hello,

I need your help to let my customers (website users - guest checkout is disabled) to buy only one of two specific products.

Let's say I have a product A and a product B. So if the customer have purchased product A, he/she can not buy product B and vice versa. This limitation should also apply for the future purchases of this customer, which means that the customer who has purchased product A in past should never be able to buy product B (and vise versa), even if he/she will try to do so using new purchase(transaction). Hikashop should look into the customer's purchasing history using product's ID and act using that information.

Regards,
ZoomyMan