/*
 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``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 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.

  FreeBSD: src/lib/libc/stdio/vswprintf.c,v 1.6 2005/02/21 19:41:44 fjoe Exp
  NetBSD: vswprintf.c,v 1.1 2005/05/14 23:51:02 christos Exp
 */
#include  <LibConfig.h>
#include  <sys/EfiCdefs.h>

#include  <errno.h>
#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>
#include  <stdarg.h>
#include  "reentrant.h"
#include  "local.h"

int
vswprintf(wchar_t * __restrict s, size_t n, const wchar_t * __restrict fmt,
    va_list ap)
{
  static const mbstate_t initial = { 0 };
  mbstate_t mbs;
  FILE f;
  char *mbp;
  int ret, sverrno;
  size_t nwc;
  struct __sfileext fext;

  if (n == 0) {
    errno = EINVAL;
    return (-1);
  }

  _FILEEXT_SETUP(&f, &fext);
  f._file = -1;
  f._flags = __SWR | __SSTR | __SALC;
  f._bf._base = f._p = (unsigned char *)malloc(128);
  if (f._bf._base == NULL) {
    errno = ENOMEM;
    return (-1);
  }
  f._bf._size = f._w = 127;   /* Leave room for the NUL */
  ret = __vfwprintf_unlocked(&f, fmt, ap);
  if (ret < 0) {
    sverrno = errno;
    free(f._bf._base);
    errno = sverrno;
    return (-1);
  }
  *f._p = '\0';
  mbp = (char *)f._bf._base;
  /*
   * XXX Undo the conversion from wide characters to multibyte that
   * fputwc() did in __vfwprintf().
   */
  mbs = initial;
  nwc = mbsrtowcs(s, (const char **)&mbp, n, &mbs);
  free(f._bf._base);
  if (nwc == (size_t)-1) {
    errno = EILSEQ;
    return (-1);
  }
  if (nwc == n) {
    s[n - 1] = L'\0';
    errno = EOVERFLOW;
    return (-1);
  }

  return (ret);
}