/*
 * The Npic library and tools
 *
 * Copyright (C) 2003 Edouard Thiel <Edouard.Thiel@lif.univ-mrs.fr>
 *
 * This program is free software under the terms of the 
 * GNU Lesser General Public License (LGPL) version 2.1.
*/

/*
 * npic-diff.c - 19/08/2008
 *
*/

#include <npic.h>

void ShowUsage ()
{
    printf (
        "npic-diff - Compare two images, pixel per pixel.\n"
        "Usage:\n"
        "  npic-diff  -h | -help | --help : print help\n"
        "  npic-diff in1 in2 options      : compare pixels\n"
        "\n"
        "Options:\n"
        "  -c|-l|-d  : convert pixel type to char, long, double for both images\n"
        "  -b        : binary comparison (pixel == 0 or != 0)\n"
        "  -p  x     : max number of printed differences, default is 20\n"
        "\n"
        "in1, in2 : image in " NPIC_KNOWN_IMAGE_EXT " format\n"
    );
}

void ArgcExit (int argc, int n)
{
    if (argc < n) {
        fprintf (stderr, "ERROR: %d argument(s) missing, "
                         "type \"npic-diff -h\" to get help.\n", n-argc);
        exit (1);
    }
}

void ArgShift (int *argc, char **argv[], int n)
{
    *argc -= n; *argv += n;
}

int main (int argc, char *argv[])
{
    char *in1, *in2, do_conv = ' ';
    Npic_image *np1, *np2;
    int do_bin = 0;
    long i, maxdiff = 10;
    ArgcExit (argc, 2);
    
    if (strcmp (argv[1], "-h") == 0 || strcmp (argv[1], "-help") == 0 ||
        strcmp (argv[1], "--help") == 0) { ShowUsage (); exit (0); }
    
    ArgcExit (argc, 2+1);
    in1 = argv[1];
    in2 = argv[2];
    ArgShift (&argc, &argv, 2);
    
    while (argc > 1) {
        if (strcmp (argv[1], "-p") == 0) {
            ArgcExit (argc, 2+1);
            maxdiff = atoi(argv[2]);
            ArgShift (&argc, &argv, 2);
        } else if (strcmp (argv[1], "-b") == 0) {
            do_bin = 1; ArgShift (&argc, &argv, 1);
        } else if (strcmp (argv[1], "-l") == 0 ||
                   strcmp (argv[1], "-c") == 0 ||
                   strcmp (argv[1], "-d") == 0) {
            do_conv = argv[1][1]; ArgShift (&argc, &argv, 1);
        } else {
            fprintf (stderr, "ERROR: unknown argument \"%s\", "
                     "type \"npic-diff -h\" to get help.\n", argv[1]);
            exit (1);
        }
    }
    
    printf ("Loading \"%s\"\n", in1);
    np1 = NpicReadImage (in1);
    if (np1 == NULL) exit (1);

    printf ("Loading \"%s\"\n", in2);
    np2 = NpicReadImage (in2);
    if (np2 == NULL) exit (1);

    switch (do_conv) {
        case 'c' : NpicConvertImage_c (np1); NpicConvertImage_c (np2); break;
        case 'l' : NpicConvertImage_l (np1); NpicConvertImage_l (np2); break;
        case 'd' : NpicConvertImage_d (np1); NpicConvertImage_d (np2); break;
    }

    if (do_bin)
         i = NpicCompareBin (np1, np2, maxdiff);
    else i = NpicCompare (np1, np2, maxdiff);

    if (i == 0) { printf ("0 pixels differ, same images\n"); exit (0); }
    if (i > 0) printf ("%ld pixels differ\n", i);
    exit (1);
}