/* ximtoppm.c - read an Xim file and produce a portable pixmap
**
** Copyright (C) 1991 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#define _DEFAULT_SOURCE 1  /* New name for SVID & BSD source defines */
#define _BSD_SOURCE 1      /* Make sure strdup() is in string.h */
#define _XOPEN_SOURCE 500  /* Make sure strdup() is in string.h */

#include <string.h>

#include "pm_c_util.h"
#include "ppm.h"
#include "xim.h"
#include "shhopt.h"
#include "nstring.h"

struct cmdlineInfo {
    /* All the information the user supplied in the command line,
       in a form easy for the program to use.
    */
    const char *input_filename;
    const char *alpha_filename;
    bool alpha_stdout;
};



static void
parseCommandLine(int argc, char ** argv,
                 struct cmdlineInfo *cmdlineP) {
/*----------------------------------------------------------------------------
   Note that many of the strings that this function returns in the
   *cmdlineP structure are actually in the supplied argv array.  And
   sometimes, one of these strings is actually just a suffix of an entry
   in argv!
-----------------------------------------------------------------------------*/
    optEntry option_def[100];
    optStruct3 opt;

    unsigned int option_def_index;

    unsigned int alphaoutSpec;

    option_def_index = 0;   /* incremented by OPTENT3 */
    OPTENT3(0,   "alphaout",   OPT_STRING, 
            &cmdlineP->alpha_filename, &alphaoutSpec, 0);

    opt.opt_table = option_def;
    opt.short_allowed = FALSE;  /* We have no short (old-fashioned) options */
    opt.allowNegNum = FALSE;  /* We have no parms that are negative numbers */

    pm_optParseOptions3(&argc, argv, opt, sizeof(opt), 0);
        /* Uses and sets argc, argv, and all of *cmdlineP. */

    if (!alphaoutSpec)
        cmdlineP->alpha_filename = NULL;

    if (argc - 1 == 0)
        cmdlineP->input_filename = "-";  /* he wants stdin */
    else if (argc - 1 == 1)
        cmdlineP->input_filename = strdup(argv[1]);
    else 
        pm_error("Too many arguments.  The only argument accepted "
                 "is the input file specification");

    if (cmdlineP->alpha_filename && 
        streq(cmdlineP->alpha_filename, "-"))
        cmdlineP->alpha_stdout = TRUE;
    else 
        cmdlineP->alpha_stdout = FALSE;
}



/* The subroutines are excerpted and slightly modified from the
   X.V11R4 version of xim_io.c. 
*/

static int
ReadXimHeader(FILE *     const in_fp,
              XimImage * const header) {

    int  i;
    char *cp;
    XimAsciiHeader  a_head;

    cp = (char *) header;
    for (i = 0; i < sizeof(XimImage); ++i )
    *cp++ = 0;
    /* Read header and verify image file formats */
    if (fread((char *)&a_head, sizeof(ImageHeader), 1, in_fp) != 1) {
        pm_message("ReadXimHeader: unable to read file header" );
        return(0);
    }
    if (atoi(a_head.header_size) != sizeof(ImageHeader)) {
        pm_message("ReadXimHeader: header size mismatch" );
        return(0);
    }
    if (atoi(a_head.file_version) != IMAGE_VERSION) {
        pm_message("ReadXimHeader: incorrect Image_file version" );
        return(0);
    }
    header->width = atoi(a_head.image_width);
    header->height = atoi(a_head.image_height);
    header->ncolors = atoi(a_head.num_colors);
    header->nchannels = atoi(a_head.num_channels);
    header->bytes_per_line = atoi(a_head.bytes_per_line);
/*    header->npics = atoi(a_head.num_pictures);
*/
    header->bits_channel = atoi(a_head.bits_per_channel);
    header->alpha_flag = atoi(a_head.alpha_channel);
    if (strlen(a_head.author)) {
        if (!(header->author = calloc((unsigned int)strlen(a_head.author)+1,
                1))) {
            pm_message("ReadXimHeader: can't calloc author string" );
            return(0);
        }
    header->width = atoi(a_head.image_width);
        strncpy(header->author, a_head.author, strlen(a_head.author));
    }
    if (strlen(a_head.date)) {
        if (!(header->date =calloc((unsigned int)strlen(a_head.date)+1,1))){
            pm_message("ReadXimHeader: can't calloc date string" );
            return(0);
        }
    header->width = atoi(a_head.image_width);
        strncpy(header->date, a_head.date, strlen(a_head.date));
    }
    if (strlen(a_head.program)) {
        if (!(header->program = calloc(
                    (unsigned int)strlen(a_head.program) + 1, 1))) {
            pm_message("ReadXimHeader: can't calloc program string" );
            return(0);
        }
    header->width = atoi(a_head.image_width);
        strncpy(header->program, a_head.program,strlen(a_head.program));
    }
    /* Do double checking for bakwards compatibility */
    if (header->npics == 0)
        header->npics = 1;
    if (header->bits_channel == 0)
        header->bits_channel = 8;
    else if (header->bits_channel == 24) {
        header->nchannels = 3;
        header->bits_channel = 8;
    }
    if ((int)header->bytes_per_line == 0)
        header->bytes_per_line = 
            (header->bits_channel == 1 && header->nchannels == 1) ?
                (header->width + 7) / 8 :
                header->width;
    header->datasize =(unsigned int)header->bytes_per_line * header->height;
    if (header->nchannels == 3 && header->bits_channel == 8)
        header->ncolors = 0;
    else if (header->nchannels == 1 && header->bits_channel == 8) {
        header->colors = (Color *)calloc((unsigned int)header->ncolors,
                sizeof(Color));
        if (header->colors == NULL) {
            pm_message("ReadXimHeader: can't calloc colors" );
            return(0);
        }
        for (i=0; i < header->ncolors; i++) {
            header->colors[i].red = a_head.c_map[i][0];
            header->colors[i].grn = a_head.c_map[i][1];
            header->colors[i].blu = a_head.c_map[i][2];
        }
    }
    return(1);
}



