/*
 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, 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.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */
/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#ifndef HAVE_GETOPT_LONG

#if !defined(WINDOWS)
#include <err.h>
#endif
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "getopt.h"

#if defined(WINDOWS)
#define warnx	printf
#endif

#define GNU_COMPATIBLE		/* Be more compatible, configure's use us! */

#define	REPLACE_GETOPT		/* use this getopt as the system getopt(3) */

#ifdef REPLACE_GETOPT
int opterr = 1;			/* if error message should be printed */
int optind = 1;			/* index into parent argv vector */
int optopt = '?';		/* character checked for validity */
int optreset;			/* reset getopt */
char *optarg;			/* argument associated with option */
#endif

#define PRINT_ERROR	((opterr) && (*options != ':'))

#define FLAG_PERMUTE	0x01	/* permute non-options to the end of argv */
#define FLAG_ALLARGS	0x02	/* treat non-options as args to option "-1" */
#define FLAG_LONGONLY	0x04	/* operate as getopt_long_only */

/* return values */
#define	BADCH		(int)'?'
#define	BADARG		((*options == ':') ? (int)':' : (int)'?')
#define	INORDER 	(int)1

#define	EMSG		""

#ifdef GNU_COMPATIBLE
#define NO_PREFIX	(-1)
#define D_PREFIX	0
#define DD_PREFIX	1
#define W_PREFIX	2
#endif

static int getopt_internal (int, char *const *, const char *,
			    const struct option *, int *, int);
static int parse_long_options (char *const *, const char *,
			       const struct option *, int *, int, int);
static int gcd (int, int);
static void permute_args (int, int, int, char *const *);

static char *place = EMSG;	/* option letter processing */

/* XXX: set optreset to 1 rather than these two */
static int nonopt_start = -1;	/* first non option argument (for permute) */
static int nonopt_end = -1;	/* first option after non options (for permute) */

/* Error messages */
static const char recargchar[] = "option requires an argument -- %c";
static const char illoptchar[] = "illegal option -- %c";	/* From P1003.2 */
#ifdef GNU_COMPATIBLE
static int dash_prefix = NO_PREFIX;
static const char gnuoptchar[] = "invalid option -- %c";

static const char recargstring[] = "option `%s%s' requires an argument";
static const char ambig[] = "option `%s%.*s' is ambiguous";
static const char noarg[] = "option `%s%.*s' doesn't allow an argument";
static const char illoptstring[] = "unrecognized option `%s%s'";
#else
static const char recargstring[] = "option requires an argument -- %s";
static const char ambig[] = "ambiguous option -- %.*s";
static const char noarg[] = "option doesn't take an argument -- %.*s";
static const char illoptstring[] = "unknown option -- %s";
#endif

/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd (int a, int b)
{
  int c;

  c = a % b;
  while (c != 0)
    {
      a = b;
      b = c;
      c = a % b;
    }

  return (b);
}

/*
 * Exchange the block from nonopt_start to nonopt_end with the block
 * from nonopt_end to opt_end (keeping the same order of arguments
 * in each block).
 */
static void
permute_args (int panonopt_start, int panonopt_end, int opt_end,
	      char *const *nargv)
{
  int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
  char *swap;

  /*
   * compute lengths of blocks and number and size of cycles
   */
  nnonopts = panonopt_end - panonopt_start;
  nopts = opt_end - panonopt_end;
  ncycle = gcd (nnonopts, nopts);
  cyclelen = (opt_end - panonopt_start) / ncycle;

  for (i = 0; i < ncycle; i++)
    {
      cstart = panonopt_end + i;
      pos = cstart;
      for (j = 0; j < cyclelen; j++)
	{
	  if (pos >= panonopt_end)
	    pos -= nnonopts;
	  else
	    pos += nopts;
	  swap = nargv[pos];
	  /* LINTED const cast */
	  ((char **) nargv)[pos] = nargv[cstart];
	  /* LINTED const cast */
	  ((char **) nargv)[cstart] = swap;
	}
    }
}

