/*
 *  Copyright (C) 2005-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */

#include "CharsetConverter.h"

#include "LangInfo.h"
#include "guilib/LocalizeStrings.h"
#include "log.h"
#include "settings/Settings.h"
#include "settings/lib/Setting.h"
#include "settings/lib/SettingDefinitions.h"
#include "utils/StringUtils.h"
#include "utils/Utf8Utils.h"

#include <algorithm>

#include <fribidi.h>
#include <iconv.h>

#ifdef WORDS_BIGENDIAN
  #define ENDIAN_SUFFIX "BE"
#else
  #define ENDIAN_SUFFIX "LE"
#endif

#if defined(TARGET_DARWIN)
  #define WCHAR_IS_UCS_4 1
  #define UTF16_CHARSET "UTF-16" ENDIAN_SUFFIX
  #define UTF32_CHARSET "UTF-32" ENDIAN_SUFFIX
  #define UTF8_SOURCE "UTF-8-MAC"
  #define WCHAR_CHARSET UTF32_CHARSET
#elif defined(TARGET_WINDOWS)
  #define WCHAR_IS_UTF16 1
  #define UTF16_CHARSET "UTF-16" ENDIAN_SUFFIX
  #define UTF32_CHARSET "UTF-32" ENDIAN_SUFFIX
  #define UTF8_SOURCE "UTF-8"
  #define WCHAR_CHARSET UTF16_CHARSET
#elif defined(TARGET_FREEBSD)
  #define WCHAR_IS_UCS_4 1
  #define UTF16_CHARSET "UTF-16" ENDIAN_SUFFIX
  #define UTF32_CHARSET "UTF-32" ENDIAN_SUFFIX
  #define UTF8_SOURCE "UTF-8"
  #define WCHAR_CHARSET UTF32_CHARSET
#elif defined(TARGET_ANDROID)
  #define WCHAR_IS_UCS_4 1
  #define UTF16_CHARSET "UTF-16" ENDIAN_SUFFIX
  #define UTF32_CHARSET "UTF-32" ENDIAN_SUFFIX
  #define UTF8_SOURCE "UTF-8"
  #define WCHAR_CHARSET UTF32_CHARSET
#else
  #define UTF16_CHARSET "UTF-16" ENDIAN_SUFFIX
  #define UTF32_CHARSET "UTF-32" ENDIAN_SUFFIX
  #define UTF8_SOURCE "UTF-8"
  #define WCHAR_CHARSET "WCHAR_T"
  #if __STDC_ISO_10646__
    #ifdef SIZEOF_WCHAR_T
      #if SIZEOF_WCHAR_T == 4
        #define WCHAR_IS_UCS_4 1
      #elif SIZEOF_WCHAR_T == 2
        #define WCHAR_IS_UCS_2 1
      #endif
    #endif
  #endif
#endif

#define NO_ICONV ((iconv_t)-1)

enum SpecialCharset
{
  NotSpecialCharset = 0,
  SystemCharset,
  UserCharset /* locale.charset */,
  SubtitleCharset /* subtitles.charset */,
};

class CConverterType : public CCriticalSection
{
public:
  CConverterType(const std::string&  sourceCharset,        const std::string&  targetCharset,        unsigned int targetSingleCharMaxLen = 1);
  CConverterType(enum SpecialCharset sourceSpecialCharset, const std::string&  targetCharset,        unsigned int targetSingleCharMaxLen = 1);
  CConverterType(const std::string&  sourceCharset,        enum SpecialCharset targetSpecialCharset, unsigned int targetSingleCharMaxLen = 1);
  CConverterType(enum SpecialCharset sourceSpecialCharset, enum SpecialCharset targetSpecialCharset, unsigned int targetSingleCharMaxLen = 1);
  CConverterType(const CConverterType& other);
  ~CConverterType();

  iconv_t GetConverter(CSingleLock& converterLock);

  void Reset(void);
  void ReinitTo(const std::string& sourceCharset, const std::string& targetCharset, unsigned int targetSingleCharMaxLen = 1);
  std::string GetSourceCharset(void) const  { return m_sourceCharset; }
  std::string GetTargetCharset(void) const  { return m_targetCharset; }
  unsigned int GetTargetSingleCharMaxLen(void) const  { return m_targetSingleCharMaxLen; }

private:
  static std::string ResolveSpecialCharset(enum SpecialCharset charset);

  enum SpecialCharset m_sourceSpecialCharset;
  std::string         m_sourceCharset;
  enum SpecialCharset m_targetSpecialCharset;
  std::string         m_targetCharset;
  iconv_t             m_iconv;
  unsigned int        m_targetSingleCharMaxLen;
};

