landline telephone pseudo-PABX

(Apologies in advance if I have already posted this here long
enough ago that I don't remember doing it.)

Does anyone here happen to know of software and hardware that
works on/with a Raspberry Pi for landline telephone that combines
caller-ID blocking with a multi-box answering machine?

Here are the features I'm looking for:
    = Caller-ID routing:
        - Numbers/names in whitelist ring through or go to
          answering machine if not picked up in N rings.
        - Numbers/names in blacklist go directly to answering
          machine with a greeting similar to "You have been
          blacklisted. welcome to purgatory."  (Other numbers get
          a nicer greeting.)
        - Other numbers are prompted to press a digit to ring
          through.  If no digit, go to answering machine.
        - Transfer call logs to other computer via SD card or
          over network.
    = Answering machine function:
        - Allow messages to be moved to one of multiple boxes,
          ideally separating blacklist, whitelist, and non-list
          messages as they are received.
        - At least three boxes for messages to be moved to after
          receipt.
        - Copy messages to an SD card or transfer over network.
    = User interface:
        - Preferably a keypad or touch screen.

I'm understand there are USB devices that could handle the
hardware interface, and I'm sure the Raspberry Pi is more than
fast enough.  I'd love to develop the software to do that if I
only had the spare time.

Does anyone know of existing software (or maybe even just a
software toolkit/library) and a best-known hardware
bill-of-materials for doing that?

Thanks,