static int
ReadImageChannel(FILE *         const infp,
                 byte *         const buf,
                 unsigned int * const bufsize,
                 int            const encoded) {

    int  i, runlen, nbytes;
    unsigned int  j;
    byte *line;
    long  marker;

    if (!encoded)
        j = fread((char *)buf, 1, (int)*bufsize, infp);
    else {
        if ((line=(byte *)malloc((unsigned int)BUFSIZ)) == NULL) {
            pm_message("ReadImageChannel: can't malloc() fread string" );
            return(0);
        }
        /* Unrunlength encode data */
        marker = ftell(infp);
        j = 0;
        while (((nbytes=fread((char *)line, 1, BUFSIZ, infp)) > 0) &&
            (j < *bufsize)) {
            for (i=0; (i < nbytes) && (j < *bufsize); i++) {
                runlen = (int)line[i]+1;
                i++;
                while (runlen--)
                    buf[j++] = line[i];
            }
            marker += i;
        }
        /* return to the beginning of the next image's bufffer */
        if (fseek(infp, marker, 0) == -1) {
            pm_message("ReadImageChannel: can't fseek to location in image buffer" );
            return(0);
        }
        free((char *)line);
    }
    if (j != *bufsize) {
        pm_message("unable to complete channel: %u / %u (%d%%)",
            j, *bufsize, (int)(j*100.0 / *bufsize) );
        *bufsize = j;
    }
    return(1);
}



static int
ReadXimImage(FILE *     const in_fp,
             XimImage * const xim) {

    if (xim->data) {
        free((char *)xim->data);
        xim->data = (byte *)0;
    }
    if (xim->grn_data) {
        free((char *)xim->grn_data);
        xim->grn_data = (byte *)0;
    }
    if (xim->blu_data) {
        free((char *)xim->blu_data);
        xim->blu_data = (byte *)0;
    }
    if (xim->other) {
        free((char *)xim->other);
        xim->other = (byte *)0;
    }
    xim->npics = 0;
    if (!(xim->data = (byte *)calloc(xim->datasize, 1))) {
        pm_message("ReadXimImage: can't malloc pixmap data" );
        return(0);
    }
    if (!ReadImageChannel(in_fp, xim->data, &xim->datasize, 0)) {
        pm_message("ReadXimImage: end of the images" );
        return(0);
    }
    if (xim->nchannels == 3) {
        xim->grn_data = (byte *)malloc(xim->datasize);
        xim->blu_data = (byte *)malloc(xim->datasize);
        if (xim->grn_data == NULL || xim->blu_data == NULL) {
            pm_message("ReadXimImage: can't malloc rgb channel data" );
            free((char *)xim->data);
            if (xim->grn_data)  free((char *)xim->grn_data);
            if (xim->blu_data)  free((char *)xim->blu_data);
            xim->data = xim->grn_data = xim->blu_data = (byte*)0;
            return(0);
        }
        if (!ReadImageChannel(in_fp, xim->grn_data, &xim->datasize, 0))
            return(0);
        if (!ReadImageChannel(in_fp, xim->blu_data, &xim->datasize, 0))
            return(0);
    }
    if (xim->nchannels > 3) {
        /* In theory, this can be any fourth channel, but the only one we
           know about is an Alpha channel, so we'll call it that, even
           though we process it generically.
           */
        if ((xim->other = (byte *)malloc(xim->datasize)) == NULL) {
            pm_message("ReadXimImage: can't malloc alpha data" );
            return(0);
        }
        if (!ReadImageChannel(in_fp, xim->other, &xim->datasize, 0))
            return(0);
    }
    xim->npics = 1;
    return(1);
}



