/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include "libport.h"
#include "tif_config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "tiffio.h"
#include "tiffiop.h"

#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif
#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif

#define streq(a, b) (strcmp(a, b) == 0)
#define strneq(a, b, n) (strncmp(a, b, n) == 0)

#define CopyField(tag, v)                                                      \
    if (TIFFGetField(in, tag, &v))                                             \
    TIFFSetField(out, tag, v)

uint32_t imagewidth;
uint32_t imagelength;
int threshold = 128;

static void usage(int code);

/*
 * Floyd-Steinberg error propragation with threshold.
 * This code is stolen from tiffmedian.
 */
static int fsdither(TIFF *in, TIFF *out)
{
    unsigned char *outline, *inputline, *inptr;
    short *thisline, *nextline, *tmpptr;
    register unsigned char *outptr;
    register short *thisptr, *nextptr;
    register uint32_t i, j;
    uint32_t imax, jmax;
    int lastline, lastpixel;
    int bit;
    tsize_t outlinesize;
    int errcode = 0;

    imax = imagelength - 1;
    jmax = imagewidth - 1;
    inputline = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(in));
    thisline = (short *)_TIFFmalloc(
        TIFFSafeMultiply(tmsize_t, imagewidth, sizeof(short)));
    nextline = (short *)_TIFFmalloc(
        TIFFSafeMultiply(tmsize_t, imagewidth, sizeof(short)));
    outlinesize = TIFFScanlineSize(out);
    outline = (unsigned char *)_TIFFmalloc(outlinesize);
    if (!(inputline && thisline && nextline && outline))
    {
        fprintf(stderr, "Out of memory.\n");
        goto skip_on_error;
    }
    if (imagewidth > TIFFScanlineSize(in))
    {
        fprintf(stderr, "Image width exceeds scanline size.\n");
        goto skip_on_error;
    }

    /*
     * Get first line
     */
    if (TIFFReadScanline(in, inputline, 0, 0) <= 0)
        goto skip_on_error;

    inptr = inputline;
    nextptr = nextline;
    for (j = 0; j < imagewidth; ++j)
        *nextptr++ = *inptr++;
    for (i = 0; i < imagelength; ++i)
    {
        tmpptr = thisline;
        thisline = nextline;
        nextline = tmpptr;
        lastline = (i == imax);
        if (TIFFReadScanline(in, inputline, i, 0) <= 0)
            goto skip_on_error;
        inptr = inputline;
        nextptr = nextline;
        for (j = 0; j < imagewidth; ++j)
            *nextptr++ = *inptr++;
        thisptr = thisline;
        nextptr = nextline;
        _TIFFmemset(outptr = outline, 0, outlinesize);
        bit = 0x80;
        for (j = 0; j < imagewidth; ++j)
        {
            register int v;

            lastpixel = (j == jmax);
            v = *thisptr++;
            if (v < 0)
                v = 0;
            else if (v > 255)
                v = 255;
            if (v > threshold)
            {
                *outptr |= bit;
                v -= 255;
            }
            bit >>= 1;
            if (bit == 0)
            {
                outptr++;
                bit = 0x80;
            }
            if (!lastpixel)
                thisptr[0] += v * 7 / 16;
            if (!lastline)
            {
                if (j != 0)
                    nextptr[-1] += v * 3 / 16;
                *nextptr++ += v * 5 / 16;
                if (!lastpixel)
                    nextptr[0] += v / 16;
            }
        }
        if (TIFFWriteScanline(out, outline, i, 0) < 0)
            goto skip_on_error;
    }
    goto exit_label;

skip_on_error:
    errcode = 1;
exit_label:
    _TIFFfree(inputline);
    _TIFFfree(thisline);
    _TIFFfree(nextline);
    _TIFFfree(outline);
    return errcode;
}

static uint16_t compression = COMPRESSION_PACKBITS;
static uint16_t predictor = 0;
static uint32_t group3options = 0;

