languages::GetCurrentTwine() returns language in our twine translations compatible format.

2 files changed, 27 insertions, 1 deletions

diff --git a/platform/preferred_languages.cpp b/platform/preferred_languages.cpp
index 7b26271865..a6982956f8 100644
--- a/platform/preferred_languages.cpp
+++ b/platform/preferred_languages.cpp
@@ -172,4 +172,27 @@ string GetCurrentNorm()
   return Normalize(GetCurrentOrig());
 }
 
+string GetCurrentTwine()
+{
+  string const lang = GetCurrentOrig();
+  // Special cases for different Chinese variations.
+  if (lang.find("zh") == 0)
+  {
+    string lower = lang;
+    strings::AsciiToLower(lower);
+
+    // Traditional Chinese.
+    for (char const * s : {"hant", "tw", "hk", "mo"})
+    {
+      if (lower.find(s) != string::npos)
+        return "zh-Hant";
+    }
+
+    // Simplified Chinese by default for all other cases.
+    return "zh-Hans";
+  }
+  // Use short 2-chars versions for all other languages.
+  return Normalize(lang);
 }
+
+}  // namespace languages
diff --git a/platform/preferred_languages.hpp b/platform/preferred_languages.hpp
index 557febe048..679a9eb75f 100644
--- a/platform/preferred_languages.hpp
+++ b/platform/preferred_languages.hpp
@@ -5,7 +5,7 @@
 namespace languages
 {
 
-/// @note This functions are heavy enough to call them often. Be careful.
+/// @note These functions are heavy enough to call them often. Be careful.
 //@{
 
 /// @return List of original system languages in the form "en-US|ru-RU|es|zh-Hant".
@@ -14,6 +14,9 @@ string GetPreferred();
 /// @return Original language code for the current user in the form "en-US", "zh-Hant".
 string GetCurrentOrig();
 
+/// @return Current language in out Twine translations compatible format, e.g. "en", "pt" or "zh-Hant".
+string GetCurrentTwine();
+
 /// @return Normalized language code for the current user in the form "en", "zh".
 //@{
 /// Returned languages are normalized to our supported languages in the core, see multilang_utf8_string.cpp