/// Represents the current user selection in the arranger
#[derive(PartialEq, Clone, Copy, Debug, Default)] pub enum Selection {
    #[default]
    /// Nothing is selected
    Nothing,
    /// The whole mix is selected
    Mix,
    /// A MIDI input is selected.
    Input(usize),
    /// A MIDI output is selected.
    Output(usize),
    /// A scene is selected.
    #[cfg(feature = "scene")] Scene(usize),
    /// A track is selected.
    #[cfg(feature = "track")] Track(usize),
    /// A clip (track × scene) is selected.
    #[cfg(feature = "track")] TrackClip   { track: usize, scene:  usize },
    /// A track's MIDI input connection is selected.
    #[cfg(feature = "track")] TrackInput  { track: usize, port:   usize },
    /// A track's MIDI output connection is selected.
    #[cfg(feature = "track")] TrackOutput { track: usize, port:   usize },
    /// A track device slot is selected.
    #[cfg(feature = "track")] TrackDevice { track: usize, device: usize },
}

/// 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>>>>,
}

/// Arranger.
///
/// ```
/// let arranger = tek::Arrangement::default();
/// ```
#[derive(Default, Debug)] pub struct Arrangement {
    /// Project name.
    pub name:       Arc<str>,
    /// Base color.
    pub color:      ItemTheme,
    /// JACK client handle.
    pub jack:       Jack<'static>,
    /// FIXME a render of the project arrangement, redrawn on update.
    /// TODO rename to "render_cache" or smth
    pub arranger:   Arc<RwLock<Buffer>>,
    /// Display size
    pub size:       Measure<Tui>,
    /// Display size of clips area
    pub size_inner: Measure<Tui>,
    /// Source of time
    #[cfg(feature = "clock")]  pub clock: Clock,
    /// Allows one MIDI clip to be edited
    #[cfg(feature = "editor")] pub editor: Option<MidiEditor>,
    /// List of global midi inputs
    #[cfg(feature = "port")]   pub midi_ins:   Vec<MidiInput>,
    /// List of global midi outputs
    #[cfg(feature = "port")]   pub midi_outs:  Vec<MidiOutput>,
    /// List of global audio inputs
    #[cfg(feature = "port")]   pub audio_ins:  Vec<AudioInput>,
    /// List of global audio outputs
    #[cfg(feature = "port")]   pub audio_outs: Vec<AudioOutput>,
    /// Selected UI element
    #[cfg(feature = "select")] pub selection: Selection,
    /// Last track number (to avoid duplicate port names)
    #[cfg(feature = "track")]  pub track_last:   usize,
    /// List of tracks
    #[cfg(feature = "track")]  pub tracks: Vec<Track>,
    /// Scroll offset of tracks
    #[cfg(feature = "track")]  pub track_scroll: usize,
    /// List of scenes
    #[cfg(feature = "scene")]  pub scenes: Vec<Scene>,
    /// Scroll offset of scenes
    #[cfg(feature = "scene")]  pub scene_scroll: usize,
}

pub trait ClipsView: TracksView + ScenesView {

    fn view_scenes_clips <'a> (&'a self)
        -> impl Draw<Tui> + 'a
    {
        self.clips_size().of(wh_full(above(
            wh_full(origin_se(Tui::fg(Green, format!("{}x{}", self.clips_size().w(), self.clips_size().h())))),
            Thunk::new(|to: &mut Tui|for (
                track_index, track, _, _
            ) in self.tracks_with_sizes() {
                to.place(&w_exact(track.width as u16,
                    h_full(self.view_track_clips(track_index, track))))
            }))))
    }

    fn view_track_clips <'a> (&'a self, track_index: usize, track: &'a Track) -> impl Draw<Tui> + 'a {
        Thunk::new(move|to: &mut Tui|for (
            scene_index, scene, ..
        ) in self.scenes_with_sizes() {
            let (name, theme): (Arc<str>, ItemTheme) = if let Some(Some(clip)) = &scene.clips.get(track_index) {
                let clip = clip.read().unwrap();
                (format!(" ⏹ {}", &clip.name).into(), clip.color)
            } else {
                (" ⏹ -- ".into(), ItemTheme::G[32])
            };
            let fg = theme.lightest.rgb;
            let mut outline = theme.base.rgb;
            let bg = if self.selection().track() == Some(track_index)
                && self.selection().scene() == Some(scene_index)
            {
                outline = theme.lighter.rgb;
                theme.light.rgb
            } else if self.selection().track() == Some(track_index)
                || self.selection().scene() == Some(scene_index)
            {
                outline = theme.darkest.rgb;
                theme.base.rgb
            } else {
                theme.dark.rgb
            };
            let w = if self.selection().track() == Some(track_index)
                && let Some(editor) = self.editor ()
            {
                (editor.measure_width() as usize).max(24).max(track.width)
            } else {
                track.width
            } as u16;
            let y = if self.selection().scene() == Some(scene_index)
                && let Some(editor) = self.editor ()
            {
                (editor.measure_height() as usize).max(12)
            } else {
                Self::H_SCENE as usize
            } as u16;

