/*
 *  Copyright (c) 2005-2006 Cyrille Berger <cberger@cberger.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
 
 // A big thank to Glenn Randers-Pehrson for it's wonderfull documentation of libpng available at http://www.libpng.org/pub/png/libpng-1.2.5-manual.html
#include "kis_png_converter.h"

#include <stdio.h>

#include <tqfile.h>

#include <tdeapplication.h>
#include <kmessagebox.h>
#include <klocale.h>

#include <KoDocumentInfo.h>

#include <tdeio/netaccess.h>

#include <kis_abstract_colorspace.h>
#include <kis_colorspace_factory_registry.h>
#include <kis_doc.h>
#include <kis_image.h>
#include <kis_iterators_pixel.h>
#include <kis_layer.h>
#include <kis_meta_registry.h>
#include <kis_profile.h>
#include <kis_paint_layer.h>
#include <kis_group_layer.h>

#include <zlib.h>

namespace {

    const TQ_UINT8 PIXEL_BLUE = 0;
    const TQ_UINT8 PIXEL_GREEN = 1;
    const TQ_UINT8 PIXEL_RED = 2;
    const TQ_UINT8 PIXEL_ALPHA = 3;

    
    int getColorTypeforColorSpace( KisColorSpace * cs , bool alpha)
    {
        if ( cs->id() == KisID("GRAYA") || cs->id() == KisID("GRAYA16") )
        {
            return alpha ? PNG_COLOR_TYPE_GRAY_ALPHA : PNG_COLOR_TYPE_GRAY;
        }
        if ( cs->id() == KisID("RGBA") || cs->id() == KisID("RGBA16") )
        {
            return alpha ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB;
        }

        KMessageBox::error(0, i18n("Cannot export images in %1.\n").arg(cs->id().name()) ) ;
        return -1;

    }

    
    TQString getColorSpaceForColorType(int color_type,int color_nb_bits) {
        if(color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
        {
            switch(color_nb_bits)
            {
                case 8:
                    return "GRAYA";
                case 16:
                    return "GRAYA16";
            }
        } else if(color_type == PNG_COLOR_TYPE_RGB_ALPHA || color_type == PNG_COLOR_TYPE_RGB) {
            switch(color_nb_bits)
            {
                case 8:
                    return "RGBA";
                case 16:
                    return "RGBA16";
            }
        } else if(color_type ==  PNG_COLOR_TYPE_PALETTE) {
            return "RGBA"; // <-- we will convert the index image to RGBA
        }
        return "";
    }


    void fillText(png_text* p_text, char* key, TQString& text)
    {
        p_text->compression = PNG_TEXT_COMPRESSION_zTXt;
        p_text->key = key;
        char* textc = new char[text.length()+1];
        strcpy(textc, text.ascii());
        p_text->text = textc;
        p_text->text_length = text.length()+1;
    }

}

KisPNGConverter::KisPNGConverter(KisDoc *doc, KisUndoAdapter *adapter)
{
    Q_ASSERT(doc);
    Q_ASSERT(adapter);
    
    m_doc = doc;
    m_adapter = adapter;
    m_stop = false;
    m_max_row = 0;
    m_img = 0;
}

KisPNGConverter::~KisPNGConverter()
{
}

class KisPNGStream {
    public:
        KisPNGStream(TQ_UINT8* buf,  TQ_UINT32 depth ) : m_posinc(8),m_depth(depth), m_buf(buf) { *m_buf = 0;};
        int nextValue()
        {
            if( m_posinc == 0)
            {
                m_posinc = 8;
                m_buf++;
            }
            m_posinc -= m_depth;
            return (( (*m_buf) >> (m_posinc) ) & ( ( 1 << m_depth ) - 1 ) );
        }
        void setNextValue(int v)
        {
            if( m_posinc == 0)
            {
                m_posinc = 8;
                m_buf++;
                *m_buf = 0;
            }
            m_posinc -= m_depth;
            *m_buf = (v << m_posinc) | *m_buf;
        }
    private:
        TQ_UINT32 m_posinc, m_depth;
        TQ_UINT8* m_buf;
};

