use crate::*;

use super::Arranger;

/// A collection of phrases to play on each track.
pub struct Scene {
    pub name:  String,
    pub clips: Vec<Option<usize>>,
}

impl Scene {
    pub fn new (name: impl AsRef<str>, clips: impl AsRef<[Option<usize>]>) -> Self {
        let name = name.as_ref().into();
        let clips = clips.as_ref().iter().map(|x|x.clone()).collect();
        Self { name, clips, }
    }
    /// Returns the pulse length of the longest phrase in the scene
    pub fn pulses (&self, tracks: &[SequencerTrack]) -> usize {
        self.clips.iter().enumerate()
            .filter_map(|(i, c)|c.map(|c|tracks[i].phrases.get(c)))
            .filter_map(|p|p)
            .fold(0, |a, p|a.max(p.read().unwrap().length))
    }
    /// Returns true if all phrases in the scene are currently playing
    pub fn is_playing (&self, tracks: &[SequencerTrack]) -> bool {
        self.clips.iter().enumerate()
            .all(|(track_index, phrase_index)|match phrase_index {
                Some(i) => tracks[track_index].sequence == Some(*i),
                None => true
            })
    }
}

pub fn scene_name_max_len (scenes: &[Scene]) -> usize {
    scenes.iter()
        .map(|s|s.name.len())
        .fold(0, usize::max)
}

pub fn scene_ppqs (tracks: &[SequencerTrack], scenes: &[Scene]) -> Vec<(usize, usize)> {
    let mut total = 0;
    let mut scenes: Vec<(usize, usize)> = scenes.iter().map(|scene|{
        let pulses = scene.pulses(tracks);
        total = total + pulses;
        (pulses, total - pulses)
    }).collect();
    scenes.push((0, total));
    scenes
}

/// Scene management methods
impl Arranger {
    pub fn scene (&self) -> Option<&Scene> {
        self.selected.scene().map(|s|self.scenes.get(s)).flatten()
    }
    pub fn scene_mut (&mut self) -> Option<&mut Scene> {
        self.selected.scene().map(|s|self.scenes.get_mut(s)).flatten()
    }
    pub fn scene_next (&mut self) {
        self.selected.scene_next(self.scenes.len() - 1)
    }
    pub fn scene_prev (&mut self) {
        self.selected.scene_prev()
    }
    pub fn scene_add (&mut self, name: Option<&str>) -> Usually<&mut Scene> {
        let clips = vec![None;self.tracks.len()];
        self.scenes.push(match name {
            Some(name) => Scene::new(name, clips),
            None       => Scene::new(&self.scene_default_name(), clips),
        });
        let index = self.scenes.len() - 1;
        Ok(&mut self.scenes[index])
    }
    pub fn scene_del (&mut self) {
        unimplemented!("Arranger::scene_del");
    }
    pub fn scene_default_name (&self) -> String {
        format!("Scene {}", self.scenes.len() + 1)
    }
}