            to.place(&wh_exact(w, y, below(
                wh_full(Outer(true, Style::default().fg(outline))),
                wh_full(below(
                    below(
                        Tui::fg_bg(outline, bg, wh_full("")),
                        wh_full(origin_nw(Tui::fg_bg(fg, bg, Tui::bold(true, name)))),
                    ),
                    wh_full(when(self.selection().track() == Some(track_index)
                      && self.selection().scene() == Some(scene_index)
                      && self.is_editing(), self.editor())))))));
        })
    }

}

pub trait TracksView: ScenesView + HasMidiIns + HasMidiOuts + HasTrackScroll + Measured<Tui> {

    fn tracks_width_available (&self) -> u16 {
        (self.measure_width() as u16).saturating_sub(40)
    }

    /// Iterate over tracks with their corresponding sizes.
    fn tracks_with_sizes (&self) -> impl TracksSizes<'_> {
        let _editor_width = self.editor().map(|e|e.measure_width());
        let _active_track = self.selection().track();
        let mut x = 0;
        self.tracks().iter().enumerate().map_while(move |(index, track)|{
            let width = track.width.max(8);
            if x + width < self.clips_size().w() as usize {
                let data = (index, track, x, x + width);
                x += width + Self::TRACK_SPACING;
                Some(data)
            } else {
                None
            }
        })
    }

    fn view_track_names (&self, theme: ItemTheme) -> impl Draw<Tui> {
        let track_count = self.tracks().len();
        let scene_count = self.scenes().len();
        let selected = self.selection();
        let button = south(
            button_3("t", "rack ", format!("{}{track_count}", selected.track()
                .map(|track|format!("{track}/")).unwrap_or_default()), false),
            button_3("s", "cene ", format!("{}{scene_count}", selected.scene()
                .map(|scene|format!("{scene}/")).unwrap_or_default()), false));
        let button_2 = south(
            button_2("T", "+", false),
            button_2("S", "+", false));
        view_track_row_section(theme, button, button_2, Tui::bg(theme.darker.rgb,
            h_exact(2, Thunk::new(|to: &mut Tui|{
                for (index, track, x1, _x2) in self.tracks_with_sizes() {
                    to.place(&x_push(x1 as u16, w_exact(track_width(index, track),
                        Tui::bg(if selected.track() == Some(index) {
                            track.color.light.rgb
                        } else {
                            track.color.base.rgb
                        }, south(w_full(origin_nw(east(
                            format!("·t{index:02} "),
                            Tui::fg(Rgb(255, 255, 255), Tui::bold(true, &track.name))
                        ))), "")))  ));}}))))
    }

    fn view_track_outputs <'a> (&'a self, theme: ItemTheme, _h: u16) -> impl Draw<Tui> {
        view_track_row_section(theme,
            south(w_full(origin_w(button_2("o", "utput", false))),
                Thunk::new(|to: &mut Tui|for port in self.midi_outs().iter() {
                    to.place(&w_full(origin_w(port.port_name())));
                })),
            button_2("O", "+", false),
            Tui::bg(theme.darker.rgb, origin_w(Thunk::new(|to: &mut Tui|{
                for (index, track, _x1, _x2) in self.tracks_with_sizes() {
                    to.place(&w_exact(track_width(index, track),
                        origin_nw(h_full(iter_south(1, ||track.sequencer.midi_outs.iter(),
                            |port, index|Tui::fg(Rgb(255, 255, 255),
                                h_exact(1, Tui::bg(track.color.dark.rgb, w_full(origin_w(
                                    format!("·o{index:02} {}", port.port_name())))))))))));}}))))
    }

