Different referral rate for coupons vs affiliate link

Is it possible to set up a different earning rate for an order placed through a referral link ($1.00) vs an order placed through a coupon code (8%)? I would like to give 8% referral rate but if I make it 8% for an affiliate link and then the customer uses an advertised coupon code that discounts their order 20%, I would be losing 28% per order and I only have a 25% markup. So I’d like to give $1.00 for an order placed through a referral link, the cusomter can still use their 20% discount and I still make money. But if someone enters the affiliates coupon code, then thats the only coupon applied.

Possible?