CConverterType::CConverterType(const std::string& sourceCharset, const std::string& targetCharset, unsigned int targetSingleCharMaxLen /*= 1*/) : CCriticalSection(),
  m_sourceSpecialCharset(NotSpecialCharset),
  m_sourceCharset(sourceCharset),
  m_targetSpecialCharset(NotSpecialCharset),
  m_targetCharset(targetCharset),
  m_iconv(NO_ICONV),
  m_targetSingleCharMaxLen(targetSingleCharMaxLen)
{
}

CConverterType::CConverterType(enum SpecialCharset sourceSpecialCharset, const std::string& targetCharset, unsigned int targetSingleCharMaxLen /*= 1*/) : CCriticalSection(),
  m_sourceSpecialCharset(sourceSpecialCharset),
  m_sourceCharset(),
  m_targetSpecialCharset(NotSpecialCharset),
  m_targetCharset(targetCharset),
  m_iconv(NO_ICONV),
  m_targetSingleCharMaxLen(targetSingleCharMaxLen)
{
}

CConverterType::CConverterType(const std::string& sourceCharset, enum SpecialCharset targetSpecialCharset, unsigned int targetSingleCharMaxLen /*= 1*/) : CCriticalSection(),
  m_sourceSpecialCharset(NotSpecialCharset),
  m_sourceCharset(sourceCharset),
  m_targetSpecialCharset(targetSpecialCharset),
  m_targetCharset(),
  m_iconv(NO_ICONV),
  m_targetSingleCharMaxLen(targetSingleCharMaxLen)
{
}

CConverterType::CConverterType(enum SpecialCharset sourceSpecialCharset, enum SpecialCharset targetSpecialCharset, unsigned int targetSingleCharMaxLen /*= 1*/) : CCriticalSection(),
  m_sourceSpecialCharset(sourceSpecialCharset),
  m_sourceCharset(),
  m_targetSpecialCharset(targetSpecialCharset),
  m_targetCharset(),
  m_iconv(NO_ICONV),
  m_targetSingleCharMaxLen(targetSingleCharMaxLen)
{
}

CConverterType::CConverterType(const CConverterType& other) : CCriticalSection(),
  m_sourceSpecialCharset(other.m_sourceSpecialCharset),
  m_sourceCharset(other.m_sourceCharset),
  m_targetSpecialCharset(other.m_targetSpecialCharset),
  m_targetCharset(other.m_targetCharset),
  m_iconv(NO_ICONV),
  m_targetSingleCharMaxLen(other.m_targetSingleCharMaxLen)
{
}

CConverterType::~CConverterType()
{
  CSingleLock lock(*this);
  if (m_iconv != NO_ICONV)
    iconv_close(m_iconv);
  lock.Leave(); // ensure unlocking before final destruction
}

iconv_t CConverterType::GetConverter(CSingleLock& converterLock)
{
  // ensure that this unique instance is locked externally
  if (&converterLock.get_underlying() != this)
    return NO_ICONV;

  if (m_iconv == NO_ICONV)
  {
    if (m_sourceSpecialCharset)
      m_sourceCharset = ResolveSpecialCharset(m_sourceSpecialCharset);
    if (m_targetSpecialCharset)
      m_targetCharset = ResolveSpecialCharset(m_targetSpecialCharset);

    m_iconv = iconv_open(m_targetCharset.c_str(), m_sourceCharset.c_str());

    if (m_iconv == NO_ICONV)
      CLog::Log(LOGERROR, "%s: iconv_open() for \"%s\" -> \"%s\" failed, errno = %d (%s)",
                __FUNCTION__, m_sourceCharset.c_str(), m_targetCharset.c_str(), errno, strerror(errno));
  }

  return m_iconv;
}

void CConverterType::Reset(void)
{
  CSingleLock lock(*this);
  if (m_iconv != NO_ICONV)
  {
    iconv_close(m_iconv);
    m_iconv = NO_ICONV;
  }

  if (m_sourceSpecialCharset)
    m_sourceCharset.clear();
  if (m_targetSpecialCharset)
    m_targetCharset.clear();

