/*-
 * Copyright (c) 2002-2004 Tim J. Robbins.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */


size_t
wcsnrtombs_l(char * __restrict dst, const wchar_t ** __restrict src,
    size_t nwc, size_t len, mbstate_t * __restrict ps, locale_t loc)
{
  FIX_LOCALE(loc);
  mbstate_t mbsbak;
  char buf[MB_CUR_MAX_L(loc)];
  const wchar_t *s;
  size_t nbytes;
  size_t nb;

  s = *src;
  nbytes = 0;

  if (dst == NULL) {
    while (nwc-- > 0) {
      if ((nb = wcrtomb_l(buf, *s, ps, loc)) == (size_t)-1)
        /* Invalid character - wcrtomb() sets errno. */
        return ((size_t)-1);
      else if (*s == L'\0')
        return (nbytes + nb - 1);
      s++;
      nbytes += nb;
    }
    return (nbytes);
  }

  while (len > 0 && nwc-- > 0) {
    if (len > (size_t)MB_CUR_MAX_L(loc)) {
      /* Enough space to translate in-place. */
      if ((nb = wcrtomb_l(dst, *s, ps, loc)) == (size_t)-1) {
        *src = s;
        return ((size_t)-1);
      }
    } else {
      /*
       * May not be enough space; use temp. buffer.
       *
       * We need to save a copy of the conversion state
       * here so we can restore it if the multibyte
       * character is too long for the buffer.
       */
      mbsbak = *ps;
      if ((nb = wcrtomb_l(buf, *s, ps, loc)) == (size_t)-1) {
        *src = s;
        return ((size_t)-1);
      }
      if (nb > (int)len) {
        /* MB sequence for character won't fit. */
        *ps = mbsbak;
        break;
      }
      memcpy(dst, buf, nb);
    }
    if (*s == L'\0') {
      *src = NULL;
      return (nbytes + nb - 1);
    }
    s++;
    dst += nb;
    len -= nb;
    nbytes += nb;
  }
  *src = s;
  return (nbytes);
}