/* argmatch.c -- find a match for a string in an array

   Copyright (C) 1990, 1998-1999, 2001-2007, 2009-2018 Free Software

   Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by David MacKenzie <djm@ai.mit.edu>

   Modified by Akim Demaille <demaille@inf.enst.fr> */

#include <config.h>

/* Specification.  */

#include "argmatch.h"

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "gettext.h"

#define _(msgid) gettext (msgid)

#include "error.h"

#include "quotearg.h"

#include "quote.h"

#include "getprogname.h"

#if USE_UNLOCKED_IO

# include "unlocked-io.h"

#endif

/* When reporting an invalid argument, show nonprinting characters

   by using the quoting style ARGMATCH_QUOTING_STYLE.  Do not use

   literal_quoting_style.  */

#ifndef ARGMATCH_QUOTING_STYLE

# define ARGMATCH_QUOTING_STYLE locale_quoting_style

#endif

/* Non failing version of argmatch call this function after failing. */

#ifndef ARGMATCH_DIE

# include "exitfail.h"

# define ARGMATCH_DIE exit (exit_failure)

#endif

#ifdef ARGMATCH_DIE_DECL

ARGMATCH_DIE_DECL;

#endif

static void

__argmatch_die (void)

{

  ARGMATCH_DIE;

}

/* Used by XARGMATCH and XARGCASEMATCH.  See description in argmatch.h.

   Default to __argmatch_die, but allow caller to change this at run-time. */

argmatch_exit_fn argmatch_die = __argmatch_die;

/* If ARG is an unambiguous match for an element of the

   NULL-terminated array ARGLIST, return the index in ARGLIST

   of the matched element, else -1 if it does not match any element

   or -2 if it is ambiguous (is a prefix of more than one element).

   If VALLIST is none null, use it to resolve ambiguities limited to

   synonyms, i.e., for

     "yes", "yop" -> 0

     "no", "nope" -> 1

   "y" is a valid argument, for 0, and "n" for 1.  */

ptrdiff_t

argmatch (const char *arg, const char *const *arglist,

          const char *vallist, size_t valsize)

{

  size_t i;                     /* Temporary index in ARGLIST.  */

  size_t arglen;                /* Length of ARG.  */

  ptrdiff_t matchind = -1;      /* Index of first nonexact match.  */

  bool ambiguous = false;       /* If true, multiple nonexact match(es).  */

  arglen = strlen (arg);

  /* Test all elements for either exact match or abbreviated matches.  */

  for (i = 0; arglist[i]; i++)

    {

      if (!strncmp (arglist[i], arg, arglen))

        {

          if (strlen (arglist[i]) == arglen)

            /* Exact match found.  */

            return i;

          else if (matchind == -1)

            /* First nonexact match found.  */

            matchind = i;

          else

            {

              /* Second nonexact match found.  */

              if (vallist == NULL

                  || memcmp (vallist + valsize * matchind,

                             vallist + valsize * i, valsize))

                {

                  /* There is a real ambiguity, or we could not

                     disambiguate. */

                  ambiguous = true;

                }

            }

        }

    }

  if (ambiguous)

    return -2;

  else

    return matchind;

}

/* Error reporting for argmatch.

   CONTEXT is a description of the type of entity that was being matched.

   VALUE is the invalid value that was given.

   PROBLEM is the return value from argmatch.  */

void

argmatch_invalid (const char *context, const char *value, ptrdiff_t problem)

{

  char const *format = (problem == -1

                        ? _("invalid argument %s for %s")

                        : _("ambiguous argument %s for %s"));

  error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value),

         quote_n (1, context));

}

/* List the valid arguments for argmatch.

   ARGLIST is the same as in argmatch.

   VALLIST is a pointer to an array of values.

   VALSIZE is the size of the elements of VALLIST */

void

argmatch_valid (const char *const *arglist,

                const char *vallist, size_t valsize)

{

  size_t i;

  const char *last_val = NULL;

  /* We try to put synonyms on the same line.  The assumption is that

     synonyms follow each other */

  fputs (_("Valid arguments are:"), stderr);

  for (i = 0; arglist[i]; i++)

    if ((i == 0)

        || memcmp (last_val, vallist + valsize * i, valsize))

      {

        fprintf (stderr, "\n  - %s", quote (arglist[i]));

        last_val = vallist + valsize * i;

      }

    else

      {

        fprintf (stderr, ", %s", quote (arglist[i]));

      }

  putc ('\n', stderr);

}

/* Never failing versions of the previous functions.

   CONTEXT is the context for which argmatch is called (e.g.,

   "--version-control", or "$VERSION_CONTROL" etc.).  Upon failure,

   calls the (supposed never to return) function EXIT_FN. */

ptrdiff_t

__xargmatch_internal (const char *context,

                      const char *arg, const char *const *arglist,

                      const char *vallist, size_t valsize,

                      argmatch_exit_fn exit_fn)

{

  ptrdiff_t res = argmatch (arg, arglist, vallist, valsize);

  if (res >= 0)

    /* Success. */

    return res;

  /* We failed.  Explain why. */

  argmatch_invalid (context, arg, res);

  argmatch_valid (arglist, vallist, valsize);

  (*exit_fn) ();

  return -1; /* To please the compilers. */

}

/* Look for VALUE in VALLIST, an array of objects of size VALSIZE and

   return the first corresponding argument in ARGLIST */

const char *

argmatch_to_argument (const char *value,

                      const char *const *arglist,

                      const char *vallist, size_t valsize)

{

  size_t i;

  for (i = 0; arglist[i]; i++)

    if (!memcmp (value, vallist + valsize * i, valsize))

      return arglist[i];

  return NULL;

}

#ifdef TEST

/*

 * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu>

 */

/* When to make backup files.  */

enum backup_type

{

  /* Never make backups.  */

  no_backups,

  /* Make simple backups of every file.  */

  simple_backups,

  /* Make numbered backups of files that already have numbered backups,

     and simple backups of the others.  */

  numbered_existing_backups,

  /* Make numbered backups of every file.  */

  numbered_backups

};

/* Two tables describing arguments (keys) and their corresponding

   values */

static const char *const backup_args[] =

{

  "no", "none", "off",

  "simple", "never",

  "existing", "nil",

  "numbered", "t",

  0

};

static const enum backup_type backup_vals[] =

{

  no_backups, no_backups, no_backups,

  simple_backups, simple_backups,

  numbered_existing_backups, numbered_existing_backups,

  numbered_backups, numbered_backups

};

int

main (int argc, const char *const *argv)

{

  const char *cp;

  enum backup_type backup_type = no_backups;

  if (argc > 2)

    {

      fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", getprogname ());

      exit (1);

    }

  if ((cp = getenv ("VERSION_CONTROL")))

    backup_type = XARGMATCH ("$VERSION_CONTROL", cp,

                             backup_args, backup_vals);

  if (argc == 2)

    backup_type = XARGMATCH (getprogname (), argv[1],

                             backup_args, backup_vals);

  printf ("The version control is '%s'\n",

          ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals));

  return 0;

}

#endif