/* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
#include <msvcrt/stdio.h>
#include <msvcrt/wchar.h>
#include <msvcrt/errno.h>
#include <msvcrt/internal/file.h>


/*
 * @implemented
 */
int ungetc(int c, FILE *f)
{
  if (!__validfp (f) || !OPEN4READING(f)) {
      __set_errno (EINVAL);
      return EOF;
    }

  if (c == EOF)
    return EOF;

  if (f->_ptr == NULL || f->_base == NULL)
    return EOF;

  if (f->_ptr == f->_base)
    {
      if (f->_cnt == 0)
        f->_ptr++;
      else
        return EOF;
    }

  f->_cnt++;
  f->_ptr--;
  if (*f->_ptr != c)
    {
      f->_flag |= _IOUNGETC;
      *f->_ptr = c;
    }
  return c;
}


/*
 * @implemented
 */
wint_t
ungetwc(wchar_t c, FILE *f)
{
  if (!__validfp (f) || !OPEN4READING(f)) {
      __set_errno(EINVAL);
      return EOF;
    }

  if (c == (wchar_t)EOF)
    return EOF;

  if (f->_ptr == NULL || f->_base == NULL)
    return EOF;

  if (f->_ptr == f->_base)
    {
      if (f->_cnt == 0)
        f->_ptr+=sizeof(wchar_t);
      else
        return EOF;
    }

  f->_cnt+=sizeof(wchar_t);
  f->_ptr-=sizeof(wchar_t);

  f->_flag |= _IOUNGETC;
  *((wchar_t *)(f->_ptr)) = c;

  return c;
}