Ask about the chat's own folder when deleting a chat

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/src/api.rs

@@ -86,6 +86,7 @@ pub fn router(app: AppState) -> Router {
         .route("/sessions/{id}/search", get(search_in_session))
         .route("/sessions/{id}/media", get(session_media))
         .route("/sessions/{id}", get(get_session).patch(update_session).delete(delete_session))
+        .route("/sessions/{id}/folder", get(session_folder))
         .route("/sessions/{id}/prompt", post(prompt))
         .route("/sessions/{id}/abort", post(abort))
         .route("/sessions/{id}/compact", post(compact))
@@ -1056,8 +1057,83 @@ async fn put_file_tabs(Extension(user): Extension<User>, State(app): State<AppSt
     Ok(Json(json!({"ok": true})))
 }
 
-async fn delete_session(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>) -> ApiResult {
-    writable(&app, &user, &id)?;
+/// The folder a chat owns: inside the owner's folders (never one of them), not a link, and no
+/// other chat works in it, below it or above it (then it belongs to a project, not to this chat).
+/// Returns the folder and the titles of chats that prevent it.
+fn own_folder(app: &App, session: &Session) -> (Option<PathBuf>, Vec<String>) {
+    let Ok(dir) = std::fs::canonicalize(&session.cwd) else { return (None, vec![]) };
+    if std::fs::symlink_metadata(&session.cwd).map(|m| m.file_type().is_symlink()).unwrap_or(true) || !dir.is_dir() {
+        return (None, vec![]);
+    }
+    let roots: Vec<PathBuf> = app.user_roots(session.owner_id.as_deref()).iter().filter_map(|r| std::fs::canonicalize(r).ok()).collect();
+    if !roots.iter().any(|r| dir.starts_with(r) && dir != *r) {
+        return (None, vec![]);
+    }
+    let mut blockers = Vec::new();
+    for (title, cwd) in app.store.other_session_cwds(&session.id).unwrap_or_default() {
+        let Ok(other) = std::fs::canonicalize(&cwd) else { continue };
+        if other.starts_with(&dir) || dir.starts_with(&other) {
+            blockers.push(if title.is_empty() { "(untitled)".to_string() } else { title });
+        }
+    }
+    if blockers.is_empty() { (Some(dir), blockers) } else { (None, blockers) }
+}
+
+/// Facts for the delete dialog: does the chat have a folder of its own, and what is in it?
+async fn session_folder(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>) -> ApiResult {
+    let session = writable(&app, &user, &id)?;
+    let (dir, blockers) = own_folder(&app, &session);
+    let Some(dir) = dir else { return Ok(Json(json!({"own": false, "shared_with": blockers}))) };
+    let (files, bytes, git, truncated) = tokio::task::spawn_blocking({
+        let dir = dir.clone();
+        move || {
+            let (mut files, mut bytes, mut seen) = (0u64, 0u64, 0u64);
+            let mut stack = vec![dir.clone()];
+            let mut truncated = false;
+            while let Some(d) = stack.pop() {
+                let Ok(rd) = std::fs::read_dir(&d) else { continue };
+                for e in rd.flatten() {
+                    // Git's own files are not "the chat's files".
+                    if e.file_name() == ".git" {
+                        continue;
+                    }
+                    seen += 1;
+                    if seen > 50_000 {
+                        truncated = true;
+                        stack.clear();
+                        break;
+                    }
+                    let Ok(m) = e.metadata() else { continue };
+                    if m.is_dir() && !e.file_type().map(|t| t.is_symlink()).unwrap_or(true) {
+                        stack.push(e.path());
+                    } else if m.is_file() {
+                        files += 1;
+                        bytes += m.len();
+                    }
+                }
+            }
+            (files, bytes, dir.join(".git").exists(), truncated)
+        }
+    })
+    .await
+    .unwrap_or((0, 0, false, false));
+    Ok(Json(json!({"own": true, "path": dir, "files": files, "bytes": bytes, "git": git, "truncated": truncated})))
+}
+
+#[derive(Deserialize)]
+struct DeleteQ {
+    /// Also delete the chat's own folder (only if it really is one – checked again here).
+    #[serde(default)]
+    delete_folder: bool,
+}
+
+async fn delete_session(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>, Query(q): Query<DeleteQ>) -> ApiResult {
+    let session = writable(&app, &user, &id)?;
+    // Decide about the folder while the chat and all the others still exist.
+    let folder = if q.delete_folder { own_folder(&app, &session).0 } else { None };
+    if q.delete_folder && folder.is_none() {
+        return Err(ApiError(StatusCode::CONFLICT, "this chat has no folder of its own (other chats use it, or it is a project folder)".into()));
+    }
     // Notify before deleting: visibility is checked against the stored session.
     app.emit(Event::SessionDeleted { session_id: id.clone() });
     runner::abort(&app, &id);
@@ -1071,7 +1147,20 @@ async fn delete_session(Extension(user): Extension<User>, State(app): State<AppS
             tracing::warn!("image cleanup: {e:#}");
         }
     });
-    Ok(Json(json!({"ok": true})))
+    let mut folder_error = None;
+    let mut folder_deleted = false;
+    if let Some(dir) = folder {
+        let shown = dir.display().to_string();
+        match tokio::task::spawn_blocking(move || std::fs::remove_dir_all(&dir)).await {
+            Ok(Ok(())) => {
+                folder_deleted = true;
+                app.audit(Some(&user), "session.delete_folder", &shown, "");
+            }
+            Ok(Err(e)) => folder_error = Some(format!("the chat was deleted, but not its folder: {e}")),
+            Err(e) => folder_error = Some(format!("the chat was deleted, but not its folder: {e}")),
+        }
+    }
+    Ok(Json(json!({"ok": true, "folder_deleted": folder_deleted, "folder_error": folder_error})))
 }
 
 /// An image of a chat message (see blobs.rs). Addressed by the SHA-256 of its bytes,

server/src/store.rs

@@ -409,6 +409,16 @@ impl Store {
         Ok(())
     }
 
+    /// (title, cwd) of all other chats (subagent sessions of this chat excluded).
+    pub fn other_session_cwds(&self, id: &str) -> Result<Vec<(String, String)>> {
+        let conn = self.conn.lock().unwrap();
+        let mut stmt = conn.prepare(
+            "SELECT COALESCE(json_extract(data, '$.title'), ''), COALESCE(json_extract(data, '$.cwd'), '') FROM sessions WHERE id != ?1 AND COALESCE(parent_id, '') != ?1",
+        )?;
+        let rows = stmt.query_map([id], |r| Ok((r.get(0)?, r.get(1)?)))?;
+        Ok(rows.collect::<std::result::Result<_, _>>()?)
+    }
+
     pub fn add_message(&self, session_id: &str, m: &Message) -> Result<()> {
         // Images go to the blob table (encoded before taking the lock).
         let mut m = m.clone();