This is early alpha stages, only use as a starting point. Help needed.
The intent of this module is to check cart contents against a category group with the handle productPacks. Then based on the fields in each of the categories (specific product packs) apply a discount.
The way the categories are set up is that they have a numeric field with the handle productPackDiscountAmount, which corresponds to the amount of discount.
Then there is a relatedProducts Commerce Products field that is checked against which products are related. Then there is a productVariants Commerce Variants field that has all the variants from the products that one wants to be enabled for the combo discount.
Very basic checking and comparing carts contents with categories that are essentially 'packs'.