/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



#include "rtl/textcvt.h"
#include <tools/debug.hxx>

namespace { // anonymous namespace

// ====================================================================

#define MAX_CVT_SELECT 6

class ConverterCache
{
public:
	explicit	ConverterCache( void );
				~ConverterCache( void );
	sal_uInt16	convertOne( int nSelect, sal_Unicode );
	void		convertStr( int nSelect, const sal_Unicode* pSrc, sal_uInt16* pDst, int nCount );
protected:
	void		ensureConverter( int nSelect );
private:
	rtl_UnicodeToTextConverter maConverterCache[ MAX_CVT_SELECT+1 ];
	rtl_UnicodeToTextContext maContexts[ MAX_CVT_SELECT+1 ];
};

// ====================================================================

ConverterCache::ConverterCache( void)
{
	for( int i = 0; i <= MAX_CVT_SELECT; ++i)
	{
		maConverterCache[i] = NULL;
		maContexts[i] = NULL;
	}
}

// --------------------------------------------------------------------

ConverterCache::~ConverterCache( void)
{
	for( int i = 0; i <= MAX_CVT_SELECT; ++i)
	{
		if( !maContexts[i] )
			continue;
		rtl_destroyUnicodeToTextContext( maConverterCache[i], maContexts[i] );
		rtl_destroyUnicodeToTextConverter( maConverterCache[i] );
	}
}

// --------------------------------------------------------------------

void ConverterCache::ensureConverter( int nSelect )
{
	// DBG_ASSERT( (2<=nSelect) && (nSelect<=MAX_CVT_SELECT)), "invalid XLAT.Converter requested" );
	rtl_UnicodeToTextContext aContext = maContexts[ nSelect ];
	if( !aContext )
	{
		rtl_TextEncoding eRecodeFrom = RTL_TEXTENCODING_UNICODE;
		switch( nSelect )
		{
			default: nSelect = 1; // fall through to unicode recoding
			case 1: eRecodeFrom = RTL_TEXTENCODING_UNICODE; break;
			case 2: eRecodeFrom = RTL_TEXTENCODING_SHIFT_JIS; break;
			case 3: eRecodeFrom = RTL_TEXTENCODING_GB_2312; break;
			case 4: eRecodeFrom = RTL_TEXTENCODING_BIG5; break;
			case 5: eRecodeFrom = RTL_TEXTENCODING_MS_949; break;
			case 6: eRecodeFrom = RTL_TEXTENCODING_MS_1361; break;
		}
		rtl_UnicodeToTextConverter aRecodeConverter = rtl_createUnicodeToTextConverter( eRecodeFrom );
		maConverterCache[ nSelect ] = aRecodeConverter;

		aContext = rtl_createUnicodeToTextContext( aRecodeConverter );
		maContexts[ nSelect ] = aContext;
	}

	rtl_resetUnicodeToTextContext( maConverterCache[ nSelect ], aContext );
}

// --------------------------------------------------------------------

sal_uInt16 ConverterCache::convertOne( int nSelect, sal_Unicode aChar )
{
	ensureConverter( nSelect );

	sal_Unicode aUCS2Char = aChar;
	sal_Char aTempArray[8];
	sal_Size nTempSize;
	sal_uInt32 nCvtInfo;

	// TODO: use direct unicode->mbcs converter should there ever be one
	int nCodeLen = rtl_convertUnicodeToText(
			maConverterCache[ nSelect ], maContexts[ nSelect ],
			&aUCS2Char, 1, aTempArray, sizeof(aTempArray),
			RTL_UNICODETOTEXT_FLAGS_UNDEFINED_0
			| RTL_UNICODETOTEXT_FLAGS_INVALID_0,
			&nCvtInfo, &nTempSize );

	sal_uInt16 aCode = aTempArray[0];
	for( int i = 1; i < nCodeLen; ++i )
		aCode = (aCode << 8) + (aTempArray[i] & 0xFF);
	return aCode;
}

// --------------------------------------------------------------------

void ConverterCache::convertStr( int nSelect, const sal_Unicode* pSrc, sal_uInt16* pDst, int nCount )
{
	ensureConverter( nSelect );

	for( int n = 0; n < nCount; ++n )
	{
		sal_Unicode aUCS2Char = pSrc[n];

		sal_Char aTempArray[8];
		sal_Size nTempSize;
		sal_uInt32 nCvtInfo;

		// assume that non-unicode-fonts do not support codepoints >U+FFFF
		// TODO: use direct unicode->mbcs converter should there ever be one
		int nCodeLen = rtl_convertUnicodeToText(
			maConverterCache[ nSelect ], maContexts[ nSelect ],
			&aUCS2Char, 1, aTempArray, sizeof(aTempArray),
			RTL_UNICODETOTEXT_FLAGS_UNDEFINED_0
			| RTL_UNICODETOTEXT_FLAGS_INVALID_0,
			&nCvtInfo, &nTempSize );

		sal_uInt16 aCode = aTempArray[0];
		for( int i = 1; i < nCodeLen; ++i )
			aCode = (aCode << 8) + (aTempArray[i] & 0xFF);
		pDst[n] = aCode;
	}
}

} // anonymous namespace

// ====================================================================

#include "xlat.hxx"

namespace vcl
{

static ConverterCache aCC;

sal_uInt16 TranslateChar12(sal_uInt16 src)
{
    return aCC.convertOne( 2, src);
}

sal_uInt16 TranslateChar13(sal_uInt16 src)
{
    return aCC.convertOne( 3, src);
}

sal_uInt16 TranslateChar14(sal_uInt16 src)
{
    return aCC.convertOne( 4, src);
}

sal_uInt16 TranslateChar15(sal_uInt16 src)
{
    return aCC.convertOne( 5, src);
}

sal_uInt16 TranslateChar16(sal_uInt16 src)
{
    return aCC.convertOne( 6, src);
}
    
void TranslateString12(sal_uInt16 *src, sal_uInt16 *dst, sal_uInt32 n)
{
	aCC.convertStr( 2, src, dst, n);
}
            
void TranslateString13(sal_uInt16 *src, sal_uInt16 *dst, sal_uInt32 n)
{
	aCC.convertStr( 3, src, dst, n);
}
        
void TranslateString14(sal_uInt16 *src, sal_uInt16 *dst, sal_uInt32 n)
{
	aCC.convertStr( 4, src, dst, n);
}
        
void TranslateString15(sal_uInt16 *src, sal_uInt16 *dst, sal_uInt32 n)
{
	aCC.convertStr( 5, src, dst, n);
}

void TranslateString16(sal_uInt16 *src, sal_uInt16 *dst, sal_uInt32 n)
{
	aCC.convertStr( 6, src, dst, n);
}
        
} // namespace vcl