}

void CConverterType::ReinitTo(const std::string& sourceCharset, const std::string& targetCharset, unsigned int targetSingleCharMaxLen /*= 1*/)
{
  CSingleLock lock(*this);
  if (sourceCharset != m_sourceCharset || targetCharset != m_targetCharset)
  {
    if (m_iconv != NO_ICONV)
    {
      iconv_close(m_iconv);
      m_iconv = NO_ICONV;
    }

    m_sourceSpecialCharset = NotSpecialCharset;
    m_sourceCharset = sourceCharset;
    m_targetSpecialCharset = NotSpecialCharset;
    m_targetCharset = targetCharset;
    m_targetSingleCharMaxLen = targetSingleCharMaxLen;
  }
}

std::string CConverterType::ResolveSpecialCharset(enum SpecialCharset charset)
{
  switch (charset)
  {
  case SystemCharset:
    return "";
  case UserCharset:
    return g_langInfo.GetGuiCharSet();
  case SubtitleCharset:
    return g_langInfo.GetSubtitleCharSet();
  case NotSpecialCharset:
  default:
    return "UTF-8"; /* dummy value */
  }
}

enum StdConversionType /* Keep it in sync with CCharsetConverter::CInnerConverter::m_stdConversion */
{
  NoConversion = -1,
  Utf8ToUtf32 = 0,
  Utf32ToUtf8,
  Utf32ToW,
  WToUtf32,
  SubtitleCharsetToUtf8,
  Utf8ToUserCharset,
  UserCharsetToUtf8,
  Utf32ToUserCharset,
  WtoUtf8,
  Utf16LEtoW,
  Utf16BEtoUtf8,
  Utf16LEtoUtf8,
  Utf8toW,
  Utf8ToSystem,
  SystemToUtf8,
  Ucs2CharsetToUtf8,
  NumberOfStdConversionTypes /* Dummy sentinel entry */
};

/* We don't want to pollute header file with many additional includes and definitions, so put
   here all staff that require usage of types defined in this file or in additional headers */
class CCharsetConverter::CInnerConverter
{
public:
  static bool logicalToVisualBiDi(const std::u32string& stringSrc,
                                  std::u32string& stringDst,
                                  FriBidiCharType base = FRIBIDI_TYPE_LTR,
                                  const bool failOnBadString = false,
                                  int* visualToLogicalMap = nullptr);

  template<class INPUT,class OUTPUT>
  static bool stdConvert(StdConversionType convertType, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar = false);
  template<class INPUT,class OUTPUT>
  static bool customConvert(const std::string& sourceCharset, const std::string& targetCharset, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar = false);

  template<class INPUT,class OUTPUT>
  static bool convert(iconv_t type, int multiplier, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar = false);

  static CConverterType m_stdConversion[NumberOfStdConversionTypes];
  static CCriticalSection m_critSectionFriBiDi;
};

/* single symbol sizes in chars */
const int CCharsetConverter::m_Utf8CharMinSize = 1;
const int CCharsetConverter::m_Utf8CharMaxSize = 4;

CConverterType CCharsetConverter::CInnerConverter::m_stdConversion[NumberOfStdConversionTypes] = /* keep it in sync with enum StdConversionType */
{
  /* Utf8ToUtf32 */         CConverterType(UTF8_SOURCE,     UTF32_CHARSET),
  /* Utf32ToUtf8 */         CConverterType(UTF32_CHARSET,   "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf32ToW */            CConverterType(UTF32_CHARSET,   WCHAR_CHARSET),
  /* WToUtf32 */            CConverterType(WCHAR_CHARSET,   UTF32_CHARSET),
  /* SubtitleCharsetToUtf8*/CConverterType(SubtitleCharset, "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf8ToUserCharset */   CConverterType(UTF8_SOURCE,     UserCharset),
  /* UserCharsetToUtf8 */   CConverterType(UserCharset,     "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf32ToUserCharset */  CConverterType(UTF32_CHARSET,   UserCharset),
  /* WtoUtf8 */             CConverterType(WCHAR_CHARSET,   "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf16LEtoW */          CConverterType("UTF-16LE",      WCHAR_CHARSET),
  /* Utf16BEtoUtf8 */       CConverterType("UTF-16BE",      "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf16LEtoUtf8 */       CConverterType("UTF-16LE",      "UTF-8", CCharsetConverter::m_Utf8CharMaxSize),
  /* Utf8toW */             CConverterType(UTF8_SOURCE,     WCHAR_CHARSET),
  /* Utf8ToSystem */        CConverterType(UTF8_SOURCE,     SystemCharset),
  /* SystemToUtf8 */        CConverterType(SystemCharset,   UTF8_SOURCE),
  /* Ucs2CharsetToUtf8 */   CConverterType("UCS-2LE",       "UTF-8", CCharsetConverter::m_Utf8CharMaxSize)
};

CCriticalSection CCharsetConverter::CInnerConverter::m_critSectionFriBiDi;

template<class INPUT,class OUTPUT>
bool CCharsetConverter::CInnerConverter::stdConvert(StdConversionType convertType, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar /*= false*/)
{
  strDest.clear();
  if (strSource.empty())
    return true;

  if (convertType < 0 || convertType >= NumberOfStdConversionTypes)
    return false;

