use crate::*;

/// A clip, rendered as a horizontal piano roll.
///
/// ```
/// let piano = tek::PianoHorizontal::default();
/// ```
#[derive(Clone, Default)]
pub struct PianoHorizontal {
    pub clip: Option<Arc<RwLock<MidiClip>>>,
    /// Buffer where the whole clip is rerendered on change
    pub buffer: Arc<RwLock<BigBuffer>>,
    /// Size of actual notes area
    pub size: Sizer,
    /// The display window
    pub range: MidiSelection,
    /// The note cursor
    pub point: MidiCursor,
    /// The highlight color palette
    pub color: ItemTheme,
    /// Width of the keyboard
    pub keys_width: u16,
}

impl_has!(Sizer: |self: PianoHorizontal| self.size);

impl Draw<Tui> for PianoHorizontal {
    fn draw (&self, to: &mut Tui) -> Drawn<u16> {
        south(
            east(
                format!("{}x{}", self.size.w(), self.size.h()).exact_w(5),
                self.timeline()
            ),
            east(
                self.keys(),
                self.size.of(below(self.notes().full_wh(), self.cursor().full_wh()))
            ),
        ).draw(to)
    }
}

impl PianoHorizontal {

    pub fn new (clip: Option<&Arc<RwLock<MidiClip>>>) -> Self {
        let size = Sizer::default();
        let mut range = MidiSelection::from((12, true));
        range.time_axis = size.0.clone();
        range.note_axis = size.1.clone();
        let piano = Self {
            keys_width: 5,
            size,
            range,
            buffer: RwLock::new(Default::default()).into(),
            point:  MidiCursor::default(),
            clip: clip.cloned(),
            color: clip.as_ref().map(|p|p.try_read().unwrap().color).unwrap_or(ItemTheme::G[64]),
        };
        piano.redraw();
        piano
    }

    /// Draw the piano roll background.
    ///
    /// This mode uses full blocks on note on and half blocks on legato: █▄ █▄ █▄
    fn draw_bg (buf: &mut BigBuffer, clip: &MidiClip, zoom: usize, note_len: usize, note_point: usize, time_point: usize) {
        for (y, note) in (0..=127).rev().enumerate() {
            for (x, time) in (0..buf.width).map(|x|(x, x*zoom)) {
                let cell = buf.get_mut(x, y).unwrap();
                if note == (127-note_point) || time == time_point {
                    cell.set_bg(Rgb(0,0,0));
                } else {
                    cell.set_bg(clip.color.darkest.term);
                }
                if time % 384 == 0 {
                    cell.set_fg(clip.color.darker.term);
                    cell.set_char('│');
                } else if time % 96 == 0 {
                    cell.set_fg(clip.color.dark.term);
                    cell.set_char('╎');
                } else if time % note_len == 0 {
                    cell.set_fg(clip.color.darker.term);
                    cell.set_char('┊');
                } else if (127 - note) % 12 == 0 {
                    cell.set_fg(clip.color.darker.term);
                    cell.set_char('=');
                } else if (127 - note) % 6 == 0 {
                    cell.set_fg(clip.color.darker.term);
                    cell.set_char('—');
                } else {
                    cell.set_fg(clip.color.darker.term);
                    cell.set_char('·');
                }
            }
        }
    }

    /// Draw the piano roll foreground.
    ///
    /// This mode uses full blocks on note on and half blocks on legato: █▄ █▄ █▄
    fn draw_fg (buf: &mut BigBuffer, clip: &MidiClip, zoom: usize) {
        let style = Style::default().fg(clip.color.base.term);//.bg(Rgb(0, 0, 0));
        let mut notes_on = [false;128];
        for (x, time_start) in (0..clip.length).step_by(zoom).enumerate() {
            for (_y, note) in (0..=127).rev().enumerate() {
                if let Some(cell) = buf.get_mut(x, note) {
                    if notes_on[note] {
                        cell.set_char('▂');
                        cell.set_style(style);
                    }
                }
            }
            let time_end = time_start + zoom;
            for time in time_start..time_end.min(clip.length) {
                for event in clip.notes[time].iter() {
                    match event {
                        MidiMessage::NoteOn { key, .. } => {
                            let note = key.as_int() as usize;
                            if let Some(cell) = buf.get_mut(x, note) {
                                cell.set_char('█');
                                cell.set_style(style);
                            }
                            notes_on[note] = true
                        },
                        MidiMessage::NoteOff { key, .. } => {
                            notes_on[key.as_int() as usize] = false
                        },
                        _ => {}
                    }
                }
            }

