/*
 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
 *   British Columbia.
 * Copyright (c) 2001-2003 Michael David Adams.
 * All rights reserved.
 */

/* __START_OF_JASPER_LICENSE__
 *
 * JasPer License Version 2.0
 *
 * Copyright (c) 2001-2006 Michael David Adams
 * Copyright (c) 1999-2000 Image Power, Inc.
 * Copyright (c) 1999-2000 The University of British Columbia
 *
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person (the
 * "User") 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, 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:
 *
 * 1.  The above copyright notices and this permission notice (which
 * includes the disclaimer below) shall be included in all copies or
 * substantial portions of the Software.
 *
 * 2.  The name of a copyright holder shall not be used to endorse or
 * promote products derived from the Software without specific prior
 * written permission.
 *
 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
 * LICENSE.  NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
 * THIS DISCLAIMER.  THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
 * "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 OF THIRD PARTY RIGHTS.  IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  NO ASSURANCES ARE
 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
 * PROPERTY RIGHTS OR OTHERWISE.  AS A CONDITION TO EXERCISING THE RIGHTS
 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY.  THE SOFTWARE
 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
 * RISK ACTIVITIES").  THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
 *
 * __END_OF_JASPER_LICENSE__
 */

/*
 * Portable Pixmap/Graymap Format Support
 *
 * $Id$
 */

/******************************************************************************\
* Includes.
\******************************************************************************/

#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>

#include "jasper/jas_types.h"
#include "jasper/jas_stream.h"
#include "jasper/jas_image.h"

#include "pnm_cod.h"

/******************************************************************************\
* Local function prototypes.
\******************************************************************************/

static int pnm_gethdr(jas_stream_t *in, pnm_hdr_t *hdr);
static int pnm_getdata(jas_stream_t *in, pnm_hdr_t *hdr, jas_image_t *image);

static int pnm_getsintstr(jas_stream_t *in, int_fast32_t *val);
static int pnm_getuintstr(jas_stream_t *in, uint_fast32_t *val);
static int pnm_getbitstr(jas_stream_t *in, int *val);
static int pnm_getc(jas_stream_t *in);

static int pnm_getsint(jas_stream_t *in, int wordsize, int_fast32_t *val);
static int pnm_getuint(jas_stream_t *in, int wordsize, uint_fast32_t *val);
static int pnm_getint16(jas_stream_t *in, int *val);
#define	pnm_getuint32(in, val)	pnm_getuint(in, 32, val)

/******************************************************************************\
* Local data.
\******************************************************************************/

static int pnm_allowtrunc = 1;

/******************************************************************************\
* Load function.
\******************************************************************************/

jas_image_t *pnm_decode(jas_stream_t *in, char *opts)
{
    pnm_hdr_t hdr;
    jas_image_t *image;
    jas_image_cmptparm_t cmptparms[3];
    jas_image_cmptparm_t *cmptparm;
    int i;

    if (opts) {
        jas_eprintf("warning: ignoring options\n");
    }

    /* Read the file header. */
    if (pnm_gethdr(in, &hdr)) {
        return 0;
    }

    /* Create an image of the correct size. */
    for (i = 0, cmptparm = cmptparms; i < hdr.numcmpts; ++i, ++cmptparm) {
        cmptparm->tlx = 0;
        cmptparm->tly = 0;
        cmptparm->hstep = 1;
        cmptparm->vstep = 1;
        cmptparm->width = hdr.width;
        cmptparm->height = hdr.height;
        cmptparm->prec = pnm_maxvaltodepth(hdr.maxval);
        cmptparm->sgnd = hdr.sgnd;
    }
    if (!(image = jas_image_create(hdr.numcmpts, cmptparms, JAS_CLRSPC_UNKNOWN))) {
        return 0;
    }

    if (hdr.numcmpts == 3) {
        jas_image_setclrspc(image, JAS_CLRSPC_SRGB);
        jas_image_setcmpttype(image, 0,
          JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_R));
        jas_image_setcmpttype(image, 1,
          JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_G));
        jas_image_setcmpttype(image, 2,
          JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_RGB_B));
    } else {
        jas_image_setclrspc(image, JAS_CLRSPC_SGRAY);
        jas_image_setcmpttype(image, 0,
          JAS_IMAGE_CT_COLOR(JAS_CLRSPC_CHANIND_GRAY_Y));
    }

    /* Read image data from stream into image. */
    if (pnm_getdata(in, &hdr, image)) {
        jas_image_destroy(image);
        return 0;
    }

    return image;
}

/******************************************************************************\
* Validation function.
\******************************************************************************/

int pnm_validate(jas_stream_t *in)
{
    uchar buf[2];
    int i;
    int n;

    assert(JAS_STREAM_MAXPUTBACK >= 2);