static void processG3Options(char *cp)
{
    if ((cp = strchr(cp, ':')))
    {
        do
        {
            cp++;
            if (strneq(cp, "1d", 2))
                group3options &= ~GROUP3OPT_2DENCODING;
            else if (strneq(cp, "2d", 2))
                group3options |= GROUP3OPT_2DENCODING;
            else if (strneq(cp, "fill", 4))
                group3options |= GROUP3OPT_FILLBITS;
            else
                usage(EXIT_FAILURE);
        } while ((cp = strchr(cp, ':')));
    }
}

static int processCompressOptions(char *opt)
{
    if (streq(opt, "none"))
        compression = COMPRESSION_NONE;
    else if (streq(opt, "packbits"))
        compression = COMPRESSION_PACKBITS;
    else if (strneq(opt, "g3", 2))
    {
        processG3Options(opt);
        compression = COMPRESSION_CCITTFAX3;
    }
    else if (streq(opt, "g4"))
        compression = COMPRESSION_CCITTFAX4;
    else if (strneq(opt, "lzw", 3))
    {
        char *cp = strchr(opt, ':');
        if (cp)
            predictor = atoi(cp + 1);
        compression = COMPRESSION_LZW;
    }
    else if (strneq(opt, "zip", 3))
    {
        char *cp = strchr(opt, ':');
        if (cp)
            predictor = atoi(cp + 1);
        compression = COMPRESSION_ADOBE_DEFLATE;
    }
    else
        return (0);
    return (1);
}

int main(int argc, char *argv[])
{
    TIFF *in, *out;
    uint16_t samplesperpixel, bitspersample = 1, shortv;
    float floatv;
    char thing[1024];
    uint32_t rowsperstrip = (uint32_t)-1;
    uint16_t fillorder = 0;
    int c;
#if !HAVE_DECL_OPTARG
    extern int optind;
    extern char *optarg;
#endif

    while ((c = getopt(argc, argv, "c:f:r:t:h")) != -1)
        switch (c)
        {
            case 'c': /* compression scheme */
                if (!processCompressOptions(optarg))
                    usage(EXIT_FAILURE);
                break;
            case 'f': /* fill order */
                if (streq(optarg, "lsb2msb"))
                    fillorder = FILLORDER_LSB2MSB;
                else if (streq(optarg, "msb2lsb"))
                    fillorder = FILLORDER_MSB2LSB;
                else
                    usage(EXIT_FAILURE);
                break;
            case 'r': /* rows/strip */
                rowsperstrip = atoi(optarg);
                break;
            case 't':
                threshold = atoi(optarg);
                if (threshold < 0)
                    threshold = 0;
                else if (threshold > 255)
                    threshold = 255;
                break;
            case 'h':
                usage(EXIT_SUCCESS);
                /*NOTREACHED*/
                break;
            case '?':
                usage(EXIT_FAILURE);
                /*NOTREACHED*/
                break;
        }
    if (argc - optind < 2)
        usage(EXIT_FAILURE);
    in = TIFFOpen(argv[optind], "r");
    if (in == NULL)
        return (EXIT_FAILURE);
    TIFFGetField(in, TIFFTAG_SAMPLESPERPIXEL, &samplesperpixel);
    if (samplesperpixel != 1)
    {
        fprintf(stderr, "%s: Not a b&w image.\n", argv[0]);
        TIFFClose(in);
        return (EXIT_FAILURE);
    }
    TIFFGetField(in, TIFFTAG_BITSPERSAMPLE, &bitspersample);
    if (bitspersample != 8)
    {
        fprintf(stderr, " %s: Sorry, only handle 8-bit samples.\n", argv[0]);
        TIFFClose(in);
        return (EXIT_FAILURE);
    }
    out = TIFFOpen(argv[optind + 1], "w");
    if (out == NULL)
    {
        TIFFClose(in);
        return (EXIT_FAILURE);
    }

