/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2002-2004 Tim J. Robbins.
 * All rights reserved.
 *
 * Copyright (c) 2011 The FreeBSD Foundation
 *
 * Portions of this software were developed by David Chisnall
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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.
 */

#include "namespace.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "local.h"
#include "mblocal.h"

wchar_t *
fgetws_l(wchar_t * __restrict ws, int n, FILE * __restrict fp, locale_t locale)
{
        int sret;
        wchar_t *wsp, *ret;
        size_t nconv;
        const char *src;
        unsigned char *nl;
        FIX_LOCALE(locale);
        struct xlocale_ctype *l = XLOCALE_CTYPE(locale);

        FLOCKFILE_CANCELSAFE(fp);
        ORIENT(fp, 1);

        if (n <= 0) {
                fp->_flags |= __SERR;
                errno = EINVAL;
                goto error;
        }

        wsp = ws;
        if (n == 1)
                goto ok;

        if (fp->_r <= 0 && __srefill(fp))
                /* EOF or ferror */
                goto error;

        sret = 0;
        do {
                src = fp->_p;
                nl = memchr(fp->_p, '\n', fp->_r);
                nconv = l->__mbsnrtowcs(wsp, &src,
                    nl != NULL ? (nl - fp->_p + 1) : fp->_r,
                    n - 1, &fp->_mbstate);
                if (nconv == (size_t)-1) {
                        /* Conversion error */
                        fp->_flags |= __SERR;
                        goto error;
                }
                if (src == NULL) {
                        /*
                         * We hit a null byte. Increment the character count,
                         * since mbsnrtowcs()'s return value doesn't include
                         * the terminating null, then resume conversion
                         * after the null.
                         */
                        nconv++;
                        src = memchr(fp->_p, '\0', fp->_r);
                        src++;
                }
                fp->_r -= (unsigned char *)src - fp->_p;
                fp->_p = (unsigned char *)src;
                n -= nconv;
                wsp += nconv;
        } while ((wsp == ws || wsp[-1] != L'\n') && n > 1 && (fp->_r > 0 ||
            (sret = __srefill(fp)) == 0));
        if (sret && !__sfeof(fp))
                /* ferror */
                goto error;
        if (!l->__mbsinit(&fp->_mbstate)) {
                /* Incomplete character */
                fp->_flags |= __SERR;
                errno = EILSEQ;
                goto error;
        }
        if (wsp == ws)
                /* EOF */
                goto error;
ok:
        *wsp = L'\0';
        ret = ws;
end:
        FUNLOCKFILE_CANCELSAFE();
        return (ret);

error:
        ret = NULL;
        goto end;
}

wchar_t *
fgetws(wchar_t * __restrict ws, int n, FILE * __restrict fp)
{
        return fgetws_l(ws, n, fp, __get_locale());
}