Separating a pdf into cover and text files

I'm hoping someone could help me create a script that would extract the first two and the last two pages of a document and then save the new four page document with _cov appended.

Step 2 would save what is remaining of the origianl documet with _text appended to the filename.

So from one document I would end up with two files (filename_cov.pdf) and (filename_text.pdf)

I work in a print shop and we receive single files for books. Because the print on different stocks I have been manually separating the covers from the text portion before imposing for print. Thanks in advance to anyone willing to help.