    do
    {
        CopyField(TIFFTAG_IMAGEWIDTH, imagewidth);
        TIFFGetField(in, TIFFTAG_IMAGELENGTH, &imagelength);
        TIFFSetField(out, TIFFTAG_IMAGELENGTH, imagelength - 1);
        TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 1);
        TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, 1);
        TIFFSetField(out, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
        TIFFSetField(out, TIFFTAG_COMPRESSION, compression);
        if (fillorder)
            TIFFSetField(out, TIFFTAG_FILLORDER, fillorder);
        else
            CopyField(TIFFTAG_FILLORDER, shortv);
        snprintf(thing, sizeof(thing), "Dithered B&W version of %s",
                 argv[optind]);
        TIFFSetField(out, TIFFTAG_IMAGEDESCRIPTION, thing);
        CopyField(TIFFTAG_PHOTOMETRIC, shortv);
        CopyField(TIFFTAG_ORIENTATION, shortv);
        CopyField(TIFFTAG_XRESOLUTION, floatv);
        CopyField(TIFFTAG_YRESOLUTION, floatv);
        CopyField(TIFFTAG_RESOLUTIONUNIT, shortv);
        rowsperstrip = TIFFDefaultStripSize(out, rowsperstrip);
        TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, rowsperstrip);
        switch (compression)
        {
            case COMPRESSION_CCITTFAX3:
                TIFFSetField(out, TIFFTAG_GROUP3OPTIONS, group3options);
                break;
            case COMPRESSION_LZW:
            case COMPRESSION_ADOBE_DEFLATE:
            case COMPRESSION_DEFLATE:
                if (predictor)
                    TIFFSetField(out, TIFFTAG_PREDICTOR, predictor);
                break;
        }
        fsdither(in, out);
        TIFFWriteDirectory(out);
    } while (TIFFReadDirectory(in));

    TIFFClose(in);
    TIFFClose(out);
    return (EXIT_SUCCESS);
}

static const char usage_info[] =
    "Convert a greyscale image to bilevel using dithering\n\n"
    "usage: tiffdither [options] input.tif output.tif\n"
    "where options are:\n"
    " -r #      make each strip have no more than # rows\n"
    " -t #      set the threshold value for dithering (default 128)\n"
    " -f lsb2msb    force lsb-to-msb FillOrder for output\n"
    " -f msb2lsb    force msb-to-lsb FillOrder for output\n"
    "\n"
#ifdef LZW_SUPPORT
    " -c lzw[:opts] compress output with Lempel-Ziv & Welch encoding\n"
    "    #          set predictor value\n"
    "    For example, -c lzw:2 for LZW-encoded data with horizontal "
    "differencing\n"
#endif
#ifdef ZIP_SUPPORT
    " -c zip[:opts] compress output with deflate encoding\n"
    "    #          set predictor value\n"
#endif
#ifdef PACKBITS_SUPPORT
    " -c packbits   compress output with packbits encoding\n"
#endif
#ifdef CCITT_SUPPORT
    " -c g3[:opts]  compress output with CCITT Group 3 encoding\n"
    "    Group 3 options:\n"
    "    1d         use default CCITT Group 3 1D-encoding\n"
    "    2d         use optional CCITT Group 3 2D-encoding\n"
    "    fill       byte-align EOL codes\n"
    "    For example, -c g3:2d:fill for G3-2D-encoded data with byte-aligned "
    "EOLs\n"
    " -c g4         compress output with CCITT Group 4 encoding\n"
#endif
#if defined(LZW_SUPPORT) || defined(ZIP_SUPPORT) ||                            \
    defined(PACKBITS_SUPPORT) || defined(CCITT_SUPPORT)
    " -c none       use no compression algorithm on output\n"
#endif
    "\n";

static void usage(int code)
{
    FILE *out = (code == EXIT_SUCCESS) ? stdout : stderr;

    fprintf(out, "%s\n\n", TIFFGetVersion());
    fprintf(out, "%s", usage_info);
    exit(code);
}