use crate::*;
impl Content for Sequencer<Tui> {
    type Engine = Tui;
    fn content (&self) -> impl Widget<Engine = Tui> {
        Stack::down(move|add|{
            add(&self.transport)?;
            add(&self.phrases.clone()
                .split(Direction::Right, 20, &self.editor as &dyn Widget<Engine = Tui>)
                .min_y(20))
        })
    }
}
// TODO: Display phrases always in order of appearance
impl Content for PhrasePool<Tui> {
    type Engine = Tui;
    fn content (&self) -> impl Widget<Engine = Tui> {
        let Self { focused, phrases, mode, .. } = self;
        let content = col!(
            (i, phrase) in phrases.iter().enumerate() => Layers::new(|add|{
                let Phrase { ref name, color, length, .. } = *phrase.read().unwrap();
                let mut length = PhraseLength::new(length, None);
                if let Some(PhrasePoolMode::Length(phrase, new_length, focus)) = mode {
                    if *focused && i == *phrase {
                        length.pulses = *new_length;
                        length.focus  = Some(*focus);
                    }
                }
                let length = length.align_e().fill_x();
                let row1 = lay!(format!(" {i}").align_w().fill_x(), length).fill_x();
                let mut row2 = format!(" {name}");
                if let Some(PhrasePoolMode::Rename(phrase, _)) = mode {
                    if *focused && i == *phrase { row2 = format!("{row2}▄"); }
                };
                let row2 = TuiStyle::bold(row2, true);
                let bg = if i == self.phrase { color } else { color };
                add(&col!(row1, row2).fill_x().bg(bg))?;
                if *focused && i == self.phrase { add(&CORNERS)?; }
                Ok(())
            })
        );
        let border_color = if *focused {Color::Rgb(100, 110, 40)} else {Color::Rgb(70, 80, 50)};
        let border       = Lozenge(Style::default().bg(Color::Rgb(40, 50, 30)).fg(border_color));
        let content      = content.fill_xy().bg(Color::Rgb(28, 35, 25)).border(border);
        let title_color  = if *focused {Color::Rgb(150, 160, 90)} else {Color::Rgb(120, 130, 100)};
        let title        = format!("Phrases ({})", phrases.len());
        let title        = TuiStyle::fg(title, title_color).push_x(1);
        Layers::new(move|add|{ add(&content)?; add(&title)?; Ok(()) })
    }
}
impl Content for PhraseEditor<Tui> {
    type Engine = Tui;
    fn content (&self) -> impl Widget<Engine = Tui> {
        let Self { focused, entered, keys, phrase, buffer, note_len, .. } = self;
        let FixedAxis {
            start: note_start, point: note_point, clamp: note_clamp
        } = *self.note_axis.read().unwrap();
        let ScaledAxis {
            start: time_start, point: time_point, clamp: time_clamp, scale: time_scale
        } = *self.time_axis.read().unwrap();
        let color = Color::Rgb(0,255,0);
        let color = phrase.as_ref().map(|p|p.read().unwrap().color).unwrap_or(color);
        let keys = CustomWidget::new(|to:[u16;2]|Ok(Some(to.clip_w(5))), move|to: &mut TuiOutput|{
            if to.area().h() >= 2 {
                to.buffer_update(to.area().set_w(5), &|cell, x, y|{
                    let y = y + note_start as u16;
                    if x < keys.area.width && y < keys.area.height {
                        *cell = keys.get(x, y).clone()
                    }
                });
            }
            Ok(())
        }).fill_y();
        let notes_bg_null = Color::Rgb(28, 35, 25);
        let notes = CustomWidget::new(|to|Ok(Some(to)), move|to: &mut TuiOutput|{
            let w = to.area.w() as usize;
            let h = to.area.h() as usize;
            self.width.store(w, Ordering::Relaxed);
            self.height.store(h, Ordering::Relaxed);
            let mut axis = self.note_axis.write().unwrap();
            if let Some(point) = axis.point {
                if point.saturating_sub(axis.start) >= (h * 2).saturating_sub(1) {
                    axis.start += 1;
                }
            }
            if to.area().h() >= 2 {
                let area = to.area();
                to.buffer_update(area, &move |cell, x, y|{
                    cell.set_bg(notes_bg_null);
                    let src_x = (x as usize + time_start) * time_scale;
                    let src_y = y as usize + note_start;
                    if src_x < buffer.width && src_y < buffer.height - 1 {
                        buffer.get(src_x, buffer.height - src_y - 1).map(|src|{
                            cell.set_symbol(src.symbol());
                            cell.set_fg(src.fg);
                            cell.set_bg(src.bg);
                        });