        }
    }

    fn notes (&self) -> impl Draw<Tui> {
        let time_start = self.get_time_start();
        let note_lo    = self.get_note_lo();
        let note_hi    = self.get_note_hi();
        let buffer     = self.buffer.clone();
        draw(move|to: &mut Tui|{
            let xywh = to.area().into();
            let XYWH(x0, y0, w, _h) = xywh;
            let source = buffer.try_read().unwrap();
            //if h as usize != note_axis {
                //panic!("area height mismatch: {h} <> {note_axis}");
            //}
            if let Tui::Draw(to, ..) = to {
                for (area_x, screen_x) in (x0..x0+w).enumerate() {
                    for (area_y, screen_y, _note) in note_y_iter(note_lo, note_hi, y0) {
                        let source_x = time_start + area_x;
                        let source_y = note_hi    - area_y;
                        // TODO: enable loop rollover:
                        //let source_x = (time_start + area_x) % source.width.max(1);
                        //let source_y = (note_hi    - area_y) % source.height.max(1);
                        let is_in_x = source_x < source.width;
                        let is_in_y = source_y < source.height;
                        if is_in_x && is_in_y {
                            if let Some(source_cell) = source.get(source_x, source_y) {
                                if let Some(cell) = to.cell_mut(ratatui::prelude::Position::from((screen_x, screen_y))) {
                                    *cell = source_cell.clone();
                                }
                            }
                        }
                    }
                }
            }
            Ok(Some(xywh))
        })
    }

    fn cursor (&self) -> impl Draw<Tui> {
        let note_hi    = self.get_note_hi();
        let note_lo    = self.get_note_lo();
        let note_pos   = self.get_note_pos();
        let note_len   = self.get_note_len();
        let time_pos   = self.get_time_pos();
        let time_start = self.get_time_start();
        let time_zoom  = self.get_time_zoom();
        let style      = Some(Style::default().fg(self.color.lightest.term));
        draw(move|to: &mut Tui|{
            let xywh = to.area().into();
            let XYWH(x0, y0, w, _h) = xywh;
            for (_area_y, screen_y, note) in note_y_iter(note_lo, note_hi, y0) {
                if note == note_pos {
                    for x in 0..w {
                        let screen_x = x0 + x;
                        let time_1 = time_start + x as usize * time_zoom;
                        let time_2 = time_1 + time_zoom;
                        if time_1 <= time_pos && time_pos < time_2 {
                            to.blit(&"█", screen_x, screen_y, style);
                            let tail = note_len as u16 / time_zoom as u16;
                            for x_tail in (screen_x + 1)..(screen_x + tail) {
                                to.blit(&"▂", x_tail, screen_y, style);
                            }
                            break
                        }
                    }
                    break
                }
            }
            Ok(Some(xywh))
        })
    }

    fn keys (&self) -> impl Draw<Tui> {
        let state      = self;
        let color      = state.color;
        let note_lo    = state.get_note_lo();
        let note_hi    = state.get_note_hi();
        let note_pos   = state.get_note_pos();
        let key_style  = Some(Style::default().fg(Rgb(192, 192, 192)).bg(Rgb(0, 0, 0)));
        let off_style  = Some(Style::default().fg(g(255)));
        let on_style   = Some(Style::default().fg(Rgb(255,0,0)).bg(color.base.term).bold());
        draw(move|to: &mut Tui|{
            let xywh = to.area().into();
            let XYWH(x, y0, _w, _h) = xywh;
            for (_area_y, screen_y, note) in note_y_iter(note_lo, note_hi, y0) {
                to.blit(&to_key(note), x, screen_y, key_style);
                if note > 127 {
                    continue
                }
                if note == note_pos {
                    to.blit(&format!("{:<5}", note_pitch_to_name(note)), x, screen_y, on_style)
                } else {
                    to.blit(&note_pitch_to_name(note), x, screen_y, off_style)
                };
            }
            Ok(Some(xywh))
        }).exact_w(self.keys_width).full_h()
    }

