fix: ensure correct key bindings are shown in legend

src/config.rs

@@ -54,6 +54,39 @@ impl KeyBinding {
 
         key.modifiers.contains(KeyModifiers::SHIFT) == self.modifiers.contains(KeyModifiers::SHIFT)
     }
+
+    fn label(&self) -> String {
+        let mut parts = Vec::new();
+        if self.modifiers.contains(KeyModifiers::CONTROL) {
+            parts.push("ctrl".to_string());
+        }
+        if self.modifiers.contains(KeyModifiers::ALT) {
+            parts.push("alt".to_string());
+        }
+        if self.modifiers.contains(KeyModifiers::SHIFT)
+            && !matches!(self.code, KeyCode::Char(ch) if ch.is_ascii_uppercase())
+        {
+            parts.push("shift".to_string());
+        }
+
+        parts.push(match self.code {
+            KeyCode::Backspace => "backspace".to_string(),
+            KeyCode::Enter => "enter".to_string(),
+            KeyCode::Left => "left".to_string(),
+            KeyCode::Right => "right".to_string(),
+            KeyCode::Up => "up".to_string(),
+            KeyCode::Down => "down".to_string(),
+            KeyCode::Home => "home".to_string(),
+            KeyCode::End => "end".to_string(),
+            KeyCode::PageUp => "pageup".to_string(),
+            KeyCode::PageDown => "pagedown".to_string(),
+            KeyCode::Esc => "esc".to_string(),
+            KeyCode::Char(ch) => ch.to_string(),
+            _ => "?".to_string(),
+        });
+
+        parts.join("-")
+    }
 }
 
 #[derive(Clone, Debug)]
@@ -127,6 +160,14 @@ impl KeyBindings {
                 .is_some_and(|bindings| bindings.iter().any(|binding| binding.matches(key)))
         })
     }
+
+    pub(crate) fn primary_label_for_action(&self, action: Action) -> String {
+        self.bindings_by_action
+            .get(&action)
+            .and_then(|bindings| bindings.first())
+            .map(KeyBinding::label)
+            .unwrap_or_else(|| "?".to_string())
+    }
 }
 
 const ACTION_ORDER: &[Action] = &[
@@ -388,4 +429,24 @@ mod tests {
             Some(Action::PageDown)
         );
     }
+
+    #[test]
+    fn primary_label_uses_configured_binding() {
+        let mut bindings = KeyBindings::default();
+        apply_config(
+            &mut bindings,
+            r#"
+            [keybindings]
+            page_down = "J"
+            previous_file = "alt-left"
+            "#,
+        )
+        .expect("config should parse");
+
+        assert_eq!(bindings.primary_label_for_action(Action::PageDown), "J");
+        assert_eq!(
+            bindings.primary_label_for_action(Action::PreviousFile),
+            "alt-left"
+        );
+    }
 }

src/render.rs

@@ -12,6 +12,7 @@ use syntect::{
 };
 
 use crate::{
+    config::{Action, KeyBindings},
     model::{
         DiffFileView, LineHighlightKind, PaneOffsets, PaneSide, ResolvedComparison, ThemeMode,
     },
@@ -139,6 +140,29 @@ fn syntax_for_language(language: &str) -> Option<&'static SyntaxReference> {
         .or_else(|| syntaxes.find_syntax_by_extension(language))
 }
 
+fn action_pair_label(keybindings: &KeyBindings, left: Action, right: Action) -> String {
+    format!(
+        "{}/{}",
+        keybindings.primary_label_for_action(left),
+        keybindings.primary_label_for_action(right)
+    )
+}
+
+fn key_legend(keybindings: &KeyBindings) -> String {
+    format!(
+        "{}: file  {}: scroll  {}: page  {}: top/bottom  {}: search  {}: match  {}: hunk  {}: reviewed  {}: quit",
+        action_pair_label(keybindings, Action::PreviousFile, Action::NextFile),
+        action_pair_label(keybindings, Action::ScrollDown, Action::ScrollUp),
+        action_pair_label(keybindings, Action::PageUp, Action::PageDown),
+        action_pair_label(keybindings, Action::Top, Action::Bottom),
+        keybindings.primary_label_for_action(Action::Search),
+        action_pair_label(keybindings, Action::NextMatch, Action::PreviousMatch),
+        action_pair_label(keybindings, Action::NextHunk, Action::PreviousHunk),
+        keybindings.primary_label_for_action(Action::ToggleReviewed),
+        keybindings.primary_label_for_action(Action::Quit),
+    )
+}
+
 fn base_style(tint_background: Option<Color>) -> Style {
     let mut style = Style::default();
     if let Some(color) = tint_background {
@@ -336,6 +360,7 @@ pub(crate) fn get_pane_for_column(column: usize, layout: &FrameLayout) -> Option
 pub(crate) fn render_frame(
     files: &[DiffFileView],
     comparison: &ResolvedComparison,
+    keybindings: &KeyBindings,
     file_index: usize,
     scroll_offset: usize,
     pane_offsets: PaneOffsets,
@@ -488,7 +513,7 @@ pub(crate) fn render_frame(
         layout.columns,
     )));
     lines.push(Line::from(fit_line(
-        "h/l: file  j/k: scroll  ctrl-u/d: page  g/G: top/bottom  /: search  n/N: match  }/{: hunk  r: reviewed  q: quit",
+        &key_legend(keybindings),
         layout.columns,
     )));
     lines.push(Line::from(fit_line(

src/terminal.rs

@@ -26,12 +26,14 @@ fn draw_app<B: Backend>(
     terminal: &mut Terminal<B>,
     files: &[DiffFileView],
     comparison: &ResolvedComparison,
+    keybindings: &KeyBindings,
     app: &mut AppState,
 ) -> Result<()> {
     let size = terminal.size()?;
     let render_output = render_frame(
         files,
         comparison,
+        keybindings,
         app.file_index,
         app.scroll_offset,
         app.current_offsets(),
@@ -65,7 +67,7 @@ fn run_event_loop<B: Backend>(
 ) -> Result<()> {
     let initial_reviewed = review_store.reviewed_flags_for_files(files);
     let mut app = AppState::new(files.len(), initial_reviewed);
-    draw_app(terminal, files, comparison, &mut app)?;
+    draw_app(terminal, files, comparison, keybindings, &mut app)?;
 
     loop {
         match event::read().context("failed to read terminal event")? {
@@ -96,7 +98,7 @@ fn run_event_loop<B: Backend>(
             Event::FocusGained | Event::FocusLost | Event::Paste(_) => {}
         }
 
-        draw_app(terminal, files, comparison, &mut app)?;
+        draw_app(terminal, files, comparison, keybindings, &mut app)?;
     }
 
     Ok(())