/* Copyright (C) 2001-2023 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 the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, 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;
    jddp.PassThrough = 0;
    jddp.device = (void *)NULL;
    jddp.PassThroughfn = 0;

    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) {
        code = gs_throw(-1, "premature EOF or error in jpeg");
        goto error;
    }

    /* 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) {
        rc_increment(ctx->gray);
        image->colorspace = ctx->gray;
    }
    if (image->comps == 3) {
        rc_increment(ctx->srgb);
        image->colorspace = ctx->srgb;
    }
    if (image->comps == 4) {
        rc_increment(ctx->cmyk);
        image->colorspace = ctx->cmyk;
    }

    if (jddp.dinfo.density_unit == 1)
    {
        /* According to the XPS specification we should also use the EXIF and APP13 marker segments
         * to set the resolution, but we don't and adding that would be more effort than we want to
         * go to for XPS currently. This at least means that images won't go completely AWOL.
         */
        if (jddp.dinfo.X_density != 0)
            image->xres = jddp.dinfo.X_density;
        else
            image->xres = 96;
        if (jddp.dinfo.Y_density != 0)
            image->yres = jddp.dinfo.Y_density;
        else
            image->yres = 96;
    }
    else if (jddp.dinfo.density_unit == 2)
    {
        image->xres = (int)(jddp.dinfo.X_density * 2.54 + 0.5);
        image->yres = (int)(jddp.dinfo.Y_density * 2.54 + 0.5);
    }
    else
    {
        image->xres = 96;
        image->yres = 96;
    }

    wlen = image->stride * image->height;
    wbuf = xps_alloc(ctx, wlen);
    if (!wbuf) {
        code = gs_throw1(gs_error_VMerror, "out of memory allocating samples: %d", wlen);
        goto error;
    }

    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) {
        code = gs_throw1(-1, "error in jpeg (code = %d)", code);
        goto error;
    }

    code = gs_okay;
error:
    gs_jpeg_destroy(&state);
    if (jddp.scanline_buffer != NULL) {
        gs_free_object(gs_memory_stable(ctx->memory),
                       jddp.scanline_buffer,
                       "xps_decode_jpeg");
    }

    return code;
}
