/* Copyright (C) 2006-2010 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen  Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* XPS interpreter - JPEG image support */

#include "ghostxps.h"

#include "stream.h"
#include "strimpl.h"
#include "gsstate.h"
#include "jpeglib_.h"
#include "sdct.h"
#include "sjpeg.h"

static int
xps_report_error(stream_state * st, const char *str)
{
    (void) gs_throw1(-1, "%s", str);
    return 0;
}

int
xps_decode_jpeg(xps_context_t *ctx, byte *rbuf, int rlen, xps_image_t *image)
{
    jpeg_decompress_data jddp;
    stream_DCT_state state;
    stream_cursor_read rp;
    stream_cursor_write wp;
    int code;
    int wlen;
    byte *wbuf;
    jpeg_saved_marker_ptr curr_marker;

    s_init_state((stream_state*)&state, &s_DCTD_template, ctx->memory);
    state.report_error = xps_report_error;

    s_DCTD_template.set_defaults((stream_state*)&state);

    state.jpeg_memory = ctx->memory;
    state.data.decompress = &jddp;

    jddp.templat = s_DCTD_template;
    jddp.memory = ctx->memory;
    jddp.scanline_buffer = NULL;

    if ((code = gs_jpeg_create_decompress(&state)) < 0)
        return gs_throw(-1, "cannot gs_jpeg_create_decompress");

    s_DCTD_template.init((stream_state*)&state);

    rp.ptr = rbuf - 1;
    rp.limit = rbuf + rlen - 1;

    /* read the header only by not having a write buffer */
    wp.ptr = 0;
    wp.limit = 0;

    /* Set up to save the ICC marker APP2.
     * According to the spec we should be getting APP1 APP2 and APP13.
     * Library gets APP0 and APP14. */
    jpeg_save_markers(&(jddp.dinfo), 0xe2, 0xFFFF);

    code = s_DCTD_template.process((stream_state*)&state, &rp, &wp, true);
    if (code != 1)
        return gs_throw(-1, "premature EOF or error in jpeg");

    /* Check if we had an ICC profile */
    curr_marker = jddp.dinfo.marker_list;
    while (curr_marker != NULL)
    {
        if (curr_marker->marker == 0xe2)
        {
            /* Found ICC profile. Create a buffer and copy over now.
             * Strip JPEG APP2 14 byte header */
            image->profilesize = curr_marker->data_length - 14;
            image->profile = xps_alloc(ctx, image->profilesize);
            if (image->profile)
            {
                /* If we can't create it, just ignore */
                memcpy(image->profile, &(curr_marker->data[14]), image->profilesize);
            }
            break;
        }
        curr_marker = curr_marker->next;
    }

    image->width = jddp.dinfo.output_width;
    image->height = jddp.dinfo.output_height;
    image->comps = jddp.dinfo.output_components;
    image->bits = 8;
    image->stride = image->width * image->comps;

    if (image->comps == 1)
        image->colorspace = ctx->gray;
    if (image->comps == 3)
        image->colorspace = ctx->srgb;
    if (image->comps == 4)
        image->colorspace = ctx->cmyk;

    if (jddp.dinfo.density_unit == 1)
    {
        image->xres = jddp.dinfo.X_density;
        image->yres = jddp.dinfo.Y_density;
    }
    else if (jddp.dinfo.density_unit == 2)
    {
        image->xres = jddp.dinfo.X_density * 2.54;
        image->yres = jddp.dinfo.Y_density * 2.54;
    }
    else
    {
        image->xres = 96;
        image->yres = 96;
    }

    wlen = image->stride * image->height;
    wbuf = xps_alloc(ctx, wlen);
    if (!wbuf)
        return gs_throw1(-1, "out of memory allocating samples: %d", wlen);

    image->samples = wbuf;

    wp.ptr = wbuf - 1;
    wp.limit = wbuf + wlen - 1;

    code = s_DCTD_template.process((stream_state*)&state, &rp, &wp, true);
    if (code != EOFC)
        return gs_throw1(-1, "error in jpeg (code = %d)", code);

    gs_jpeg_destroy(&state);

    return gs_okay;
}