use super::*;

/// A scene consists of a set of clips to play together.
///
/// ```
/// let scene: tek::Scene = Default::default();
/// let _ = scene.pulses();
/// let _ = scene.is_playing(&[]);
/// ```
#[derive(Debug, Default)] pub struct Scene {
    /// Name of scene
    pub name:  Arc<str>,
    /// Identifying color of scene
    pub color: ItemTheme,
    /// Clips in scene, one per track
    pub clips: Vec<Option<Arc<RwLock<MidiClip>>>>,
}

impl Scene {
    pub const DEFAULT_HEIGHT: usize = 2;

    /// Get currently playing clip, if any
    pub fn clip (&self, index: usize) -> Option<&Arc<RwLock<MidiClip>>> {
        if let Some(Some(clip)) = self.clips.get(index) {
            Some(clip)
        } else {
            None
        }
    }

    /// Get pulse length of the longest clip in the scene
    pub fn pulses (&self) -> usize {
        self.clips.iter().fold(0, |a, p|{
            a.max(p.as_ref().map(|q|q.try_read().unwrap().length).unwrap_or(0))
        })
    }

    /// True if all clips in scene are currently playing on given tracks.
    pub fn is_playing (&self, tracks: &[Track]) -> bool {
        self.clips.iter().any(|clip|clip.is_some()) && self.clips.iter().enumerate()
            .all(|(track_index, clip)|match clip {
                Some(c) => tracks
                    .get(track_index)
                    .map(|track|{
                        if let Some((_, Some(clip))) = track.sequencer().play_clip() {
                            *clip.try_read().unwrap() == *c.try_read().unwrap()
                        } else {
                            false
                        }
                    })
                    .unwrap_or(false),
                None => true
            })
    }

}

#[cfg(all(feature = "select"))] impl_as_ref_opt!(Scene: |self: App| self.project.as_ref_opt());
#[cfg(all(feature = "select"))] impl_as_mut_opt!(Scene: |self: App| self.project.as_mut_opt());
#[cfg(all(feature = "select"))] impl_as_ref_opt!(Scene: |self: Arrangement| self.selected_scene());
#[cfg(all(feature = "select"))] impl_as_mut_opt!(Scene: |self: Arrangement| self.selected_scene_mut());

impl<T: AsRefOpt<Scene> + AsMutOpt<Scene> + Send + Sync> HasScene for T {}

pub trait HasScene: AsRefOpt<Scene> + AsMutOpt<Scene> {
    fn scene (&self) -> Option<&Scene> {
        self.as_ref_opt()
    }
    fn scene_mut (&mut self) -> Option<&mut Scene> {
        self.as_mut_opt()
    }
}

impl<T: HasScene
    + Namespace<usize>
    + Namespace<Arc<str>>
    + Namespace<ItemTheme>
> SceneController for T {}

#[tek_proc::commands(SceneCommand)]
pub trait SceneController: HasScene
    + Namespace<usize>
    + Namespace<Arc<str>>
    + Namespace<ItemTheme>
{
    #[command(SetSize = "size")]
    fn scene_set_size (&mut self, _size: usize) -> Perhaps<SceneCommand>
        where Self: Namespace<usize>
    {
        todo!()
    }
    #[command(SetZoom = "zoom")]
    fn scene_set_zoom (&mut self, _size: usize) -> Perhaps<SceneCommand>
        where Self: Namespace<usize>
    {
        todo!()
    }
    #[command(SetName = "name")]
    fn scene_set_name (&mut self, name: Arc<str>) -> Perhaps<SceneCommand>
        where Self: Namespace<Arc<str>>
    {
        Ok(self.scene_mut().map(|scene|swap_value(
            &mut scene.name,
            &name,
            |name|SceneCommand::SetName { name }
        )).transpose()?.flatten())
    }
    #[command(SetColor = "color")]
    fn scene_set_color (&mut self, color: ItemTheme) -> Perhaps<SceneCommand>
        where Self: Namespace<ItemTheme>
    {
        Ok(self.scene_mut().map(|scene|swap_value(
            &mut scene.color,
            &color,
            |color|SceneCommand::SetColor { color }
        )).transpose()?.flatten())
    }
}

pub type SceneWith<'a, T> = (usize, &'a Scene, usize, usize, T);

def_sizes_iter!(ScenesSizes => Scene);
impl_has!(Vec<Scene>: |self: Arrangement| self.scenes);
impl_as_ref!(Vec<Scene>: |self: App| self.project.as_ref());
impl_as_mut!(Vec<Scene>: |self: App| self.project.as_mut());

