/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  ISO2022kr conversion plugin

*

*/

// INCLUDES

#include <e32std.h>

#include <charconv.h>

#include <convgeneratedcpp.h>

#include <ecom/implementationproxy.h>

#include "cp949table.h"

#include "charactersetconverter.h"

static const TUint KBitsForNonStandardStates = 0x03;

static const TUint KShiftedToKSCState = 0x01;

static const TUint KMaxSizeOfTmpBuffer = 1024;

static const TUint8 KMaxAscii = 0x9f;

_LIT8(KLit8EscapeSequence, "\x1b\x24\x43");

#define SHIFT_IN_BYTE  0x0F

#define SHIFT_OUT_BYTE 0x0E

typedef enum

{

    EISO2022Initialize,

    EISO2022Ascii,

    EISO2022KSC

} TISO2022FromUniState;

// New Interface class

class CISO2022KRImplementation : public CCharacterSetConverterPluginInterface

{

    public:

        virtual const TDesC8& ReplacementForUnconvertibleUnicodeCharacters();

        virtual TInt ConvertFromUnicode(

            CCnvCharacterSetConverter::TEndianness aDefaultEndiannessOfForeignCharacters, 

            const TDesC8& aReplacementForUnconvertibleUnicodeCharacters, 

            TDes8& aForeign, 

            const TDesC16& aUnicode, 

            CCnvCharacterSetConverter::TArrayOfAscendingIndices& aIndicesOfUnconvertibleCharacters );

        virtual TInt ConvertToUnicode(

            CCnvCharacterSetConverter::TEndianness aDefaultEndiannessOfForeignCharacters, 

            TDes16& aUnicode, 

            const TDesC8& aForeign, 

            TInt& aState, 

            TInt& aNumberOfUnconvertibleCharacters, 

            TInt& aIndexOfFirstByteOfFirstUnconvertibleCharacter );

        virtual TBool IsInThisCharacterSetL(

            TBool& aSetToTrue, 

            TInt& aConfidenceLevel, 

            const TDesC8& );

        static CISO2022KRImplementation* NewL();

        virtual ~CISO2022KRImplementation();

    private:

        CISO2022KRImplementation();

};

// FUNCTION DEFINITIONS

const TDesC8& CISO2022KRImplementation::ReplacementForUnconvertibleUnicodeCharacters()

	{

	return CnvCp949Table::ReplacementForUnconvertibleUnicodeCharacters();

	}

TInt CISO2022KRImplementation::ConvertFromUnicode(

    CCnvCharacterSetConverter::TEndianness aDefaultEndiannessOfForeignCharacters, 

    const TDesC8& aReplacementForUnconvertibleUnicodeCharacters, 

    TDes8& aForeign, 

    const TDesC16& aUnicode, 

    CCnvCharacterSetConverter::TArrayOfAscendingIndices& aIndicesOfUnconvertibleCharacters)

	{

    TInt ret;

    TInt currPos = 3;

    TUint outputConversionFlags = 0;

    TUint inputConversionFlags = CCnvCharacterSetConverter::EInputConversionFlagAppend;

    TISO2022FromUniState currState = EISO2022Initialize;

    TUint8 shiftByte = 0;

    TPtr8 shiftBytePtr(NULL, 0);

    aForeign.SetLength(0);

    /* Start with escape sequence */

    aForeign.Append( KLit8EscapeSequence );

    ret = CCnvCharacterSetConverter::DoConvertFromUnicode( CnvCp949Table::ConversionData(),

                                                           aDefaultEndiannessOfForeignCharacters,

                                                           aReplacementForUnconvertibleUnicodeCharacters,

                                                           aForeign,

                                                           aUnicode,

                                                           aIndicesOfUnconvertibleCharacters,

                                                           outputConversionFlags, 

                                                           inputConversionFlags );

    /* Append shift in and out bytes as needed */

    while( currPos < aForeign.Length() )

        {

        TUint8 *currChar = (TUint8 *)aForeign.Mid(currPos).Ptr();

        if( *currChar > KMaxAscii )

