[core] Respect system language order

Signed-off-by: Yannik Bloscheck <git@yannikbloscheck.com>

indexer/feature_utils.cpp

@@ -6,6 +6,7 @@
 #include "indexer/ftypes_matcher.hpp"
 #include "indexer/scales.hpp"
 
+#include "platform/preferred_languages.hpp"
 #include "platform/localization.hpp"
 #include "platform/distance.hpp"
 
@@ -124,6 +125,14 @@ bool IsNativeLang(feature::RegionData const & regionData, int8_t deviceLang)
 vector<int8_t> MakeLanguagesPriorityList(int8_t deviceLang, bool preferDefault)
 {
   vector<int8_t> langPriority = {deviceLang};
+  for (auto const & lang : languages::GetPreferredLangIndexes())
+  {
+    if (find(langPriority.begin(), langPriority.end(), lang) == langPriority.end())
+    {
+      langPriority.push_back(lang);
+    }
+  }
+  
   if (preferDefault)
     langPriority.push_back(StrUtf8::kDefaultCode);
 

platform/preferred_languages.cpp

@@ -188,6 +188,22 @@ std::string GetCurrentMapLanguage()
   return languageCode;
 }
 
+std::vector<int8_t> GetPreferredLangIndexes()
+{
+  std::vector<int8_t> langs = {};
+  for (auto const & systemLanguage : GetSystemPreferred())
+  {
+    auto normalizedLang = Normalize(systemLanguage);
+    int8_t lang = StringUtf8Multilang::GetLangIndex(normalizedLang);
+    if (lang != StringUtf8Multilang::kUnsupportedLanguageCode
+           && find(langs.begin(), langs.end(), lang) == langs.end())
+    {
+      langs.push_back(lang);
+    }
+  }
+  return langs;
+}
+
 std::string GetTwine(std::string const & lang)
 {
   // Special cases for different Chinese variations.

platform/preferred_languages.hpp

@@ -25,6 +25,7 @@ std::string GetCurrentMapTwine();
 std::string Normalize(std::string_view lang);
 std::string GetCurrentNorm();
 std::string GetCurrentMapLanguage();
+std::vector<int8_t> GetPreferredLangIndexes();
 
 buffer_vector<std::string, 4> const & GetSystemPreferred();
 }  // namespace languages