/*
 * Little cms
 * Copyright (C) 1998-2004 Marti Maria
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
 * KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * iccprofile.c
 *
 * This file provides code to read and write International Color Consortium
 * (ICC) device profiles embedded in JFIF JPEG image files.  The ICC has
 * defined a standard format for including such data in JPEG "APP2" markers.
 * The code given here does not know anything about the internal structure
 * of the ICC profile data; it just knows how to put the profile data into
 * a JPEG file being written, or get it back out when reading.
 *
 * This code depends on new features added to the IJG JPEG library as of
 * IJG release 6b; it will not compile or work with older IJG versions.
 *
 * NOTE: this code would need surgery to work on 16-bit-int machines
 * with ICC profiles exceeding 64K bytes in size.  If you need to do that,
 * change all the "unsigned int" variables to "INT32".  You'll also need
 * to find a malloc() replacement that can allocate more than 64K.
 */

#include "iccjpeg.h"
#include <stdlib.h>    /* define malloc() */


/**
 * Since an ICC profile can be larger than the maximum size of a JPEG marker
 * (64K), we need provisions to split it into multiple markers.  The format
 * defined by the ICC specifies one or more APP2 markers containing the
 * following data:
 *    Identifying string    ASCII "ICC_PROFILE\0"  (12 bytes)
 *    Marker sequence number    1 for first APP2, 2 for next, etc (1 byte)
 *    Number of markers    Total number of APP2's used (1 byte)
 *      Profile data        (remainder of APP2 data)
 * Decoders should use the marker sequence numbers to reassemble the profile,
 * rather than assuming that the APP2 markers appear in the correct sequence.
 */
#define ICC_MARKER                (JPEG_APP0 + 2)    /* JPEG marker code for ICC          */
#define ICC_OVERHEAD_LEN          14                 /* size of non-profile data in APP2  */
#define MAX_BYTES_IN_MARKER       65533              /* maximum data len of a JPEG marker */
#define MAX_DATA_BYTES_IN_MARKER  (MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN)


/**
 * This routine writes the given ICC profile data into a JPEG file.
 * It *must* be called AFTER calling jpeg_start_compress() and BEFORE
 * the first call to jpeg_write_scanlines().
 * (This ordering ensures that the APP2 marker(s) will appear after the
 * SOI and JFIF or Adobe markers, but before all else.)
 */
void write_icc_profile(j_compress_ptr cinfo,
                       const JOCTET *icc_data_ptr,
                       unsigned int icc_data_len)
{
    unsigned int num_markers = 0;   /* total number of markers we'll write     */
    int cur_marker           = 1;   /* per spec, counting starts at 1          */
    unsigned int length      = 0;   /* number of bytes to write in this marker */

    /* Calculate the number of markers we'll need, rounding up of course */
    num_markers = icc_data_len / MAX_DATA_BYTES_IN_MARKER;

    if (num_markers * MAX_DATA_BYTES_IN_MARKER != icc_data_len)
        num_markers++;

    while (icc_data_len > 0)
    {
        /* length of profile to put in this marker */
        length = icc_data_len;

        if (length > MAX_DATA_BYTES_IN_MARKER)
            length = MAX_DATA_BYTES_IN_MARKER;

        icc_data_len -= length;

        /* Write the JPEG marker header (APP2 code and marker length) */
        jpeg_write_m_header(cinfo, ICC_MARKER, (unsigned int) (length + ICC_OVERHEAD_LEN));

        /* Write the marker identifying string "ICC_PROFILE" (null-terminated).
         * We code it in this less-than-transparent way so that the code works
         * even if the local character set is not ASCII.
         */
        jpeg_write_m_byte(cinfo, 0x49);
        jpeg_write_m_byte(cinfo, 0x43);
        jpeg_write_m_byte(cinfo, 0x43);
        jpeg_write_m_byte(cinfo, 0x5F);
        jpeg_write_m_byte(cinfo, 0x50);
        jpeg_write_m_byte(cinfo, 0x52);
        jpeg_write_m_byte(cinfo, 0x4F);
        jpeg_write_m_byte(cinfo, 0x46);
        jpeg_write_m_byte(cinfo, 0x49);
        jpeg_write_m_byte(cinfo, 0x4C);
        jpeg_write_m_byte(cinfo, 0x45);
        jpeg_write_m_byte(cinfo, 0x0);

        /* Add the sequencing info */
        jpeg_write_m_byte(cinfo, cur_marker);
        jpeg_write_m_byte(cinfo, (int) num_markers);

        /* Add the profile data */
        while (length--)
        {
            jpeg_write_m_byte(cinfo, *icc_data_ptr);
            icc_data_ptr++;
        }

        cur_marker++;
    }
}


/**
 * Prepare for reading an ICC profile
 */
void setup_read_icc_profile (j_decompress_ptr cinfo)
{
    /* Tell the library to keep any APP2 data it may find */
    jpeg_save_markers(cinfo, ICC_MARKER, 0xFFFF);
}