    fn view_track_inputs <'a> (&'a self, theme: ItemTheme) -> impl Draw<Tui> {
        let mut h = 0u16;
        for track in self.tracks().iter() {
            h = h.max(track.sequencer.midi_ins.len() as u16);
        }
        let content = Thunk::new(move|to: &mut Tui|for (index, track, _x1, _x2) in self.tracks_with_sizes() {
            to.place(&wh_exact(track_width(index, track), h + 1,
                origin_nw(south(
                    Tui::bg(track.color.base.rgb,
                        w_full(origin_w(east!(
                            either(track.sequencer.monitoring, Tui::fg(Green, "●mon "), "·mon "),
                            either(track.sequencer.recording,  Tui::fg(Red, "●rec "), "·rec "),
                            either(track.sequencer.overdub,    Tui::fg(Yellow, "●dub "), "·dub "),
                        )))),
                    iter_south(1, ||track.sequencer.midi_ins.iter(),
                        |port, index|Tui::fg_bg(Rgb(255, 255, 255), track.color.dark.rgb,
                            w_full(origin_w(format!("·i{index:02} {}", port.port_name())))))))));
        });
        view_track_row_section(theme, button_2("i", "nput", false), button_2("I", "+", false),
            Tui::bg(theme.darker.rgb, origin_w(content)))
    }

}

pub trait ScenesView: HasEditor + HasSelection + HasSceneScroll + HasClipsSize + Send + Sync {
    /// Default scene height.
    const H_SCENE:  usize = 2;
    /// Default editor height.
    const H_EDITOR: usize = 15;
    fn h_scenes (&self) -> u16;
    fn w_side   (&self) -> u16;
    fn w_mid    (&self) -> u16;
    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 {
                Self::H_SCENE
            };
            if y + height <= self.clips_size().h() as usize {
                let data = (s, scene, y, y + height);
                y += height;
                Some(data)
            } else {
                None
            }
        })
    }

    fn view_scenes_names (&self) -> impl Draw<Tui> {
        w_exact(20, Thunk::new(|to: &mut Tui|for (index, scene, ..) in self.scenes_with_sizes() {
            to.place(&self.view_scene_name(index, scene));
        }))
    }

    fn view_scene_name <'a> (&'a self, index: usize, scene: &'a Scene) -> impl Draw<Tui> + 'a {
        let h = if self.selection().scene() == Some(index) && let Some(_editor) = self.editor() {
            7
        } else {
            Self::H_SCENE as u16
        };
        let bg = if self.selection().scene() == Some(index) {
            scene.color.light.rgb
        } else {
            scene.color.base.rgb
        };
        let a = w_full(origin_w(east(format!("·s{index:02} "),
            Tui::fg(Tui::g(255), Tui::bold(true, &scene.name)))));
        let b = when(self.selection().scene() == Some(index) && self.is_editing(),
            wh_full(origin_nw(south(
                self.editor().as_ref().map(|e|e.clip_status()),
                self.editor().as_ref().map(|e|e.edit_status())))));
        wh_exact(20, h, Tui::bg(bg, origin_nw(south(a, b))))
    }