    fn timeline (&self) -> impl Draw<Tui> + '_ {
        draw(move|to: &mut Tui|{
            let xywh = to.area().into();
            let XYWH(x, y, w, _h) = xywh;
            let style = Some(Style::default().dim());
            let length = self.clip.as_ref().map(|p|p.try_read().unwrap().length).unwrap_or(1);
            for (area_x, screen_x) in (0..w).map(|d|(d, d+x)) {
                let t = area_x as usize * self.time_zoom().load(Relaxed);
                if t < length {
                    to.blit(&"|", screen_x, y, style);
                }
            }
            Ok(Some(xywh))
        }).exact_h(1).full_w()
    }
}

impl TimeRange for PianoHorizontal {
    fn time_len   (&self) -> &AtomicUsize { self.range.time_len()   }
    fn time_zoom  (&self) -> &AtomicUsize { self.range.time_zoom()  }
    fn time_lock  (&self) -> &AtomicBool  { self.range.time_lock()  }
    fn time_start (&self) -> &AtomicUsize { self.range.time_start() }
    fn time_axis  (&self) -> &AtomicUsize { self.range.time_axis()  }
}

impl NoteRange for PianoHorizontal {
    fn note_lo    (&self) -> &AtomicUsize { self.range.note_lo()    }
    fn note_axis  (&self) -> &AtomicUsize { self.range.note_axis()  }
}

impl NotePoint for PianoHorizontal {
    fn note_len (&self) -> &AtomicUsize { self.point.note_len() }
    fn note_pos (&self) -> &AtomicUsize { self.point.note_pos() }
}

impl TimePoint for PianoHorizontal {
    fn time_pos (&self) -> &AtomicUsize { self.point.time_pos() }
}

impl MidiViewer for PianoHorizontal {
    fn clip (&self) -> &Option<Arc<RwLock<MidiClip>>> { &self.clip }
    fn clip_mut (&mut self) -> &mut Option<Arc<RwLock<MidiClip>>> { &mut self.clip }
    /// Determine the required space to render the clip.
    fn buffer_size (&self, clip: &MidiClip) -> (usize, usize) {
        (clip.length / self.range.time_zoom().load(Relaxed), 128)
    }
    fn redraw (&self) {
        *self.buffer.try_write().unwrap() = if let Some(clip) = self.clip.as_ref() {
            let clip       = clip.try_read().unwrap();
            let buf_size   = self.buffer_size(&clip);
            let mut buffer = BigBuffer::from(buf_size);
            let time_zoom  = self.get_time_zoom();
            self.time_len().store(clip.length, Relaxed);
            PianoHorizontal::draw_bg(&mut buffer, &clip, time_zoom,self.get_note_len(), self.get_note_pos(), self.get_time_pos());
            PianoHorizontal::draw_fg(&mut buffer, &clip, time_zoom);
            buffer
        } else {
            Default::default()
        }
    }
    fn set_clip (&mut self, clip: Option<&Arc<RwLock<MidiClip>>>) {
        *self.clip_mut() = clip.cloned();
        self.color = clip.map(|p|p.try_read().unwrap().color).unwrap_or(ItemTheme::G[64]);
        self.redraw();
    }
}

impl std::fmt::Debug for PianoHorizontal {
    fn fmt (&self, f: &mut Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        let buffer = self.buffer.try_read().unwrap();
        f.debug_struct("PianoHorizontal")
            .field("time_zoom", &self.range.time_zoom)
            .field("buffer", &format!("{}x{}", buffer.width, buffer.height))
            .finish()
    }
}