/**
 * Handy subroutine to test whether a saved marker is an ICC profile marker.
 */
static boolean marker_is_icc (jpeg_saved_marker_ptr marker)
{
  return (marker->marker              == ICC_MARKER       &&
          marker->data_length         >= ICC_OVERHEAD_LEN &&
          /* verify the identifying string */
          GETJOCTET(marker->data[0])  == 0x49             &&
          GETJOCTET(marker->data[1])  == 0x43             &&
          GETJOCTET(marker->data[2])  == 0x43             &&
          GETJOCTET(marker->data[3])  == 0x5F             &&
          GETJOCTET(marker->data[4])  == 0x50             &&
          GETJOCTET(marker->data[5])  == 0x52             &&
          GETJOCTET(marker->data[6])  == 0x4F             &&
          GETJOCTET(marker->data[7])  == 0x46             &&
          GETJOCTET(marker->data[8])  == 0x49             &&
          GETJOCTET(marker->data[9])  == 0x4C             &&
          GETJOCTET(marker->data[10]) == 0x45             &&
          GETJOCTET(marker->data[11]) == 0x0);
}


/**
 * See if there was an ICC profile in the JPEG file being read;
 * if so, reassemble and return the profile data.
 *
 * TRUE is returned if an ICC profile was found, FALSE if not.
 * If TRUE is returned, *icc_data_ptr is set to point to the
 * returned data, and *icc_data_len is set to its length.
 *
 * IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
 * and must be freed by the caller with free() when the caller no longer
 * needs it.  (Alternatively, we could write this routine to use the
 * IJG library's memory allocator, so that the data would be freed implicitly
 * at jpeg_finish_decompress() time.  But it seems likely that many apps
 * will prefer to have the data stick around after decompression finishes.)
 *
 * NOTE: if the file contains invalid ICC APP2 markers, we just silently
 * return FALSE.  You might want to issue an error message instead.
 */
boolean read_icc_profile(j_decompress_ptr cinfo,
                         JOCTET **icc_data_ptr,
                         unsigned int *icc_data_len)
{
    jpeg_saved_marker_ptr marker;
    int num_markers           = 0;
    int seq_no                = 0;
    JOCTET* icc_data          = NULL;
    unsigned int total_length = 0;

#define MAX_SEQ_NO  255 /* sufficient since marker numbers are bytes */

    char marker_present[MAX_SEQ_NO+1];      /* 1 if marker found              */
    unsigned int data_length[MAX_SEQ_NO+1]; /* size of profile data in marker */
    unsigned int data_offset[MAX_SEQ_NO+1]; /* offset for data in marker      */

    *icc_data_ptr = NULL;                   /* avoid confusion if FALSE return */
    *icc_data_len = 0;

    /* This first pass over the saved markers discovers whether there are
     * any ICC markers and verifies the consistency of the marker numbering.
     */

    for (seq_no = 1; seq_no <= MAX_SEQ_NO; seq_no++)
        marker_present[seq_no] = 0;

    for (marker = cinfo->marker_list; marker != NULL; marker = marker->next)
    {
        if (marker_is_icc(marker))
        {
            if (num_markers == 0)
                num_markers = GETJOCTET(marker->data[13]);
            else if (num_markers != GETJOCTET(marker->data[13]))
                return FALSE;       /* inconsistent num_markers fields */

            seq_no = GETJOCTET(marker->data[12]);

            if (seq_no <= 0 || seq_no > num_markers)
                return FALSE;       /* bogus sequence number */

            if (marker_present[seq_no])
                return FALSE;       /* duplicate sequence numbers */

            marker_present[seq_no] = 1;
            data_length[seq_no]    = marker->data_length - ICC_OVERHEAD_LEN;
        }
    }

    if (num_markers == 0)
        return FALSE;

    /* Check for missing markers, count total space needed,
     * compute offset of each marker's part of the data.
     */

    total_length = 0;

    for (seq_no = 1; seq_no <= num_markers; seq_no++)
    {
        if (marker_present[seq_no] == 0)
            return FALSE;        /* missing sequence number */

        data_offset[seq_no] = total_length;
        total_length += data_length[seq_no];
    }

    if (total_length == 0)
        return FALSE;        /* found only empty markers? */

    /* Allocate space for assembled data */
    icc_data = (JOCTET *) malloc(total_length * sizeof(JOCTET));

    if (icc_data == NULL)
        return FALSE;        /* oops, out of memory */

    /* and fill it in */
    for (marker = cinfo->marker_list; marker != NULL; marker = marker->next)
    {
        if (marker_is_icc(marker))
        {
            JOCTET FAR *src_ptr = NULL;
            JOCTET *dst_ptr     = NULL;
            unsigned int length = 0;

            seq_no  = GETJOCTET(marker->data[12]);
            dst_ptr = icc_data + data_offset[seq_no];
            src_ptr = marker->data + ICC_OVERHEAD_LEN;
            length  = data_length[seq_no];

            while (length--)
            {
                *dst_ptr++ = *src_ptr++;
            }
        }
    }

    *icc_data_ptr = icc_data;
    *icc_data_len = total_length;

    return TRUE;
}