KisImageBuilder_Result KisPNGConverter::decode(const KURL& uri)
{
    kdDebug(41008) << "Start decoding PNG File" << endl;
    // open the file
    kdDebug(41008) << TQString(TQFile::encodeName(uri.path())) << " " << uri.path() << " " << uri << endl;
    FILE *fp = fopen(TQFile::encodeName(uri.path()), "rb");
    if (!fp)
    {
        return (KisImageBuilder_RESULT_NOT_EXIST);
    }
    png_byte signature[8];
    fread(signature, 1, 8, fp);
    if (!png_check_sig(signature, 8))
    {
        return (KisImageBuilder_RESULT_BAD_FETCH);
    }

    // Initialize the internal structures
    png_structp png_ptr =  png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, (png_error_ptr)NULL, (png_error_ptr)NULL);
    if (!KisImageBuilder_RESULT_FAILURE)
        return (KisImageBuilder_RESULT_FAILURE);

    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr)
    {
        png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
        return (KisImageBuilder_RESULT_FAILURE);
    }

    png_infop end_info = png_create_info_struct(png_ptr);
    if (!end_info)
    {
        png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
        return (KisImageBuilder_RESULT_FAILURE);
    }

    // Catch errors
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
        fclose(fp);
        return (KisImageBuilder_RESULT_FAILURE);
    }
    
    png_init_io(png_ptr, fp);
    png_set_sig_bytes(png_ptr, 8);
    
    // read all PNG info up to image data
    png_read_info(png_ptr, info_ptr);

    // Read information about the png
    png_uint_32 width, height;
    int color_nb_bits, color_type, interlace_type;
    png_get_IHDR(png_ptr, info_ptr, &width, &height, &color_nb_bits, &color_type, &interlace_type, NULL, NULL);
    kdDebug(41008) << "it's an " << color_nb_bits << " depth image" << endl;

    // swap byteorder on little endian machines.
    #ifndef WORDS_BIGENDIAN
    if (color_nb_bits > 8 )
        png_set_swap(png_ptr);
    #endif

    // Determine the colorspace
    TQString csName = getColorSpaceForColorType(color_type, color_nb_bits);
    if(csName.isEmpty()) {
        png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
        return KisImageBuilder_RESULT_UNSUPPORTED_COLORSPACE;
    }
    bool hasalpha = (color_type == PNG_COLOR_TYPE_RGB_ALPHA || color_type == PNG_COLOR_TYPE_GRAY_ALPHA);
    
    // Read image profile
    png_charp profile_name, profile_data;
#if PNG_LIBPNG_VER_MAJOR > 1 || ( PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5 )
    unsigned char* uprofile_data = reinterpret_cast<unsigned char*>(profile_data);
#endif
    int compression_type;
    png_uint_32 proflen;
    int number_of_passes = 1;

    if (interlace_type == PNG_INTERLACE_ADAM7)
        number_of_passes = png_set_interlace_handling(png_ptr);

    KisProfile* profile = 0;
#if PNG_LIBPNG_VER_MAJOR > 1 || ( PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5 )
    if(png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &uprofile_data, &proflen))
#else
    if(png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &proflen))
#endif
    {
        TQByteArray profile_rawdata;
        // XXX: Hardcoded for icc type -- is that correct for us?
        if (TQString::compare(profile_name, "icc") == 0) {
            profile_rawdata.resize(proflen);
            memcpy(profile_rawdata.data(), profile_data, proflen);
            profile = new KisProfile(profile_rawdata);
            TQ_CHECK_PTR(profile);
            if (profile) {
                kdDebug(41008) << "profile name: " << profile->productName() << " profile description: " << profile->productDescription() << " information sur le produit: " << profile->productInfo() << endl;
                if(!profile->isSuitableForOutput())
                {
                    kdDebug(41008) << "the profile is not suitable for output and therefore cannot be used in chalk, we need to convert the image to a standard profile" << endl; // TODO: in ko2 popup a selection menu to inform the user
                }
            }
        }
    }