  CConverterType& convType = m_stdConversion[convertType];
  CSingleLock converterLock(convType);

  return convert(convType.GetConverter(converterLock), convType.GetTargetSingleCharMaxLen(), strSource, strDest, failOnInvalidChar);
}

template<class INPUT,class OUTPUT>
bool CCharsetConverter::CInnerConverter::customConvert(const std::string& sourceCharset, const std::string& targetCharset, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar /*= false*/)
{
  strDest.clear();
  if (strSource.empty())
    return true;

  iconv_t conv = iconv_open(targetCharset.c_str(), sourceCharset.c_str());
  if (conv == NO_ICONV)
  {
    CLog::Log(LOGERROR, "%s: iconv_open() for \"%s\" -> \"%s\" failed, errno = %d (%s)",
              __FUNCTION__, sourceCharset.c_str(), targetCharset.c_str(), errno, strerror(errno));
    return false;
  }
  const int dstMultp = (targetCharset.compare(0, 5, "UTF-8") == 0) ? CCharsetConverter::m_Utf8CharMaxSize : 1;
  const bool result = convert(conv, dstMultp, strSource, strDest, failOnInvalidChar);
  iconv_close(conv);

  return result;
}

/* iconv may declare inbuf to be char** rather than const char** depending on platform and version,
    so provide a wrapper that handles both */
struct charPtrPtrAdapter
{
  const char** pointer;
  explicit charPtrPtrAdapter(const char** p) :
    pointer(p) { }
  operator char**()
  { return const_cast<char**>(pointer); }
  operator const char**()
  { return pointer; }
};

template<class INPUT,class OUTPUT>
bool CCharsetConverter::CInnerConverter::convert(iconv_t type, int multiplier, const INPUT& strSource, OUTPUT& strDest, bool failOnInvalidChar /*= false*/)
{
  if (type == NO_ICONV)
    return false;

  //input buffer for iconv() is the buffer from strSource
  size_t      inBufSize  = (strSource.length() + 1) * sizeof(typename INPUT::value_type);
  const char* inBuf      = (const char*)strSource.c_str();

  //allocate output buffer for iconv()
  size_t      outBufSize = (strSource.length() + 1) * sizeof(typename OUTPUT::value_type) * multiplier;
  char*       outBuf     = (char*)malloc(outBufSize);
  if (outBuf == NULL)
  {
    CLog::Log(LOGFATAL, "%s: malloc failed", __FUNCTION__);
    return false;
  }

  size_t      inBytesAvail  = inBufSize;  //how many bytes iconv() can read
  size_t      outBytesAvail = outBufSize; //how many bytes iconv() can write
  const char* inBufStart    = inBuf;      //where in our input buffer iconv() should start reading
  char*       outBufStart   = outBuf;     //where in out output buffer iconv() should start writing

  size_t returnV;
  while(true)
  {
    //iconv() will update inBufStart, inBytesAvail, outBufStart and outBytesAvail
    returnV = iconv(type, charPtrPtrAdapter(&inBufStart), &inBytesAvail, &outBufStart, &outBytesAvail);

    if (returnV == (size_t)-1)
    {
      if (errno == E2BIG) //output buffer is not big enough
      {
        //save where iconv() ended converting, realloc might make outBufStart invalid
        size_t bytesConverted = outBufSize - outBytesAvail;

        //make buffer twice as big
        outBufSize   *= 2;
        char* newBuf  = (char*)realloc(outBuf, outBufSize);
        if (!newBuf)
        {
          CLog::Log(LOGFATAL, "%s realloc failed with errno=%d(%s)", __FUNCTION__, errno,
                    strerror(errno));
          break;
        }
        outBuf = newBuf;

        //update the buffer pointer and counter
        outBufStart   = outBuf + bytesConverted;
        outBytesAvail = outBufSize - bytesConverted;

        //continue in the loop and convert the rest
        continue;
      }
      else if (errno == EILSEQ) //An invalid multibyte sequence has been encountered in the input
      {
        if (failOnInvalidChar)
          break;

        //skip invalid byte
        inBufStart++;
        inBytesAvail--;
        //continue in the loop and convert the rest
        continue;
      }
      else if (errno == EINVAL) /* Invalid sequence at the end of input buffer */
      {
        if (!failOnInvalidChar)
          returnV = 0; /* reset error status to use converted part */

        break;
      }
      else //iconv() had some other error
      {
        CLog::Log(LOGERROR, "%s: iconv() failed, errno=%d (%s)",
                  __FUNCTION__, errno, strerror(errno));
      }
    }
    break;
  }

