Thinking of developing a sync plugin for Music.app through Applescript

[hmijail]

I'm currently using Music.app to maintain my library, and it's a bit of a pain in the ass, which I've made more sustainable by developing a bunch of Applescript scripts.

But it's a bit of a neverending story of creating small bandaids with bad materials hoping to numb a bit the pain, just to kick the can a bit further down the road instead of jumping ship to fix more substantial problems.
I say "bad materials" because Apple has allowed Applescript to languish for years if not decades, so at every new upgrade I fear that they will finally pull the plug and leave me stranded in Music.app.

Beets seems to do a lot of what I would want, so I'm wondering how much would it take to write a sync plugin to extract information from Music.app, and return it later. This is what tools like iTunes Collection Tool and BeaTunes do, and allows to keep the files and metadata under the control of Music.app, which keeps it also sync-able to iOS devices, some DJ software, etc.

So my question is: is there any plugin for Beets that allow it to manage another program's existing library, so that I can see what is expected from Beets' side?

The process I envision is syncing on command, just like those programs I mentioned:

1. on startup of Beets (or on command), get the current state of Music.app, updating Beet's own DB
2. Beets works by using the sound files in their current location and its own copy of metadata
3. on quit (or on command), Beets sends its modified metadata back to Music.app

Note that the sync points are explicitly defined and coarse, and allow the user to just leave Music.app forever ... or go back. Probably it'd be possible to do a more frequent and fine-grained sync, but if anything I'd leave that for later.