// This library is distributed under the conditions of the GNU LGPL.
#include "config.h"

#ifdef HAVE_OPENJPEG

#include <unistd.h>
#include "jp2.h"

#if !defined(__STDC_LIMIT_MACROS)
#define __STDC_LIMIT_MACROS
#endif

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif

#include <openjpeg.h>

#include <kdebug.h>
#include <tdetempfile.h>
#include <tqcolor.h>
#include <tqcstring.h>
#include <tqfile.h>
#include <tqimage.h>
#include <tqmemarray.h>

/*
 * JPEG-2000 Plugin for KImageIO.
 *
 * Current limitations:
 * - Only reads sRGB/Grayscale images (doesn't convert colorspace).
 * - Doesn't support writing images.
 * - Doesn't support OPJ_CODEC_J2K.
 * - Doesn't support subsampling.
 * - Doesn't read ICC profiles.
 * - Doesn't write images.
 *
 * Improvements:
 * - kimgio_jp2_read_srgba/kimgio_jp2_read_grayscale could be merged.
 *
 * The API documentation is rather poor, so good references on how to use OpenJPEG
 * are the tools provided by OpenJPEG, such as 'opj_decompress':
 *   https://github.com/uclouvain/openjpeg/blob/master/src/bin/jp2/opj_decompress.c
 *   https://github.com/uclouvain/openjpeg/blob/master/src/bin/jp2/opj_compress.c
 */

// kdDebug category
constexpr int kCategory = 399;

struct KIMGJP2Wrapper
{
 public:
    opj_codec_t *codec { nullptr };
    opj_image_t *image { nullptr };
    opj_stream_t *stream { nullptr };
    KTempFile tempFile;

    ~KIMGJP2Wrapper()
    {
        if (stream)
        {
            opj_stream_destroy(stream);
        }
        if (image)
        {
            opj_image_destroy(image);
        }
        if (codec)
        {
            opj_destroy_codec(codec);
        }
    }
};

static void kimgio_jp2_err_handler(const char *message, void *data)
{
    kdError(kCategory) << "Error decoding JP2 image: " << message;
}

static void kimgio_jp2_info_handler(const char *message, void *data)
{
    // Reports status, e.g.: Main header has been correctly decoded.
    // kdDebug(kCategory) << "JP2 decoding message: " << message;
}

static void kimgio_jp2_warn_handler(const char *message, void *data)
{
    kdWarning(kCategory) << "Warning decoding JP2 image: " << message;
}

static void kimgio_jp2_read_srgba(TQImage &image, const KIMGJP2Wrapper &jp2)
{
    const int height = image.height();
    const int width = image.width();

    unsigned char alphaMask = 0x0;

    for (int row = 0; row < height; row++)
    {
        for (int col = 0; col < width; col++)
        {
            const int offset = row * width + col;
            OPJ_INT32 r, g, b, a = 0xFF;

            // Convert to unsigned
            r = jp2.image->comps[0].data[offset];
            r += (jp2.image->comps[0].sgnd ? 1 << (jp2.image->comps[0].prec - 1) : 0);

            g = jp2.image->comps[1].data[offset];
            g += (jp2.image->comps[0].sgnd ? 1 << (jp2.image->comps[1].prec - 1) : 0);

            b = jp2.image->comps[2].data[offset];
            b += (jp2.image->comps[2].sgnd ? 1 << (jp2.image->comps[2].prec - 1) : 0);

            if (jp2.image->numcomps > 3 && jp2.image->comps[3].alpha)
            {
                a = jp2.image->comps[3].data[offset];
                a += (jp2.image->comps[3].sgnd ? 1 << (jp2.image->comps[3].prec - 1) : 0);
            }

            image.setPixel(col, row, tqRgba(r, g, b, a));
            alphaMask |= (255 - a);
        }
    }

    if (alphaMask != 0x0)
    {
        image.setAlphaBuffer(true);
    }
}

static void kimgio_jp2_read_grayscale(TQImage &image, const KIMGJP2Wrapper &jp2)
{
    const int height = image.height();
    const int width = image.width();

    unsigned char alphaMask = 0x0;

    for (int row = 0; row < height; row++)
    {
        for (int col = 0; col < width; col++)
        {
            const int offset = row * width + col;
            OPJ_INT32 g, a = 0xFF;

