//! Help modal / command palette.

use crate::{core::*, view::*};

/// Command palette.
pub struct HelpModal {
    cursor: usize,
    search: Option<String>,
    exited: bool,
}
impl HelpModal {
    pub fn new () -> Self {
        Self { cursor: 0, search: None, exited: false }
    }
}
impl Exit for HelpModal {
    fn exited (&self) -> bool {
        self.exited
    }
    fn exit (&mut self) {
        self.exited = true;
    }
}

render!(HelpModal |self, buf, area|{
    for cell in buf.content.iter_mut() {
        cell.bg = ratatui::style::Color::Rgb(30,30,30);
        cell.fg = ratatui::style::Color::Rgb(100,100,100);
        cell.modifier = ratatui::style::Modifier::DIM;
    }
    let width  = 64.min(area.width * 3 / 5);
    let height = 20.min(area.width * 3 / 5);
    let x = area.x + (area.width  - width)  / 2;
    let y = area.y + (area.height - height) / 2;
    let area = Rect { x, y, width, height };
    fill_fg(buf, area, Color::Reset);
    fill_bg(buf, area, Nord::bg_lo(true, true));
    fill_char(buf, area, ' ');
    let x = area.x + 2;
    let y = area.y + 1;
    "Command:"
        .blit(buf, x,     y, Some(Style::default().bold()))?;
    " ".repeat(area.width as usize - 13)
        .blit(buf, x + 9, y, Some(Style::default().bg(Color::Reset)))?;
    if let Some(search) = self.search.as_ref() {
        search.blit(buf, x + 9, y, Some(Style::default().not_dim()))?;
    }
    let y = y + 1;
    fill_char(buf, Rect { y, height: 1, ..area }, '-');
    let y = y + 1;
    for i in 0..height-3 {
        let y = y + i;
        if let Some(command) = crate::control::KEYMAP_FOCUS.get(i as usize) {
            format!("{:?}", command.0).blit(buf, x, y, Some(Style::default().white().bold()))?;
            command.2.blit(buf, x + 11, y, Some(Style::default().white().bold()))?;
            command.3.blit(buf, x + 26, y, Some(Style::default().white().dim()))?;
        } else if let Some(command) = crate::control::KEYMAP_GLOBAL.get((i as usize) - crate::control::KEYMAP_FOCUS.len()) {
            format!("{:?}", command.0).blit(buf, x, y, Some(Style::default().white().bold()))?;
            command.2.blit(buf, x + 11, y, Some(Style::default().white().bold()))?;
            command.3.blit(buf, x + 26, y, Some(Style::default().white().dim()))?;
        } else {
            break
        }
    }
    let hi_area = Rect { x: area.x + 1, width: area.width - 2, y: area.y + 3 + self.cursor as u16, height: 1 };
    fill_bg(buf, hi_area, Nord::bg_hi(true, true));
    fill_fg(buf, hi_area, Color::White);
    Lozenge(Style::default()).draw(buf, area)
});

handle!(HelpModal |self, e| {
    if handle_keymap(self, e, KEYMAP_HELP)? {
        return Ok(true)
    }
    Ok(match e {
        AppEvent::Input(Event::Key(KeyEvent {
            code:      KeyCode::Char(c),
            modifiers: KeyModifiers::NONE, ..
        })) => {
            if self.search.is_none() {
                self.search = Some(String::new());
            }
            self.search.as_mut().unwrap().push(*c);
            true
        },
        _ => true
    })
});

pub const KEYMAP_HELP: &'static [KeyBinding<HelpModal>] = keymap!(HelpModal {
    [Esc,  NONE, "help_close", "close help dialog",       |modal: &mut HelpModal|{
        modal.exit();
        Ok(true)
    }],
    [Up,   NONE, "help_prev",  "select previous command", |modal: &mut HelpModal|{
        modal.cursor = modal.cursor.saturating_sub(1);
        Ok(true)
    }],
    [Down, NONE, "help_next",  "select next command",     |modal: &mut HelpModal|{
        modal.cursor = modal.cursor + 1;
        Ok(true)
    }],
});