WIP: menu

src/views/help_view.rs

@@ -0,0 +1,139 @@
+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, Paragraph};
+use ratatui::Frame;
+
+use crate::app::App;
+
+const STATIC_DOCS: &[(&str, &str)] = &[
+    ("Keybindings", include_str!("../../docs/keybindings.md")),
+    ("Sequencer", include_str!("../../docs/sequencer.md")),
+];
+
+const TOPICS: &[&str] = &["Keybindings", "Sequencer"];
+
+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);
+
+    let topic = TOPICS[app.ui.help_topic];
+    render_markdown_content(frame, app, content_area, topic);
+}
+
+fn render_topics(frame: &mut Frame, app: &App, area: Rect) {
+    let items: Vec<ListItem> = TOPICS
+        .iter()
+        .enumerate()
+        .map(|(i, name)| {
+            let style = if i == app.ui.help_topic {
+                Style::new().fg(Color::Cyan).add_modifier(Modifier::BOLD)
+            } else {
+                Style::new().fg(Color::White)
+            };
+            let prefix = if i == app.ui.help_topic { "> " } 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_markdown_content(frame: &mut Frame, app: &App, area: Rect, topic: &str) {
+    let md = STATIC_DOCS
+        .iter()
+        .find(|(name, _)| *name == topic)
+        .map(|(_, content)| *content)
+        .unwrap_or("");
+    let lines = parse_markdown(md);
+
+    let visible_height = area.height.saturating_sub(2) as usize;
+    let total_lines = lines.len();
+    let max_scroll = total_lines.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)
+        .collect();
+
+    let para = Paragraph::new(visible).block(Block::default().borders(Borders::ALL).title(topic));
+    frame.render_widget(para, area);
+}
+
+fn parse_markdown(md: &str) -> Vec<RLine<'static>> {
+    let text = minimad::Text::from(md);
+    let mut lines = Vec::new();
+
+    for line in text.lines {
+        match line {
+            Line::Normal(composite) => {
+                lines.push(composite_to_line(composite));
+            }
+            Line::TableRow(_) | Line::HorizontalRule | Line::CodeFence(_) | Line::TableRule(_) => {
+                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)
+}
+
+pub fn topic_count() -> usize {
+    TOPICS.len()
+}