            // Convert to unsigned
            g = jp2.image->comps[0].data[offset];
            g += (jp2.image->comps[0].sgnd ? (1 << jp2.image->comps[0].prec - 1) : 0);

            if (jp2.image->numcomps > 1 && jp2.image->comps[1].alpha)
            {
                a = jp2.image->comps[1].data[offset];
                a = (jp2.image->comps[1].sgnd ? (1 << jp2.image->comps[1].prec - 1) : 0);
            }

            image.setPixel(col, row, tqRgba(g, g, g, a));
            alphaMask |= (255 - a);
        }
    }

    if (alphaMask != 0x0)
    {
        image.setAlphaBuffer(true);
    }
}

static const char *colorspaceToString(COLOR_SPACE clr)
{
    switch (clr)
    {
        case OPJ_CLRSPC_SRGB:
        {
            return "sRGB";
        }
        case OPJ_CLRSPC_GRAY:
        {
            return "sRGB Grayscale";
        }
        case OPJ_CLRSPC_SYCC:
        {
            return "YUV";
        }
        case OPJ_CLRSPC_EYCC:
        {
            return "YCbCr";
        }
        case OPJ_CLRSPC_CMYK:
        {
            return "CMYK";
        }
        case OPJ_CLRSPC_UNSPECIFIED:
        {
            return "Unspecified";
        }
        default:
        {
            return "Unknown";
        }
    }
}

TDE_EXPORT void kimgio_jp2_read(TQImageIO* io)
{
    KIMGJP2Wrapper jp2;
    opj_dparameters_t parameters;

    if (auto tqfile = dynamic_cast<TQFile *>(io->ioDevice()))
    {
        jp2.stream = opj_stream_create_default_file_stream(tqfile->name().local8Bit().data(), OPJ_TRUE);
    }
    else
    {
        // 4096 (=4k) is a common page size.
        constexpr int pageSize = 4096;

        // Use a temporary file, since TQSocket::size() reports bytes
        // available to read *now*, not the file size.
        if (jp2.tempFile.status() != 0)
        {
            kdError(kCategory) << "Failed to create temporary file for non-TQFile IO" << endl;
            return;
        }
        jp2.tempFile.setAutoDelete(true);

        TQFile *tempFile = jp2.tempFile.file();
        TQByteArray b(pageSize);
        TQ_LONG bytesRead;

        // 0 or -1 is EOF / error
        while ((bytesRead = io->ioDevice()->readBlock(b.data(), pageSize)) > 0)
        {
            if ((tempFile->writeBlock(b.data(), bytesRead)) == -1)
            {
                break;
            }
        }

        // flush everything out to disk
        tempFile->flush();
        jp2.stream = opj_stream_create_default_file_stream(tempFile->name().local8Bit().data(), OPJ_TRUE);
    }

    if (nullptr == jp2.stream)
    {
        kdError(kCategory) << "Failed to create input stream for JP2" << endl;
        io->setStatus(IO_ResourceError);
        return;
    }

    jp2.codec = opj_create_decompress(OPJ_CODEC_JP2);
    if (nullptr == jp2.codec)
    {
        kdError(kCategory) << "Unable to create decompressor for JP2" << endl;
        io->setStatus(IO_ResourceError);
        return;
    }
    opj_set_error_handler(jp2.codec, kimgio_jp2_err_handler, nullptr);
    opj_set_info_handler(jp2.codec, kimgio_jp2_info_handler, nullptr);
    opj_set_warning_handler(jp2.codec, kimgio_jp2_warn_handler, nullptr);

    opj_set_default_decoder_parameters(&parameters);
    if (OPJ_FALSE == opj_setup_decoder(jp2.codec, &parameters))
    {
        kdError(kCategory) << "Failed to setup decoder for JP2" << endl;
        io->setStatus(IO_ResourceError);
        return;
    }