                    }
                });
            }
            Ok(())
        }).fill_x();
        let cursor = CustomWidget::new(|to|Ok(Some(to)), move|to: &mut TuiOutput|{
            if *entered {
                let area = to.area();
                if let (Some(time), Some(note)) = (time_point, note_point) {
                    let x1 = area.x() + (time / time_scale) as u16;
                    let x2 = x1 + (self.note_len / time_scale) as u16;
                    let y = area.y() + note.saturating_sub(note_start) as u16 / 2;
                    let c = if note % 2 == 0 { "▀" } else { "▄" };
                    for x in x1..x2 {
                        to.blit(&c, x, y, Some(Style::default().fg(color)));
                    }
                }
            }
            Ok(())
        });
        let playhead_inactive = Style::default().fg(Color::Rgb(255,255,255)).bg(Color::Rgb(0,0,0));
        let playhead_active   = playhead_inactive.clone().yellow().bold().not_dim();
        let playhead = CustomWidget::new(
            |to:[u16;2]|Ok(Some(to.clip_h(1))),
            move|to: &mut TuiOutput|{
                if let Some(_) = phrase {
                    let now = self.now.load(Ordering::Relaxed); // TODO FIXME: self.now % phrase.read().unwrap().length;
                    let time_clamp = time_clamp
                        .expect("time_axis of sequencer expected to be clamped");
                    for x in 0..time_clamp/time_scale {
                        let this_step = (x * time_scale + time_start + 0) * time_scale;
                        let next_step = (x * time_scale + time_start + 1) * time_scale;
                        let x         = to.area().x() + x as u16;
                        let active    = this_step <= now && now < next_step;
                        let character = if active { "|" } else { "·" };
                        let style     = if active { playhead_active } else { playhead_inactive };
                        to.blit(&character, x, to.area.y(), Some(style));
                    }
                }
                Ok(())
            }
        ).push_x(6).align_sw();
        let border_color = if *focused{Color::Rgb(100, 110, 40)}else{Color::Rgb(70,   80,  50)};
        let title_color  = if *focused{Color::Rgb(150, 160, 90)}else{Color::Rgb(120, 130, 100)};
        let border       = Lozenge(Style::default().bg(Color::Rgb(40, 50, 30)).fg(border_color));
        let note_area    = lay!(notes, cursor).fill_x();
        let piano_roll   = row!(keys, note_area).fill_x();
        let content_bg   = Color::Rgb(40, 50, 30);
        let content      = piano_roll.bg(content_bg).border(border);
        let content      = lay!(content, playhead);
        let mut upper_left  = String::from("Sequencer");
        if let Some(phrase) = phrase {
            upper_left = format!("{upper_left}: {}", phrase.read().unwrap().name);
        }
        let mut upper_right = format!("Zoom: {} (+{}:{}*{}|{})",
            pulses_to_name(time_scale),
            time_start, time_point.unwrap_or(0),
            time_scale, time_clamp.unwrap_or(0),
        );
        if *focused && *entered {
            upper_right = format!("Note: {} (+{}:{}|{})  {upper_right}",
                pulses_to_name(*note_len),
                note_start,
                note_point.unwrap_or(0),
                note_clamp.unwrap_or(0),
            );
        }
        let lower_right = format!(
            "{}x{}",
            self.width.load(Ordering::Relaxed),
            self.height.load(Ordering::Relaxed),
        );
        lay!(
            content,
            TuiStyle::fg(upper_left.to_string(),  title_color).push_x(1).align_nw().fill_xy(),
            TuiStyle::fg(upper_right.to_string(), title_color).pull_x(1).align_ne().fill_xy(),
            TuiStyle::fg(lower_right.to_string(), title_color).pull_x(1).align_se().fill_xy(),
        )
    }
}
impl<E: Engine> PhraseEditor<E> {
    pub fn put (&mut self) {
        if let (Some(phrase), Some(time), Some(note)) = (
            &self.phrase,
            self.time_axis.read().unwrap().point,
            self.note_axis.read().unwrap().point,
        ) {
            let mut phrase = phrase.write().unwrap();
            let key: u7 = u7::from((127 - note) as u8);
            let vel: u7 = 100.into();
            let start = time;
            let end   = (start + self.note_len) % phrase.length;
            phrase.notes[time].push(MidiMessage::NoteOn { key, vel });
            phrase.notes[end].push(MidiMessage::NoteOff { key, vel });
            self.buffer = Self::redraw(&phrase);
        }
    }
    /// Select which pattern to display. This pre-renders it to the buffer at full resolution.