    // Retrieve a pointer to the colorspace
    KisColorSpace* cs;
    if (profile && profile->isSuitableForOutput())
    {
        kdDebug(41008) << "image has embedded profile: " << profile -> productName() << "\n";
        cs = KisMetaRegistry::instance()->csRegistry()->getColorSpace(csName, profile);
    }
    else
        cs = KisMetaRegistry::instance()->csRegistry()->getColorSpace(KisID(csName,""),"");

    if(cs == 0)
    {
        png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
        return KisImageBuilder_RESULT_UNSUPPORTED_COLORSPACE;
    }
    
    // Create the cmsTransform if needed 
    cmsHTRANSFORM transform = 0;
    if(profile && !profile->isSuitableForOutput())
    {
        transform = cmsCreateTransform(profile->profile(), cs->colorSpaceType(),
                                       cs->getProfile()->profile() , cs->colorSpaceType(),
                                       INTENT_PERCEPTUAL, 0);
    }

    // Read comments/texts...
    png_text* text_ptr;
    int num_comments;
    png_get_text(png_ptr, info_ptr, &text_ptr, &num_comments);
    KoDocumentInfo * info = m_doc->documentInfo();
    KoDocumentInfoAbout * aboutPage = static_cast<KoDocumentInfoAbout *>(info->page( "about" ));
    KoDocumentInfoAuthor * authorPage = static_cast<KoDocumentInfoAuthor *>(info->page( "author"));
    kdDebug(41008) << "There are " << num_comments << " comments in the text" << endl;
    for(int i = 0; i < num_comments; i++)
    {
        kdDebug(41008) << "key is " << text_ptr[i].key << " containing " << text_ptr[i].text << endl;
        if(TQString::compare(text_ptr[i].key, "title") == 0)
        {
                aboutPage->setTitle(text_ptr[i].text);
        } else if(TQString::compare(text_ptr[i].key, "abstract")  == 0)
        {
                aboutPage->setAbstract(text_ptr[i].text);
        } else if(TQString::compare(text_ptr[i].key, "author") == 0)
        {
                authorPage->setFullName(text_ptr[i].text);
        }
    }
    
    // Read image data
    png_bytep row_pointer = 0;
    try
    {
        png_uint_32 rowbytes = png_get_rowbytes(png_ptr, info_ptr);
        row_pointer = new png_byte[rowbytes];
    }
    catch(std::bad_alloc& e)
    {
        // new png_byte[] may raise such an exception if the image
        // is invalid / to large.
        kdDebug(41008) << "bad alloc: " << e.what() << endl;
        // Free only the already allocated png_byte instances.
        png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
        return (KisImageBuilder_RESULT_FAILURE);
    }
    
    // Read the palette if the file is indexed
    png_colorp palette ;
    int num_palette;
    if(color_type == PNG_COLOR_TYPE_PALETTE) {
        png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette);
    }
//     png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL );
//     png_bytepp row_pointers = png_get_rows(png_ptr, info_ptr); // By using this function libpng will take care of freeing memory
//    png_read_image(png_ptr, row_pointers);
    
    // Finish reading the file
//    png_read_end(png_ptr, end_info);
//    fclose(fp);
    
    // Creating the KisImageSP
    if( ! m_img) {
        m_img = new KisImage(m_doc->undoAdapter(), width, height, cs, "built image");
        m_img->blockSignals(true); // Don't send out signals while we're building the image
        TQ_CHECK_PTR(m_img);
        if(profile && !profile->isSuitableForOutput())
        {
            m_img -> addAnnotation( profile->annotation() );
        }
    }

