use crate::*;

pub trait HasPlayClip: HasClock {

    fn reset (&self) -> bool;

    fn reset_mut (&mut self) -> &mut bool;

    fn play_clip (&self) -> &Option<(Moment, Option<Arc<RwLock<MidiClip>>>)>;

    fn play_clip_mut (&mut self) -> &mut Option<(Moment, Option<Arc<RwLock<MidiClip>>>)>;

    fn next_clip (&self) -> &Option<(Moment, Option<Arc<RwLock<MidiClip>>>)>;

    fn next_clip_mut (&mut self) -> &mut Option<(Moment, Option<Arc<RwLock<MidiClip>>>)>;

    fn pulses_since_start (&self) -> Option<f64> {
        if let Some((started, Some(_))) = self.play_clip().as_ref() {
            let elapsed = self.clock().playhead.pulse.get() - started.pulse.get();
            return Some(elapsed)
        }
        None
    }

    fn pulses_since_start_looped (&self) -> Option<(f64, f64)> {
        if let Some((started, Some(clip))) = self.play_clip().as_ref() {
            let elapsed = self.clock().playhead.pulse.get() - started.pulse.get();
            let length  = clip.read().unwrap().length.max(1); // prevent div0 on empty clip
            let times   = (elapsed as usize / length) as f64;
            let elapsed = (elapsed as usize % length) as f64;
            return Some((times, elapsed))
        }
        None
    }

    fn enqueue_next (&mut self, clip: Option<&Arc<RwLock<MidiClip>>>) {
        *self.next_clip_mut() = Some((self.clock().next_launch_instant(), clip.cloned()));
        *self.reset_mut() = true;
    }

    fn play_status (&self) -> impl Content<TuiOut> {
        let (name, color): (Arc<str>, ItemTheme) = if let Some((_, Some(clip))) = self.play_clip() {
            let MidiClip { ref name, color, .. } = *clip.read().unwrap();
            (name.clone(), color)
        } else {
            ("".into(), Tui::g(64).into())
        };
        let time: String = self.pulses_since_start_looped()
            .map(|(times, time)|format!("{:>3}x {:>}", times+1.0, self.clock().timebase.format_beats_1(time)))
            .unwrap_or_else(||String::from("        ")).into();
        FieldV(color, "Now:", format!("{} {}", time, name))
    }

    fn next_status (&self) -> impl Content<TuiOut> {
        let mut time: Arc<str> = String::from("--.-.--").into();
        let mut name: Arc<str> = String::from("").into();
        let mut color = ItemTheme::G[64];
        let clock = self.clock();
        if let Some((t, Some(clip))) = self.next_clip() {
            let clip = clip.read().unwrap();
            name  = clip.name.clone();
            color = clip.color.clone();
            time  = {
                let target  = t.pulse.get();
                let current = clock.playhead.pulse.get();
                if target > current {
                    let remaining = target - current;
                    format!("-{:>}", clock.timebase.format_beats_1(remaining))
                } else {
                    String::new()
                }
            }.into()
        } else if let Some((t, Some(clip))) = self.play_clip() {
            let clip = clip.read().unwrap();
            if clip.looped {
                name  = clip.name.clone();
                color = clip.color.clone();
                let target  = t.pulse.get() + clip.length as f64;
                let current = clock.playhead.pulse.get();
                if target > current {
                    time = format!("-{:>}", clock.timebase.format_beats_0(target - current)).into()
                }
            } else {
                name  = "Stop".to_string().into();
            }
        };
        FieldV(color, "Next:", format!("{} {}", time, name))
    }
}