use crate::{core::*, model::*};

/// Represents the tracks and scenes of the composition.
pub struct Arranger {
    /// Display mode of arranger
    pub mode:     bool,
    /// Currently selected element.
    pub selected: ArrangerFocus,
    /// Collection of tracks.
    pub tracks:   Vec<Track>,
    /// Collection of scenes.
    pub scenes:   Vec<Scene>,

    pub focused: bool,
    pub entered: bool,
}

impl Arranger {
    pub fn new () -> Self {
        Self {
            mode:     false,
            selected: ArrangerFocus::Clip(0, 0),
            scenes:   vec![],
            tracks:   vec![],
            entered:  true,
            focused:  true,
        }
    }
    pub fn activate (&mut self) {
        match self.selected {
            ArrangerFocus::Scene(s) => {
                for (track_index, track) in self.tracks.iter_mut().enumerate() {
                    track.sequence = self.scenes[s].clips[track_index];
                    track.reset = true;
                }
            },
            ArrangerFocus::Clip(t, s) => {
                self.tracks[t].sequence = self.scenes[s].clips[t];
                self.tracks[t].reset = true;
            },
            _ => {}
        }
    }
}

/// Track management methods
impl Arranger {
    pub fn track (&self) -> Option<&Track> {
        self.selected.track().map(|t|self.tracks.get(t)).flatten()
    }
    pub fn track_mut (&mut self) -> Option<&mut Track> {
        self.selected.track().map(|t|self.tracks.get_mut(t)).flatten()
    }
    pub fn track_next (&mut self) {
        self.selected.track_next(self.tracks.len())
    }
    pub fn track_prev (&mut self) {
        self.selected.track_prev()
    }
    pub fn track_add (&mut self, name: Option<&str>) -> Usually<&mut Track> {
        self.tracks.push(name.map_or_else(
            || Track::new(&self.track_default_name()),
            |name| Track::new(name),
        )?);
        let index = self.tracks.len() - 1;
        Ok(&mut self.tracks[index])
    }
    pub fn track_del (&mut self) {
        unimplemented!("Arranger::track_del");
    }
    pub fn track_default_name (&self) -> String {
        format!("Track {}", self.tracks.len() + 1)
    }
}

/// 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())
    }
    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.track_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)
    }
}

/// Phrase management methods
impl Arranger {
    pub fn phrase (&self) -> Option<&Arc<RwLock<Phrase>>> {
        let track_id = self.selected.track()?;
        self.tracks.get(track_id)?.phrases.get((*self.scene()?.clips.get(track_id)?)?)
    }
    //pub fn phrase_mut (&mut self) -> Option<&mut Phrase> {
        //let track_id = self.selected.track()?;
        //let clip = *self.scene()?.clips.get(track_id)?;
        //self.tracks.get_mut(track_id)?.phrases.get_mut(clip?)
    //}
    pub fn phrase_next (&mut self) {
        unimplemented!();
        //if let Some((track_index, track)) = self.track_mut() {
            //let phrases = track.phrases.len();
            //if let Some((_, scene)) = self.scene_mut() {
                //if let Some(phrase_index) = scene.clips[track_index] {
                    //if phrase_index >= phrases - 1 {
                        //scene.clips[track_index] = None;
                    //} else {
                        //scene.clips[track_index] = Some(phrase_index + 1);
                    //}
                //} else if phrases > 0 {
                    //scene.clips[track_index] = Some(0);
                //}
            //}
        //}
    }
    pub fn phrase_prev (&mut self) {
        unimplemented!();
        //if let Some((track_index, track)) = self.track_mut() {
            //let phrases = track.phrases.len();
            //if let Some((_, scene)) = self.scene_mut() {
                //if let Some(phrase_index) = scene.clips[track_index] {
                    //scene.clips[track_index] = if phrase_index == 0 {
                        //None
                    //} else {
                        //Some(phrase_index - 1)
                    //};
                //} else if phrases > 0 {
                    //scene.clips[track_index] = Some(phrases - 1);
                //}
            //}
        //}
    }
}

#[derive(PartialEq)]
/// Represents the current user selection in the arranger
pub enum ArrangerFocus {
    /// The whole mix is selected
    Mix,
    /// A track is selected.
    Track(usize),
    /// A scene is selected.
    Scene(usize),
    /// A clip (track × scene) is selected.
    Clip(usize, usize),
}

/// Identification methods
impl ArrangerFocus {
    pub fn is_track (&self) -> bool {
        match self { Self::Track(_) => true, _ => false }
    }
    pub fn is_scene (&self) -> bool {
        match self { Self::Scene(_) => true, _ => false }
    }
    pub fn is_clip (&self) -> bool {
        match self { Self::Clip(_, _) => true, _ => false }
    }
}

/// Track methods
impl ArrangerFocus {
    pub fn track (&self) -> Option<usize> {
        match self {
            Self::Clip(t, _) => Some(*t),
            Self::Track(t)   => Some(*t),
            _ => None
        }
    }
    pub fn track_next (&mut self, last_track: usize) {
        *self = match self {
            Self::Mix        => Self::Track(0),
            Self::Track(t)   => Self::Track(last_track.min(*t + 1)),
            Self::Scene(s)   => Self::Clip(0, *s),
            Self::Clip(t, s) => Self::Clip(last_track.min(*t + 1), *s),
        }
    }
    pub fn track_prev (&mut self) {
        *self = match self {
            Self::Mix        => Self::Mix,
            Self::Scene(s)   => Self::Scene(*s),
            Self::Track(0)   => Self::Mix,
            Self::Track(t)   => Self::Track(*t - 1),
            Self::Clip(t, s) => Self::Clip(t.saturating_sub(1), *s),
        }
    }
}

/// Scene methods
impl ArrangerFocus {
    pub fn scene (&self) -> Option<usize> {
        match self {
            Self::Clip(_, s) => Some(*s),
            Self::Scene(s)   => Some(*s),
            _ => None
        }
    }
    pub fn scene_next (&mut self, last_scene: usize) {
        *self = match self {
            Self::Mix        => Self::Scene(0),
            Self::Track(t)   => Self::Scene(*t),
            Self::Scene(s)   => Self::Scene(last_scene.min(*s + 1)),
            Self::Clip(t, s) => Self::Clip(*t, last_scene.min(*s + 1)),
        }
    }
    pub fn scene_prev (&mut self) {
        *self = match self {
            Self::Mix        => Self::Mix,
            Self::Track(t)   => Self::Track(*t),
            Self::Scene(0)   => Self::Mix,
            Self::Scene(s)   => Self::Scene(*s - 1),
            Self::Clip(t, s) => Self::Clip(*t, s.saturating_sub(1)),
        }
    }
}