/*
   getopt_long.c - implementation of getopt_long() for systems that lack it

   Copyright (C) 2001, 2002, 2008, 2012 Arthur de Jong

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301 USA
*/

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

#include "getopt_long.h"

/* this is a (poor) getopt_long() replacement for systems that don't have it
   (getopt_long() is generaly a GNU extention)
   this implementation is by no meens flawless, especialy the optional arguments
   to options and options following filenames is not quite right, allso
   minimal error checking is provided
   */
int getopt_long(int argc, char *const argv[],
                const char *optstring,
                const struct option *longopts, int *longindex)
{
  int i, l;
  /* first check if there realy is a -- option */
  if ((optind > 0) && (optind < argc) &&
      (strncmp(argv[optind], "--", 2) == 0) &&
      (argv[optind][2] != '\0'))
  {
    /* check the longopts list for a valid option */
    for (i = 0; longopts[i].name != NULL; i++)
    {
      /* save the length for later */
      l = strlen(longopts[i].name);
      if (strncmp(argv[optind] + 2, longopts[i].name, l) == 0)
      {
        /* we have a match */
        if ((longopts[i].has_arg == no_argument) &&
            (argv[optind][2 + l] == '\0'))
        {
          optind++;
          return longopts[i].val;
        }
        else if ((longopts[i].has_arg == required_argument) &&
                 (argv[optind][2 + l] == '='))
        {
          optarg = argv[optind] + 3 + l;
          optind++;
          return longopts[i].val;
        }
        else if ((longopts[i].has_arg == required_argument) &&
                 (argv[optind][2 + l] == '\0'))
        {
          optarg = argv[optind + 1];
          optind += 2;
          return longopts[i].val;
        }
        else if ((longopts[i].has_arg == optional_argument) &&
                 (argv[optind][2 + l] == '='))
        {
          optarg = argv[optind] + 3 + l;
          optind++;
          return longopts[i].val;
        }
        else if ((longopts[i].has_arg == optional_argument) &&
                 (argv[optind][2 + l] == '\0'))
        {
          optind++;
          return longopts[i].val;
        }
      }
    }
  }
  /* if all else fails use plain getopt() */
  return getopt(argc, argv, optstring);
}