use crate::*;
use super::*;
/// A clip, rendered as a horizontal piano roll.
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:   Measure<TuiOut>,
    /// The display window
    pub range:  MidiRangeModel,
    /// The note cursor
    pub point:  MidiPointModel,
    /// The highlight color palette
    pub color:  ItemPalette,
    /// Width of the keyboard
    pub keys_width: u16,
}
impl PianoHorizontal {
    pub fn new (clip: Option<&Arc<RwLock<MidiClip>>>) -> Self {
        let size = Measure::new();
        let mut range  = MidiRangeModel::from((24, true));
        range.time_axis = size.x.clone();
        range.note_axis = size.y.clone();
        let piano = Self {
            keys_width: 5,
            size,
            range,
            buffer: RwLock::new(Default::default()).into(),
            point:  MidiPointModel::default(),
            clip: clip.cloned(),
            color: clip.as_ref()
                .map(|p|p.read().unwrap().color)
                .unwrap_or(ItemPalette::from(ItemColor::from(TuiTheme::g(64)))),
        };
        piano.redraw();
        piano
    }
}
pub(crate) fn note_y_iter (note_lo: usize, note_hi: usize, y0: u16) -> impl Iterator<Item=(usize, u16, usize)> {
    (note_lo..=note_hi).rev().enumerate().map(move|(y, n)|(y, y0 + y as u16, n))
}
render!(TuiOut: (self: PianoHorizontal) => Bsp::s( // the freeze is in the Measure
    Fixed::y(1, Bsp::e(
        Fixed::x(self.keys_width, ""),
        Fill::x(PianoHorizontalTimeline(self)),
    )),
    Fill::xy(Bsp::e(
        Fixed::x(self.keys_width, PianoHorizontalKeys(self)),
        Fill::xy(self.size.of(lay!(self.notes(), self.cursor()))),
    )),
));
impl PianoHorizontal {
    /// Draw the piano roll foreground using full blocks on note on and half blocks on legato: █▄ █▄ █▄
    fn draw_bg (buf: &mut BigBuffer, clip: &MidiClip, zoom: usize, note_len: 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();
                cell.set_bg(clip.color.darkest.rgb);
                cell.set_fg(clip.color.darker.rgb);
                cell.set_char(if time % 384 == 0 {
                    '│'
                } else if time % 96 == 0 {
                    '╎'
                } else if time % note_len == 0 {
                    '┊'
                } else if (127 - note) % 12 == 0 {
                    '='
                } else if (127 - note) % 6 == 0 {
                    '—'
                } else {
                    '·'
                });
            }
        }
    }
    /// Draw the piano roll background using 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.rgb);//.bg(Color::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;
                            let cell = buf.get_mut(x, note).unwrap();
                            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 Content<TuiOut> {
        let time_start = self.time_start().get();
        let note_axis  = self.note_axis().get();
        let note_lo    = self.note_lo().get();
        let note_hi    = self.note_hi();
        let note_point = self.note_point();
        let buffer     = self.buffer.clone();
        RenderThunk::new(move|render: &mut TuiOut|{
            let source = buffer.read().unwrap();
            let [x0, y0, w, h] = render.area().xywh();
            //if h as usize != note_axis {
                //panic!("area height mismatch: {h} <> {note_axis}");
            //}
            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) = render.buffer.cell_mut(ratatui::prelude::Position::from((screen_x, screen_y))) {
                                *cell = source_cell.clone();
                            }
                        }
                    }
                }
            }
        })
    }
    fn cursor (&self) -> impl Content<TuiOut> {
        let style = Some(Style::default().fg(self.color.lightest.rgb));
        let note_hi    = self.note_hi();
        let note_len   = self.note_len();
        let note_lo    = self.note_lo().get();
        let note_point = self.note_point();
        let time_point = self.time_point();
        let time_start = self.time_start().get();
        let time_zoom  = self.time_zoom().get();
        RenderThunk::new(move|render: &mut TuiOut|{
            let [x0, y0, w, _] = render.area().xywh();
            for (_area_y, screen_y, note) in note_y_iter(note_lo, note_hi, y0) {
                if note == note_point {
                    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_point && time_point < time_2 {
                            render.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) {
                                render.blit(&"▂", x_tail, screen_y, style);
                            }
                            break
                        }
                    }
                    break
                }
            }
        })
    }
}

has_size!(<TuiOut>|self:PianoHorizontal|&self.size);

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) -> usize { self.point.note_len() }
    fn set_note_len (&self, x: usize) { self.point.set_note_len(x) }
    fn note_point (&self) -> usize { self.point.note_point() }
    fn set_note_point (&self, x: usize) { self.point.set_note_point(x) }
}
impl TimePoint for PianoHorizontal {
    fn time_point (&self) -> usize { self.point.time_point() }
    fn set_time_point (&self, x: usize) { self.point.set_time_point(x) }
}
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().get(), 128)
    }
    fn redraw (&self) {
        let buffer = if let Some(clip) = self.clip.as_ref() {
            let clip     = clip.read().unwrap();
            let buf_size   = self.buffer_size(&clip);
            let mut buffer = BigBuffer::from(buf_size);
            let note_len   = self.note_len();
            let time_zoom  = self.time_zoom().get();
            self.time_len().set(clip.length);
            PianoHorizontal::draw_bg(&mut buffer, &clip, time_zoom, note_len);
            PianoHorizontal::draw_fg(&mut buffer, &clip, time_zoom);
            buffer
        } else {
            Default::default()
        };
        *self.buffer.write().unwrap() = buffer
    }
    fn set_clip (&mut self, clip: Option<&Arc<RwLock<MidiClip>>>) {
        *self.clip_mut() = clip.cloned();
        self.color = clip.map(|p|p.read().unwrap().color)
            .unwrap_or(ItemPalette::from(ItemColor::from(TuiTheme::g(64))));
        self.redraw();
    }
}

impl std::fmt::Debug for PianoHorizontal {
    fn fmt (&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
        let buffer = self.buffer.read().unwrap();
        f.debug_struct("PianoHorizontal")
            .field("time_zoom", &self.range.time_zoom)
            .field("buffer", &format!("{}x{}", buffer.width, buffer.height))
            .finish()
    }
}
        // Update sequencer playhead indicator
        //self.now().set(0.);
        //if let Some((ref started_at, Some(ref playing))) = self.player.play_clip {
            //let clip = clip.read().unwrap();
            //if *playing.read().unwrap() == *clip {
                //let pulse = self.current().pulse.get();
                //let start = started_at.pulse.get();
                //let now   = (pulse - start) % clip.length as f64;
                //self.now().set(now);
            //}
        //}