Tvheadend

I'd like to create a post processing script for recordings that will rename the files with season and episode numbers that can be used by XBMC. I need help with two problems.

The first is that very little of the XMLTV data is available during post processing. It looks like I'll need to put the channel name, date, and time in the filename and then use that information to retrieve the rest of the metadata for the recording.

Renaming would be much easier if I could access the original air date in the date tag from the XMLTV data during post processing. Is there any way to access this date directly from the post processing script?

The second problem I'm having is that renaming a recording file breaks it in the recordings list. I thought TVHeadEnd used the metadata from the MKV files to build the list of recordings rather than a database. Shouldn't I be able to rename or delete a file in the recordings directory? If I can't do that, is there a command I'm supposed to call after I rename or delete a recording?

Eventually I want to use the show name and the original air date to lookup the season and episode numbers in TheTVDB. With that information I can move the file to the show's correct folder and rename it for XBMC. The script can then tell XBMC to update its library, so it will pull the rest of the metadata for the show into the library.

Thanks,
Alan