    if (OPJ_FALSE == opj_read_header(jp2.stream, jp2.codec, &jp2.image))
    {
        kdError(kCategory) << "Failed to read JP2 header" << endl;
        io->setStatus(IO_ReadError);
        return;
    }

    if (OPJ_FALSE == opj_decode(jp2.codec, jp2.stream, jp2.image))
    {
        kdError(kCategory) << "Failed to decode JP2 image" << endl;
        io->setStatus(IO_ReadError);
        return;
    }

    if (OPJ_FALSE == opj_end_decompress(jp2.codec, jp2.stream))
    {
        kdError(kCategory) << "Failed to decode JP2 image ending" << endl;
        io->setStatus(IO_ReadError);
        return;
    }

    OPJ_UINT32 width = jp2.image->x1 - jp2.image->x0;
    OPJ_UINT32 height = jp2.image->y1 - jp2.image->y0;
    TQImage image(width, height, 32);

    switch (jp2.image->color_space)
    {
        case OPJ_CLRSPC_SRGB:
        {
            kimgio_jp2_read_srgba(image, jp2);
            break;
        }
        case OPJ_CLRSPC_GRAY:
        {
            kimgio_jp2_read_grayscale(image, jp2);
            break;
        }
        default:
        {
            kdError(kCategory) << "Unsupported colorspace detected: "
                               << colorspaceToString(jp2.image->color_space)
                               << endl;
            io->setStatus(IO_ReadError);
            return;
        }
    }

    io->setImage(image);
    io->setStatus(IO_Ok);
}


static void kimgio_jp2_write_handler(void *buffer, OPJ_SIZE_T buffer_size, void *user_data)
{
    // TODO(mio):
}

TDE_EXPORT void kimgio_jp2_write(TQImageIO *io)
{
    kdDebug(kCategory) << "Writing JP2 with OpenJPEG is not supported yet." << endl;
}

/*

#define DEFAULT_RATE 0.10
#define MAXCMPTS 256


typedef struct {
    jas_image_t* image;

    int	cmptlut[MAXCMPTS];

    jas_image_t* altimage;
} gs_t;


jas_image_t*
read_image( const TQImageIO* io )
{
    jas_stream_t* in = 0;
    // for TQIODevice's other than TQFile, a temp. file is used.
    KTempFile* tempf = 0;

    TQFile* qf = 0;
    if( ( qf = dynamic_cast<TQFile*>( io->ioDevice() ) ) ) {
        // great, it's a TQFile. Let's just take the filename.
        in = jas_stream_fopen( TQFile::encodeName( qf->name() ), "rb" );
    } else {
        // not a TQFile. Copy the whole data to a temp. file.
        tempf = new KTempFile();
        if( tempf->status() != 0 ) {
            delete tempf;
            return 0;
        } // if
        tempf->setAutoDelete( true );
        TQFile* out = tempf->file();
        // 4096 (=4k) is a common page size.
        TQByteArray b( 4096 );
        TQ_LONG size;
        // 0 or -1 is EOF / error
        while( ( size = io->ioDevice()->readBlock( b.data(), 4096 ) ) > 0 ) {
            // in case of a write error, still give the decoder a try
            if( ( out->writeBlock( b.data(), size ) ) == -1 ) break;
        } // while
        // flush everything out to disk
        out->flush();

        in = jas_stream_fopen( TQFile::encodeName( tempf->name() ), "rb" );
    } // else
    if( !in ) {
        delete tempf;
        return 0;
    } // if

    jas_image_t* image = jas_image_decode( in, -1, 0 );
    jas_stream_close( in );
    delete tempf;