            { /* KSC character */

            if( currState != EISO2022KSC )

                { /* Insert shift out byte */

                shiftByte = SHIFT_OUT_BYTE;

                currState = EISO2022KSC;

                }

            /* Clear the 8th bit */

            *currChar = (*currChar & ~(0x80));

            }

        else

            { /* ASCII character */

            if( currState != EISO2022Ascii )

                { /* Insert shift in byte */

                shiftByte = SHIFT_IN_BYTE;

                currState = EISO2022Ascii;

                }

            }

        if( shiftByte )

            {

            if( (aForeign.Length() + 1) > aForeign.MaxLength() )

                { /* Make room for shift byte */

                if( aForeign[ (aForeign.Length() - 1) ] > KMaxAscii )

                    { /* Drop a dual byte KSC character */

                    aForeign.SetLength( aForeign.Length() - 2 );

                    }

                else

                    { /* Drop a single byte ASCII character */

                    aForeign.SetLength( aForeign.Length() - 1 );

                    }

                    /* Increase unconverted amount */

                    ret++;

                /* TBD, propably should try to fix aIndicesOfUnconvertibleCharacters

                        if possible */

                }

                shiftBytePtr.Set( &shiftByte, 1, 1 );

                aForeign.Insert( currPos, shiftBytePtr );

                currPos++;

                shiftByte = 0;

            }

        /* Skip current character */

        currPos++;

        }

    return ret;

    }

TInt CISO2022KRImplementation::ConvertToUnicode(

    CCnvCharacterSetConverter::TEndianness aDefaultEndiannessOfForeignCharacters, 

    TDes16& aUnicode, 

    const TDesC8& aForeign, 

    TInt& aState, 

    TInt& aNumberOfUnconvertibleCharacters, 

    TInt& aIndexOfFirstByteOfFirstUnconvertibleCharacter)

	{

    TInt err;

    TInt ret = 0;

    TInt currPos = 0;

    TInt convPos = 0;

    TInt shiftInPos = KErrNotFound;

    TInt shiftOutPos = KErrNotFound;

    TInt shiftPos = KErrNotFound;

    TInt escPos = KErrNotFound;

    TPtrC8 currSegment;

    TPtrC8 convSegment;

    TBool changeState = EFalse;

    TUint outputConversionFlags = 0;

    TUint inputConversionFlags = CCnvCharacterSetConverter::EInputConversionFlagAppend;

    TInt numberOfUnconvertibleCharacters = 0;

    TInt indexOfFirstByteOfFirstUnconvertibleCharacter = 0;

    aNumberOfUnconvertibleCharacters = 0;

    while( currPos < aForeign.Length() )

        {

        currSegment.Set( aForeign.Mid( currPos ) );

        /* First change state if needed */

        if( changeState )

            {

            changeState = EFalse;

            if( (aState & KBitsForNonStandardStates) == KShiftedToKSCState )

                { /* Switch back to default ASCII */

                aState &= ~(KShiftedToKSCState);

                }

            else

                { /* Switch to KSC */

                aState |= KShiftedToKSCState; 

                }

            }

        /* Search for escape which should be skipped */

        escPos = currSegment.Find( KLit8EscapeSequence );

        /* Search for shift in byte */

        shiftInPos = currSegment.Locate( SHIFT_IN_BYTE );

        /* Search for shift out byte */

        shiftOutPos = currSegment.Locate( SHIFT_OUT_BYTE );

        /* Set shift pos according to found shift bytes */

        if( shiftInPos == KErrNotFound &&

            shiftOutPos == KErrNotFound )

            { /* Neither found */

            shiftPos = KErrNotFound;

            }

        else

            {

            if( (shiftInPos != KErrNotFound) &&

                ((shiftInPos < shiftOutPos) || (shiftOutPos == KErrNotFound)) )

                { /* shift in is nearer or shift out not found */

                shiftPos = shiftInPos;

                /* Set state change if needed */

                if( (aState & KBitsForNonStandardStates) == KShiftedToKSCState )

                    {

                    changeState = ETrue;