/*
 * parse_long_options --
 *	Parse long options in argc/argv argument vector.
 * Returns -1 if short_too is set and the option does not match long_options.
 */
static int
parse_long_options (char *const *nargv, const char *options,
		    const struct option *long_options, int *idx,
		    int short_too, int flags)
{
  char *current_argv, *has_equal;
#ifdef GNU_COMPATIBLE
  char *current_dash;
#endif
  size_t current_argv_len;
  int i, match, exact_match, second_partial_match;

  current_argv = place;
#ifdef GNU_COMPATIBLE
  switch (dash_prefix)
    {
    case D_PREFIX:
      current_dash = "-";
      break;
    case DD_PREFIX:
      current_dash = "--";
      break;
    case W_PREFIX:
      current_dash = "-W ";
      break;
    default:
      current_dash = "";
      break;
    }
#endif
  match = -1;
  exact_match = 0;
  second_partial_match = 0;

  optind++;

  if ((has_equal = strchr (current_argv, '=')) != NULL)
    {
      /* argument found (--option=arg) */
      current_argv_len = has_equal - current_argv;
      has_equal++;
    }
  else
    current_argv_len = strlen (current_argv);

  for (i = 0; long_options[i].name; i++)
    {
      /* find matching long option */
      if (strncmp (current_argv, long_options[i].name, current_argv_len))
	continue;

      if (strlen (long_options[i].name) == current_argv_len)
	{
	  /* exact match */
	  match = i;
	  exact_match = 1;
	  break;
	}
      /*
       * If this is a known short option, don't allow
       * a partial match of a single character.
       */
      if (short_too && current_argv_len == 1)
	continue;

      if (match == -1)		/* first partial match */
	match = i;
      else if ((flags & FLAG_LONGONLY) ||
	       long_options[i].has_arg !=
	       long_options[match].has_arg ||
	       long_options[i].flag != long_options[match].flag ||
	       long_options[i].val != long_options[match].val)
	second_partial_match = 1;
    }
  if (!exact_match && second_partial_match)
    {
      /* ambiguous abbreviation */
      if (PRINT_ERROR)
	warnx (ambig,
#ifdef GNU_COMPATIBLE
	       current_dash,
#endif
	       (int) current_argv_len, current_argv);
      optopt = 0;
      return (BADCH);
    }
  if (match != -1)
    {				/* option found */
      if (long_options[match].has_arg == no_argument && has_equal)
	{
	  if (PRINT_ERROR)
	    warnx (noarg,
#ifdef GNU_COMPATIBLE
		   current_dash,
#endif
		   (int) current_argv_len, current_argv);
	  /*
	   * XXX: GNU sets optopt to val regardless of flag
	   */
	  if (long_options[match].flag == NULL)
	    optopt = long_options[match].val;
	  else
	    optopt = 0;
#ifdef GNU_COMPATIBLE
	  return (BADCH);
#else
	  return (BADARG);
#endif
	}
      if (long_options[match].has_arg == required_argument ||
	  long_options[match].has_arg == optional_argument)
	{
	  if (has_equal)
	    optarg = has_equal;
	  else if (long_options[match].has_arg == required_argument)
	    {
	      /*
	       * optional argument doesn't use next nargv
	       */
	      optarg = nargv[optind++];
	    }
	}
      if ((long_options[match].has_arg == required_argument)
	  && (optarg == NULL))
	{
	  /*
	   * Missing argument; leading ':' indicates no error
	   * should be generated.
	   */
	  if (PRINT_ERROR)
	    warnx (recargstring,
#ifdef GNU_COMPATIBLE
		   current_dash,
#endif
		   current_argv);
	  /*
	   * XXX: GNU sets optopt to val regardless of flag
	   */
	  if (long_options[match].flag == NULL)
	    optopt = long_options[match].val;
	  else
	    optopt = 0;
	  --optind;
	  return (BADARG);
	}
    }
  else
    {				/* unknown option */
      if (short_too)
	{
	  --optind;
	  return (-1);
	}
      if (PRINT_ERROR)
	warnx (illoptstring,
#ifdef GNU_COMPATIBLE
	       current_dash,
#endif
	       current_argv);
      optopt = 0;
      return (BADCH);
    }
  if (idx)
    *idx = match;
  if (long_options[match].flag)
    {
      *long_options[match].flag = long_options[match].val;
      return (0);
    }
  else
    return (long_options[match].val);
}

