extract common behavior

src/providers/base_provider.cpp

@@ -246,6 +246,49 @@ auto base_provider::get_api_path_from_source(const std::string &source_path,
   return api_error::item_not_found;
 }
 
+auto base_provider::get_directory_items(const std::string &api_path,
+                                        directory_item_list &list) const
+    -> api_error {
+  bool exists{};
+  auto res = is_directory(api_path, exists);
+  if (res != api_error::success) {
+    return res;
+  }
+  if (not exists) {
+    return api_error::directory_not_found;
+  }
+
+  try {
+    res = get_directory_items_impl(api_path, list);
+    if (res != api_error::success) {
+      return res;
+    }
+  } catch (const std::exception &e) {
+    utils::error::raise_api_path_error(__FUNCTION__, api_path, e,
+                                       "failed to get directory items");
+    return api_error::error;
+  }
+
+  std::sort(list.begin(), list.end(),
+            [](const auto &item1, const auto &item2) -> bool {
+              return (item1.directory && not item2.directory) ||
+                     (not(item2.directory && not item1.directory) &&
+                      (item1.api_path.compare(item2.api_path) < 0));
+            });
+
+  list.insert(list.begin(), directory_item{
+                                "..",
+                                "",
+                                true,
+                            });
+  list.insert(list.begin(), directory_item{
+                                ".",
+                                "",
+                                true,
+                            });
+  return api_error::success;
+}
+
 auto base_provider::get_file_size(const std::string &api_path,
                                   std::uint64_t &file_size) const -> api_error {
   bool exists{};