    KisPaintLayer* layer = new KisPaintLayer(m_img, m_img -> nextLayerName(), TQ_UINT8_MAX);
    for (int i = 0; i < number_of_passes; i++)
    {
        for (png_uint_32 y = 0; y < height; y++) {
            KisHLineIterator it = layer -> paintDevice() -> createHLineIterator(0, y, width, true);
            png_read_rows(png_ptr, &row_pointer, NULL, 1);

            switch(color_type)
            {
                case PNG_COLOR_TYPE_GRAY:
                case PNG_COLOR_TYPE_GRAY_ALPHA:
                    if(color_nb_bits == 16)
                    {
                        TQ_UINT16 *src = reinterpret_cast<TQ_UINT16 *>(row_pointer);
                        while (!it.isDone()) {
                            TQ_UINT16 *d = reinterpret_cast<TQ_UINT16 *>(it.rawData());
                            d[0] = *(src++);
                            if(transform) cmsDoTransform(transform, d, d, 1);
                            if(hasalpha) d[1] = *(src++);
                            else d[1] = TQ_UINT16_MAX;
                            ++it;
                        }
                    } else {
                        TQ_UINT8 *src = row_pointer;
                        while (!it.isDone()) {
                            TQ_UINT8 *d = it.rawData();
                            d[0] = *(src++);
                            if(transform) cmsDoTransform(transform, d, d, 1);
                            if(hasalpha) d[1] = *(src++);
                            else d[1] = TQ_UINT8_MAX;
                            ++it;
                        }
                    }
                //FIXME:should be able to read 1 and 4 bits depth and scale them to 8 bits
                    break;
                case PNG_COLOR_TYPE_RGB:
                case PNG_COLOR_TYPE_RGB_ALPHA:
                    if(color_nb_bits == 16)
                    {
                        TQ_UINT16 *src = reinterpret_cast<TQ_UINT16 *>(row_pointer);
                        while (!it.isDone()) {
                            TQ_UINT16 *d = reinterpret_cast<TQ_UINT16 *>(it.rawData());
                            d[2] = *(src++);
                            d[1] = *(src++);
                            d[0] = *(src++);
                            if(transform) cmsDoTransform(transform, d, d, 1);
                            if(hasalpha) d[3] = *(src++);
                            else d[3] = TQ_UINT16_MAX;
                            ++it;
                        }
                    } else {
                        TQ_UINT8 *src = row_pointer;
                        while (!it.isDone()) {
                            TQ_UINT8 *d = it.rawData();
                            d[2] = *(src++);
                            d[1] = *(src++);
                            d[0] = *(src++);
                            if(transform) cmsDoTransform(transform, d, d, 1);
                            if(hasalpha) d[3] = *(src++);
                            else d[3] = TQ_UINT8_MAX;
                            ++it;
                        }
                    }
                    break;
                case PNG_COLOR_TYPE_PALETTE:
                    {
                        KisPNGStream stream(row_pointer, color_nb_bits);
                        while (!it.isDone()) {
                            TQ_UINT8 *d = it.rawData();
                            png_color c = palette[ stream.nextValue() ];
                            d[2] = c.red;
                            d[1] = c.green;
                            d[0] = c.blue;
                            d[3] = TQ_UINT8_MAX;
                            ++it;
                        }
                    }
                    break;
                default:
                    return KisImageBuilder_RESULT_UNSUPPORTED;
            }
        }
    }
    m_img->addLayer(layer, m_img->rootLayer(), 0);

    png_read_end(png_ptr, end_info);
    fclose(fp);

    // Freeing memory
    png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);

    delete [] row_pointer;

    return KisImageBuilder_RESULT_OK;

}

KisImageBuilder_Result KisPNGConverter::buildImage(const KURL& uri)
{
    kdDebug(41008) << TQString(TQFile::encodeName(uri.path())) << " " << uri.path() << " " << uri << endl;
    if (uri.isEmpty())
        return KisImageBuilder_RESULT_NO_URI;

    if (!TDEIO::NetAccess::exists(uri, false, tqApp -> mainWidget())) {
        return KisImageBuilder_RESULT_NOT_EXIST;
    }

