/* Removes leading and/or trailing whitespaces

   Copyright (C) 2006-2017 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 <http://www.gnu.org/licenses/>.  */

/* Written by Davide Angelocola <davide.angelocola@gmail.com> */

#include <config.h>

/* Specification.  */

#include "trim.h"

#include <ctype.h>

#include <string.h>

#include <stddef.h>

#include <stdlib.h>

#include "mbchar.h"

#include "mbiter.h"

#include "xalloc.h"

/* Use this to suppress gcc's "...may be used before initialized" warnings. */

#if defined GCC_LINT || defined lint

# define IF_LINT(Code) Code

#else

# define IF_LINT(Code) /* empty */

#endif

char *

trim2 (const char *s, int how)

{

  char *d;

  d = strdup (s);

  if (!d)

    xalloc_die ();

  if (MB_CUR_MAX > 1)

    {

      mbi_iterator_t i;

      /* Trim leading whitespaces. */

      if (how != TRIM_TRAILING)

        {

          mbi_init (i, d, strlen (d));

          for (; mbi_avail (i) && mb_isspace (mbi_cur (i)); mbi_advance (i))

            ;

          memmove (d, mbi_cur_ptr (i), strlen (mbi_cur_ptr (i)) + 1);

        }

      /* Trim trailing whitespaces. */

      if (how != TRIM_LEADING)

        {

          unsigned int state = 0;

          char *r IF_LINT (= NULL); /* used only while state = 2 */

          mbi_init (i, d, strlen (d));

          for (; mbi_avail (i); mbi_advance (i))

            {

              if (state == 0 && mb_isspace (mbi_cur (i)))

                continue;

              if (state == 0 && !mb_isspace (mbi_cur (i)))

                {

                  state = 1;

                  continue;

                }

              if (state == 1 && !mb_isspace (mbi_cur (i)))

                continue;

              if (state == 1 && mb_isspace (mbi_cur (i)))

                {

                  state = 2;

                  r = (char *) mbi_cur_ptr (i);

                }

              else if (state == 2 && mb_isspace (mbi_cur (i)))

                {

                  /* empty */

                }

              else

                {

                  state = 1;

                }

            }

          if (state == 2)

            *r = '\0';

        }

    }

  else

    {

      char *p;

      /* Trim leading whitespaces. */

      if (how != TRIM_TRAILING)

        {

          for (p = d; *p && isspace ((unsigned char) *p); p++)

            ;

          memmove (d, p, strlen (p) + 1);

        }

      /* Trim trailing whitespaces. */

      if (how != TRIM_LEADING)

        {

          for (p = d + strlen (d) - 1;

               p >= d && isspace ((unsigned char) *p); p--)

            *p = '\0';

        }

    }

  return d;

}