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#include "base/text_normalizer.h"

#include <string>

#include "base/util.h"

namespace mozc {
namespace {

// Unicode vender specific character table:
// http://hp.vector.co.jp/authors/VA010341/unicode/
// http://www.notoinsatu.co.jp/font/omake/OTF_other.pdf
//
// Example: WAVE_DASH / FULLWIDTH TILDE
// http://ja.wikipedia.org/wiki/%E6%B3%A2%E3%83%80%E3%83%83%E3%82%B7%E3%83%A5
// Windows CP932 (shift-jis) maps WAVE_DASH to FULL_WIDTH_TILDA.
// Since the font of WAVE-DASH is ugly on Windows, here we convert WAVE-DHASH to
// FULL_WIDTH_TILDA as CP932 does.
//
// As Unicode has became the defact default encoding.  We have reduced
// the number of characters to be normalized.
inline char32 NormalizeCharForWindows(char32 c) {
  switch (c) {
    case 0x301C:      // WAVE DASH
      return 0xFF5E;  // FULLWIDTH TILDE
      break;
    case 0x2212:      // MINUS SIGN
      return 0xFF0D;  // FULLWIDTH HYPHEN MINUS
      break;
    default:
      return c;
      break;
  }
}

std::string NormalizeTextForWindows(absl::string_view input) {
  std::string output;
  for (ConstChar32Iterator iter(input); !iter.Done(); iter.Next()) {
    Util::Ucs4ToUtf8Append(NormalizeCharForWindows(iter.Get()), &output);
  }
  return output;
}
}  // namespace

std::string TextNormalizer::NormalizeTextWithFlag(absl::string_view input,
                                                  TextNormalizer::Flag flag) {
  if (flag == TextNormalizer::kDefault) {
#ifdef OS_WIN
    flag = TextNormalizer::kAll;
#else  // OS_WIN
    flag = TextNormalizer::kNone;
#endif  // OS_WIN
  }

  if (flag != TextNormalizer::kAll) {
    return std::string(input.data(), input.size());
  }

  return NormalizeTextForWindows(input);
}
}  // namespace mozc