impl<T: AsRef<Vec<Scene>> + AsMut<Vec<Scene>>> HasScenes for T {}

pub trait HasScenes: AsRef<Vec<Scene>> + AsMut<Vec<Scene>> {
    fn scenes (&self) -> &Vec<Scene> {
        self.as_ref()
    }
    fn scenes_mut (&mut self) -> &mut Vec<Scene> {
        self.as_mut()
    }
    /// Generate the default name for a new scene
    fn scenes_default_name (&self) -> Arc<str> {
        format!("s{:3>}", self.scenes().len() + 1).into()
    }
    fn scenes_longest_name (&self) -> usize {
        self.scenes().iter().map(|s|s.name.len()).fold(0, usize::max)
    }
    /// Add multiple scenes
    fn scenes_add_many (&mut self, n: usize)
        -> Usually<()> where Self: HasTracks
    {
        let scene_color_1 = ItemColor::random();
        let scene_color_2 = ItemColor::random();
        for i in 0..n {
            let _ = self.scenes_add_one(None, Some(
                scene_color_1.mix(scene_color_2, i as f32 / n as f32).into()
            ))?;
        }
        Ok(())
    }
    /// Add a scene
    fn scenes_add_one (&mut self, name: Option<Arc<str>>, color: Option<ItemTheme>)
        -> Usually<(usize, &mut Scene)>
    where
        Self: HasTracks
    {
        let scene = Scene {
            name:  name.map_or_else(||self.scenes_default_name(), |x|x.to_string().into()),
            clips: vec![None;self.tracks().len()],
            color: color.unwrap_or_else(ItemTheme::random),
        };
        self.scenes_mut().push(scene);
        let index = self.scenes().len() - 1;
        Ok((index, &mut self.scenes_mut()[index]))
    }
}

impl<T: HasScenes
    + HasTracks
    + HasTrackScroll
    + HasJack<'static>
    + Namespace<usize>
    + Namespace<Option<ItemTheme>>
    + Namespace<Option<Arc<str>>>
> ScenesController for T {}

#[tek_proc::commands(ScenesCommand)]
pub trait ScenesController: HasScenes
    + HasTracks
    + HasTrackScroll
    + HasJack<'static>
    + Namespace<usize>
    + Namespace<Option<ItemTheme>>
    + Namespace<Option<Arc<str>>>
{
    #[command(Add = "add")]
    fn scenes_add (&mut self) -> Perhaps<ScenesCommand>
        where Self: HasScenes + HasJack<'static>
    {
        let (_index, _) = self.scenes_add_one(None, None)?;
        Ok(None)
    }
    // TODO
}

pub trait ScenesView: HasEditor + HasSelection + HasSceneScroll + HasClipsSize + Send + Sync {
    fn h_scenes (&self) -> u16;
    fn w_side   (&self) -> u16;
    fn w_mid    (&self) -> u16;

    fn view_scenes_names (&self) -> impl Draw<Tui> {
        let select  = self.selection();
        let editor  = self.editor();
        let editing = self.is_editing();
        draw(move |to: &mut Tui|{
            for (index, scene, ..) in self.scenes_with_sizes() {
                view_scene_name(select, editor, index, scene, editing).draw(to)?;
            }
            Ok(Some(XYWH(1, 1, 1, 1)))
        })
            .exact_w(20)
    }

    fn scenes_with_sizes (&self) -> impl ScenesSizes<'_> {
        let mut y = 0;
        self.scenes().iter().enumerate().skip(self.scene_scroll()).map_while(move|(s, scene)|{
            let height = if self.selection().scene() == Some(s) && self.editor().is_some() {
                8
            } else {
                Scene::DEFAULT_HEIGHT
            };
            if y + height <= self.clips_size().h() as usize {
                let data = (s, scene, y, y + height);
                y += height;
                Some(data)
            } else {
                None
            }
        })
    }
}

impl ScenesView for App {
    fn w_mid (&self) -> u16 {
        (self.size.w() as u16).saturating_sub(self.w_side())
    }
    fn w_side (&self) -> u16 {
        20
    }
    fn h_scenes (&self) -> u16 {
        (self.size.h() as u16).saturating_sub(20)
    }
}

impl ScenesView for Arrangement {
    fn h_scenes (&self) -> u16 {
        (self.size.h() as u16).saturating_sub(20)
    }
    fn w_side (&self) -> u16 {
        (self.size.w() as u16 * 2 / 10).max(20)
    }
    fn w_mid (&self) -> u16 {
        (self.size.w() as u16).saturating_sub(2 * self.w_side()).max(40)
    }
}

pub trait HasSceneScroll: HasScenes {
    fn scene_scroll (&self) -> usize;
}

impl HasSceneScroll for Arrangement {
    fn scene_scroll (&self) -> usize {
        self.scene_scroll
    }
}

impl HasSceneScroll for App {
    fn scene_scroll (&self) -> usize {
        self.project.scene_scroll()
    }
}

pub fn view_scene_name <'a> (
    select:  &Selection,
    editor:  Option<&'a MidiEditor>,
    index:   usize,
    scene:   &Scene,
    editing: bool
) -> impl Draw<Tui> {
    let h = if select.scene() == Some(index) && let Some(_editor) = editor {
        7
    } else {
        Scene::DEFAULT_HEIGHT as u16
    };
    let a = east(format!("·s{index:02} "),
        fg(g(255), bold(true, &scene.name))).align_w().full_w();
    let b = when(select.scene() == Some(index) && editing, south(
        editor.as_ref().map(|e|e.clip_status()),
        editor.as_ref().map(|e|e.edit_status())).align_nw().full_wh());
    let c = if select.scene() == Some(index) {
        scene.color.light.term
    } else {
        scene.color.base.term
    };
    bg(c, south(a, b).align_nw()).exact_wh(20, h)
}