/*
 * getopt_internal --
 *	Parse argc/argv argument vector.  Called by user level routines.
 */
static int
getopt_internal (int nargc, char *const *nargv, const char *options,
		 const struct option *long_options, int *idx, int flags)
{
  char *oli;			/* option letter list index */
  int optchar, short_too;
  int posixly_correct;		/* no static, can be changed on the fly */

  if (options == NULL)
    return (-1);

  /*
   * Disable GNU extensions if POSIXLY_CORRECT is set or options
   * string begins with a '+'.
   */
  posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL);
#ifdef GNU_COMPATIBLE
  if (*options == '-')
    flags |= FLAG_ALLARGS;
  else if (posixly_correct || *options == '+')
    flags &= ~FLAG_PERMUTE;
#else
  if (posixly_correct || *options == '+')
    flags &= ~FLAG_PERMUTE;
  else if (*options == '-')
    flags |= FLAG_ALLARGS;
#endif
  if (*options == '+' || *options == '-')
    options++;

  /*
   * XXX Some GNU programs (like cvs) set optind to 0 instead of
   * XXX using optreset.  Work around this braindamage.
   */
  if (optind == 0)
    optind = optreset = 1;

  optarg = NULL;
  if (optreset)
    nonopt_start = nonopt_end = -1;
start:
  if (optreset || !*place)
    {				/* update scanning pointer */
      optreset = 0;
      if (optind >= nargc)
	{			/* end of argument vector */
	  place = EMSG;
	  if (nonopt_end != -1)
	    {
	      /* do permutation, if we have to */
	      permute_args (nonopt_start, nonopt_end, optind, nargv);
	      optind -= nonopt_end - nonopt_start;
	    }
	  else if (nonopt_start != -1)
	    {
	      /*
	       * If we skipped non-options, set optind
	       * to the first of them.
	       */
	      optind = nonopt_start;
	    }
	  nonopt_start = nonopt_end = -1;
	  return (-1);
	}
      if (*(place = nargv[optind]) != '-' ||
#ifdef GNU_COMPATIBLE
	  place[1] == '\0')
	{
#else
	  (place[1] == '\0' && strchr (options, '-') == NULL))
      {
#endif
	place = EMSG;		/* found non-option */
	if (flags & FLAG_ALLARGS)
	  {
	    /*
	     * GNU extension:
	     * return non-option as argument to option 1
	     */
	    optarg = nargv[optind++];
	    return (INORDER);
	  }
	if (!(flags & FLAG_PERMUTE))
	  {
	    /*
	     * If no permutation wanted, stop parsing
	     * at first non-option.
	     */
	    return (-1);
	  }
	/* do permutation */
	if (nonopt_start == -1)
	  nonopt_start = optind;
	else if (nonopt_end != -1)
	  {
	    permute_args (nonopt_start, nonopt_end, optind, nargv);
	    nonopt_start = optind - (nonopt_end - nonopt_start);
	    nonopt_end = -1;
	  }
	optind++;
	/* process next argument */
	goto start;
      }
      if (nonopt_start != -1 && nonopt_end == -1)
	nonopt_end = optind;

      /*
       * If we have "-" do nothing, if "--" we are done.
       */
      if (place[1] != '\0' && *++place == '-' && place[1] == '\0')
	{
	  optind++;
	  place = EMSG;
	  /*
	   * We found an option (--), so if we skipped
	   * non-options, we have to permute.
	   */
	  if (nonopt_end != -1)
	    {
	      permute_args (nonopt_start, nonopt_end, optind, nargv);
	      optind -= nonopt_end - nonopt_start;
	    }
	  nonopt_start = nonopt_end = -1;
	  return (-1);
	}
    }