    // We're not set up to handle asynchronous loading at the moment.
    KisImageBuilder_Result result = KisImageBuilder_RESULT_FAILURE;
    TQString tmpFile;

    if (TDEIO::NetAccess::download(uri, tmpFile, tqApp -> mainWidget())) {
        KURL uriTF;
        uriTF.setPath( tmpFile );
        result = decode(uriTF);
        TDEIO::NetAccess::removeTempFile(tmpFile);
    }

    return result;
}


KisImageSP KisPNGConverter::image()
{
    return m_img;
}

KisImageBuilder_Result KisPNGConverter::buildFile(const KURL& uri, KisPaintLayerSP layer, vKisAnnotationSP_it annotationsStart, vKisAnnotationSP_it annotationsEnd, int compression, bool interlace, bool alpha)
{
    kdDebug(41008) << "Start writing PNG File" << endl;
    if (!layer)
        return KisImageBuilder_RESULT_INVALID_ARG;

    KisImageSP img = layer -> image();
    if (!img)
        return KisImageBuilder_RESULT_EMPTY;

    if (uri.isEmpty())
        return KisImageBuilder_RESULT_NO_URI;

    if (!uri.isLocalFile())
        return KisImageBuilder_RESULT_NOT_LOCAL;
    // Open file for writing
    FILE *fp = fopen(TQFile::encodeName(uri.path()), "wb");
    if (!fp)
    {
        return (KisImageBuilder_RESULT_FAILURE);
    }
    int height = img->height();
    int width = img->width();
    // Initialize structures
    png_structp png_ptr =  png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, (png_error_ptr)NULL, (png_error_ptr)NULL);
    if (!png_ptr)
    {
        TDEIO::del(uri);
        return (KisImageBuilder_RESULT_FAILURE);
    }

    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr)
    {
        TDEIO::del(uri);
        png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
        return (KisImageBuilder_RESULT_FAILURE);
    }

    // If an error occurs during writing, libpng will jump here
    if (setjmp(png_jmpbuf(png_ptr)))
    {
        TDEIO::del(uri);
        png_destroy_write_struct(&png_ptr, &info_ptr);
        fclose(fp);
        return (KisImageBuilder_RESULT_FAILURE);
    }
    // Initialize the writing
    png_init_io(png_ptr, fp);
    // Setup the progress function
// FIXME    png_set_write_status_fn(png_ptr, progress);
//     setProgressTotalSteps(100/*height*/);
    

    /* set the zlib compression level */
    png_set_compression_level(png_ptr, compression);

    /* set other zlib parameters */
    png_set_compression_mem_level(png_ptr, 8);
    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
    png_set_compression_window_bits(png_ptr, 15);
    png_set_compression_method(png_ptr, 8);
    png_set_compression_buffer_size(png_ptr, 8192);
    
    int color_nb_bits = 8 * layer->paintDevice()->pixelSize() / layer->paintDevice()->nChannels();
    int color_type = getColorTypeforColorSpace(layer->paintDevice()->colorSpace(), alpha);
    
    if(color_type == -1)
    {
        return KisImageBuilder_RESULT_UNSUPPORTED;
    }
    