    /* Read the first two characters that constitute the signature. */
    if ((n = jas_stream_read(in, buf, 2)) < 0) {
        return -1;
    }
    /* Put these characters back to the stream. */
    for (i = n - 1; i >= 0; --i) {
        if (jas_stream_ungetc(in, buf[i]) == EOF) {
            return -1;
        }
    }
    /* Did we read enough data? */
    if (n < 2) {
        return -1;
    }
    /* Is this the correct signature for a PNM file? */
    if (buf[0] == 'P' && isdigit(buf[1])) {
        return 0;
    }
    return -1;
}

/******************************************************************************\
* Functions for reading the header.
\******************************************************************************/

static int pnm_gethdr(jas_stream_t *in, pnm_hdr_t *hdr)
{
    int_fast32_t maxval;
    int_fast32_t width;
    int_fast32_t height;
    if (pnm_getint16(in, &hdr->magic) || pnm_getsintstr(in, &width) ||
      pnm_getsintstr(in, &height)) {
        return -1;
    }
    hdr->width = width;
    hdr->height = height;
    if (pnm_type(hdr->magic) != PNM_TYPE_PBM) {
        if (pnm_getsintstr(in, &maxval)) {
            return -1;
        }
    } else {
        maxval = 1;
    }
    if (maxval < 0) {
        hdr->maxval = -maxval;
        hdr->sgnd = true;
    } else {
        hdr->maxval = maxval;
        hdr->sgnd = false;
    }

    switch (pnm_type(hdr->magic)) {
    case PNM_TYPE_PBM:
    case PNM_TYPE_PGM:
        hdr->numcmpts = 1;
        break;
    case PNM_TYPE_PPM:
        hdr->numcmpts = 3;
        break;
    default:
        abort();
        break;
    }

    return 0;
}

/******************************************************************************\
* Functions for processing the sample data.
\******************************************************************************/

static int pnm_getdata(jas_stream_t *in, pnm_hdr_t *hdr, jas_image_t *image)
{
    int ret;
#if 0
    int numcmpts;
#endif
    int cmptno;
    int fmt;
    jas_matrix_t *data[3];
    int x;
    int y;
    int_fast64_t v;
    int depth;
    int type;
    int c;
    int n;

    ret = -1;

#if 0
    numcmpts = jas_image_numcmpts(image);
#endif
    fmt = pnm_fmt(hdr->magic);
    type = pnm_type(hdr->magic);
    depth = pnm_maxvaltodepth(hdr->maxval);

    data[0] = 0;
    data[1] = 0;
    data[2] = 0;
    for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
        if (!(data[cmptno] = jas_matrix_create(1, hdr->width))) {
            goto done;
        }
    }

    for (y = 0; y < hdr->height; ++y) {
        if (type == PNM_TYPE_PBM) {
            if (fmt == PNM_FMT_BIN) {
                for (x = 0; x < hdr->width;) {
                    if ((c = jas_stream_getc(in)) == EOF) {
                        goto done;
                    }
                    n = 8;
                    while (n > 0 && x < hdr->width) {
                        jas_matrix_set(data[0], 0, x, 1 - ((c >> 7) & 1));
                        c <<= 1;
                        --n;
                        ++x;
                    }
                }
            } else {
                for (x = 0; x < hdr->width; ++x) {
                    int uv;
                    if (pnm_getbitstr(in, &uv)) {
                        goto done;
                    }
                    jas_matrix_set(data[0], 0, x, 1 - uv);
                }
            }
        } else {
            for (x = 0; x < hdr->width; ++x) {
                for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
                    if (fmt == PNM_FMT_BIN) {
                        /* The sample data is in binary format. */
                        if (hdr->sgnd) {
                            /* The sample data is signed. */
                            int_fast32_t sv;
                            if (pnm_getsint(in, depth, &sv)) {
                                if (!pnm_allowtrunc) {
                                    goto done;
                                }
                                sv = 0;
                            }
                            v = sv;
                        } else {
                            /* The sample data is unsigned. */
                            uint_fast32_t uv;
                            if (pnm_getuint(in, depth, &uv)) {
                                if (!pnm_allowtrunc) {
                                    goto done;
                                }
                                uv = 0;
                            }
                            v = uv;
                        }
                    } else {
                        /* The sample data is in text format. */
                        if (hdr->sgnd) {
                            /* The sample data is signed. */
                            int_fast32_t sv;
                            if (pnm_getsintstr(in, &sv)) {
                                if (!pnm_allowtrunc) {
                                    goto done;
                                }
                                sv = 0;
                            }
                            v = sv;
                        } else {
                            /* The sample data is unsigned. */
                            uint_fast32_t uv;
                            if (pnm_getuintstr(in, &uv)) {
                                if (!pnm_allowtrunc) {
                                    goto done;
                                }
                                uv = 0;
                            }
                            v = uv;
                        }
                    }
                    jas_matrix_set(data[cmptno], 0, x, v);
                }
            }
        }
        for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
            if (jas_image_writecmpt(image, cmptno, 0, y, hdr->width, 1,
              data[cmptno])) {
                goto done;
            }
        }
    }

