use crate::*;

const SYM_NAME:    &'static str = ":name";
const SYM_GAIN:    &'static str = ":gain";
const SYM_SAMPLER: &'static str = "sampler";
const SYM_LV2:     &'static str = "lv2";

impl<E: Engine> Track<E> {
    pub fn from_edn <'a, 'e> (jack: &Arc<RwLock<JackClient>>, args: &[Edn<'e>]) -> Usually<Self> {
        let mut _gain = 0.0f64;
        let mut track = Self::new("")?;
        #[allow(unused_mut)]
        let mut devices: Vec<JackDevice<E>> = vec![];
        edn!(edn in args {
            Edn::Map(map) => {
                if let Some(Edn::Str(n)) = map.get(&Edn::Key(SYM_NAME)) {
                    track.name = n.to_string();
                }
                if let Some(Edn::Double(g)) = map.get(&Edn::Key(SYM_GAIN)) {
                    _gain = f64::from(*g);
                }
            },
            Edn::List(args) => match args.get(0) {
                // Add a sampler device to the track
                Some(Edn::Symbol(SYM_SAMPLER)) => {
                    devices.push(Sampler::from_edn(jack, &args[1..])?);
                    panic!(
                        "unsupported in track {}: {:?}; tek_mixer not compiled with feature \"sampler\"",
                        &track.name,
                        args.get(0).unwrap()
                    )
                },
                // Add a LV2 plugin to the track.
                Some(Edn::Symbol(SYM_LV2)) => {
                    devices.push(LV2Plugin::from_edn(jack, &args[1..])?);
                    panic!(
                        "unsupported in track {}: {:?}; tek_mixer not compiled with feature \"plugin\"",
                        &track.name,
                        args.get(0).unwrap()
                    )
                },
                None =>
                    panic!("empty list track {}", &track.name),
                _ =>
                    panic!("unexpected in track {}: {:?}", &track.name, args.get(0).unwrap())
            },
            _ => {}
        });
        for device in devices {
            track.add_device(device);
        }
        Ok(track)
    }
}