/*      $NetBSD: citrus_mskanji.c,v 1.13 2008/06/14 16:01:08 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.
 */

/*
 *    ja_JP.SJIS locale table for BSD4.4/rune
 *    version 1.0
 *    (C) Sin'ichiro MIYATANI / Phase One, Inc
 *    May 12, 1995
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Phase One, Inc.
 * 4. The name of Phase One, Inc. 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 <sys/types.h>

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdbool.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_bcs.h"
#include "citrus_module.h"
#include "citrus_stdenc.h"
#include "citrus_mskanji.h"


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

typedef struct _MSKanjiState {
        int      chlen;
        char     ch[2];
} _MSKanjiState;

typedef struct {
        int      mode;
#define MODE_JIS2004    1
} _MSKanjiEncodingInfo;

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

#define _FUNCNAME(m)                    _citrus_MSKanji_##m
#define _ENCODING_INFO                  _MSKanjiEncodingInfo
#define _ENCODING_STATE                 _MSKanjiState
#define _ENCODING_MB_CUR_MAX(_ei_)      2
#define _ENCODING_IS_STATE_DEPENDENT    0
#define _STATE_NEEDS_EXPLICIT_INIT(_ps_)        0


static bool
_mskanji1(int c)
{

        return ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xfc));
}

static bool
_mskanji2(int c)
{

        return ((c >= 0x40 && c <= 0x7e) || (c >= 0x80 && c <= 0xfc));
}

static __inline void
/*ARGSUSED*/
_citrus_MSKanji_init_state(_MSKanjiEncodingInfo * __restrict ei __unused,
    _MSKanjiState * __restrict s)
{

        s->chlen = 0;
}

#if 0
static __inline void
/*ARGSUSED*/
_citrus_MSKanji_pack_state(_MSKanjiEncodingInfo * __restrict ei __unused,
    void * __restrict pspriv, const _MSKanjiState * __restrict s)
{

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

static __inline void
/*ARGSUSED*/
_citrus_MSKanji_unpack_state(_MSKanjiEncodingInfo * __restrict ei __unused,
    _MSKanjiState * __restrict s, const void * __restrict pspriv)
{

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

static int
/*ARGSUSED*/
_citrus_MSKanji_mbrtowc_priv(_MSKanjiEncodingInfo * __restrict ei,
    wchar_t * __restrict pwc, char ** __restrict s, size_t n,
    _MSKanjiState * __restrict psenc, size_t * __restrict nresult)
{
        char *s0;
        wchar_t wchar;
        int chlenbak, len;

        s0 = *s;

        if (s0 == NULL) {
                _citrus_MSKanji_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:
                break;
        default:
                /* illegal state */
                goto encoding_error;
        }

        len = _mskanji1(psenc->ch[0] & 0xff) ? 2 : 1;
        while (psenc->chlen < len) {
                if (n < 1)
                        goto restart;
                psenc->ch[psenc->chlen] = *s0++;
                psenc->chlen++;
                n--;
        }

        *s = s0;

        switch (len) {
        case 1:
                wchar = psenc->ch[0] & 0xff;
                break;
        case 2:
                if (!_mskanji2(psenc->ch[1] & 0xff))
                        goto encoding_error;
                wchar = ((psenc->ch[0] & 0xff) << 8) | (psenc->ch[1] & 0xff);
                break;
        default:
                /* illegal state */
                goto encoding_error;
        }

        psenc->chlen = 0;

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

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

restart:
        *nresult = (size_t)-2;
        *s = s0;
        return (0);
}


static int
_citrus_MSKanji_wcrtomb_priv(_MSKanjiEncodingInfo * __restrict ei __unused,
    char * __restrict s, size_t n, wchar_t wc,
    _MSKanjiState * __restrict psenc __unused, size_t * __restrict nresult)
{
        int ret;

        /* check invalid sequence */
        if (wc & ~0xffff) {
                ret = EILSEQ;
                goto err;
        }

        if (wc & 0xff00) {
                if (n < 2) {
                        ret = E2BIG;
                        goto err;
                }

                s[0] = (wc >> 8) & 0xff;
                s[1] = wc & 0xff;
                if (!_mskanji1(s[0] & 0xff) || !_mskanji2(s[1] & 0xff)) {
                        ret = EILSEQ;
                        goto err;
                }

                *nresult = 2;
                return (0);
        } else {
                if (n < 1) {
                        ret = E2BIG;
                        goto err;
                }

                s[0] = wc & 0xff;
                if (_mskanji1(s[0] & 0xff)) {
                        ret = EILSEQ;
                        goto err;
                }

                *nresult = 1;
                return (0);
        }

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


static __inline int
/*ARGSUSED*/
_citrus_MSKanji_stdenc_wctocs(_MSKanjiEncodingInfo * __restrict ei,
    _csid_t * __restrict csid, _index_t * __restrict idx, wchar_t wc)
{
        _index_t col, row;
        int offset;

        if ((_wc_t)wc < 0x80) {
                /* ISO-646 */
                *csid = 0;
                *idx = (_index_t)wc;
        } else if ((_wc_t)wc < 0x100) {
                /* KANA */
                *csid = 1;
                *idx = (_index_t)wc & 0x7F;
        } else {
                /* Kanji (containing Gaiji zone) */
                /*
                 * 94^2 zone (contains a part of Gaiji (0xED40 - 0xEEFC)):
                 * 0x8140 - 0x817E -> 0x2121 - 0x215F
                 * 0x8180 - 0x819E -> 0x2160 - 0x217E
                 * 0x819F - 0x81FC -> 0x2221 - 0x227E
                 *
                 * 0x8240 - 0x827E -> 0x2321 - 0x235F
                 *  ...
                 * 0x9F9F - 0x9FFc -> 0x5E21 - 0x5E7E
                 *
                 * 0xE040 - 0xE07E -> 0x5F21 - 0x5F5F
                 *  ...
                 * 0xEF9F - 0xEFFC -> 0x7E21 - 0x7E7E
                 *
                 * extended Gaiji zone:
                 * 0xF040 - 0xFCFC
                 *
                 * JIS X0213-plane2:
                 * 0xF040 - 0xF09E -> 0x2121 - 0x217E
                 * 0xF140 - 0xF19E -> 0x2321 - 0x237E
                 * ...
                 * 0xF240 - 0xF29E -> 0x2521 - 0x257E
                 *
                 * 0xF09F - 0xF0FC -> 0x2821 - 0x287E
                 * 0xF29F - 0xF2FC -> 0x2C21 - 0x2C7E
                 * ...
                 * 0xF44F - 0xF49E -> 0x2F21 - 0x2F7E
                 *
                 * 0xF49F - 0xF4FC -> 0x6E21 - 0x6E7E
                 * ...
                 * 0xFC9F - 0xFCFC -> 0x7E21 - 0x7E7E
                 */
                row = ((_wc_t)wc >> 8) & 0xFF;
                col = (_wc_t)wc & 0xFF;
                if (!_mskanji1(row) || !_mskanji2(col))
                        return (EILSEQ);
                if ((ei->mode & MODE_JIS2004) == 0 || row < 0xF0) {
                        *csid = 2;
                        offset = 0x81;
                } else {
                        *csid = 3;
                        if ((_wc_t)wc <= 0xF49E) {
                                offset = (_wc_t)wc >= 0xF29F ||
                                    ((_wc_t)wc >= 0xF09F &&
                                    (_wc_t)wc <= 0xF0FC) ? 0xED : 0xF0;
                        } else
                                offset = 0xCE;
                }
                row -= offset;
                if (row >= 0x5F)
                        row -= 0x40;
                row = row * 2 + 0x21;
                col -= 0x1F;
                if (col >= 0x61)
                        col -= 1;
                if (col > 0x7E) {
                        row += 1;
                        col -= 0x5E;
                }
                *idx = ((_index_t)row << 8) | col;
        }

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_MSKanji_stdenc_cstowc(_MSKanjiEncodingInfo * __restrict ei,
    wchar_t * __restrict wc, _csid_t csid, _index_t idx)
{
        uint32_t col, row;
        int offset;

        switch (csid) {
        case 0:
                /* ISO-646 */
                if (idx >= 0x80)
                        return (EILSEQ);
                *wc = (wchar_t)idx;
                break;
        case 1:
                /* kana */
                if (idx >= 0x80)
                        return (EILSEQ);
                *wc = (wchar_t)idx + 0x80;
                break;
        case 3:
                if ((ei->mode & MODE_JIS2004) == 0)
                        return (EILSEQ);
        /*FALLTHROUGH*/
        case 2:
                /* kanji */
                row = (idx >> 8);
                if (row < 0x21)
                        return (EILSEQ);
                if (csid == 3) {
                        if (row <= 0x2F)
                                offset = (row == 0x22 || row >= 0x26) ?
                                    0xED : 0xF0;
                        else if (row >= 0x4D && row <= 0x7E)
                                offset = 0xCE;
                        else
                                return (EILSEQ);
                } else {
                        if (row > 0x97)
                                return (EILSEQ);
                        offset = (row < 0x5F) ? 0x81 : 0xC1;
                }
                col = idx & 0xFF;
                if (col < 0x21 || col > 0x7E)
                        return (EILSEQ);
                row -= 0x21; col -= 0x21;
                if ((row & 1) == 0) {
                        col += 0x40;
                        if (col >= 0x7F)
                                col += 1;
                } else
                        col += 0x9F;
                row = row / 2 + offset;
                *wc = ((wchar_t)row << 8) | col;
                break;
        default:
                return (EILSEQ);
        }

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_MSKanji_stdenc_get_state_desc_generic(_MSKanjiEncodingInfo * __restrict ei __unused,
    _MSKanjiState * __restrict psenc, int * __restrict rstate)
{

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

static int
/*ARGSUSED*/
_citrus_MSKanji_encoding_module_init(_MSKanjiEncodingInfo *  __restrict ei,
    const void * __restrict var, size_t lenvar)
{
        const char *p;

        p = var;
        memset((void *)ei, 0, sizeof(*ei));
        while (lenvar > 0) {
                switch (_bcs_toupper(*p)) {
                case 'J':
                        MATCH(JIS2004, ei->mode |= MODE_JIS2004);
                        break;
                }
                ++p;
                --lenvar;
        }

        return (0);
}

static void
_citrus_MSKanji_encoding_module_uninit(_MSKanjiEncodingInfo *ei __unused)
{

}

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

_CITRUS_STDENC_DECLS(MSKanji);
_CITRUS_STDENC_DEF_OPS(MSKanji);

#include "citrus_stdenc_template.h"