AppleScript Rule for Mail (Mac)

I want to create a rule in Mail, for each incoming message that has one or more PDF attachment(s). When that rule is triggered, I need an AppleScript to run, which would extract the appended PDF file(s) and copy it/them into a directory on the Desktop called 'Incoming PDF' As there might be different PDF files with the same name coming into this directory, the AppleScript should make sure that each PDF gets a unique name.