Convert plugin: support skip, in-place, and force options

[gaafiz]

Hello everyone :)

I started using the convert plugin and noticed that there is a focus on his role as an "exporter", which is reflected by the fact that everything acts on a dest folder and everything is always copied there independently if it's skipped (i.e. when matching no_convert rules) or even when keep-new flag is true.

While this is indeed useful to generate alternatives of your library/playlist for other devices or similar needs, sometimes one just wants to use it to manage their own library and convert some existing tracks (i.e. from WAV to FLAC) or want to have "power" on what to convert over what is configured in config.yaml.

Following this, I'd like to propose three additional flags/options that may allow more use-cases without breaking any of the existing ones (I hope :D)

• --force or -F -> flag usable when running beet convert -F [QUERY] manually, which forces its way on converting all tracks that matches [QUERY], ignoring other configured checks such as no_convert, max_bitrate, same formats as source, etc.
  • This is particularly useful when you need to convert a handful of tracks, without having to quickly edit your config.yaml and then revert back to previous configs after converting.
• --[skip or true-skip] or -[sS] -> when running beet convert -S [Query] it will allow to actually skip processing tracks that matched rules such as no_convert and co. Tracks that match these rules are currently still copied over to dest, and sometime that copy-over is simply not needed.
  • skip or true-skip (I'm not the best at naming) could potentially be used also as a config for convert plugin with false as default value to keep backward-compatibility
• --in-place -> when running beet convert --in-place [QUERY] it will make the conversions happening "in place" in your library, replacing your existing tracks matching QUERY, with the new converted tracks.
  • As long as it reaches the end goal, the implementation is up for debate. It could create files in the temp dir or it could work exactly like the --keep-new flag while deleting any leftover files in the dest folder.

Let me know if any of these makes sense to you or if those cases are already achievable with a different combo of configs + command params