Delete all groups and layers that are switched off, even if they are locked

Hi,

I need help with a script that will do the following:

Delete all groups (including layers inside) and layers if they are are not visible - with the following requirements

a. Even if the group or layer is locked

b. Even if layers inside the group are locked

c. Even if layers inside the group are visible, though the parent group is switched off

So...the logic required would be

Is this group or layer switched off? yes, then delete it all regardless of anything else, ELSE move on to the next group/layer

Basically, i have lots of groups and layers here and i want to parse the layers to leave just the layers which are visible in the final document. Merge visible or flatten will not work as i want to retain the visible groups, and visible layers. Delete hidden layers does not work. And file/scrips/delete empty layers does not work because the layers are not empty. They're just not required.

Working with CS6.

Thanks