/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright 2013 Garrett D'Amore <garrett@damore.org>
 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
 * Copyright (c) 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Paul Borman at Krystal Technologies.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <errno.h>
#include <limits.h>
#include <runetype.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include "mblocal.h"

static size_t   _none_mbrtowc(wchar_t * __restrict, const char * __restrict,
                    size_t, mbstate_t * __restrict);
static int      _none_mbsinit(const mbstate_t *);
static size_t   _none_mbsnrtowcs(wchar_t * __restrict dst,
                    const char ** __restrict src, size_t nms, size_t len,
                    mbstate_t * __restrict ps __unused);
static size_t   _none_wcrtomb(char * __restrict, wchar_t,
                    mbstate_t * __restrict);
static size_t   _none_wcsnrtombs(char * __restrict, const wchar_t ** __restrict,
                    size_t, size_t, mbstate_t * __restrict);

/* setup defaults */

int __mb_cur_max = 1;
int __mb_sb_limit = 256; /* Expected to be <= _CACHED_RUNES */

int
_none_init(struct xlocale_ctype *l, _RuneLocale *rl)
{

        l->__mbrtowc = _none_mbrtowc;
        l->__mbsinit = _none_mbsinit;
        l->__mbsnrtowcs = _none_mbsnrtowcs;
        l->__wcrtomb = _none_wcrtomb;
        l->__wcsnrtombs = _none_wcsnrtombs;
        l->runes = rl;
        l->__mb_cur_max = 1;
        l->__mb_sb_limit = 256;
        return(0);
}

static int
_none_mbsinit(const mbstate_t *ps __unused)
{

        /*
         * Encoding is not state dependent - we are always in the
         * initial state.
         */
        return (1);
}

static size_t
_none_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
    mbstate_t * __restrict ps __unused)
{

        if (s == NULL)
                /* Reset to initial shift state (no-op) */
                return (0);
        if (n == 0)
                /* Incomplete multibyte sequence */
                return ((size_t)-2);
        if (pwc != NULL)
                *pwc = (unsigned char)*s;
        return (*s == '\0' ? 0 : 1);
}

static size_t
_none_wcrtomb(char * __restrict s, wchar_t wc,
    mbstate_t * __restrict ps __unused)
{

        if (s == NULL)
                /* Reset to initial shift state (no-op) */
                return (1);
        if (wc < 0 || wc > UCHAR_MAX) {
                errno = EILSEQ;
                return ((size_t)-1);
        }
        *s = (unsigned char)wc;
        return (1);
}

static size_t
_none_mbsnrtowcs(wchar_t * __restrict dst, const char ** __restrict src,
    size_t nms, size_t len, mbstate_t * __restrict ps __unused)
{
        const char *s;
        size_t nchr;

        if (dst == NULL) {
                s = memchr(*src, '\0', nms);
                return (s != NULL ? s - *src : nms);
        }

        s = *src;
        nchr = 0;
        while (len-- > 0 && nms-- > 0) {
                if ((*dst++ = (unsigned char)*s++) == L'\0') {
                        *src = NULL;
                        return (nchr);
                }
                nchr++;
        }
        *src = s;
        return (nchr);
}

static size_t
_none_wcsnrtombs(char * __restrict dst, const wchar_t ** __restrict src,
    size_t nwc, size_t len, mbstate_t * __restrict ps __unused)
{
        const wchar_t *s;
        size_t nchr;

        if (dst == NULL) {
                for (s = *src; nwc > 0 && *s != L'\0'; s++, nwc--) {
                        if (*s < 0 || *s > UCHAR_MAX) {
                                errno = EILSEQ;
                                return ((size_t)-1);
                        }
                }
                return (s - *src);
        }

        s = *src;
        nchr = 0;
        while (len-- > 0 && nwc-- > 0) {
                if (*s < 0 || *s > UCHAR_MAX) {
                        *src = s;
                        errno = EILSEQ;
                        return ((size_t)-1);
                }
                if ((*dst++ = *s++) == '\0') {
                        *src = NULL;
                        return (nchr);
                }
                nchr++;
        }
        *src = s;
        return (nchr);
}

/* setup defaults */

struct xlocale_ctype __xlocale_global_ctype = {
        {{0}, "C"},
        (_RuneLocale*)&_DefaultRuneLocale,
        _none_mbrtowc,
        _none_mbsinit,
        _none_mbsnrtowcs,
        _none_wcrtomb,
        _none_wcsnrtombs,
        1, /* __mb_cur_max, */
        256 /* __mb_sb_limit */
};

struct xlocale_ctype __xlocale_C_ctype = {
        {{0}, "C"},
        (_RuneLocale*)&_DefaultRuneLocale,
        _none_mbrtowc,
        _none_mbsinit,
        _none_mbsnrtowcs,
        _none_wcrtomb,
        _none_wcsnrtombs,
        1, /* __mb_cur_max, */
        256 /* __mb_sb_limit */
};