    pub fn show (&mut self, phrase: Option<&Arc<RwLock<Phrase>>>) {
        if let Some(phrase) = phrase {
            self.phrase = Some(phrase.clone());
            self.time_axis.write().unwrap().clamp = Some(phrase.read().unwrap().length);
            self.buffer = Self::redraw(&*phrase.read().unwrap());
        } else {
            self.phrase = None;
            self.time_axis.write().unwrap().clamp = Some(0);
            self.buffer = Default::default();
        }
    }
    fn redraw (phrase: &Phrase) -> BigBuffer {
        let mut buf = BigBuffer::new(usize::MAX.min(phrase.length), 65);
        Self::fill_seq_bg(&mut buf, phrase.length, phrase.ppq);
        Self::fill_seq_fg(&mut buf, &phrase);
        buf
    }
    fn fill_seq_bg (buf: &mut BigBuffer, length: usize, ppq: usize) {
        for x in 0..buf.width {
            if x as usize >= length {
                break
            }
            let style = Style::default();
            buf.get_mut(x, 0).map(|cell|{
                cell.set_char('-');
                cell.set_style(style);
            });
            for y in 0 .. buf.height {
                buf.get_mut(x, y).map(|cell|{
                    cell.set_char(if ppq == 0 {
                        '·'
                    } else if x % (4 * ppq) == 0 {
                        '│'
                    } else if x % ppq == 0 {
                        '╎'
                    } else {
                        '·'
                    });
                    cell.set_fg(Color::Rgb(48, 64, 56));
                    cell.modifier = Modifier::DIM;
                });
            }
        }
    }
    fn fill_seq_fg (buf: &mut BigBuffer, phrase: &Phrase) {
        let mut notes_on = [false;128];
        for x in 0..buf.width {
            if x as usize >= phrase.length {
                break
            }
            if let Some(notes) = phrase.notes.get(x as usize) {
                if phrase.percussive {
                    for note in notes {
                        match note {
                            MidiMessage::NoteOn { key, .. } =>
                                notes_on[key.as_int() as usize] = true,
                            _ => {}
                        }
                    }
                } else {
                    for note in notes {
                        match note {
                            MidiMessage::NoteOn { key, .. } =>
                                notes_on[key.as_int() as usize] = true,
                            MidiMessage::NoteOff { key, .. } =>
                                notes_on[key.as_int() as usize] = false,
                            _ => {}
                        }
                    }
                }
                for y in 0..buf.height {
                    if y >= 64 {
                        break
                    }
                    if let Some(block) = half_block(
                        notes_on[y as usize * 2],
                        notes_on[y as usize * 2 + 1],
                    ) {
                        buf.get_mut(x, y).map(|cell|{
                            cell.set_char(block);
                            cell.set_fg(Color::White);
                        });
                    }
                }
                if phrase.percussive {
                    notes_on.fill(false);
                }
            }
        }
    }
}
/// Colors of piano keys
const KEY_COLORS: [(Color, Color);6] = [
    (Color::Rgb(255, 255, 255), Color::Rgb(255, 255, 255)),
    (Color::Rgb(0, 0, 0),       Color::Rgb(255, 255, 255)),
    (Color::Rgb(0, 0, 0),       Color::Rgb(255, 255, 255)),
    (Color::Rgb(0, 0, 0),       Color::Rgb(255, 255, 255)),
    (Color::Rgb(255, 255, 255), Color::Rgb(0, 0, 0)),
    (Color::Rgb(255, 255, 255), Color::Rgb(0, 0, 0)),
];
pub(crate) fn keys_vert () -> Buffer {
    let area = [0, 0, 5, 64];
    let mut buffer = Buffer::empty(Rect {
        x: area.x(), y: area.y(), width: area.w(), height: area.h()
    });
    buffer_update(&mut buffer, area, &|cell, x, y| {
        let y = 63 - y;
        match x {
            0 => {
                cell.set_char('▀');
                let (fg, bg) = KEY_COLORS[((6 - y % 6) % 6) as usize];
                cell.set_fg(fg);
                cell.set_bg(bg);
            },
            1 => {
                cell.set_char('▀');
                cell.set_fg(Color::White);
                cell.set_bg(Color::White);
            },
            2 => if y % 6 == 0 { cell.set_char('C'); },
            3 => if y % 6 == 0 { cell.set_symbol(NTH_OCTAVE[(y / 6) as usize]); },
            _ => {}
        }
    });
    buffer
}
impl Content for PhraseLength<Tui> {
    type Engine = Tui;
    fn content (&self) -> impl Widget<Engine = Tui> {
        Layers::new(move|add|{
            match self.focus {
                None => add(&row!(
                    " ", self.bars_string(),
                    ".", self.beats_string(),
                    ".", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Bar) => add(&row!(
                    "[", self.bars_string(),
                    "]", self.beats_string(),
                    ".", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Beat) => add(&row!(
                    " ", self.bars_string(),
                    "[", self.beats_string(),
                    "]", self.ticks_string(),
                    " "
                )),
                Some(PhraseLengthFocus::Tick) => add(&row!(
                    " ", self.bars_string(),
                    ".", self.beats_string(),
                    "[", self.ticks_string(),
                    "]"
                )),
            }
        })
    }
}