  //complete the conversion (reset buffers), otherwise the current data will prefix the data on the next call
  if (iconv(type, NULL, NULL, &outBufStart, &outBytesAvail) == (size_t)-1)
    CLog::Log(LOGERROR, "%s failed cleanup errno=%d(%s)", __FUNCTION__, errno, strerror(errno));

  if (returnV == (size_t)-1)
  {
    free(outBuf);
    return false;
  }
  //we're done

  const typename OUTPUT::size_type sizeInChars = (typename OUTPUT::size_type) (outBufSize - outBytesAvail) / sizeof(typename OUTPUT::value_type);
  typename OUTPUT::const_pointer strPtr = (typename OUTPUT::const_pointer) outBuf;
  /* Make sure that all buffer is assigned and string is stopped at end of buffer */
  if (strPtr[sizeInChars-1] == 0 && strSource[strSource.length()-1] != 0)
    strDest.assign(strPtr, sizeInChars-1);
  else
    strDest.assign(strPtr, sizeInChars);

  free(outBuf);

  return true;
}

bool CCharsetConverter::CInnerConverter::logicalToVisualBiDi(
    const std::u32string& stringSrc,
    std::u32string& stringDst,
    FriBidiCharType base /*= FRIBIDI_TYPE_LTR*/,
    const bool failOnBadString /*= false*/,
    int* visualToLogicalMap /*= nullptr*/)
{
  stringDst.clear();

  const size_t srcLen = stringSrc.length();
  if (srcLen == 0)
    return true;

  stringDst.reserve(srcLen);
  size_t lineStart = 0;

  // libfribidi is not threadsafe, so make sure we make it so
  CSingleLock lock(m_critSectionFriBiDi);
  do
  {
    size_t lineEnd = stringSrc.find('\n', lineStart);
    if (lineEnd >= srcLen) // equal to 'lineEnd == std::string::npos'
      lineEnd = srcLen;
    else
      lineEnd++; // include '\n'

    const size_t lineLen = lineEnd - lineStart;

    FriBidiChar* visual = (FriBidiChar*) malloc((lineLen + 1) * sizeof(FriBidiChar));
    if (visual == NULL)
    {
      free(visual);
      CLog::Log(LOGFATAL, "%s: can't allocate memory", __FUNCTION__);
      return false;
    }

    bool bidiFailed = false;
    FriBidiCharType baseCopy = base; // preserve same value for all lines, required because fribidi_log2vis will modify parameter value
    if (fribidi_log2vis(reinterpret_cast<const FriBidiChar*>(stringSrc.c_str() + lineStart),
                        lineLen, &baseCopy, visual, nullptr,
                        !visualToLogicalMap ? nullptr : visualToLogicalMap + lineStart, nullptr))
    {
      // Removes bidirectional marks
      const int newLen = fribidi_remove_bidi_marks(
          visual, lineLen, nullptr, !visualToLogicalMap ? nullptr : visualToLogicalMap + lineStart,
          nullptr);
      if (newLen > 0)
        stringDst.append((const char32_t*)visual, (size_t)newLen);
      else if (newLen < 0)
        bidiFailed = failOnBadString;
    }
    else
      bidiFailed = failOnBadString;

    free(visual);

    if (bidiFailed)
      return false;

    lineStart = lineEnd;
  } while (lineStart < srcLen);

  return !stringDst.empty();
}

static struct SCharsetMapping
{
  const char* charset;
  const char* caption;
} g_charsets[] = {
  { "ISO-8859-1", "Western Europe (ISO)" }
  , { "ISO-8859-2", "Central Europe (ISO)" }
  , { "ISO-8859-3", "South Europe (ISO)" }
  , { "ISO-8859-4", "Baltic (ISO)" }
  , { "ISO-8859-5", "Cyrillic (ISO)" }
  , { "ISO-8859-6", "Arabic (ISO)" }
  , { "ISO-8859-7", "Greek (ISO)" }
  , { "ISO-8859-8", "Hebrew (ISO)" }
  , { "ISO-8859-9", "Turkish (ISO)" }
  , { "CP1250", "Central Europe (Windows)" }
  , { "CP1251", "Cyrillic (Windows)" }
  , { "CP1252", "Western Europe (Windows)" }
  , { "CP1253", "Greek (Windows)" }
  , { "CP1254", "Turkish (Windows)" }
  , { "CP1255", "Hebrew (Windows)" }
  , { "CP1256", "Arabic (Windows)" }
  , { "CP1257", "Baltic (Windows)" }
  , { "CP1258", "Vietnamese (Windows)" }
  , { "CP874", "Thai (Windows)" }
  , { "BIG5", "Chinese Traditional (Big5)" }
  , { "GBK", "Chinese Simplified (GBK)" }
  , { "SHIFT_JIS", "Japanese (Shift-JIS)" }
  , { "CP949", "Korean" }
  , { "BIG5-HKSCS", "Hong Kong (Big5-HKSCS)" }
  , { NULL, NULL }
};