                    }

                }

            else

                { /* shift out must be nearer or shift in not fouind */

                shiftPos = shiftOutPos;

                /* Set state change if needed */

                if( (aState & KBitsForNonStandardStates) != KShiftedToKSCState )

                    {

                    changeState = ETrue;

                    }

                }

            }

        if( shiftPos == KErrNotFound )

            { /* Shift byte not found, same coding for the rest of the data */

            if( escPos == KErrNotFound )

                { /* No escape sequence either, just convert the rest */

                convSegment.Set( currSegment );

                }

            }

        else if( ((escPos != KErrNotFound) && (shiftPos < escPos)) ||

                 (escPos == KErrNotFound) )

            { /* Shift byte found and it comes before escape sequence or no escape

                 sequence was found, convert data preceeding the shift byte if shift

                 byte isn't the first character */

                if( shiftPos == 0 )

                { /* No data to convert preceeds the shift byte, just skip it and continue */

                    currPos += 1;

                    continue;

                }

                convSegment.Set( currSegment.Left( shiftPos ) );

                /* Clear to prevent convert to escape sequence */

                escPos = KErrNotFound;

            }

        if( escPos != KErrNotFound )

            { /* Escape sequence found before any shift bytes,

                 clear possible state change and convert data

                 preceeding the escape sequence if

                 escape sequence is not at the beginning */

            changeState = EFalse;

            if( escPos == 0 )

                { /* No data to convert preceeds the escape sequence, just skip it continue */

                currPos += KLit8EscapeSequence().Length();

                continue;

                }

            convSegment.Set( currSegment.Left( escPos ) );

            }

        if( (aState & KBitsForNonStandardStates) == KShiftedToKSCState )

            { /* Convert KSC encoded */

            HBufC8 *tmpForeign = NULL;

            if( (convSegment.Length() & 0x1) )

                { /* KSC should have even amount of bytes */

                ret = CCnvCharacterSetConverter::EErrorIllFormedInput;

                }

            else

                {

                convPos = 0;

                while( convPos < convSegment.Length() )

                    {

                    TRAP( err, tmpForeign = HBufC8::NewL( KMaxSizeOfTmpBuffer ) );

                    if( err != KErrNone )

                        {

                        User::Panic( _L("ISO-2022-KR"), err );

                        }

                    if( convSegment.Length() < KMaxSizeOfTmpBuffer )

                        { /* Convert whole segment */

                        tmpForeign->Des().Copy( convSegment );

                        }

                    else

                        { /* Convert in chunks */

                        if( (convPos + KMaxSizeOfTmpBuffer) >= convSegment.Length() )

                            { /* Last chunk */

                            tmpForeign->Des().Copy( convSegment.Mid( convPos ) );

                            }

                        else

                            {

                            tmpForeign->Des().Copy( convSegment.Mid( convPos, KMaxSizeOfTmpBuffer ) );

                            }

                        }

                    TUint8 *chars = (TUint8 *)tmpForeign->Des().Ptr();

                    for( TInt i = 0 ; i < tmpForeign->Length() ; i++ )

                        { /* Set highest bit in characters */

                        chars[i] |= 0x80;

                        }

                    numberOfUnconvertibleCharacters = 0;

                    ret = CCnvCharacterSetConverter::DoConvertToUnicode( CnvCp949Table::ConversionData(),

                                                                         aDefaultEndiannessOfForeignCharacters,

                                                                         aUnicode, *tmpForeign,

                                                                         numberOfUnconvertibleCharacters,

                                                                         indexOfFirstByteOfFirstUnconvertibleCharacter,

                                                                         outputConversionFlags,

                                                                         inputConversionFlags );

                    if( numberOfUnconvertibleCharacters != 0 &&

                        aNumberOfUnconvertibleCharacters == 0 )

                        { /* First uncovertible found, set index relative to actual input buffer*/

                        aIndexOfFirstByteOfFirstUnconvertibleCharacter = (currPos + convPos + indexOfFirstByteOfFirstUnconvertibleCharacter);

