I'd like to publish links on our company intranet directory of the type:
  <a href="xmpp:firstname.lastname@googlemail.com">

If someone clicks on these, then firefox will open the relevant protocol handler, and it's quite easy to associate xmpp:  with /usr/bin/empathy

Now if I run the command:
  /usr/bin/empathy xmpp:firstname.lastname@googlemail.com
at the moment, empathy starts, but ignores the argument.

What I'd like it to do is:
 - If I have that user in my chat address book, it should launch a video call to them.
 - If I haven't got that user in my address book, it should attempt to add them as a contact.


Thanks - Richard