/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */

#include <stdio.h>
#include <stdlib.h>
#include "setjmp.h"
#include "jpeg/jpeglib.h"
#include "jpeg/jerror.h"
#include "jpeg.h"
#include "rtl/alloc.h"
#include "osl/diagnose.h"

struct my_error_mgr
{
    struct jpeg_error_mgr pub;
    jmp_buf setjmp_buffer;
};

void jpeg_svstream_src (j_decompress_ptr cinfo, void* infile);
void jpeg_svstream_dest (j_compress_ptr cinfo, void* outfile);

METHODDEF( void )
my_error_exit (j_common_ptr cinfo)
{
    my_error_ptr myerr = (my_error_ptr) cinfo->err;
    (*cinfo->err->output_message) (cinfo);
    longjmp(myerr->setjmp_buffer, 1);
}


METHODDEF( void )
my_output_message (j_common_ptr cinfo)
{
    char buffer[JMSG_LENGTH_MAX];
    (*cinfo->err->format_message) (cinfo, buffer);
}

/* TODO: when incompatible changes are possible again
   the preview size hint should be redone */
static int nPreviewWidth = 0;
static int nPreviewHeight = 0;
void SetJpegPreviewSizeHint( int nWidth, int nHeight )
{
    nPreviewWidth = nWidth;
    nPreviewHeight = nHeight;
}

void ReadJPEG( void* pJPEGReader, void* pIStm, long* pLines )
{
    struct jpeg_decompress_struct   cinfo;
    struct my_error_mgr             jerr;
    struct JPEGCreateBitmapParam    aCreateBitmapParam;
    HPBYTE                          pDIB;
    HPBYTE                          pTmp;
    long                            nWidth;
    long                            nHeight;
    long                            nAlignedWidth;
    JSAMPLE * range_limit;
    HPBYTE pScanLineBuffer = NULL;
    long nScanLineBufferComponents = 0;
    // declare bDecompCreated volatile because of gcc
    // warning: variable 'bDecompCreated' might be clobbered by `longjmp' or `vfork'
    volatile long                   bDecompCreated = 0;

    /* Falls der Stream nicht ausreicht (IO_PENDING)
     wird ueber ein longjmp in der Schleife nach Exit
     gesprungen, wir geben dann die Anzahl
     der bisher bearbeiteten Scanlines zurueck*/
    if ( setjmp( jerr.setjmp_buffer ) )
        goto Exit;

    cinfo.err = jpeg_std_error( &jerr.pub );
    jerr.pub.error_exit = my_error_exit;
    jerr.pub.output_message = my_output_message;

    jpeg_create_decompress( &cinfo );
    bDecompCreated = 1;
        jpeg_svstream_src( &cinfo, pIStm );
    jpeg_read_header( &cinfo, sal_True );

    cinfo.scale_num = 1;
    cinfo.scale_denom = 1;
    cinfo.output_gamma = 1.0;
    cinfo.raw_data_out = sal_False;
    cinfo.quantize_colors = sal_False;
    if ( cinfo.jpeg_color_space == JCS_YCbCr )
        cinfo.out_color_space = JCS_RGB;
    else if ( cinfo.jpeg_color_space == JCS_YCCK )
        cinfo.out_color_space = JCS_CMYK;

    OSL_ASSERT(cinfo.out_color_space == JCS_CMYK || cinfo.out_color_space == JCS_GRAYSCALE || cinfo.out_color_space == JCS_RGB);

    /* change scale for preview import */
    if( nPreviewWidth || nPreviewHeight )
    {
        if( nPreviewWidth == 0 ) {
            nPreviewWidth = ( cinfo.image_width*nPreviewHeight )/cinfo.image_height;
            if( nPreviewWidth <= 0 )
                nPreviewWidth = 1;
        } else if( nPreviewHeight == 0 ) {
            nPreviewHeight = ( cinfo.image_height*nPreviewWidth )/cinfo.image_width;
            if( nPreviewHeight <= 0 )
                nPreviewHeight = 1;
        }

        for( cinfo.scale_denom = 1; cinfo.scale_denom < 8; cinfo.scale_denom *= 2 )
        {
            if( cinfo.image_width < nPreviewWidth * cinfo.scale_denom )
                break;
            if( cinfo.image_height < nPreviewHeight * cinfo.scale_denom )
                break;
        }

        if( cinfo.scale_denom > 1 )
        {
            cinfo.dct_method            = JDCT_FASTEST;
            cinfo.do_fancy_upsampling   = sal_False;
            cinfo.do_block_smoothing    = sal_False;
        }
    }

    jpeg_start_decompress( &cinfo );

    nWidth = cinfo.output_width;
    nHeight = cinfo.output_height;
    aCreateBitmapParam.nWidth = nWidth;
    aCreateBitmapParam.nHeight = nHeight;

