/*      $NetBSD: citrus_euctw.c,v 1.11 2008/06/14 16:01:07 tnozaki Exp $        */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c)2002 Citrus Project,
 * 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.
 *
 * 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.
 */

/*-
 * Copyright (c)1999 Citrus Project,
 * 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.
 *
 * 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.
 *
 *      $Citrus: xpg4dl/FreeBSD/lib/libc/locale/euctw.c,v 1.13 2001/06/21 01:51:44 yamt Exp $
 */

#include <sys/types.h>

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>

#include "citrus_namespace.h"
#include "citrus_types.h"
#include "citrus_module.h"
#include "citrus_stdenc.h"
#include "citrus_euctw.h"


/* ----------------------------------------------------------------------
 * private stuffs used by templates
 */

typedef struct {
        int      chlen;
        char     ch[4];
} _EUCTWState;

typedef struct {
        int      dummy;
} _EUCTWEncodingInfo;

#define _SS2    0x008e
#define _SS3    0x008f

#define _CEI_TO_EI(_cei_)               (&(_cei_)->ei)
#define _CEI_TO_STATE(_cei_, _func_)    (_cei_)->states.s_##_func_

#define _FUNCNAME(m)                    _citrus_EUCTW_##m
#define _ENCODING_INFO                  _EUCTWEncodingInfo
#define _ENCODING_STATE                 _EUCTWState
#define _ENCODING_MB_CUR_MAX(_ei_)      4
#define _ENCODING_IS_STATE_DEPENDENT    0
#define _STATE_NEEDS_EXPLICIT_INIT(_ps_)        0

static __inline int
_citrus_EUCTW_cs(unsigned int c)
{

        c &= 0xff;

        return ((c & 0x80) ? (c == _SS2 ? 2 : 1) : 0);
}

static __inline int
_citrus_EUCTW_count(int cs)
{

        switch (cs) {
        case 0:
                /*FALLTHROUGH*/
        case 1:
                /*FALLTHROUGH*/
        case 2:
                return (1 << cs);
        case 3:
                abort();
                /*NOTREACHED*/
        }
        return (0);
}

static __inline void
/*ARGSUSED*/
_citrus_EUCTW_init_state(_EUCTWEncodingInfo * __restrict ei __unused,
    _EUCTWState * __restrict s)
{

        memset(s, 0, sizeof(*s));
}

#if 0
static __inline void
/*ARGSUSED*/
_citrus_EUCTW_pack_state(_EUCTWEncodingInfo * __restrict ei __unused,
    void * __restrict pspriv, const _EUCTWState * __restrict s)
{

        memcpy(pspriv, (const void *)s, sizeof(*s));
}

static __inline void
/*ARGSUSED*/
_citrus_EUCTW_unpack_state(_EUCTWEncodingInfo * __restrict ei __unused,
    _EUCTWState * __restrict s, const void * __restrict pspriv)
{

        memcpy((void *)s, pspriv, sizeof(*s));
}
#endif

static int
/*ARGSUSED*/
_citrus_EUCTW_encoding_module_init(_EUCTWEncodingInfo * __restrict ei,
    const void * __restrict var __unused, size_t lenvar __unused)
{

        memset((void *)ei, 0, sizeof(*ei));

        return (0);
}

static void
/*ARGSUSED*/
_citrus_EUCTW_encoding_module_uninit(_EUCTWEncodingInfo *ei __unused)
{

}

static int
_citrus_EUCTW_mbrtowc_priv(_EUCTWEncodingInfo * __restrict ei,
    wchar_t * __restrict pwc, char ** __restrict s,
    size_t n, _EUCTWState * __restrict psenc, size_t * __restrict nresult)
{
        char *s0;
        wchar_t wchar;
        int c, chlenbak, cs;

        s0 = *s;

        if (s0 == NULL) {
                _citrus_EUCTW_init_state(ei, psenc);
                *nresult = 0; /* state independent */
                return (0);
        }

        chlenbak = psenc->chlen;

        /* make sure we have the first byte in the buffer */
        switch (psenc->chlen) {
        case 0:
                if (n < 1)
                        goto restart;
                psenc->ch[0] = *s0++;
                psenc->chlen = 1;
                n--;
                break;
        case 1:
        case 2:
                break;
        default:
                /* illgeal state */
                goto ilseq;
        }

        c = _citrus_EUCTW_count(cs = _citrus_EUCTW_cs(psenc->ch[0] & 0xff));
        if (c == 0)
                goto ilseq;
        while (psenc->chlen < c) {
                if (n < 1)
                        goto ilseq;
                psenc->ch[psenc->chlen] = *s0++;
                psenc->chlen++;
                n--;
        }