    // image may be 0, but that's Ok
    return image;
} // read_image

static bool
convert_colorspace( gs_t& gs )
{
    jas_cmprof_t *outprof = jas_cmprof_createfromclrspc( JAS_CLRSPC_SRGB );
    if( !outprof ) return false;

    gs.altimage = jas_image_chclrspc( gs.image, outprof,
                                      JAS_CMXFORM_INTENT_PER );
    if( !gs.altimage ) return false;

    return true;
} // convert_colorspace

static bool
render_view( gs_t& gs, TQImage& qti )
{
    if((gs.cmptlut[0] = jas_image_getcmptbytype(gs.altimage,
                                                JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_R))) < 0 ||
       (gs.cmptlut[1] = jas_image_getcmptbytype(gs.altimage,
                                                JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_G))) < 0 ||
       (gs.cmptlut[2] = jas_image_getcmptbytype(gs.altimage,
                                                JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_B))) < 0) {
        return false;
    } // if

    const int* cmptlut = gs.cmptlut;
    int v[3];

    // check that all components have the same size.
    const int width = jas_image_cmptwidth( gs.altimage, cmptlut[0] );
    const int height = jas_image_cmptheight( gs.altimage, cmptlut[0] );
    for( int i = 1; i < 3; ++i ) {
        if (jas_image_cmptwidth( gs.altimage, cmptlut[i] ) != width ||
            jas_image_cmptheight( gs.altimage, cmptlut[i] ) != height)
            return false;
    } // for

    if( !qti.create( jas_image_width( gs.altimage ),
                     jas_image_height( gs.altimage ), 32 ) )
        return false;

    uint32_t* data = (uint32_t*)qti.bits();

    for( int y = 0; y < height; ++y ) {
        for( int x = 0; x < width; ++x ) {
            for( int k = 0; k < 3; ++k ) {
                v[k] = jas_image_readcmptsample( gs.altimage, cmptlut[k], x, y );
                // if the precision of the component is too small, increase
                // it to use the complete value range.
                v[k] <<= 8 - jas_image_cmptprec( gs.altimage, cmptlut[k] );

                if( v[k] < 0 ) v[k] = 0;
                else if( v[k] > 255 ) v[k] = 255;
            } // for k

            *data++ = tqRgb( v[0], v[1], v[2] );
        } // for x
    } // for y
    return true;
} // render_view


TDE_EXPORT void
kimgio_jp2_read( TQImageIO* io )
{
	if( jas_init() ) return;

	gs_t gs;
	if( !(gs.image = read_image( io )) ) return;

	if( !convert_colorspace( gs ) ) return;

	TQImage image;
	render_view( gs, image );

	if( gs.image ) jas_image_destroy( gs.image );
	if( gs.altimage ) jas_image_destroy( gs.altimage );

	io->setImage( image );
	io->setStatus( 0 );
} // kimgio_jp2_read


static jas_image_t*
create_image( const TQImage& qi )
{
    // prepare the component parameters
    jas_image_cmptparm_t* cmptparms = new jas_image_cmptparm_t[ 3 ];

    for ( int i = 0; i < 3; ++i ) {
        // x and y offset
        cmptparms[i].tlx = 0;
        cmptparms[i].tly = 0;

        // the resulting image will be hstep*width x vstep*height !
        cmptparms[i].hstep = 1;
        cmptparms[i].vstep = 1;
        cmptparms[i].width = qi.width();
        cmptparms[i].height = qi.height();

        // we write everything as 24bit truecolor ATM
        cmptparms[i].prec = 8;
        cmptparms[i].sgnd = false;
    }

    jas_image_t* ji = jas_image_create( 3 /* number components *//*, cmptparms, JAS_CLRSPC_UNKNOWN );
    delete[] cmptparms;