  /*
   * Check long options if:
   *  1) we were passed some
   *  2) the arg is not just "-"
   *  3) either the arg starts with -- we are getopt_long_only()
   */
  if (long_options != NULL && place != nargv[optind]
      && (*place == '-' || (flags & FLAG_LONGONLY)))
    {
      short_too = 0;
#ifdef GNU_COMPATIBLE
      dash_prefix = D_PREFIX;
#endif
      if (*place == '-')
	{
	  place++;		/* --foo long option */
#ifdef GNU_COMPATIBLE
	  dash_prefix = DD_PREFIX;
#endif
	}
      else if (*place != ':' && strchr (options, *place) != NULL)
	short_too = 1;		/* could be short option too */

      optchar = parse_long_options (nargv, options, long_options,
				    idx, short_too, flags);
      if (optchar != -1)
	{
	  place = EMSG;
	  return (optchar);
	}
    }

  if ((optchar = (int) *place++) == (int) ':' ||
      (optchar == (int) '-' && *place != '\0') ||
      (oli = strchr (options, optchar)) == NULL)
    {
      /*
       * If the user specified "-" and  '-' isn't listed in
       * options, return -1 (non-option) as per POSIX.
       * Otherwise, it is an unknown option character (or ':').
       */
      if (optchar == (int) '-' && *place == '\0')
	return (-1);
      if (!*place)
	++optind;
#ifdef GNU_COMPATIBLE
      if (PRINT_ERROR)
	warnx (posixly_correct ? illoptchar : gnuoptchar, optchar);
#else
      if (PRINT_ERROR)
	warnx (illoptchar, optchar);
#endif
      optopt = optchar;
      return (BADCH);
    }
  if (long_options != NULL && optchar == 'W' && oli[1] == ';')
    {
      /* -W long-option */
      if (*place)		/* no space */
	/* NOTHING */ ;
      else if (++optind >= nargc)
	{			/* no arg */
	  place = EMSG;
	  if (PRINT_ERROR)
	    warnx (recargchar, optchar);
	  optopt = optchar;
	  return (BADARG);
	}
      else			/* white space */
	place = nargv[optind];
#ifdef GNU_COMPATIBLE
      dash_prefix = W_PREFIX;
#endif
      optchar = parse_long_options (nargv, options, long_options,
				    idx, 0, flags);
      place = EMSG;
      return (optchar);
    }
  if (*++oli != ':')
    {				/* doesn't take argument */
      if (!*place)
	++optind;
    }
  else
    {				/* takes (optional) argument */
      optarg = NULL;
      if (*place)		/* no white space */
	optarg = place;
      else if (oli[1] != ':')
	{			/* arg not optional */
	  if (++optind >= nargc)
	    {			/* no arg */
	      place = EMSG;
	      if (PRINT_ERROR)
		warnx (recargchar, optchar);
	      optopt = optchar;
	      return (BADARG);
	    }
	  else
	    optarg = nargv[optind];
	}
      place = EMSG;
      ++optind;
    }
  /* dump back option letter */
  return (optchar);
}

#ifdef REPLACE_GETOPT
/*
 * getopt --
 *	Parse argc/argv argument vector.
 *
 * [eventually this will replace the BSD getopt]
 */
int
getopt (int nargc, char *const *nargv, const char *options)
{

  /*
   * We don't pass FLAG_PERMUTE to getopt_internal() since
   * the BSD getopt(3) (unlike GNU) has never done this.
   *
   * Furthermore, since many privileged programs call getopt()
   * before dropping privileges it makes sense to keep things
   * as simple (and bug-free) as possible.
   */
  return (getopt_internal (nargc, nargv, options, NULL, NULL, 0));
}
#endif /* REPLACE_GETOPT */

/*
 * getopt_long --
 *	Parse argc/argv argument vector.
 */
int
getopt_long (int nargc, char *const *nargv, const char *options,
	     const struct option *long_options, int *idx)
{

  return (getopt_internal (nargc, nargv, options, long_options, idx,
			   FLAG_PERMUTE));
}

/*
 * getopt_long_only --
 *	Parse argc/argv argument vector.
 */
int
getopt_long_only (int nargc, char *const *nargv, const char *options,
		  const struct option *long_options, int *idx)
{

  return (getopt_internal (nargc, nargv, options, long_options, idx,
			   FLAG_PERMUTE | FLAG_LONGONLY));
}
#endif /* !HAVE_GETOPT_LONG */