}
pub trait HasSceneScroll: HasScenes { fn scene_scroll (&self) -> usize; }
pub trait HasTrackScroll: HasTracks { fn track_scroll (&self) -> usize; }
pub trait HasScene: AsRefOpt<Scene> + AsMutOpt<Scene> {
    fn scene_mut (&mut self) -> Option<&mut Scene> { self.as_mut_opt() }
    fn scene     (&self)     -> Option<&Scene>     { self.as_ref_opt() }
}
pub trait HasSelection: AsRef<Selection> + AsMut<Selection> {
    fn selection     (&self)     -> &Selection     { self.as_ref() }
    fn selection_mut (&mut self) -> &mut Selection { self.as_mut() }
    /// Get the active track
    #[cfg(feature = "track")]
    fn selected_track (&self) -> Option<&Track> where Self: HasTracks {
        let index = self.selection().track()?;
        self.tracks().get(index)
    }
    /// Get a mutable reference to the active track
    #[cfg(feature = "track")]
    fn selected_track_mut (&mut self) -> Option<&mut Track> where Self: HasTracks {
        let index = self.selection().track()?;
        self.tracks_mut().get_mut(index)
    }
    /// Get the active scene
    #[cfg(feature = "scene")]
    fn selected_scene (&self) -> Option<&Scene> where Self: HasScenes {
        let index = self.selection().scene()?;
        self.scenes().get(index)
    }
    /// Get a mutable reference to the active scene
    #[cfg(feature = "scene")]
    fn selected_scene_mut (&mut self) -> Option<&mut Scene> where Self: HasScenes {
        let index = self.selection().scene()?;
        self.scenes_mut().get_mut(index)
    }
    /// Get the active clip
    #[cfg(feature = "clip")]
    fn selected_clip (&self) -> Option<Arc<RwLock<MidiClip>>> where Self: HasScenes + HasTracks {
        self.selected_scene()?.clips.get(self.selection().track()?)?.clone()
    }
}
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 scene_default_name (&self) -> Arc<str> { format!("s{:3>}", self.scenes().len() + 1).into() }
    fn scene_longest_name (&self) -> usize { self.scenes().iter().map(|s|s.name.len()).fold(0, usize::max) }
    /// Add multiple scenes
    fn scenes_add (&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.scene_add(None, Some(
                scene_color_1.mix(scene_color_2, i as f32 / n as f32).into()
            ))?;
        }
        Ok(())
    }
    /// Add a scene
    fn scene_add (&mut self, name: Option<&str>, color: Option<ItemTheme>)
        -> Usually<(usize, &mut Scene)> where Self: HasTracks
    {
        let scene = Scene {
            name:  name.map_or_else(||self.scene_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]))
    }
}
pub trait HasTracks: AsRef<Vec<Track>> + AsMut<Vec<Track>> {
    fn tracks (&self) -> &Vec<Track> { self.as_ref() }
    fn tracks_mut (&mut self) -> &mut Vec<Track> { self.as_mut() }
    /// Run audio callbacks for every track and every device
    fn process_tracks (&mut self, client: &Client, scope: &ProcessScope) -> Control {
        for track in self.tracks_mut().iter_mut() {
            if Control::Quit == Audio::process(&mut track.sequencer, client, scope) {
                return Control::Quit
            }
            for device in track.devices.iter_mut() {
                if Control::Quit == DeviceAudio(device).process(client, scope) {
                    return Control::Quit
                }
            }
        }
        Control::Continue
    }
    fn track_longest_name (&self) -> usize { self.tracks().iter().map(|s|s.name.len()).fold(0, usize::max) }
    /// Stop all playing clips
    fn tracks_stop_all (&mut self) { for track in self.tracks_mut().iter_mut() { track.sequencer.enqueue_next(None); } }
    /// Stop all playing clips
    fn tracks_launch (&mut self, clips: Option<Vec<Option<Arc<RwLock<MidiClip>>>>>) {
        if let Some(clips) = clips {
            for (clip, track) in clips.iter().zip(self.tracks_mut()) { track.sequencer.enqueue_next(clip.as_ref()); }
        } else {
            for track in self.tracks_mut().iter_mut() { track.sequencer.enqueue_next(None); }
        }
    }
    /// Spacing between tracks.
    const TRACK_SPACING: usize = 0;
}
pub trait HasTrack: AsRefOpt<Track> + AsMutOpt<Track> {
    fn track (&self) -> Option<&Track> { self.as_ref_opt() }
    fn track_mut (&mut self) -> Option<&mut Track> { self.as_mut_opt() }
    #[cfg(feature = "port")] fn view_midi_ins_status <'a> (&'a self, theme: ItemTheme) -> impl Draw<Tui> + 'a {
        self.track().map(move|track|view_ports_status(theme, "MIDI ins:  ", &track.sequencer.midi_ins))
    }
    #[cfg(feature = "port")] fn view_midi_outs_status (&self, theme: ItemTheme) -> impl Draw<Tui>  + '_ {
        self.track().map(move|track|view_ports_status(theme, "MIDI outs: ", &track.sequencer.midi_outs))
    }
    #[cfg(feature = "port")] fn view_audio_ins_status (&self, theme: ItemTheme) -> impl Draw<Tui> {
        self.track().map(move|track|view_ports_status(theme, "Audio ins: ", &track.audio_ins()))
    }
    #[cfg(feature = "port")] fn view_audio_outs_status (&self, theme: ItemTheme) -> impl Draw<Tui> {
        self.track().map(move|track|view_ports_status(theme, "Audio outs:", &track.audio_outs()))
    }
}