    // Try to compute a table of color if the colorspace is RGB8f
    png_colorp palette ;
    int num_palette = 0;
    if(!alpha && layer->paintDevice()->colorSpace()->id() == KisID("RGBA") )
    { // png doesn't handle indexed images and alpha, and only have indexed for RGB8
        palette = new png_color[255];
        KisRectIteratorPixel it = layer->paintDevice()->createRectIterator(0,0, img->width(), img->height(), false);
        bool toomuchcolor = false;
        while( !it.isDone() )
        {
            const TQ_UINT8* c = it.rawData();
            bool findit = false;
            for(int i = 0; i < num_palette; i++)
            {
                if(palette[i].red == c[2] &&
                   palette[i].green == c[1] &&
                   palette[i].blue == c[0] )
                {
                    findit = true;
                    break;
                }
            }
            if(!findit)
            {
                if( num_palette == 255)
                {
                    toomuchcolor = true;
                    break;
                }
                palette[num_palette].red = c[2];
                palette[num_palette].green = c[1];
                palette[num_palette].blue = c[0];
                num_palette++;
            }
            ++it;
        }
        if(!toomuchcolor)
        {
            kdDebug(41008) << "Found a palette of " << num_palette << " colors" << endl;
            color_type = PNG_COLOR_TYPE_PALETTE;
            if( num_palette <= 2)
            {
                color_nb_bits = 1;
            } else if( num_palette <= 4)
            {
                color_nb_bits = 2;
            } else if( num_palette <= 16)
            {
                color_nb_bits = 4;
            } else {
                color_nb_bits = 8;
            }
        } else {
            delete palette;
        }
    }
    
    int interlacetype = interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
    
    png_set_IHDR(png_ptr, info_ptr,
                 width,
                 height,
                 color_nb_bits,
                 color_type, interlacetype,
                 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
    
    png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE);
    // set the palette
    if( color_type == PNG_COLOR_TYPE_PALETTE)
    {
        png_set_PLTE(png_ptr, info_ptr, palette, num_palette);
    }
    // Save annotation
    vKisAnnotationSP_it it = annotationsStart;
    while(it != annotationsEnd) {
        if (!(*it) || (*it) -> type() == TQString()) {
            kdDebug(41008) << "Warning: empty annotation" << endl;
            ++it;
            continue;
        }

        kdDebug(41008) << "Trying to store annotation of type " << (*it) -> type() << " of size " << (*it) -> annotation() . size() << endl;

        if ((*it) -> type().startsWith("chalk_attribute:")) { // Attribute
            // FIXME: it should be possible to save chalk_attributes in the "CHUNKs"
            kdDebug(41008) << "can't save this annotation : " << (*it) -> type() << endl;
        } else { // Profile
            char* name = new char[(*it)->type().length()+1];
            strcpy(name, (*it)->type().ascii());
#if PNG_LIBPNG_VER_MAJOR > 1 || ( PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5 )
            png_set_iCCP(png_ptr, info_ptr, name, PNG_COMPRESSION_TYPE_BASE, (unsigned char*)(*it)->annotation().data(), (*it) -> annotation() . size());
#else
            png_set_iCCP(png_ptr, info_ptr, name, PNG_COMPRESSION_TYPE_BASE, (char*)(*it)->annotation().data(), (*it) -> annotation() . size());
#endif
        }
        ++it;
    }

    // read comments from the document information
    png_text texts[3];
    int nbtexts = 0;
    KoDocumentInfo * info = m_doc->documentInfo();
    KoDocumentInfoAbout * aboutPage = static_cast<KoDocumentInfoAbout *>(info->page( "about" ));
    TQString title = aboutPage->title();
    if(!title.isEmpty())
    {
        fillText(texts+nbtexts, "title", title);
        nbtexts++;
    }
    TQString abstract = aboutPage->abstract();
    if(!abstract.isEmpty())
    {
        fillText(texts+nbtexts, "abstract", abstract);
        nbtexts++;
    }
    KoDocumentInfoAuthor * authorPage = static_cast<KoDocumentInfoAuthor *>(info->page( "author" ));
    TQString author = authorPage->fullName();
    if(!author.isEmpty())
    {
        fillText(texts+nbtexts, "author", author);
        nbtexts++;
    }
    
    png_set_text(png_ptr, info_ptr, texts, nbtexts);
    
    // Save the information to the file
    png_write_info(png_ptr, info_ptr);
    png_write_flush(png_ptr);