CCharsetConverter::CCharsetConverter() = default;

void CCharsetConverter::OnSettingChanged(std::shared_ptr<const CSetting> setting)
{
  if (setting == NULL)
    return;

  const std::string& settingId = setting->GetId();
  if (settingId == CSettings::SETTING_LOCALE_CHARSET)
    resetUserCharset();
  else if (settingId == CSettings::SETTING_SUBTITLES_CHARSET)
    resetSubtitleCharset();
}

void CCharsetConverter::clear()
{
}

std::vector<std::string> CCharsetConverter::getCharsetLabels()
{
  std::vector<std::string> lab;
  for(SCharsetMapping* c = g_charsets; c->charset; c++)
    lab.emplace_back(c->caption);

  return lab;
}

std::string CCharsetConverter::getCharsetLabelByName(const std::string& charsetName)
{
  for(SCharsetMapping* c = g_charsets; c->charset; c++)
  {
    if (StringUtils::EqualsNoCase(charsetName,c->charset))
      return c->caption;
  }

  return "";
}

std::string CCharsetConverter::getCharsetNameByLabel(const std::string& charsetLabel)
{
  for(SCharsetMapping* c = g_charsets; c->charset; c++)
  {
    if (StringUtils::EqualsNoCase(charsetLabel, c->caption))
      return c->charset;
  }

  return "";
}

void CCharsetConverter::reset(void)
{
  for (CConverterType& conversion : CInnerConverter::m_stdConversion)
    conversion.Reset();
}

void CCharsetConverter::resetSystemCharset(void)
{
  CInnerConverter::m_stdConversion[Utf8ToSystem].Reset();
  CInnerConverter::m_stdConversion[SystemToUtf8].Reset();
}

void CCharsetConverter::resetUserCharset(void)
{
  CInnerConverter::m_stdConversion[UserCharsetToUtf8].Reset();
  CInnerConverter::m_stdConversion[UserCharsetToUtf8].Reset();
  CInnerConverter::m_stdConversion[Utf32ToUserCharset].Reset();
  resetSubtitleCharset();
}

void CCharsetConverter::resetSubtitleCharset(void)
{
  CInnerConverter::m_stdConversion[SubtitleCharsetToUtf8].Reset();
}

void CCharsetConverter::reinitCharsetsFromSettings(void)
{
  resetUserCharset(); // this will also reinit Subtitle charsets
}

bool CCharsetConverter::utf8ToUtf32(const std::string& utf8StringSrc, std::u32string& utf32StringDst, bool failOnBadChar /*= true*/)
{
  return CInnerConverter::stdConvert(Utf8ToUtf32, utf8StringSrc, utf32StringDst, failOnBadChar);
}

std::u32string CCharsetConverter::utf8ToUtf32(const std::string& utf8StringSrc, bool failOnBadChar /*= true*/)
{
  std::u32string converted;
  utf8ToUtf32(utf8StringSrc, converted, failOnBadChar);
  return converted;
}

bool CCharsetConverter::utf8ToUtf32Visual(const std::string& utf8StringSrc, std::u32string& utf32StringDst, bool bVisualBiDiFlip /*= false*/, bool forceLTRReadingOrder /*= false*/, bool failOnBadChar /*= false*/)
{
  if (bVisualBiDiFlip)
  {
    std::u32string converted;
    if (!CInnerConverter::stdConvert(Utf8ToUtf32, utf8StringSrc, converted, failOnBadChar))
      return false;

    return CInnerConverter::logicalToVisualBiDi(converted, utf32StringDst, forceLTRReadingOrder ? FRIBIDI_TYPE_LTR : FRIBIDI_TYPE_PDF, failOnBadChar);
  }
  return CInnerConverter::stdConvert(Utf8ToUtf32, utf8StringSrc, utf32StringDst, failOnBadChar);
}

bool CCharsetConverter::utf32ToUtf8(const std::u32string& utf32StringSrc, std::string& utf8StringDst, bool failOnBadChar /*= true*/)
{
  return CInnerConverter::stdConvert(Utf32ToUtf8, utf32StringSrc, utf8StringDst, failOnBadChar);
}

std::string CCharsetConverter::utf32ToUtf8(const std::u32string& utf32StringSrc, bool failOnBadChar /*= false*/)
{
  std::string converted;
  utf32ToUtf8(utf32StringSrc, converted, failOnBadChar);
  return converted;
}

