/*
    This file is part of the Okteta Core library, part of the KDE project.

    Copyright 2004 Friedrich W. H. Kossebau <kossebau@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/

#include "ktextcharcodec.h"

// lib
#include <khechar.h>
// KDE
#include <kglobal.h>
#include <klocale.h>
#include <kcharsets.h>
// Qt
#include <QtCore/QTextCodec>


namespace KHECore {

static const char QTextCodecWhiteSpace = 63;

static struct KEncodingNames {
  CharCoding Encoding;
  const char *Name;
}
const EncodingNames[] = {
{ ISO8859_1Encoding, "ISO-8859-1" },
{ ISO8859_2Encoding, "ISO-8859-2" },
{ ISO8859_3Encoding, "ISO-8859-3" },
{ ISO8859_4Encoding, "ISO-8859-4" },
{ ISO8859_5Encoding, "ISO-8859-5" },
{ ISO8859_6Encoding, "ISO-8859-6" },
{ ISO8859_7Encoding, "ISO-8859-7" },
{ ISO8859_8Encoding, "ISO-8859-8" },
{ ISO8859_8_IEncoding, "ISO-8859-8-I" },
{ ISO8859_9Encoding, "ISO-8859-9" },
{ ISO8859_11Encoding, "TIS-620" }, // was: ISO-8859-11
{ ISO8859_13Encoding, "ISO-8859-13" },
{ ISO8859_15Encoding, "ISO-8859-15" },
{ CP1250Encoding, "windows-1250" },
{ CP1251Encoding, "windows-1251" },
{ CP1252Encoding, "windows-1252" },
{ CP1253Encoding, "windows-1253" },
{ CP1254Encoding, "windows-1254" },
{ CP1255Encoding, "windows-1255" },
{ CP1256Encoding, "windows-1256" },
{ CP1257Encoding, "windows-1257" },
{ CP1258Encoding, "windows-1258" },
{ IBM850Encoding, "IBM850" },
{ IBM866Encoding, "IBM866" },
{ KOI8_REncoding, "KOI8-R" },
{ KOI8_UEncoding, "KOI8-U" } };
//TODO: WS2
static const unsigned int NoOfEncodings = sizeof(EncodingNames)/sizeof(struct KEncodingNames);// = 26;

static bool is8Bit( QTextCodec *Codec )
{
  const QByteArray &Name = Codec->name();
  bool Found = false;
  for( unsigned int i=0; i<NoOfEncodings; ++i )
  {
    if( qstrcmp(Name,EncodingNames[i].Name) == 0 )
    {
      Found = true;
      break;
    }
  }
  return Found;
}

static QTextCodec *createLatin1()
{
  return KGlobal::charsets()->codecForName( EncodingNames[0].Name );
}

/* heuristic seems to be doomed :(
static bool is8Bit( QTextCodec *Codec )
{
  bool Result = true;

  // first test different for 0
  unsigned char c[4];
  c[0] = 0;
  c[1] = c[2] = c[3] = 230;
  QString S = Codec->toUnicode( (const char*)&c,4 );
  int Length = 1;
  QCString CS = Codec->fromUnicode( S, Length );
  //kDebug() << Codec->name() << " "<<Length ;
  if( Length > 0 )
    Result = false;
  // test if all chars survive the recoding
  else
  do
  {
    ++c[0];
    S = Codec->toUnicode( (const char*)&c,4 );
    Length = 1;
    CS = Codec->fromUnicode( S, Length );
    //kDebug() << Codec->name() << " "<<c[0]<<"->"<<CS[0]<<":"<<Length ;
    if( Length != 1 || (CS[0] != (char)c[0] && CS[0] != QTextCodecWhiteSpace) )
    {
      Result = false;
      break;
    }
  }
  while( c[0] < 255 );
  return Result;
}
const QStringList &KTextCharCodec::codecNames()
{
  // first call?
  if( CodecNames.isEmpty() )
{
    const QStringList &CharSets = KGlobal::charsets()->availableEncodingNames();

    for( QStringList::ConstIterator it = CharSets.begin(); it != CharSets.end(); ++it )
{
      bool Found = true;
      QTextCodec* Codec = KGlobal::charsets()->codecForName( *it, Found );
      if( Found && is8Bit(Codec) )
        CodecNames.append( QString::fromLatin1(Codec->name()) );
}
}

  return CodecNames;
}

QString KTextCharCodec::nameOfEncoding( CharCoding C )
{
  KTextCharCodec *Codec = 0;

  const char* N = 0;
  for( unsigned int i=0; i<NoOfEncodings; ++i )
  {
    if( EncodingNames[i].Encoding == C )
    {
      N = EncodingNames[i].Name;
      break;
    }
  }

  if( N != 0 )
  {
    QString CodeName = QString::fromLatin1( N );
  }
  return Codec;
}
 */

KTextCharCodec *KTextCharCodec::createLocalCodec()
{
  QTextCodec *Codec = KGlobal::locale()->codecForEncoding();
  if( !is8Bit(Codec) )
    Codec = createLatin1();
  return new KTextCharCodec( Codec );
}


KTextCharCodec *KTextCharCodec::createCodec( const QString &CodeName )
{
  bool Ok;
  QTextCodec *Codec = KGlobal::charsets()->codecForName( CodeName, Ok );
  if( Ok )
    Ok = is8Bit( Codec );
  return Ok ? new KTextCharCodec( Codec ) : 0;
}


const QStringList &KTextCharCodec::codecNames()
{
  static QStringList TextCodecNames;

  // first call?
  if( TextCodecNames.isEmpty() )
  {
    for( unsigned int i=0; i<NoOfEncodings; ++i )
    {
      bool Found = true;
      QString Name = QString::fromLatin1( EncodingNames[i].Name );
      QTextCodec* Codec = KGlobal::charsets()->codecForName( Name, Found );
      if( Found )
        TextCodecNames.append( QString::fromLatin1(Codec->name()) );
    }
  }

  return TextCodecNames;
}


KTextCharCodec::KTextCharCodec( QTextCodec *C )
  : Codec( C ),
    Decoder( C->makeDecoder() ),
    Encoder( C->makeEncoder() )
{}

KTextCharCodec::~KTextCharCodec()
{
  delete Decoder;
  delete Encoder;
}

bool KTextCharCodec::canEncode( const QChar &C ) const
{
  return Codec->canEncode( C );
}

bool KTextCharCodec::encode( char *D, const QChar &C ) const
{
  if( !Codec->canEncode(C) ) // TODO: do we really need the codec?
    return false;
  QByteArray T = Encoder->fromUnicode( QString(C) );
  if (T.size()) {
    *D = T[0];
    return true;
  } else
    return false;
}


KChar KTextCharCodec::decode( char Byte ) const
{
  QString S( Decoder->toUnicode(&Byte,1) );
  return KChar(S.at(0));
}


const QString& KTextCharCodec::name() const
{
  if( Name.isNull() )
    Name = QString::fromLatin1( Codec->name() );
  return Name;
}

}
