Format TUI commit activity previews

crates/tui/src/app.rs

@@ -1163,12 +1163,7 @@ impl App {
                     .as_ref()
                     .and_then(|repo| repo.full_name.as_deref())
                     .unwrap_or("repository");
-                let detail = activity
-                    .comment
-                    .as_ref()
-                    .and_then(|comment| comment.body.clone())
-                    .or(activity.content.clone())
-                    .unwrap_or_else(|| "Server activity".into());
+                let detail = activity_detail(&activity);
                 let target = match gotcha_gitea::activity::target(&activity) {
                     Some(gotcha_gitea::activity::Target::Repository { owner, repository }) => {
                         Target::Repository(
@@ -1869,6 +1864,49 @@ fn short_sha(sha: &str) -> &str {
     sha.get(..8).unwrap_or(sha)
 }
 
+fn activity_detail(activity: &models::Activity) -> String {
+    if let Some(body) = activity
+        .comment
+        .as_ref()
+        .and_then(|comment| comment.body.as_deref())
+    {
+        return body.to_string();
+    }
+    if let Some(payload) = gotcha_gitea::activity::commit_activity(activity) {
+        let noun = if payload.count == 1 {
+            "commit"
+        } else {
+            "commits"
+        };
+        let mut detail = format!("**{} {noun}**", payload.count);
+        for commit in payload.commits {
+            let message = commit.message.lines().next().unwrap_or("Commit");
+            detail.push_str("\n\n- ");
+            if !commit.sha.is_empty() {
+                detail.push('`');
+                detail.push_str(short_sha(&commit.sha));
+                detail.push_str("` ");
+            }
+            detail.push_str(message);
+            let metadata = [commit.author.as_str(), commit.timestamp.as_str()]
+                .into_iter()
+                .filter(|value| !value.is_empty())
+                .collect::<Vec<_>>()
+                .join(" · ");
+            if !metadata.is_empty() {
+                detail.push_str("  \n  ");
+                detail.push_str(&metadata);
+            }
+        }
+        return detail;
+    }
+    activity
+        .content
+        .clone()
+        .filter(|content| !content.is_empty())
+        .unwrap_or_else(|| "Server activity".into())
+}
+
 fn err(error: gotcha_gitea::Error) -> String {
     error.to_string()
 }
@@ -1950,4 +1988,23 @@ mod tests {
         assert_eq!(app.history.len(), 1);
         assert!(app.confirm.is_some());
     }
+
+    #[test]
+    fn commit_activity_preview_formats_the_payload() {
+        let activity = models::Activity {
+            content: Some(
+                r#"{"Commits":[{"Sha1":"0123456789abcdef","Message":"Fix preview\n\nDetails","AuthorName":"Octo Cat","Timestamp":"2026-08-04T19:04:30+02:00"}],"Len":1}"#
+                    .into(),
+            ),
+            ..Default::default()
+        };
+
+        let detail = activity_detail(&activity);
+
+        assert_eq!(
+            detail,
+            "**1 commit**\n\n- `01234567` Fix preview  \n  Octo Cat · 2026-08-04T19:04:30+02:00"
+        );
+        assert!(!detail.contains("\"Commits\""));
+    }
 }