/* Helper functions used by strftime/strptime to handle alternate digits.

   Copyright (C) 1995-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C 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.

   The GNU C 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 the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include "../locale/localeinfo.h"

#include <libc-lock.h>

#include <stdlib.h>

#include <wchar.h>

#include <string.h>

#include <stdint.h>

/* Some of the functions here must not be used while setlocale is called.  */

__libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)

#define CURRENT(item) (current->values[_NL_ITEM_INDEX (item)].string)

#define CURRENT_WSTR(item) \

  ((wchar_t *) current->values[_NL_ITEM_INDEX (item)].wstr)

static void

_nl_init_alt_digit (struct __locale_data *current)

{

  struct lc_time_data *data;

  if (current->private.time == NULL)

    {

      current->private.time = malloc (sizeof *current->private.time);

      if (current->private.time == NULL)

	return;

      memset (current->private.time, 0, sizeof *current->private.time);

      current->private.cleanup = &_nl_cleanup_time;

    }

  data = current->private.time;

  if (! data->alt_digits_initialized)

    {

      const char *ptr = CURRENT (ALT_DIGITS);

      size_t cnt;

      data->alt_digits_initialized = 1;

      if (ptr != NULL)

	{

	  data->alt_digits = malloc (100 * sizeof (const char *));

	  if (data->alt_digits != NULL)

	    for (cnt = 0; cnt < 100; ++cnt)

	      {

		data->alt_digits[cnt] = ptr;

		/* Skip digit format. */

		ptr = strchr (ptr, '\0') + 1;

	      }

	}

    }

}

const char *

_nl_get_alt_digit (unsigned int number, struct __locale_data *current)

{

  const char *result;

  if (number >= 100 || CURRENT (ALT_DIGITS)[0] == '\0')

    return NULL;

  __libc_rwlock_wrlock (__libc_setlocale_lock);

  if (current->private.time == NULL

      || ! current->private.time->alt_digits_initialized)

    _nl_init_alt_digit (current);

  result = ((current->private.time != NULL

	     && current->private.time->alt_digits != NULL)

	    ? current->private.time->alt_digits[number]

	    : NULL);

  __libc_rwlock_unlock (__libc_setlocale_lock);

  return result;

}

const wchar_t *

_nl_get_walt_digit (unsigned int number, struct __locale_data *current)

{

  const wchar_t *result = NULL;

  struct lc_time_data *data;

  if (number >= 100 || CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')

    return NULL;

  __libc_rwlock_wrlock (__libc_setlocale_lock);

  if (current->private.time == NULL)

    {

      current->private.time = malloc (sizeof *current->private.time);

      if (current->private.time == NULL)

	goto out;

      memset (current->private.time, 0, sizeof *current->private.time);

      current->private.cleanup = &_nl_cleanup_time;

    }

  data = current->private.time;

  if (! data->walt_digits_initialized)

    {

      const wchar_t *ptr = CURRENT_WSTR (_NL_WALT_DIGITS);

      size_t cnt;

      data->walt_digits_initialized = 1;

      if (ptr != NULL)

	{

	  data->walt_digits = malloc (100 * sizeof (const uint32_t *));

	  if (data->walt_digits != NULL)

	    for (cnt = 0; cnt < 100; ++cnt)

	      {

		data->walt_digits[cnt] = ptr;

		/* Skip digit format. */

		ptr = __wcschr (ptr, L'\0') + 1;

	      }

	}

    }

  if (data->walt_digits != NULL)

    result = data->walt_digits[number];

 out:

  __libc_rwlock_unlock (__libc_setlocale_lock);

  return (wchar_t *) result;

}

int

_nl_parse_alt_digit (const char **strp, struct __locale_data *current)

{

  const char *str = *strp;

  int result = -1;

  size_t cnt;

  size_t maxlen = 0;

  if (CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')

    return result;

  __libc_rwlock_wrlock (__libc_setlocale_lock);

  if (current->private.time == NULL

      || ! current->private.time->alt_digits_initialized)

    _nl_init_alt_digit (current);

  if (current->private.time != NULL &&

      current->private.time->alt_digits != NULL)

    /* Matching is not unambiguous.  The alternative digits could be like

       I, II, III, ... and the first one is a substring of the second

       and third.  Therefore we must keep on searching until we found

       the longest possible match.  Note that this is not specified in

       the standard.  */

    for (cnt = 0; cnt < 100; ++cnt)

      {

	const char *const dig = current->private.time->alt_digits[cnt];

	size_t len = strlen (dig);

	if (len > maxlen && strncmp (dig, str, len) == 0)

	  {

	    maxlen = len;

	    result = (int) cnt;

	  }

      }

  __libc_rwlock_unlock (__libc_setlocale_lock);

  if (result != -1)

    *strp += maxlen;

  return result;

}