Adding attributes to product via PHP

[pelomedusa]

Hi,

I'm currently developping a script to import products from an external database.

After spending many hours on the subjject, i still cannot find a way to make a product declinable via PHP.

Having the following code
 

$product = new Product( $product_id );

$attribute_group_id = 10 // The "weight" attribute group

$attribute_ids = [10, 12] // The attributes ids, ie: 1kg and 2kg

 

How would i make my product declinaible with those attributes please? I already found this thread, but some functions are deprecated,  the solution is very incomplete, and the functions are undocumented.

Thanks for your help