feat: browse GitHub GitLab and Gitea pull requests

src/tui.rs

@@ -2594,6 +2594,7 @@ fn draw_diff(
         return;
     }
     if diff.phase != Phase::View {
+        let pull_requests = diff.pull_request_remote.is_some();
         let panel = floating_panel(area);
         frame.render_widget(Clear, panel);
         let stage = if diff.phase == Phase::Before {
@@ -2601,12 +2602,18 @@ fn draw_diff(
         } else {
             "After"
         };
-        let title = format!(" Diff · Choose {stage} · {} ", diff.comparison_mode.label());
+        let title = if pull_requests {
+            " Pull requests ".into()
+        } else {
+            format!(" Diff · Choose {stage} · {} ", diff.comparison_mode.label())
+        };
         let content = diff_panel(frame, panel, &title, "", "", true);
         let notice = diff.error.as_deref().or_else(|| {
             if diff.loading {
                 Some(if diff.after.is_some() {
                     "Loading comparison…"
+                } else if pull_requests {
+                    "Loading pull requests…"
                 } else {
                     "Loading repository…"
                 })
@@ -2629,7 +2636,7 @@ fn draw_diff(
             Constraint::Length(u16::from(content.height >= 4)),
             Constraint::Length(1),
             Constraint::Length(u16::from(notice.is_some() && content.height >= 3)),
-            Constraint::Length(u16::from(content.height >= 2)),
+            Constraint::Length(u16::from(!pull_requests && content.height >= 2)),
             Constraint::Fill(1),
             Constraint::Length(u16::from(content.height >= 7)),
         ])
@@ -2638,17 +2645,18 @@ fn draw_diff(
             .before
             .as_ref()
             .map_or("not selected", |revision| revision.label.as_str());
-        frame.render_widget(
-            Paragraph::new(format!(
+        let stage_text = if pull_requests {
+            "Select a pull request to compare its branch changes".into()
+        } else {
+            format!(
                 "{} · Ctrl+b toggle · Before: {}",
                 diff.comparison_mode.label(),
                 display_text(before)
-            )),
-            stage_area,
-        );
-        if let Some(catalog) = &diff.catalog {
-            let tabs: Vec<Span> = catalog
-                .kind
+            )
+        };
+        frame.render_widget(Paragraph::new(stage_text), stage_area);
+        if pull_requests || diff.catalog.is_some() {
+            let tabs: Vec<Span> = diff
                 .categories()
                 .iter()
                 .enumerate()
@@ -2696,7 +2704,7 @@ fn draw_diff(
             );
         }
         let mut entries = diff.entries();
-        if let Some(working) = entries.next() {
+        if !pull_requests && let Some(working) = entries.next() {
             let label = format!(
                 "{} {} · pinned",
                 if diff.selected == 0 { ">" } else { " " },
@@ -2721,6 +2729,7 @@ fn draw_diff(
             1
         };
         let count = usize::from(results.height) / row_height;
+        let pinned = usize::from(!pull_requests);
         let mut key = std::collections::hash_map::DefaultHasher::new();
         (
             diff.phase as u8,
@@ -2735,17 +2744,16 @@ fn draw_diff(
         let first = PickerViewport::follow(
             &mut panels.picker_scroll.revisions,
             key.finish(),
-            diff.selected.saturating_sub(1),
+            diff.selected.saturating_sub(pinned),
             usize::from(results.height),
             row_height,
             panels.picker_scroll.distance,
-        )
-        .saturating_add(1);
+        );
         let mut lines = Vec::with_capacity(count * row_height);
         for (index, revision) in entries
             .enumerate()
-            .map(|(index, revision)| (index + 1, revision))
-            .skip(first - 1)
+            .skip(first)
+            .map(|(index, revision)| (index + pinned, revision))
             .take(count)
         {
             let style = if index == diff.selected {
@@ -2783,13 +2791,23 @@ fn draw_diff(
             }
         }
         if lines.is_empty() && !diff.loading {
-            frame.render_widget(Paragraph::new("No matching revisions"), results);
+            let empty = if pull_requests {
+                "No matching pull requests"
+            } else {
+                "No matching revisions"
+            };
+            frame.render_widget(Paragraph::new(empty), results);
         } else {
             frame.render_widget(Paragraph::new(lines), results);
         }
+        let accept = if diff.error.is_some() {
+            "retry"
+        } else {
+            "select"
+        };
         frame.render_widget(
             Paragraph::new(format!(
-                "{navigation_hint} · Tab categories · type search · Enter select · Esc close · Ctrl+p actions"
+                "{navigation_hint} · Tab categories · type search · Enter {accept} · Esc close · Ctrl+p actions"
             ))
             .style(Style::default().fg(Color::DarkGray)),
             help,
@@ -6719,6 +6737,63 @@ mod tests {
         );
     }
 
+    #[test]
+    fn pull_request_picker_renders_all_rows_without_a_pinned_offset() {
+        use crate::diff::{Catalog, Category, RepoKind, Revision, RevisionTarget};
+        for (width, height) in [(100, 16), (44, 12)] {
+            let mut diff = DiffState::pull_requests("origin".into());
+            diff.take_request();
+            let mut terminal =
+                Terminal::new(ratatui::backend::TestBackend::new(width, height)).unwrap();
+            let mut panels = WheelPanels::default();
+            render_diff(&mut terminal, &diff, &mut panels);
+            assert!(screen_text(&terminal).contains("Loading pull requests"));
+            diff.apply_result(1, Err("offline".into()));
+            render_diff(&mut terminal, &diff, &mut panels);
+            assert!(screen_text(&terminal).contains("offline"));
+            diff.handle(Input::Enter);
+            diff.take_request();
+            diff.apply_result(
+                2,
+                Ok(crate::diff::Outcome::Catalog(Catalog {
+                    kind: RepoKind::Git,
+                    entries: (0..20)
+                        .map(|index| Revision {
+                            target: RevisionTarget::PullRequest {
+                                remote: "origin".into(),
+                                base_ref: "refs/heads/main".into(),
+                                base_sha: "base".into(),
+                                head_ref: format!("refs/pull/{index}/head"),
+                                head_sha: format!("head-{index}"),
+                            },
+                            label: format!("#{index:02} Pull request"),
+                            description: "open · main ← topic".into(),
+                            category: Category::Open,
+                        })
+                        .collect(),
+                    notice: None,
+                })),
+            );
+            render_diff(&mut terminal, &diff, &mut panels);
+            let text = screen_text(&terminal);
+            assert!(text.contains("Pull requests"));
+            assert!(text.contains("Open") && text.contains("Closed") && text.contains("All"));
+            assert!(text.contains("> #00 Pull request"));
+            assert!(!text.contains("pinned"));
+            diff.handle(Input::End);
+            render_diff(&mut terminal, &diff, &mut panels);
+            let text = screen_text(&terminal);
+            assert!(text.contains("> #19 Pull request"));
+            assert!(!text.contains("#00 Pull request"));
+            diff.handle(Input::Home);
+            render_diff(&mut terminal, &diff, &mut panels);
+            assert!(screen_text(&terminal).contains("> #00 Pull request"));
+            diff.handle(Input::Char('\t'));
+            render_diff(&mut terminal, &diff, &mut panels);
+            assert!(screen_text(&terminal).contains("No matching pull requests"));
+        }
+    }
+
     #[test]
     fn diff_excerpts_render_original_lines_and_expand_without_losing_changes() {
         let before: Vec<_> = (0..80)