                        }

                    aNumberOfUnconvertibleCharacters += numberOfUnconvertibleCharacters;

                    if( ret < 0 )

                        { /* Some error, break the loop,

                             errors are handled later */

                        delete tmpForeign;

                        break;

                        }

                    if( ret > 0 )

                        { /* Not all were converted, fix return value

                             to be relative to convSegment and break the loop */

                        ret = (convSegment.Length() - convPos - tmpForeign->Length() + ret);

                        delete tmpForeign;

                        break;

                        }

                    convPos += tmpForeign->Length();

                    delete tmpForeign;

                    }

                }

            }

        else

            { /* Convert ASCII encoded by default, KSC can be used without setting highest bit */

                numberOfUnconvertibleCharacters = 0;

                ret = CCnvCharacterSetConverter::DoConvertToUnicode( CnvCp949Table::ConversionData(),

                                                                     aDefaultEndiannessOfForeignCharacters,

                                                                     aUnicode, convSegment,

                                                                     numberOfUnconvertibleCharacters,

                                                                     indexOfFirstByteOfFirstUnconvertibleCharacter,

                                                                     outputConversionFlags,

                                                                     inputConversionFlags );

                if( numberOfUnconvertibleCharacters != 0 &&

                    aNumberOfUnconvertibleCharacters == 0 )

                    { /* First uncovertible found, set index relative to actual input buffer*/

                    aIndexOfFirstByteOfFirstUnconvertibleCharacter = currPos + indexOfFirstByteOfFirstUnconvertibleCharacter;

                    }

                aNumberOfUnconvertibleCharacters += numberOfUnconvertibleCharacters;

            }

        if( ret < 0 )

            { /* Error during conversion */

            return ret;

            }

        else if( ret > 0 )

            { /* Not all characters where converted, return

                 value indicating how many bytes in total are left unconverted */

            return (aForeign.Length() - currPos - convSegment.Length() + ret);

            }

        /* Increase to skip converted data */

        currPos += convSegment.Length();

        if( escPos != KErrNotFound )

            { /* Increase to skip escape sequence */

            currPos += KLit8EscapeSequence().Length();

            }

        else if( shiftPos != KErrNotFound )

            { /* Increase to skip shift byte */

            currPos += 1;

            }

        }

    return 0;

	}

TBool CISO2022KRImplementation::IsInThisCharacterSetL(

    TBool& aSetToTrue, 

    TInt& aConfidenceLevel, 

    const TDesC8& aBuf)

	{

    aSetToTrue=ETrue;

    aConfidenceLevel=200;

    TUint8 ch(0);

    for (TInt i=0;i<aBuf.Length();i++)

        {

        ch=aBuf[i];

        if (ch<0x7F)

            {

            continue;

            }

        else if (0xa1<=ch&&ch<=0xfe)

            {

            i++;

            __ASSERT_DEBUG(i<aBuf.Length(),User::Panic(_L("IS2022KR"),__LINE__));

            }

        else

            {

            aConfidenceLevel=0;

            aSetToTrue=EFalse;

            break;

            }

        }    

	return aSetToTrue;

	}

CISO2022KRImplementation* CISO2022KRImplementation::NewL()

    {

    CISO2022KRImplementation* self = new(ELeave) CISO2022KRImplementation;

    return self;

    }

CISO2022KRImplementation::CISO2022KRImplementation()

    {

    //default constructor.. do nothing

    }

CISO2022KRImplementation::~CISO2022KRImplementation()

    {

    //default destructor .. do nothing

    }

// ECOM CREATION FUNCTION

const TImplementationProxy ImplementationTable[] = 

    {

    // Note: This is the same UID as defined in old mmp-file

    // Used also in 12221212.rss ( implementation_uid )

    IMPLEMENTATION_PROXY_ENTRY( 0x20010101, CISO2022KRImplementation::NewL )

    };

EXPORT_C const TImplementationProxy* ImplementationGroupProxy( TInt& aTableCount )

    {

    aTableCount = sizeof( ImplementationTable ) / sizeof(TImplementationProxy);

    return ImplementationTable;

    }