bool CCharsetConverter::utf32ToW(const std::u32string& utf32StringSrc, std::wstring& wStringDst, bool failOnBadChar /*= true*/)
{
#ifdef WCHAR_IS_UCS_4
  wStringDst.assign((const wchar_t*)utf32StringSrc.c_str(), utf32StringSrc.length());
  return true;
#else // !WCHAR_IS_UCS_4
  return CInnerConverter::stdConvert(Utf32ToW, utf32StringSrc, wStringDst, failOnBadChar);
#endif // !WCHAR_IS_UCS_4
}

bool CCharsetConverter::utf32logicalToVisualBiDi(const std::u32string& logicalStringSrc,
                                                 std::u32string& visualStringDst,
                                                 bool forceLTRReadingOrder /*= false*/,
                                                 bool failOnBadString /*= false*/,
                                                 int* visualToLogicalMap /*= nullptr*/)
{
  return CInnerConverter::logicalToVisualBiDi(
      logicalStringSrc, visualStringDst, forceLTRReadingOrder ? FRIBIDI_TYPE_LTR : FRIBIDI_TYPE_PDF,
      failOnBadString, visualToLogicalMap);
}

bool CCharsetConverter::wToUtf32(const std::wstring& wStringSrc, std::u32string& utf32StringDst, bool failOnBadChar /*= true*/)
{
#ifdef WCHAR_IS_UCS_4
  /* UCS-4 is almost equal to UTF-32, but UTF-32 has strict limits on possible values, while UCS-4 is usually unchecked.
   * With this "conversion" we ensure that output will be valid UTF-32 string. */
#endif
  return CInnerConverter::stdConvert(WToUtf32, wStringSrc, utf32StringDst, failOnBadChar);
}

// The bVisualBiDiFlip forces a flip of characters for hebrew/arabic languages, only set to false if the flipping
// of the string is already made or the string is not displayed in the GUI
bool CCharsetConverter::utf8ToW(const std::string& utf8StringSrc, std::wstring& wStringDst, bool bVisualBiDiFlip /*= true*/,
                                bool forceLTRReadingOrder /*= false*/, bool failOnBadChar /*= false*/)
{
  // Try to flip hebrew/arabic characters, if any
  if (bVisualBiDiFlip)
  {
    wStringDst.clear();
    std::u32string utf32str;
    if (!CInnerConverter::stdConvert(Utf8ToUtf32, utf8StringSrc, utf32str, failOnBadChar))
      return false;

    std::u32string utf32flipped;
    const bool bidiResult = CInnerConverter::logicalToVisualBiDi(utf32str, utf32flipped, forceLTRReadingOrder ? FRIBIDI_TYPE_LTR : FRIBIDI_TYPE_PDF, failOnBadChar);

    return CInnerConverter::stdConvert(Utf32ToW, utf32flipped, wStringDst, failOnBadChar) && bidiResult;
  }

  return CInnerConverter::stdConvert(Utf8toW, utf8StringSrc, wStringDst, failOnBadChar);
}

bool CCharsetConverter::subtitleCharsetToUtf8(const std::string& stringSrc, std::string& utf8StringDst)
{
  return CInnerConverter::stdConvert(SubtitleCharsetToUtf8, stringSrc, utf8StringDst, false);
}

bool CCharsetConverter::fromW(const std::wstring& wStringSrc,
                              std::string& stringDst, const std::string& enc)
{
  return CInnerConverter::customConvert(WCHAR_CHARSET, enc, wStringSrc, stringDst);
}

bool CCharsetConverter::toW(const std::string& stringSrc,
                            std::wstring& wStringDst, const std::string& enc)
{
  return CInnerConverter::customConvert(enc, WCHAR_CHARSET, stringSrc, wStringDst);
}

bool CCharsetConverter::utf8ToStringCharset(const std::string& utf8StringSrc, std::string& stringDst)
{
  return CInnerConverter::stdConvert(Utf8ToUserCharset, utf8StringSrc, stringDst);
}

bool CCharsetConverter::utf8ToStringCharset(std::string& stringSrcDst)
{
  std::string strSrc(stringSrcDst);
  return utf8ToStringCharset(strSrc, stringSrcDst);
}

bool CCharsetConverter::ToUtf8(const std::string& strSourceCharset, const std::string& stringSrc, std::string& utf8StringDst, bool failOnBadChar /*= false*/)
{
  if (strSourceCharset == "UTF-8")
  { // simple case - no conversion necessary
    utf8StringDst = stringSrc;
    return true;
  }

  return CInnerConverter::customConvert(strSourceCharset, "UTF-8", stringSrc, utf8StringDst, failOnBadChar);
}

bool CCharsetConverter::utf8To(const std::string& strDestCharset, const std::string& utf8StringSrc, std::string& stringDst)
{
  if (strDestCharset == "UTF-8")
  { // simple case - no conversion necessary
    stringDst = utf8StringSrc;
    return true;
  }