    // swap byteorder on little endian machines.
    #ifndef WORDS_BIGENDIAN
    if (color_nb_bits > 8 )
        png_set_swap(png_ptr);
    #endif

    // Write the PNG
//     png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
    
    // Fill the data structure
    png_byte** row_pointers= new png_byte*[height];
    
    for (int y = 0; y < height; y++) {
        KisHLineIterator it = layer->paintDevice()->createHLineIterator(0, y, width, false);
        row_pointers[y] = new png_byte[width*layer->paintDevice()->pixelSize()];
        switch(color_type)
        {
            case PNG_COLOR_TYPE_GRAY:
            case PNG_COLOR_TYPE_GRAY_ALPHA:
                if(color_nb_bits == 16)
                {
                    TQ_UINT16 *dst = reinterpret_cast<TQ_UINT16 *>(row_pointers[y]);
                    while (!it.isDone()) {
                        const TQ_UINT16 *d = reinterpret_cast<const TQ_UINT16 *>(it.rawData());
                        *(dst++) = d[0];
                        if(alpha) *(dst++) = d[1];
                        ++it;
                    }
                } else {
                    TQ_UINT8 *dst = row_pointers[y];
                    while (!it.isDone()) {
                        const TQ_UINT8 *d = it.rawData();
                        *(dst++) = d[0];
                        if(alpha) *(dst++) = d[1];
                        ++it;
                    }
                }
                break;
            case PNG_COLOR_TYPE_RGB:
            case PNG_COLOR_TYPE_RGB_ALPHA:
                if(color_nb_bits == 16)
                {
                    TQ_UINT16 *dst = reinterpret_cast<TQ_UINT16 *>(row_pointers[y]);
                    while (!it.isDone()) {
                        const TQ_UINT16 *d = reinterpret_cast<const TQ_UINT16 *>(it.rawData());
                        *(dst++) = d[2];
                        *(dst++) = d[1];
                        *(dst++) = d[0];
                        if(alpha) *(dst++) = d[3];
                        ++it;
                    }
                } else {
                    TQ_UINT8 *dst = row_pointers[y];
                    while (!it.isDone()) {
                        const TQ_UINT8 *d = it.rawData();
                        *(dst++) = d[2];
                        *(dst++) = d[1];
                        *(dst++) = d[0];
                        if(alpha) *(dst++) = d[3];
                        ++it;
                    }
                }
                break;
            case PNG_COLOR_TYPE_PALETTE:
            {
                TQ_UINT8 *dst = row_pointers[y];
                KisPNGStream writestream(dst, color_nb_bits);
                while (!it.isDone()) {
                    const TQ_UINT8 *d = it.rawData();
                    int i;
                    for(i = 0; i < num_palette; i++)
                    {
                        if(palette[i].red == d[2] &&
                           palette[i].green == d[1] &&
                           palette[i].blue == d[0] )
                        {
                            break;
                        }
                    }
                    writestream.setNextValue(i);
                    ++it;
                }
            }
            break;
            default:
                kdDebug(41008) << "Unsupported color type for writting : " << color_type << endl;
                TDEIO::del(uri);
                return KisImageBuilder_RESULT_UNSUPPORTED;
        }
    }
    
    png_write_image(png_ptr, row_pointers);


    // Writting is over
    png_write_end(png_ptr, info_ptr);
    
    // Free memory
    png_destroy_write_struct(&png_ptr, &info_ptr);
    for (int y = 0; y < height; y++) {
        delete[] row_pointers[y];
    }
    delete[] row_pointers;

    if( color_type == PNG_COLOR_TYPE_PALETTE)
    {
        delete palette;
    }

    fclose(fp);
    
    return KisImageBuilder_RESULT_OK;
}


void KisPNGConverter::cancel()
{
    m_stop = true;
}

void KisPNGConverter::progress(png_structp png_ptr, png_uint_32 row_number, int pass)
{
    if(png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7) return;
//     setProgress(row_number);
}


#include "kis_png_converter.moc"