use crate::core::*;
use super::*;

pub fn draw (
    s: &Sequencer,
    buf: &mut Buffer,
    mut area: Rect,
) -> Usually<Rect> {
    area.x = area.x + 13;
    let Rect { x, y, width, height } = area;
    keys(buf, area, s.note_start)?;
    timer(buf, x+6, y-1, s.time_start, s.time_start + area.width as usize, 0);
    if let Some(phrase) = s.phrase() {
        lanes(buf, x, y,
            phrase,
            s.timebase.ppq() as usize,
            s.time_zoom,
            s.time_start,
            s.time_start + area.width as usize,
            s.note_start,
            s.note_start + area.height as usize,
        );
    }
    cursor(
        buf,
        x,
        y,
        Style::default().green().not_dim(),
        s.time_cursor,
        s.note_cursor
    );
    footer(s, buf, x, y, width, height);
    Ok(Rect { x: x - 13, y, width, height })
}

pub fn timer (
    buf:   &mut Buffer,
    x:     u16,
    y:     u16,
    time0: usize,
    time1: usize,
    now:   usize
) {
    for step in time0..time1 {
        buf.set_string(x + step as u16, y, &"-", if step == now {
            Style::default().yellow().bold().not_dim()
        } else {
            Style::default()
        });
    }
}

pub fn keys (
    buf: &mut Buffer, area: Rect, note_start: usize
) -> Usually<Rect> {
    let bw = Style::default().dim();
    let Rect { x, y, width, height } = area;
    let h = height.saturating_sub(2);
    for i in 0..h {
        let y = y + i;
        let key = KEYS_VERTICAL[(i % 6) as usize];
        key.blit(buf, x + 1, y, Some(bw));
        "█".blit(buf, x + 2, y, Some(bw));
        "·".repeat(width.saturating_sub(6) as usize).blit(buf, x + 5, y, Some(bw.black()));
        //buf.set_string(x + 3, y, &format!("{i}"), Style::default());
        if i % 6 == 0 {
            let octave = format!("C{}", ((note_start - i as usize) / 6) as i8 - 4);
            buf.set_string(x + 3, y, &octave, Style::default());
        }
    }
    Ok(area)
}

pub fn lanes (
    buf:       &mut Buffer,
    x:         u16,
    y:         u16,
    phrase:    &Phrase,
    ppq:       usize,
    time_zoom: usize,
    time0:     usize,
    time1:     usize,
    note0:     usize,
    note1:     usize,
) {
    let bg = Style::default();
    let (bw, wh) = (bg.dim(), bg.white());
    for step in time0..time1 {
        let x = x as usize + 5 + step;
        let (a, b) = ((step + 0) * ppq / time_zoom, (step + 1) * ppq / time_zoom,);
        if step % 4 == 0 {
            "|".blit(buf, x as u16, y - 1, Some(Style::default().dim()));
        }
        if step % (time_zoom * 4) == 0 {
            format!("{}", step / time_zoom / 4 + 1)
                .blit(buf, x as u16, y - 1, Some(Style::default().bold().not_dim()));
        }
        let h = ((note1-note0)/2).saturating_sub(y as usize);
        for k in 0..h {
            let (character, style) = match (
                contains_note_on(phrase, u7::from_int_lossy((note0 + k * 2 + 0) as u8), a, b),
                contains_note_on(phrase, u7::from_int_lossy((note0 + k * 2 + 1) as u8), a, b),
            ) {
              (true, true)   => ("█", wh),
              (true, false)  => ("▀", wh),
              (false, true)  => ("▄", wh),
              (false, false) => ("·", bw),
            };
            let y = y as usize + k;
            character.blit(buf, x as u16, y as u16, Some(style));
        }
    }
}

pub fn cursor (buf: &mut Buffer, x: u16, y: u16, style: Style, time: usize, note: usize) {
    let x = x + 5 + time as u16;
    let y = y + note as u16 / 2;
    let c = if note % 2 == 0 { "▀" } else { "▄" };
    c.blit(buf, x, y, Some(style));
}

pub fn footer (s: &Sequencer, buf: &mut Buffer, mut x: u16, y: u16, width: u16, height: u16) {
    buf.set_string(x, y + height, format!("├{}┤", "-".repeat((width - 2).into())),
        Style::default().dim());
    buf.set_string(x, y + height + 2, format!("├{}┤", "-".repeat((width - 2).into())),
        Style::default().dim());
    x = x + 2;
    {
        for (_, [letter, title, value]) in [
            ["S", &format!("ync"),  &format!("<4/4>")],
            ["Q", &format!("uant"), &format!("<1/{}>", 4 * s.time_zoom)],
            ["N", &format!("ote"),  &format!("{} ({}-{})",
                s.note_start + s.note_cursor,
                s.note_start,
                "X")],
            ["T", &format!("ime"),  &format!("{} ({}-{})",
                s.time_start + s.time_cursor + 1,
                s.time_start + 1,
                "X")],
        ].iter().enumerate() {
            buf.set_string(x, y + height + 1, letter, Style::default().bold().yellow().dim());
            x = x + 1;
            buf.set_string(x, y + height + 1, &title, Style::default().bold().dim());
            x = x + title.len() as u16 + 1;
            buf.set_string(x, y + height + 1, &value, Style::default().not_dim());
            x = x + value.len() as u16;
            buf.set_string(x, y + height + 1, "  ", Style::default().dim());
            x = x + 2;
        }
    }
}