/***********************************************************************
*  File:   xlib.c
*  Author: Philip Thompson
*  $Date: 2019/05/31 19:44:46 $
*  $Revision: 1.1.1.1 $
*  Purpose: General xim libray of utililities
*  Copyright (c) 1988  Philip R. Thompson
*                Computer Resource Laboratory (CRL)
*                Dept. of Architecture and Planning
*                M.I.T., Rm 9-526
*                Cambridge, MA  02139
*   This  software and its documentation may be used, copied, modified,
*   and distributed for any purpose without fee, provided:
*       --  The above copyright notice appears in all copies.
*       --  This disclaimer appears in all source code copies.
*       --  The names of M.I.T. and the CRL are not used in advertising
*           or publicity pertaining to distribution of the software
*           without prior specific written permission from me or CRL.
*   I provide this software freely as a public service.  It is NOT a
*   commercial product, and therefore is not subject to an an implied
*   warranty of merchantability or fitness for a particular purpose.  I
*   provide it as is, without warranty.
*   This software is furnished  only on the basis that any party who
*   receives it indemnifies and holds harmless the parties who furnish
*   it against any claims, demands, or liabilities connected with using
*   it, furnishing it to others, or providing it to a third party.
*
*   Philip R. Thompson (phils@athena.mit.edu)
***********************************************************************/

static int
ReadXim(in_fp, xim)
    FILE *in_fp;
    XimImage *xim;
{
    if (!ReadXimHeader(in_fp, xim)) {
        pm_message("can't read xim header" );
    return(0);
    }
    if (!ReadXimImage(in_fp, xim)) {
        pm_message("can't read xim data" );
    return(0);
    }
    return(1);
}



int
main(int argc,
     char *argv[]) {

    struct cmdlineInfo cmdline;
    FILE *ifP, *imageout_file, *alpha_file;
    XimImage xim;
    pixel *pixelrow, colormap[256];
    gray *alpharow;
        /* The alpha channel of the row we're currently converting, in
           pgm fmt
        */
    int rows, cols, row, mapped;
    pixval maxval;
    bool success;

    ppm_init(&argc, argv);

    parseCommandLine(argc, argv, &cmdline);
    
    ifP = pm_openr(cmdline.input_filename);
    
    if (cmdline.alpha_stdout)
        alpha_file = stdout;
    else if (cmdline.alpha_filename == NULL) 
        alpha_file = NULL;
    else
        alpha_file = pm_openw(cmdline.alpha_filename);
    
    if (cmdline.alpha_stdout) 
        imageout_file = NULL;
    else
        imageout_file = stdout;
    
    success = ReadXim(ifP, &xim);
    if (!success)
        pm_error("can't read Xim file");

    rows = xim.height;
    cols = xim.width;

    if (xim.nchannels == 1 && xim.bits_channel == 8) {
        int i;

        mapped = true;
        maxval = 255;
        for (i = 0; i < xim.ncolors; ++i) {
            PPM_ASSIGN(
                colormap[i], xim.colors[i].red,
                xim.colors[i].grn, xim.colors[i].blu );
            /* Should be colormap[xim.colors[i].pixel], but Xim is broken. */
        }
    } else if (xim.nchannels == 3 || xim.nchannels == 4) {
        mapped = false;
        maxval = pm_bitstomaxval(xim.bits_channel);
    } else
        pm_error(
            "unknown Xim file type, nchannels == %d, bits_channel == %d",
            xim.nchannels, xim.bits_channel);

    if (imageout_file) 
        ppm_writeppminit(imageout_file, cols, rows, maxval, 0);
    if (alpha_file)
        pgm_writepgminit(alpha_file, cols, rows, maxval, 0);

    pixelrow = ppm_allocrow(cols);
    alpharow = pgm_allocrow(cols);

    for (row = 0; row < rows; ++row) {
        if (mapped) {
            byte * const ximrow = xim.data + row * xim.bytes_per_line;
            unsigned int col;
            
            for (col = 0; col < cols; ++col) 
                pixelrow[col] = colormap[ximrow[col]];
            alpharow[col] = 0;
        } else {
            byte * const redrow = xim.data     + row * xim.bytes_per_line;
            byte * const grnrow = xim.grn_data + row * xim.bytes_per_line;
            byte * const blurow = xim.blu_data + row * xim.bytes_per_line;
            byte * const othrow = xim.other    + row * xim.bytes_per_line;

            unsigned int col;

            for (col = 0; col < cols; ++col) {
                PPM_ASSIGN(pixelrow[col],
                           redrow[col], grnrow[col], blurow[col]);
                if (xim.nchannels > 3)
                    alpharow[col] = othrow[col];
                else 
                    alpharow[col] = 0;
            }
        }
        if (imageout_file) 
            ppm_writeppmrow(imageout_file, pixelrow, cols, maxval, 0);
        if (alpha_file)
            pgm_writepgmrow(alpha_file, alpharow, cols, maxval, 0);
    }
    pm_close(ifP);
    if (imageout_file)
        pm_close(imageout_file);
    if (alpha_file)
        pm_close(alpha_file);

    return 0;
}