  return CInnerConverter::customConvert(UTF8_SOURCE, strDestCharset, utf8StringSrc, stringDst);
}

bool CCharsetConverter::utf8To(const std::string& strDestCharset, const std::string& utf8StringSrc, std::u16string& utf16StringDst)
{
  return CInnerConverter::customConvert(UTF8_SOURCE, strDestCharset, utf8StringSrc, utf16StringDst);
}

bool CCharsetConverter::utf8To(const std::string& strDestCharset, const std::string& utf8StringSrc, std::u32string& utf32StringDst)
{
  return CInnerConverter::customConvert(UTF8_SOURCE, strDestCharset, utf8StringSrc, utf32StringDst);
}

bool CCharsetConverter::unknownToUTF8(std::string& stringSrcDst)
{
  std::string source(stringSrcDst);
  return unknownToUTF8(source, stringSrcDst);
}

bool CCharsetConverter::unknownToUTF8(const std::string& stringSrc, std::string& utf8StringDst, bool failOnBadChar /*= false*/)
{
  // checks whether it's utf8 already, and if not converts using the sourceCharset if given, else the string charset
  if (CUtf8Utils::isValidUtf8(stringSrc))
  {
    utf8StringDst = stringSrc;
    return true;
  }
  return CInnerConverter::stdConvert(UserCharsetToUtf8, stringSrc, utf8StringDst, failOnBadChar);
}

bool CCharsetConverter::wToUTF8(const std::wstring& wStringSrc, std::string& utf8StringDst, bool failOnBadChar /*= false*/)
{
  return CInnerConverter::stdConvert(WtoUtf8, wStringSrc, utf8StringDst, failOnBadChar);
}

bool CCharsetConverter::utf16BEtoUTF8(const std::u16string& utf16StringSrc, std::string& utf8StringDst)
{
  return CInnerConverter::stdConvert(Utf16BEtoUtf8, utf16StringSrc, utf8StringDst);
}

bool CCharsetConverter::utf16LEtoUTF8(const std::u16string& utf16StringSrc,
                                      std::string& utf8StringDst)
{
  return CInnerConverter::stdConvert(Utf16LEtoUtf8, utf16StringSrc, utf8StringDst);
}

bool CCharsetConverter::ucs2ToUTF8(const std::u16string& ucs2StringSrc, std::string& utf8StringDst)
{
  return CInnerConverter::stdConvert(Ucs2CharsetToUtf8, ucs2StringSrc,utf8StringDst);
}

bool CCharsetConverter::utf16LEtoW(const std::u16string& utf16String, std::wstring& wString)
{
  return CInnerConverter::stdConvert(Utf16LEtoW, utf16String, wString);
}

bool CCharsetConverter::utf32ToStringCharset(const std::u32string& utf32StringSrc, std::string& stringDst)
{
  return CInnerConverter::stdConvert(Utf32ToUserCharset, utf32StringSrc, stringDst);
}

bool CCharsetConverter::utf8ToSystem(std::string& stringSrcDst, bool failOnBadChar /*= false*/)
{
  std::string strSrc(stringSrcDst);
  return CInnerConverter::stdConvert(Utf8ToSystem, strSrc, stringSrcDst, failOnBadChar);
}

bool CCharsetConverter::systemToUtf8(const std::string& sysStringSrc, std::string& utf8StringDst, bool failOnBadChar /*= false*/)
{
  return CInnerConverter::stdConvert(SystemToUtf8, sysStringSrc, utf8StringDst, failOnBadChar);
}

bool CCharsetConverter::utf8logicalToVisualBiDi(const std::string& utf8StringSrc, std::string& utf8StringDst, bool failOnBadString /*= false*/)
{
  utf8StringDst.clear();
  std::u32string utf32flipped;
  if (!utf8ToUtf32Visual(utf8StringSrc, utf32flipped, true, true, failOnBadString))
    return false;

  return CInnerConverter::stdConvert(Utf32ToUtf8, utf32flipped, utf8StringDst, failOnBadString);
}

void CCharsetConverter::SettingOptionsCharsetsFiller(SettingConstPtr setting, std::vector<StringSettingOption>& list, std::string& current, void *data)
{
  std::vector<std::string> vecCharsets = g_charsetConverter.getCharsetLabels();
  sort(vecCharsets.begin(), vecCharsets.end(), sortstringbyname());

  list.emplace_back(g_localizeStrings.Get(13278), "DEFAULT"); // "Default"
  for (int i = 0; i < (int) vecCharsets.size(); ++i)
    list.emplace_back(vecCharsets[i], g_charsetConverter.getCharsetNameByLabel(vecCharsets[i]));
}
