complete local markdown resource lifecycle contract

rust/crates/mnote-web/src/routes/local_folder_source.rs

@@ -3175,6 +3175,96 @@ pub async fn open_local_file(
     Ok((StatusCode::OK, headers, bytes))
 }
 
+pub async fn stat_local_file(
+    State(state): State<AppState>,
+    Extension(context): Extension<RequestContext>,
+    Query(query): Query<LocalFileOpenQuery>,
+) -> Result<(StatusCode, HeaderMap, Json<Value>), WebError> {
+    ensure_local_workspace_read_access_with_state(&state, &context, &query.root_uri)
+        .map_err(|error| error.with_context(&context))?;
+    let root_path = parse_file_root_uri(&query.root_uri)?;
+    let canonical_root = root_path.canonicalize().map_err(|error| {
+        WebError::bad_request_code(
+            "local_folder_unavailable",
+            format!("无法访问本地文件夹: {error}"),
+        )
+        .with_context(&context)
+    })?;
+    let requested = Path::new(&query.path);
+    if requested.is_absolute()
+        || requested
+            .components()
+            .any(|component| matches!(component, std::path::Component::ParentDir))
+    {
+        return Err(WebError::bad_request_code(
+            "local_file_stat_root_escape",
+            "本地文件路径不能越过 root",
+        )
+        .with_context(&context));
+    }
+    let target = canonical_root.join(requested);
+    let metadata = match fs::symlink_metadata(&target) {
+        Ok(metadata) => metadata,
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => {
+            return Ok((
+                StatusCode::OK,
+                HeaderMap::new(),
+                Json(json!({
+                    "ok": true,
+                    "result": {
+                        "rootUri": query.root_uri,
+                        "path": query.path,
+                        "exists": false,
+                        "sourceKind": "local_folder",
+                    }
+                })),
+            ));
+        }
+        Err(error) => {
+            return Err(WebError::bad_request_code(
+                "local_file_stat_failed",
+                format!("无法读取本地文件状态 {}: {error}", target.display()),
+            )
+            .with_context(&context));
+        }
+    };
+    let canonical_target = target.canonicalize().map_err(|error| {
+        WebError::bad_request_code(
+            "local_file_stat_failed",
+            format!("无法解析本地文件路径 {}: {error}", target.display()),
+        )
+        .with_context(&context)
+    })?;
+    if !canonical_target.starts_with(&canonical_root) {
+        return Err(WebError::bad_request_code(
+            "local_file_stat_root_escape",
+            "本地文件路径不能越过 root",
+        )
+        .with_context(&context));
+    }
+    let file_name = canonical_target
+        .file_name()
+        .and_then(|value| value.to_str())
+        .unwrap_or("资源")
+        .to_string();
+    Ok((
+        StatusCode::OK,
+        HeaderMap::new(),
+        Json(json!({
+            "ok": true,
+            "result": {
+                "rootUri": query.root_uri,
+                "path": query.path,
+                "exists": true,
+                "isDirectory": metadata.is_dir(),
+                "fileName": file_name,
+                "contentType": content_type_for_path(&canonical_target).to_str().unwrap_or("application/octet-stream"),
+                "sourceKind": "local_folder",
+            }
+        })),
+    ))
+}
+
 pub async fn read_local_resource(
     State(state): State<AppState>,
     Extension(context): Extension<RequestContext>,

rust/crates/mnote-web/src/routes/mod.rs

@@ -271,6 +271,10 @@ pub fn build_router(state: AppState) -> Router {
             "/api/local-folder/files/open",
             get(local_folder_source::open_local_file),
         )
+        .route(
+            "/api/local-folder/files/stat",
+            get(local_folder_source::stat_local_file),
+        )
         .route(
             "/api/local-folder/resource/read",
             get(local_folder_source::read_local_resource),