    // returning 0 is ok
    return ji;
} // create_image


static bool
write_components( jas_image_t* ji, const TQImage& qi )
{
    const unsigned height = qi.height();
    const unsigned width = qi.width();

    jas_matrix_t* m = jas_matrix_create( height, width );
    if( !m ) return false;

    jas_image_setclrspc( ji, JAS_CLRSPC_SRGB );

    jas_image_setcmpttype( ji, 0, JAS_IMAGE_CT_RGB_R );
    for( uint y = 0; y < height; ++y )
        for( uint x = 0; x < width; ++x )
            jas_matrix_set( m, y, x, tqRed( qi.pixel( x, y ) ) );
    jas_image_writecmpt( ji, 0, 0, 0, width, height, m );

    jas_image_setcmpttype( ji, 1, JAS_IMAGE_CT_RGB_G );
    for( uint y = 0; y < height; ++y )
        for( uint x = 0; x < width; ++x )
            jas_matrix_set( m, y, x, tqGreen( qi.pixel( x, y ) ) );
    jas_image_writecmpt( ji, 1, 0, 0, width, height, m );

    jas_image_setcmpttype( ji, 2, JAS_IMAGE_CT_RGB_B );
    for( uint y = 0; y < height; ++y )
        for( uint x = 0; x < width; ++x )
            jas_matrix_set( m, y, x, tqBlue( qi.pixel( x, y ) ) );
    jas_image_writecmpt( ji, 2, 0, 0, width, height, m );
    jas_matrix_destroy( m );

    return true;
} // write_components

TDE_EXPORT void
kimgio_jp2_write( TQImageIO* io )
{
	if( jas_init() ) return;

	// open the stream. we write directly to the file if possible, to a
	// temporary file otherwise.
	jas_stream_t* stream = 0;

	TQFile* qf = 0;
	KTempFile* ktempf = 0;
	if( ( qf = dynamic_cast<TQFile*>( io->ioDevice() ) ) ) {
		// jas_stream_fdopen works here, but not when reading...
		stream = jas_stream_fdopen( dup( qf->handle() ), "w" );
	} else {
		ktempf = new KTempFile;
		ktempf->setAutoDelete( true );
		stream = jas_stream_fdopen( dup( ktempf->handle()), "w" );
	} // else


	// by here, a jas_stream_t is open
	if( !stream ) return;

	jas_image_t* ji = create_image( io->image() );
	if( !ji ) {
		delete ktempf;
		jas_stream_close( stream );
		return;
	} // if

	if( !write_components( ji, io->image() ) ) {
		delete ktempf;
		jas_stream_close( stream );
		jas_image_destroy( ji );
		return;
	} // if

	// optstr:
	// - rate=#B => the resulting file size is about # bytes
	// - rate=0.0 .. 1.0 => the resulting file size is about the factor times
	//                      the uncompressed size
	TQString rate;
	TQTextStream ts( &rate, IO_WriteOnly );
	ts << "rate="
		<< ( (io->quality() < 0) ? DEFAULT_RATE : io->quality() / 100.0F );
#	if defined(JAS_VERSION_MAJOR) && (JAS_VERSION_MAJOR >= 3)
	const jas_image_fmtinfo_t *jp2_fmtinfo = jas_image_lookupfmtbyname("jp2");
	int i = -1;
	if (jp2_fmtinfo)
	{
		i = jas_image_encode(ji, stream, jp2_fmtinfo->id, rate.utf8().data());
	}
#	else
	int i = jp2_encode( ji, stream, rate.utf8().data() );
#	endif

	jas_image_destroy( ji );
	jas_stream_close( stream );

	if( i != 0 ) { delete ktempf; return; }

	if( ktempf ) {
		// We've written to a tempfile. Copy the data to the final destination.
		TQFile* in = ktempf->file();

		TQByteArray b( 4096 );
		TQ_LONG size;

		// seek to the beginning of the file.
		if( !in->at( 0 ) ) { delete ktempf; return; }

		// 0 or -1 is EOF / error
		while( ( size = in->readBlock( b.data(), 4096 ) ) > 0 ) {
			if( ( io->ioDevice()->writeBlock( b.data(), size ) ) == -1 ) {
				delete ktempf;
				return;
			} // if
		} // while
		io->ioDevice()->flush();
		delete ktempf;

		// see if we've left the while loop due to an error.
		if( size == -1 ) return;
	} // if


	// everything went fine
	io->setStatus( IO_Ok );
} // kimgio_jp2_write

*/

#endif // HAVE_OPENJPEG