Files
Cagire/src/views/help_view.rs
2026-01-27 15:23:04 +01:00

245 lines
8.0 KiB
Rust

use minimad::{Composite, CompositeStyle, Compound, Line};
use ratatui::layout::{Constraint, Layout, Rect};
use ratatui::style::{Color, Modifier, Style};
use ratatui::text::{Line as RLine, Span};
use ratatui::widgets::{Block, Borders, List, ListItem, Padding, Paragraph, Wrap};
use ratatui::Frame;
use crate::app::App;
use crate::views::highlight;
// To add a new help topic: drop a .md file in docs/ and add one line here.
const DOCS: &[(&str, &str)] = &[
("Welcome", include_str!("../../docs/welcome.md")),
("Keybindings", include_str!("../../docs/keybindings.md")),
("Sequencer", include_str!("../../docs/sequencer.md")),
];
pub fn topic_count() -> usize {
DOCS.len()
}
pub fn render(frame: &mut Frame, app: &App, area: Rect) {
let [topics_area, content_area] =
Layout::horizontal([Constraint::Length(18), Constraint::Fill(1)]).areas(area);
render_topics(frame, app, topics_area);
render_content(frame, app, content_area);
}
fn render_topics(frame: &mut Frame, app: &App, area: Rect) {
let items: Vec<ListItem> = DOCS
.iter()
.enumerate()
.map(|(i, (name, _))| {
let selected = i == app.ui.help_topic;
let style = if selected {
Style::new().fg(Color::Cyan).add_modifier(Modifier::BOLD)
} else {
Style::new().fg(Color::White)
};
let prefix = if selected { "> " } else { " " };
ListItem::new(format!("{prefix}{name}")).style(style)
})
.collect();
let list = List::new(items).block(Block::default().borders(Borders::ALL).title("Topics"));
frame.render_widget(list, area);
}
fn render_content(frame: &mut Frame, app: &App, area: Rect) {
let (name, md) = DOCS[app.ui.help_topic];
let query = &app.ui.help_search_query;
let has_query = !query.is_empty();
let query_lower = query.to_lowercase();
let lines = parse_markdown(md);
let has_search_bar = app.ui.help_search_active || has_query;
let search_bar_height: u16 = u16::from(has_search_bar);
let visible_height = area.height.saturating_sub(6 + search_bar_height) as usize;
let max_scroll = lines.len().saturating_sub(visible_height);
let scroll = app.ui.help_scroll().min(max_scroll);
let visible: Vec<RLine> = lines
.into_iter()
.skip(scroll)
.take(visible_height)
.map(|line| {
if has_query {
highlight_line(line, &query_lower)
} else {
line
}
})
.collect();
let content_area = if has_search_bar {
let [content, search] =
Layout::vertical([Constraint::Fill(1), Constraint::Length(1)]).areas(area);
render_search_bar(frame, app, search);
content
} else {
area
};
let para = Paragraph::new(visible)
.block(
Block::default()
.borders(Borders::ALL)
.title(name)
.padding(Padding::new(2, 2, 2, 2)),
)
.wrap(Wrap { trim: false });
frame.render_widget(para, content_area);
}
fn render_search_bar(frame: &mut Frame, app: &App, area: Rect) {
let style = if app.ui.help_search_active {
Style::new().fg(Color::Yellow)
} else {
Style::new().fg(Color::DarkGray)
};
let cursor = if app.ui.help_search_active { "" } else { "" };
let text = format!(" /{}{cursor}", app.ui.help_search_query);
frame.render_widget(Paragraph::new(text).style(style), area);
}
fn highlight_line<'a>(line: RLine<'a>, query: &str) -> RLine<'a> {
let mut result: Vec<Span<'a>> = Vec::new();
for span in line.spans {
let lower = span.content.to_lowercase();
if !lower.contains(query) {
result.push(span);
continue;
}
let content = span.content.to_string();
let base_style = span.style;
let hl_style = base_style.bg(Color::Yellow).fg(Color::Black);
let mut start = 0;
let lower_bytes = lower.as_bytes();
let query_bytes = query.as_bytes();
while let Some(pos) = find_bytes(&lower_bytes[start..], query_bytes) {
let abs = start + pos;
if abs > start {
result.push(Span::styled(content[start..abs].to_string(), base_style));
}
result.push(Span::styled(
content[abs..abs + query.len()].to_string(),
hl_style,
));
start = abs + query.len();
}
if start < content.len() {
result.push(Span::styled(content[start..].to_string(), base_style));
}
}
RLine::from(result)
}
fn find_bytes(haystack: &[u8], needle: &[u8]) -> Option<usize> {
haystack.windows(needle.len()).position(|w| w == needle)
}
/// Find first line matching query across all topics. Returns (topic_index, line_index).
