/*
 * The Apache Software License, Version 1.1
 * 
 * Copyright (c) 1999-2000 The Apache Software Foundation.  All rights
 * reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
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 *    notice, this list of conditions and the following disclaimer in
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 *    distribution.
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 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 * 
 * 4. The names "Xerces" and "Apache Software Foundation" must
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 * 5. Products derived from this software may not be called "Apache",
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 * 
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation, and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */


// ---------------------------------------------------------------------------
//  Includes
// ---------------------------------------------------------------------------
#include <util/XMLASCIITranscoder.hpp>
#include <util/XMLString.hpp>
#include <util/TranscodingException.hpp>
#include <string.h>



// ---------------------------------------------------------------------------
//  XMLASCIITranscoder: Constructors and Destructor
// ---------------------------------------------------------------------------
XMLASCIITranscoder::XMLASCIITranscoder( const   XMLCh* const    encodingName
                                        , const unsigned int    blockSize) :

    XMLTranscoder(encodingName, blockSize)
{
}


XMLASCIITranscoder::~XMLASCIITranscoder()
{
}


// ---------------------------------------------------------------------------
//  XMLASCIITranscoder: Implementation of the transcoder API
// ---------------------------------------------------------------------------
unsigned int
XMLASCIITranscoder::transcodeFrom(  const   XMLByte* const       srcData
                                    , const unsigned int         srcCount
                                    ,       XMLCh* const         toFill
                                    , const unsigned int         maxChars
                                    ,       unsigned int&        bytesEaten
                                    ,       unsigned char* const charSizes)
{
    // If debugging, make sure that the block size is legal
    #if defined(XERCES_DEBUG)
    checkBlockSize(maxChars);
    #endif

    //
    //  Calculate the max chars we can do here. Its the lesser of the
    //  max output chars and the source byte count.
    //
    const unsigned int countToDo = srcCount < maxChars ? srcCount : maxChars;

    //
    //  Now loop through that many source chars and just cast each one
    //  over to the XMLCh format. Check each source that its really a
    //  valid ASCI char.
    //
    const XMLByte*  srcPtr = srcData;
    XMLCh*          outPtr = toFill;
    unsigned int    countDone = 0;
    for (; countDone < countToDo; countDone++)
    {
        // Do the optimistic work up front
        if (*srcPtr < 0x80)
        {
            *outPtr++ = XMLCh(*srcPtr++);
            continue;
        }

        //
        //  We got non source encoding char. If we got more than 32 chars,
        //  the just break out. We'll come back here later to hit this again
        //  and give an error much closer to the real source position.
        //
        if (countDone > 32)
            break;

        XMLCh tmpBuf[16];
        XMLString::binToText((unsigned int)*srcPtr, tmpBuf, 16, 16);
        ThrowXML2
        (
            TranscodingException
            , XMLExcepts::Trans_Unrepresentable
            , tmpBuf
            , getEncodingName()
        );
    }

    // Set the bytes we ate
    bytesEaten = countDone;

    // Set the char sizes to the fixed size
    memset(charSizes, 1, countDone);

    // Return the chars we transcoded
    return countDone;
}


unsigned int
XMLASCIITranscoder::transcodeTo(const   XMLCh* const    srcData
                                , const unsigned int    srcCount
                                ,       XMLByte* const  toFill
                                , const unsigned int    maxBytes
                                ,       unsigned int&   charsEaten
                                , const UnRepOpts       options)
{
    // If debugging, make sure that the block size is legal
    #if defined(XERCES_DEBUG)
    checkBlockSize(maxBytes);
    #endif

    //
    //  Calculate the max chars we can do here. Its the lesser of the
    //  max output chars and the source byte count.
    //
    const unsigned int countToDo = srcCount < maxBytes ? srcCount : maxBytes;

    const XMLCh*    srcPtr = srcData;
    XMLByte*        outPtr = toFill;
    for (unsigned int index = 0; index < countToDo; index++)
    {
        // If its legal, do it and jump back to the top
        if (*srcPtr < 0x80)
        {
            *outPtr++ = XMLByte(*srcPtr++);
            continue;
        }

        //
        //  Its not representable so use a replacement char. According to
        //  the options, either throw or use the replacement.
        //
        if (options == UnRep_Throw)
        {
            XMLCh tmpBuf[16];
            XMLString::binToText((unsigned int)*srcPtr, tmpBuf, 16, 16);
            ThrowXML2
            (
                TranscodingException
                , XMLExcepts::Trans_Unrepresentable
                , tmpBuf
                , getEncodingName()
            );
        }

        // Use the replacement char
        *outPtr++ = 0x1A;
        srcPtr++;
    }

    // Set the chars we ate
    charsEaten = countToDo;

    // Return the byte we transcoded
    return countToDo;
}


bool XMLASCIITranscoder::canTranscodeTo(const unsigned int toCheck) const
{
    return (toCheck < 0x80);
}
