Reverse layer positions from a layer group (batch)

Question

Do you know how can I create batch script in Photoshop that reverses the position of all the layers inside a layer group?

I have like 400 layer groups, each with 1-20 layers like this:

Group 1
 - layer 1
 - layer 2
 - layer 3
 ...

And i want to reverse position so it becomes like this:

Group 1
 - layer 3
 - layer 2
 - layer 1
 ...

This is because I'm adding new layers constantly and they are always placed in front, so it makes sense to put older layers last

Answer 1

Layer → Arrange → Reverse will reverse the selected layers.

I don't know how you can automate the selection of layers within a group though. I bet someone could create a script for that, if it was essential.