pub fn find_match(query: &str) -> Option<(usize, usize)> {
let query = query.to_lowercase();
for (topic_idx, (_, content)) in DOCS.iter().enumerate() {
for (line_idx, line) in content.lines().enumerate() {
if line.to_lowercase().contains(&query) {
return Some((topic_idx, line_idx));
}
}
}
None
}
fn code_border_style() -> Style {
Style::new().fg(Color::Rgb(60, 60, 70))
}
fn parse_markdown(md: &str) -> Vec<RLine<'static>> {
let text = minimad::Text::from(md);
let mut lines = Vec::new();
let mut code_line_nr: usize = 0;
for line in text.lines {
match line {
Line::Normal(composite) if composite.style == CompositeStyle::Code => {
code_line_nr += 1;
let raw: String = composite.compounds.iter().map(|c| &*c.src).collect();
let mut spans = vec![
Span::styled(format!(" {code_line_nr:>2} "), code_border_style()),
Span::styled("", code_border_style()),
];
spans.extend(
highlight::highlight_line(&raw)
.into_iter()
.map(|(style, text)| Span::styled(text, style)),
);
lines.push(RLine::from(spans));
}
Line::Normal(composite) => {
code_line_nr = 0;
lines.push(composite_to_line(composite));
}
_ => {
lines.push(RLine::from(""));
}
}
}
lines
}
fn composite_to_line(composite: Composite) -> RLine<'static> {
let base_style = match composite.style {
CompositeStyle::Header(1) => Style::new()
.fg(Color::Cyan)
.add_modifier(Modifier::BOLD | Modifier::UNDERLINED),
CompositeStyle::Header(2) => Style::new().fg(Color::Yellow).add_modifier(Modifier::BOLD),
CompositeStyle::Header(_) => Style::new().fg(Color::Magenta).add_modifier(Modifier::BOLD),
CompositeStyle::ListItem(_) => Style::new().fg(Color::White),
CompositeStyle::Quote => Style::new().fg(Color::Rgb(150, 150, 150)),
CompositeStyle::Code => Style::new().fg(Color::Green),
CompositeStyle::Paragraph => Style::new().fg(Color::White),
};
let prefix = match composite.style {
CompositeStyle::ListItem(_) => "",
CompositeStyle::Quote => "",
_ => "",
};
let mut spans: Vec<Span<'static>> = Vec::new();
if !prefix.is_empty() {
spans.push(Span::styled(prefix.to_string(), base_style));
}
for compound in composite.compounds {
spans.push(compound_to_span(compound, base_style));
}
RLine::from(spans)
}
fn compound_to_span(compound: Compound, base: Style) -> Span<'static> {
let mut style = base;
if compound.bold {
style = style.add_modifier(Modifier::BOLD);
}
if compound.italic {
style = style.add_modifier(Modifier::ITALIC);
}
if compound.code {
style = Style::new().fg(Color::Green);
}
if compound.strikeout {
style = style.add_modifier(Modifier::CROSSED_OUT);
}
Span::styled(compound.src.to_string(), style)
}