New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/storage/country_tree_helpers.cpp

@@ -0,0 +1,63 @@
+#include "storage/country_tree_helpers.hpp"
+
+#include "base/logging.hpp"
+
+#include <vector>
+#include <utility>
+
+namespace storage
+{
+CountryId GetTopmostParentFor(CountryTree const & countries, CountryId const & countryId)
+{
+  CountryTree::NodesBufferT nodes;
+  countries.Find(countryId, nodes);
+  if (nodes.empty())
+  {
+    LOG(LWARNING, ("CountryId =", countryId, "not found in countries."));
+    return {};
+  }
+
+  if (nodes.size() > 1)
+  {
+    // Disputed territory. Has multiple parents.
+    CHECK(nodes[0]->HasParent(), ());
+    auto const parentId = nodes[0]->Parent().Value().Name();
+    for (size_t i = 1; i < nodes.size(); ++i)
+    {
+      if (nodes[i]->Parent().Value().Name() != parentId)
+        return countryId;
+    }
+    return GetTopmostParentFor(countries, parentId);
+  }
+
+  auto result = nodes[0];
+
+  if (!result->HasParent())
+    return result->Value().Name();
+
+  auto parent = &(result->Parent());
+  while (parent->HasParent())
+  {
+    result = parent;
+    parent = &(result->Parent());
+  }
+
+  return result->Value().Name();
+}
+
+std::optional<CountryTree> LoadCountriesFromFile(std::string const & path)
+{
+  Affiliations affiliations;
+  CountryNameSynonyms countryNameSynonyms;
+  MwmTopCityGeoIds mwmTopCityGeoIds;
+  MwmTopCountryGeoIds mwmTopCountryGeoIds;
+  CountryTree countries;
+  auto const res = LoadCountriesFromFile(path, countries, affiliations, countryNameSynonyms,
+                                         mwmTopCityGeoIds, mwmTopCountryGeoIds);
+
+  if (res == -1)
+    return {};
+
+  return std::optional<CountryTree>(std::move(countries));
+}
+}  // namespace storage