        wchar = 0;
        switch (cs) {
        case 0:
                if (psenc->ch[0] & 0x80)
                        goto ilseq;
                wchar = psenc->ch[0] & 0xff;
                break;
        case 1:
                if (!(psenc->ch[0] & 0x80) || !(psenc->ch[1] & 0x80))
                        goto ilseq;
                wchar = ((psenc->ch[0] & 0xff) << 8) | (psenc->ch[1] & 0xff);
                wchar |= 'G' << 24;
                break;
        case 2:
                if ((unsigned char)psenc->ch[1] < 0xa1 ||
                    0xa7 < (unsigned char)psenc->ch[1])
                        goto ilseq;
                if (!(psenc->ch[2] & 0x80) || !(psenc->ch[3] & 0x80))
                        goto ilseq;
                wchar = ((psenc->ch[2] & 0xff) << 8) | (psenc->ch[3] & 0xff);
                wchar |= ('G' + psenc->ch[1] - 0xa1) << 24;
                break;
        default:
                goto ilseq;
        }

        *s = s0;
        psenc->chlen = 0;

        if (pwc)
                *pwc = wchar;
        *nresult = wchar ? c - chlenbak : 0;
        return (0);

ilseq:
        psenc->chlen = 0;
        *nresult = (size_t)-1;
        return (EILSEQ);

restart:
        *s = s0;
        *nresult = (size_t)-1;
        return (0);
}

static int
_citrus_EUCTW_wcrtomb_priv(_EUCTWEncodingInfo * __restrict ei __unused,
    char * __restrict s, size_t n, wchar_t wc,
    _EUCTWState * __restrict psenc __unused, size_t * __restrict nresult)
{
        wchar_t cs, v;
        int clen, i, ret;
        size_t len;

        cs = wc & 0x7f000080;
        clen = 1;
        if (wc & 0x00007f00)
                clen = 2;
        if ((wc & 0x007f0000) && !(wc & 0x00800000))
                clen = 3;

        if (clen == 1 && cs == 0x00000000) {
                /* ASCII */
                len = 1;
                if (n < len) {
                        ret = E2BIG;
                        goto err;
                }
                v = wc & 0x0000007f;
        } else if (clen == 2 && cs == ('G' << 24)) {
                /* CNS-11643-1 */
                len = 2;
                if (n < len) {
                        ret = E2BIG;
                        goto err;
                }
                v = wc & 0x00007f7f;
                v |= 0x00008080;
        } else if (clen == 2 && 'H' <= (cs >> 24) && (cs >> 24) <= 'M') {
                /* CNS-11643-[2-7] */
                len = 4;
                if (n < len) {
                        ret = E2BIG;
                        goto err;
                }
                *s++ = _SS2;
                *s++ = (cs >> 24) - 'H' + 0xa2;
                v = wc & 0x00007f7f;
                v |= 0x00008080;
        } else {
                ret = EILSEQ;
                goto err;
        }

        i = clen;
        while (i-- > 0)
                *s++ = (v >> (i << 3)) & 0xff;

        *nresult = len;
        return (0);

err:
        *nresult = (size_t)-1;
        return (ret);
}

static __inline int
/*ARGSUSED*/
_citrus_EUCTW_stdenc_wctocs(_EUCTWEncodingInfo * __restrict ei __unused,
    _csid_t * __restrict csid, _index_t * __restrict idx, wchar_t wc)
{

        *csid = (_csid_t)(wc >> 24) & 0xFF;
        *idx  = (_index_t)(wc & 0x7F7F);

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_EUCTW_stdenc_cstowc(_EUCTWEncodingInfo * __restrict ei __unused,
    wchar_t * __restrict wc, _csid_t csid, _index_t idx)
{

        if (csid == 0) {
                if ((idx & ~0x7F) != 0)
                        return (EINVAL);
                *wc = (wchar_t)idx;
        } else {
                if (csid < 'G' || csid > 'M' || (idx & ~0x7F7F) != 0)
                        return (EINVAL);
                *wc = (wchar_t)idx | ((wchar_t)csid << 24);
        }

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_EUCTW_stdenc_get_state_desc_generic(_EUCTWEncodingInfo * __restrict ei __unused,
    _EUCTWState * __restrict psenc, int * __restrict rstate)
{

        *rstate = (psenc->chlen == 0) ? _STDENC_SDGEN_INITIAL :
            _STDENC_SDGEN_INCOMPLETE_CHAR;
        return (0);
}

/* ----------------------------------------------------------------------
 * public interface for stdenc
 */

_CITRUS_STDENC_DECLS(EUCTW);
_CITRUS_STDENC_DEF_OPS(EUCTW);

#include "citrus_stdenc_template.h"