/*-
 * 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"

#include "getopt_long.h"

/* We need out logging to take const char *'s */

#if HAVE_CONFIG_H && !HAVE_GETOPT_LONG && !HAVE_DECL_OPTIND
#define REPLACE_GETOPT
#endif

#ifdef REPLACE_GETOPT
#ifdef __weak_alias
__weak_alias(getopt,_getopt)
#endif
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 */
#elif HAVE_CONFIG_H && !HAVE_DECL_OPTRESET
static int optreset;
#endif

#ifdef __weak_alias
__weak_alias(getopt_long,_getopt_long)
#endif

#if !HAVE_GETOPT_LONG
#define IGNORE_FIRST	(*options == '-' || *options == '+')
#define PRINT_ERROR	((opterr) && ((*options != ':') \
				      || (IGNORE_FIRST && options[1] != ':')))
#define IS_POSIXLY_CORRECT (getenv("POSIXLY_CORRECT") != NULL)
#define PERMUTE         (!IS_POSIXLY_CORRECT && !IGNORE_FIRST)
/* XXX: GNU ignores PC if *options == '-' */
#define IN_ORDER        (!IS_POSIXLY_CORRECT && *options == '-')

/* return values */
#define	BADCH	(int)'?'
#define	BADARG		((IGNORE_FIRST && options[1] == ':') \
			 || (*options == ':') ? (int)':' : (int)'?')
#define INORDER (int)1

#define	EMSG	""

static int getopt_internal __P((int, char * const *, const char *));
static int gcd __P((int, int));
static void permute_args __P((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 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 illoptchar[] = "unknown option -- %c";
static const char illoptstring[] = "unknown option -- %s";


/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd(a, b)
     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(panonopt_start, panonopt_end, opt_end, nargv)
     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;
    }
  }
}

/*
 * getopt_internal --
 *	Parse argc/argv argument vector.  Called by user level routines.
 *  Returns -2 if -- is found (can be long option or end of options marker).
 */
static int
getopt_internal(nargc, nargv, options)
     int nargc;
     char * const *nargv;
     const char *options;
{
  char *oli;				/* option letter list index */
  int optchar;

  optarg = NULL;

  /*
   * XXX Some programs (like rsyncd) expect to be able to
   * XXX re-initialize optind to 0 and have getopt_long(3)
   * XXX properly function again.  Work around this braindamage.
   */
  if (optind == 0)
    optind = 1;

  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]) != '-')
        || (place[1] == '\0')) {    /* found non-option */
      place = EMSG;
      if (IN_ORDER) {
        /*
         * GNU extension: 
         * return non-option as argument to option 1
         */
        optarg = nargv[optind++];
        return INORDER;
      }
      if (!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 (place[1] && *++place == '-') {	/* found "--" */
      place++;
      return -2;
    }
  }
  if ((optchar = (int)*place++) == (int)':' ||
      (oli = strchr(options + (IGNORE_FIRST ? 1 : 0), optchar)) == NULL) {
    /* option letter unknown or ':' */
    if (!*place)
      ++optind;
    if (PRINT_ERROR)
      fprintf(stderr, (char *)illoptchar, optchar);
    optopt = optchar;
    return BADCH;
  }
  if (optchar == 'W' && oli[1] == ';') {		/* -W long-option */
    /* XXX: what if no long options provided (called by getopt)? */
    if (*place) 
      return -2;

    if (++optind >= nargc) {	/* no arg */
      place = EMSG;
      if (PRINT_ERROR)
        fprintf(stderr, recargchar, optchar);
      optopt = optchar;
      return BADARG;
    } else				/* white space */
      place = nargv[optind];
    /*
     * Handle -W arg the same as --arg (which causes getopt to
     * stop parsing).
     */
    return -2;
  }
  if (*++oli != ':') {			/* doesn't take argument */
    if (!*place)
      ++optind;
  } else {				/* takes (optional) argument */
    optarg = NULL;
    if (*place)			/* no white space */
      optarg = place;
    /* XXX: disable test for :: if PC? (GNU doesn't) */
    else if (oli[1] != ':') {	/* arg not optional */
      if (++optind >= nargc) {	/* no arg */
        place = EMSG;
        if (PRINT_ERROR)
          fprintf(stderr, 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 real getopt]
 */
int
getopt(nargc, nargv, options)
     int nargc;
     char * const *nargv;
     const char *options;
{
  int retval;

  if ((retval = getopt_internal(nargc, nargv, options)) == -2) {
    ++optind;
    /*
     * 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;
    retval = -1;
  }
  return retval;
}
#endif

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

  /* idx may be NULL */

  if ((retval = getopt_internal(nargc, nargv, options)) == -2) {
    char *current_argv, *has_equal;
    size_t current_argv_len;
    int i, match;

    current_argv = place;
    match = -1;

    optind++;
    place = EMSG;

    if (*current_argv == '\0') {		/* found "--" */
      /*
       * 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;
    }
    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) ==
          (unsigned)current_argv_len) {
        /* exact match */
        match = i;
        break;
      }
      if (match == -1)		/* partial match */
        match = i;
      else {
        /* ambiguous abbreviation */
        if (PRINT_ERROR)
          fprintf(stderr, ambig, (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)
          fprintf(stderr, noarg, (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;
        return BADARG;
      }
      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 erroc should be generated
         */
        if (PRINT_ERROR)
          fprintf(stderr, recargstring, 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 (PRINT_ERROR)
        fprintf(stderr, illoptstring, current_argv);
      optopt = 0;
      return BADCH;
    }
    if (long_options[match].flag) {
      *long_options[match].flag = long_options[match].val;
      retval = 0;
    } else 
      retval = long_options[match].val;
    if (idx)
      *idx = match;
  }
  return retval;
}
#endif /* !GETOPT_LONG */
