metarepo-core 0.77.0

//! Help panel widget

use crate::tui::modes::Mode;
use ratatui::{
    buffer::Buffer,
    layout::Rect,
    style::{Color, Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Paragraph, Widget},
};

/// Help panel showing keybindings
pub struct HelpPanel {
    /// Current mode (affects which help to show)
    pub mode: Mode,
}

impl HelpPanel {
    pub fn new(mode: Mode) -> Self {
        Self { mode }
    }

    /// Get help text for the current mode
    fn get_help_lines(&self) -> Vec<Line<'_>> {
        let title = Line::from(vec![
            Span::styled("Keybindings", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" - Press "),
            Span::styled("?", Style::default().fg(Color::Cyan)),
            Span::raw(" to close"),
        ]);

        let mut lines = vec![title, Line::from("")];

        match self.mode {
            Mode::Normal => {
                lines.extend(vec![
                    Line::from(vec![Span::styled(
                        "Navigation:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  h/j/k/l or ←/↓/↑/→  Move cursor"),
                    Line::from("  g / G               Jump to top / bottom"),
                    Line::from("  Ctrl+u / Ctrl+d     Page up / down"),
                    Line::from(""),
                    Line::from(vec![Span::styled(
                        "Tree:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  Enter or o          Toggle expand/collapse"),
                    Line::from("  O                   Expand node"),
                    Line::from("  C                   Collapse node"),
                    Line::from(""),
                    Line::from(vec![Span::styled(
                        "Editing:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  i                   Enter insert mode"),
                    Line::from("  v                   Enter visual mode"),
                    Line::from("  d                   Delete node"),
                    Line::from("  x                   Delete character"),
                    Line::from(""),
                    Line::from(vec![Span::styled(
                        "Commands:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  :                   Enter command mode"),
                    Line::from("  Ctrl+w              Save"),
                    Line::from("  Ctrl+q              Quit"),
                    Line::from("  ?                   Show/hide help"),
                ]);
            }
            Mode::Insert => {
                lines.extend(vec![
                    Line::from(vec![Span::styled(
                        "Insert Mode:",
                        Style::default().fg(Color::Green),
                    )]),
                    Line::from("  Esc                 Return to normal mode"),
                    Line::from("  Typing              Insert text"),
                    Line::from("  Backspace           Delete previous char"),
                    Line::from("  Enter               New line / confirm"),
                    Line::from("  ←/→/↑/↓             Navigate"),
                ]);
            }
            Mode::Visual => {
                lines.extend(vec![
                    Line::from(vec![Span::styled(
                        "Visual Mode:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  Esc or v            Return to normal mode"),
                    Line::from("  j/k or ↓/↑          Extend selection"),
                    Line::from("  Ctrl+a              Select all"),
                    Line::from("  d or x              Delete selection"),
                ]);
            }
            Mode::Command => {
                lines.extend(vec![
                    Line::from(vec![Span::styled(
                        "Command Mode:",
                        Style::default().fg(Color::Magenta),
                    )]),
                    Line::from("  Esc                 Cancel command"),
                    Line::from("  Enter               Execute command"),
                    Line::from(""),
                    Line::from(vec![Span::styled(
                        "Commands:",
                        Style::default().fg(Color::Yellow),
                    )]),
                    Line::from("  :w or :write        Save changes"),
                    Line::from("  :q or :quit         Quit (fails if modified)"),
                    Line::from("  :q! or :quit!       Force quit (discard changes)"),
                    Line::from("  :wq or :x           Save and quit"),
                ]);
            }
        }

        lines
    }
}

impl Widget for HelpPanel {
    fn render(self, area: Rect, buf: &mut Buffer) {
        let lines = self.get_help_lines();

        let block = Block::default()
            .borders(Borders::ALL)
            .border_style(Style::default().fg(Color::Cyan))
            .title(" Help ");

        let paragraph = Paragraph::new(lines).block(block);

        Widget::render(paragraph, area, buf);
    }
}

/// A group of related keybindings shown under a heading in [`KeybindingHelp`].
pub struct HelpSection {
    /// Heading shown above the entries (e.g. "Navigation").
    pub heading: String,
    /// `(keys, description)` rows, e.g. `("j / ↓", "Move down")`.
    pub entries: Vec<(String, String)>,
}

impl HelpSection {
    pub fn new(heading: impl Into<String>, entries: Vec<(&str, &str)>) -> Self {
        Self {
            heading: heading.into(),
            entries: entries
                .into_iter()
                .map(|(k, d)| (k.to_string(), d.to_string()))
                .collect(),
        }
    }
}

/// A data-driven keybinding help overlay. Unlike [`HelpPanel`] (which is tied to
/// the modal `Mode` enum), this renders whatever sections the caller supplies,
/// so each TUI surface can show its own real keymap. Meant to be drawn over the
/// UI in a centered popup (clear the area first).
pub struct KeybindingHelp {
    title: String,
    sections: Vec<HelpSection>,
}

impl KeybindingHelp {
    pub fn new(title: impl Into<String>, sections: Vec<HelpSection>) -> Self {
        Self {
            title: title.into(),
            sections,
        }
    }
}

impl Widget for KeybindingHelp {
    fn render(self, area: Rect, buf: &mut Buffer) {
        // Widest key column across all sections, for aligned descriptions.
        let key_width = self
            .sections
            .iter()
            .flat_map(|s| s.entries.iter())
            .map(|(k, _)| k.chars().count())
            .max()
            .unwrap_or(0);

        let mut lines: Vec<Line> = vec![
            Line::from(vec![
                Span::raw("Press "),
                Span::styled("?", Style::default().fg(Color::Cyan)),
                Span::raw(" or "),
                Span::styled("Esc", Style::default().fg(Color::Cyan)),
                Span::raw(" to close"),
            ]),
            Line::from(""),
        ];

        for (i, section) in self.sections.iter().enumerate() {
            if i > 0 {
                lines.push(Line::from(""));
            }
            lines.push(Line::from(Span::styled(
                section.heading.clone(),
                Style::default()
                    .fg(Color::Yellow)
                    .add_modifier(Modifier::BOLD),
            )));
            for (keys, desc) in &section.entries {
                let pad = " ".repeat(key_width.saturating_sub(keys.chars().count()));
                lines.push(Line::from(vec![
                    Span::raw("  "),
                    Span::styled(keys.clone(), Style::default().fg(Color::Cyan)),
                    Span::raw(format!("{pad}   ")),
                    Span::raw(desc.clone()),
                ]));
            }
        }

        let block = Block::default()
            .borders(Borders::ALL)
            .border_style(Style::default().fg(Color::Cyan))
            .title(format!(" {} ", self.title));

        Widget::render(Paragraph::new(lines).block(block), area, buf);
    }
}