    ret = 0;

done:

    for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
        if (data[cmptno]) {
            jas_matrix_destroy(data[cmptno]);
        }
    }

    return ret;
}

/******************************************************************************\
* Miscellaneous functions.
\******************************************************************************/

static int pnm_getsint(jas_stream_t *in, int wordsize, int_fast32_t *val)
{
    uint_fast32_t tmpval;

    if (pnm_getuint(in, wordsize, &tmpval)) {
        return -1;
    }
    if (val) {
        assert((tmpval & (1 << (wordsize - 1))) == 0);
        *val = tmpval;
    }

    return 0;
}

static int pnm_getuint(jas_stream_t *in, int wordsize, uint_fast32_t *val)
{
    uint_fast32_t tmpval;
    int c;
    int n;

    tmpval = 0;
    n = (wordsize + 7) / 8;
    while (--n >= 0) {
        if ((c = jas_stream_getc(in)) == EOF) {
            return -1;
        }
        tmpval = (tmpval << 8) | c;
    }
    tmpval &= (((uint_fast64_t) 1) << wordsize) - 1;
    if (val) {
        *val = tmpval;
    }

    return 0;
}

static int pnm_getbitstr(jas_stream_t *in, int *val)
{
    int c;
    int_fast32_t v;
    for (;;) {
        if ((c = pnm_getc(in)) == EOF) {
            return -1;
        }
        if (c == '#') {
            for (;;) {
                if ((c = pnm_getc(in)) == EOF) {
                    return -1;
                }
                if (c == '\n') {
                    break;
                }
            }
        } else if (c == '0' || c == '1') {
            v = c - '0';
            break;
        }
    }
    if (val) {
        *val = v;
    }
    return 0;
}

static int pnm_getuintstr(jas_stream_t *in, uint_fast32_t *val)
{
    uint_fast32_t v;
    int c;

    /* Discard any leading whitespace. */
    do {
        if ((c = pnm_getc(in)) == EOF) {
            return -1;
        }
    } while (isspace(c));

    /* Parse the number. */
    v = 0;
    while (isdigit(c)) {
        v = 10 * v + c - '0';
        if ((c = pnm_getc(in)) < 0) {
            return -1;
        }
    }

    /* The number must be followed by whitespace. */
    if (!isspace(c)) {
        return -1;
    }

    if (val) {
        *val = v;
    }
    return 0;
}

static int pnm_getsintstr(jas_stream_t *in, int_fast32_t *val)
{
    int c;
    int s;
    int_fast32_t v;

    /* Discard any leading whitespace. */
    do {
        if ((c = pnm_getc(in)) == EOF) {
            return -1;
        }
    } while (isspace(c));

    /* Get the number, allowing for a negative sign. */
    s = 1;
    if (c == '-') {
        s = -1;
        if ((c = pnm_getc(in)) == EOF) {
            return -1;
        }
    } else if (c == '+') {
        if ((c = pnm_getc(in)) == EOF) {
            return -1;
        }
    }
    v = 0;
    while (isdigit(c)) {
        v = 10 * v + c - '0';
        if ((c = pnm_getc(in)) < 0) {
            return -1;
        }
    }

    /* The number must be followed by whitespace. */
    if (!isspace(c)) {
        return -1;
    }

    if (val) {
        *val = (s >= 0) ? v : (-v);
    }

    return 0;
}

static int pnm_getc(jas_stream_t *in)
{
    int c;
    for (;;) {
        if ((c = jas_stream_getc(in)) == EOF) {
            return -1;
        }
        if (c != '#') {
            return c;
        }
        do {
            if ((c = jas_stream_getc(in)) == EOF) {
                return -1;
            }
        } while (c != '\n' && c != '\r');
    }
}

static int pnm_getint16(jas_stream_t *in, int *val)
{
    int v;
    int c;

    if ((c = jas_stream_getc(in)) == EOF) {
        return -1;
    }
    v = c & 0xff;
    if ((c = jas_stream_getc(in)) == EOF) {
        return -1;
    }
    v = (v << 8) | (c & 0xff);
    *val = v;

    return 0;
}