Async rewrite

[Kanjirito]

I decided to give the async rewrite a go and this PR for now is just to get some feedback and see if I'm going in the right direction. This is still very much a WIP but the basics are there. The 4 interfaces are implemented and tested (well 95% of it because so far I didn't find a player that implements all of them) and there's documentation written for them so it should be usable for basic player control.

Since this is a complete rewrite because of async anyway I did not follow the current implementation very closely. It should be similar enough to be relatively easy to switch to but it's not a 1 to 1 rewrite. This of course is completely subjective and I'm fine with trying to make it similar to the way it currently is.

The big things that are missing:

1. Actually helpful errors. Right now it's just a placeholder that moves around strings with basic explanations.
2. Support for signals. This means that PlayerEvents and ProgressTracker are not implemented yet.
3. All of the checked_* methods on Player. I don't really think they are essential but they also don't really hurt anything so I'm not against them.

The nice thing about switching to async is that it's now possible to pretty easily create background tasks (through zbus) that would listen to the signals from the Tracklist and Playlists interfaces and keep the data updated. The downside is that ProgressTracker::tick() is more tricky because there's no good runtime agnostic way to sleep and zbus doesn't have timeouts as far as I know. One solution is to use the async_io crate for the sleeping since zbus already uses it when used without the tokio feature or ProgressTick could implement Future (I haven't really looked into this but I'm sure there's a way to make that work) and it would be up to the user to use select! to create a timeout. There's also the option to not be runtime agnostic and just use tokio.

[qxb3]

i see that the last commit on this is from 2months ago, are there any plans on continuing the work on this?

[Mange]

I have not looked at the code, but it's very fun to see someone working on this.

I have my own rewrite branch where I also move towards async and zbus that I have not touched in forever due to lack of motivation.

Sadly this lack of motivation right now will probably make me less likely to review this, but if you manage to get it working with all examples compiling and performing correctly, please let me know and I'll see what I can do.

Obviously, if I like the code and it gets merged then you'll become a co-owner of the repo (if you want).

[qxb3]

I actually just decided wrote my own mpris library thats just sitting on my project as a module that i can use: https://github.com/qxb3/fum/tree/full-rewrite/src/mpris as part of my rewrite of the project to use async.

I might create a pr to move that code in here if you like the api usage of it and @Kanjirito will not be continuing this pr.

Here is the example usage of the one i made:

use mpris::Mpris;
                                                                           
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mpris = Mpris::new().await?;
                                                                           
    let players = mpris.players().await?;
    println!("{:#?}", players);
                                                                           
    if let Some(spotify) = players.get("org.mpris.MediaPlayer2.spotify") {
        let metadata = spotify.metadata().await?;
                                                                           
        let title = metadata.title()?.unwrap_or("No Title".into());
        println("Current song: {title}");
    }
                                                                           
    Ok(())
}

And as for a event, and progress tracking, both Mpris and Player has a function called .watch(tx) that accepts an mpsc::channel so u can just listen to this channel.

Here is basically what that would look like, kinda complicated: https://github.com/qxb3/fum/blob/full-rewrite/src/mode/mpris.rs#L37 i currently dont have an idea how to simplify it.

EDIT: also forgot that it has some stuff that is specific to my project.

[Kanjirito]

I have not completely abandoned this but because async Rust is a bit of a mess (there's lots of different incompatible ways to do things which makes every decision require quite a bit of research) it slowed down progress to the point where I decided to take a break from it and that break ended up being pretty long. Oops. I will try to get back into it in the near future but I can't promise that it will actually get finished. Any feedback is very welcome so that I can figure out if I'm going in the right direction.

Also, @qxb3 sorry for not responding earlier. I was planning to reply but then I simply forgot.