    aCreateBitmapParam.density_unit = cinfo.density_unit;
    aCreateBitmapParam.X_density = cinfo.X_density;
    aCreateBitmapParam.Y_density = cinfo.Y_density;
    aCreateBitmapParam.bGray = cinfo.output_components == 1;
    pDIB = CreateBitmap( pJPEGReader, &aCreateBitmapParam );
    nAlignedWidth = aCreateBitmapParam.nAlignedWidth;
    range_limit=cinfo.sample_range_limit;

    if ( cinfo.out_color_space == JCS_CMYK )
    {
            nScanLineBufferComponents = cinfo.output_width * 4;
        pScanLineBuffer = rtl_allocateMemory( nScanLineBufferComponents );
    }

    if( pDIB )
    {
        if( aCreateBitmapParam.bTopDown )
            pTmp = pDIB;
        else
        {
            pTmp = pDIB + ( nHeight - 1 ) * nAlignedWidth;
            nAlignedWidth = -nAlignedWidth;
        }

        for ( *pLines = 0; *pLines < nHeight; (*pLines)++ )
        {
            if (pScanLineBuffer!=NULL) { // in other words cinfo.out_color_space == JCS_CMYK
            int i;
            int j;
            jpeg_read_scanlines( &cinfo, (JSAMPARRAY) &pScanLineBuffer, 1 );
            // convert CMYK to RGB
            for( i=0, j=0; i < nScanLineBufferComponents; i+=4, j+=3 )
            {
                int c_=255-pScanLineBuffer[i+0];
                int m_=255-pScanLineBuffer[i+1];
                int y_=255-pScanLineBuffer[i+2];
                int k_=255-pScanLineBuffer[i+3];
                pTmp[j+0]=range_limit[ 255L - ( c_ + k_ ) ];
                pTmp[j+1]=range_limit[ 255L - ( m_ + k_ ) ];
                pTmp[j+2]=range_limit[ 255L - ( y_ + k_ ) ];
            }
            } else {
            jpeg_read_scanlines( &cinfo, (JSAMPARRAY) &pTmp, 1 );
            }
            /* PENDING ??? */
            if ( cinfo.err->msg_code == 113 )
            break;

            pTmp += nAlignedWidth;
        }
    }

    jpeg_finish_decompress( &cinfo );
    if (pScanLineBuffer!=NULL) {
        rtl_freeMemory( pScanLineBuffer );
        pScanLineBuffer=NULL;
    }

Exit:

    if( bDecompCreated )
        jpeg_destroy_decompress( &cinfo );
}

long WriteJPEG( void* pJPEGWriter, void* pOStm,
                long nWidth, long nHeight, long bGreys,
                long nQualityPercent, void* pCallbackData )
{
    struct jpeg_compress_struct cinfo;
    struct my_error_mgr         jerr;
    void*                       pScanline;
    long                        nY;
    // declare bCompCreated, bRet volatile because of gcc
    // warning: variable 'bCompCreated' might be clobbered by `longjmp' or `vfork'
    volatile long               bCompCreated = 0;
    volatile long               bRet = 0;

    if ( setjmp( jerr.setjmp_buffer ) )
        goto Exit;

    cinfo.err = jpeg_std_error( &jerr.pub );
    jerr.pub.error_exit = my_error_exit;
    jerr.pub.output_message = my_output_message;

    jpeg_create_compress( &cinfo );
    bCompCreated = 1;

    jpeg_svstream_dest( &cinfo, pOStm );

    cinfo.image_width = (JDIMENSION) nWidth;
    cinfo.image_height = (JDIMENSION) nHeight;
    if ( bGreys )
    {
        cinfo.input_components = 1;
        cinfo.in_color_space = JCS_GRAYSCALE;
    }
    else
    {
        cinfo.input_components = 3;
        cinfo.in_color_space = JCS_RGB;
    }

    jpeg_set_defaults( &cinfo );
    jpeg_set_quality( &cinfo, (int) nQualityPercent, sal_False );

    if ( ( nWidth > 128 ) || ( nHeight > 128 ) )
        jpeg_simple_progression( &cinfo );

    jpeg_start_compress( &cinfo, sal_True );

    for( nY = 0; nY < nHeight; nY++ )
    {
        pScanline = GetScanline( pJPEGWriter, nY );

        if( pScanline )
            jpeg_write_scanlines( &cinfo, (JSAMPARRAY) &pScanline, 1 );

        if( JPEGCallback( pCallbackData, nY * 100L / nHeight ) )
            goto Exit;
    }

    bRet = 1;

    jpeg_finish_compress(&cinfo);

Exit:

    if ( bCompCreated )
        jpeg_destroy_compress( &cinfo );

    return bRet;
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */