#include <c10/util/Unicode.h>

namespace c10 {
#if defined(_WIN32)
std::wstring u8u16(const std::string& str) {
  if (str.empty()) {
    return std::wstring();
  }
  int size_needed = MultiByteToWideChar(
      CP_UTF8, 0, str.c_str(), static_cast<int>(str.size()), NULL, 0);
  TORCH_CHECK(size_needed > 0, "Error converting the content to Unicode");
  std::wstring wstr(size_needed, 0);
  MultiByteToWideChar(
      CP_UTF8,
      0,
      str.c_str(),
      static_cast<int>(str.size()),
      &wstr[0],
      size_needed);
  return wstr;
}
std::string u16u8(const std::wstring& wstr) {
  if (wstr.empty()) {
    return std::string();
  }
  int size_needed = WideCharToMultiByte(
      CP_UTF8,
      0,
      wstr.c_str(),
      static_cast<int>(wstr.size()),
      NULL,
      0,
      NULL,
      NULL);
  TORCH_CHECK(size_needed > 0, "Error converting the content to UTF8");
  std::string str(size_needed, 0);
  WideCharToMultiByte(
      CP_UTF8,
      0,
      wstr.c_str(),
      static_cast<int>(wstr.size()),
      &str[0],
      size_needed,
      NULL,
      NULL);
  return str;
}
#endif
} // namespace c10