/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1994-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <euc.h>
#define JFP_ICONV_STATELESS
#include "japanese.h"


void *
_icv_open(void)
{
        return (_icv_open_stateless());
}

void
_icv_close(void *cd)
{
        _icv_close_stateless(cd);
        return;
}

size_t
_icv_iconv(void *cd, char **inbuf, size_t *inbytesleft,
                                char **outbuf, size_t *outbytesleft)
{
        int                             stat;
        unsigned char   *ip, ic, *op;
        size_t                  ileft, oleft;
        size_t                  retval;

        /*
         * If inbuf and/or *inbuf are NULL, reset conversion descriptor
         * and put escape sequence if needed.
         */
        if ((inbuf == NULL) || (*inbuf == NULL)) {
                /* nothing to do here for this module */
                return ((size_t)0);
        }

        stat = ST_INIT;

        ip = (unsigned char *)*inbuf;
        op = (unsigned char *)*outbuf;
        ileft = *inbytesleft;
        oleft = *outbytesleft;

        /*
         * Main loop; basically 1 loop per 1 input byte
         */

        while ((int)ileft > 0) {
                GET(ic);
                if ((stat == ST_INCS1) || (stat == ST_INCS3)) {
                        ic = sjtojis2[ic];
                        PUT(ic | CMSB);
                        stat = ST_INIT;
                        continue;
                } else if (ISASC((int)ic)) {            /* ASCII */
                        CHECK2BIG(EUCW0,1);
                        PUT(ic);
                        continue;
                } else if (ISSJKANA(ic)) {              /* kana start */
                        CHECK2BIG((SS2W + EUCW2),1);
                        PUT(SS2);
                        PUT(ic);
                        continue;
                } else if (ISSJKANJI1(ic)) {    /* CS_1 kanji starts */
                        if ((int)ileft > 0) {
                                if (ISSJKANJI2(*ip)) {
                                        CHECK2BIG(EUCW1,1);
                                        stat = ST_INCS1;
                                        ic = sjtojis1[(ic - 0x80)];
                                        if (*ip >= 0x9f) {
                                                ic++;
                                        }
                                        PUT(ic | CMSB);
                                        continue;
                                } else {        /* 2nd byte is illegal */
                                        UNGET();
                                        errno = EILSEQ;
                                        retval = (size_t)ERR_RETURN;
                                        goto ret;
                                }
                        } else {                /* input fragment of Kanji */
                                UNGET();
                                errno = EINVAL;
                                retval = (size_t)ERR_RETURN;
                                goto ret;
                        }
                } else if (ISSJSUPKANJI1(ic)) { /* CS_3 kanji starts */
                        if ((int)ileft > 0) {
                                if (ISSJKANJI2(*ip)) {
                                        CHECK2BIG((SS3W + EUCW3),1);
                                        stat = ST_INCS3;
                                        ic = sjtojis1[(ic - 0x80)];
                                        if (*ip >= 0x9f) {
                                                ic++;
                                        }
                                        PUT(SS3);
                                        PUT(ic | CMSB);
                                        continue;
                                } else {        /* 2nd byte is illegal */
                                        UNGET();
                                        errno = EILSEQ;
                                        retval = (size_t)ERR_RETURN;
                                        goto ret;
                                }
                        } else {                /* input fragment of Kanji */
                                UNGET();
                                errno = EINVAL;
                                retval = (size_t)ERR_RETURN;
                                goto ret;
                        }
                } else if (ISSJIBM(ic) || /* Extended IBM char. area */
                        ISSJNECIBM(ic)) { /* NEC/IBM char. area */
                        /*
                         * We need a special treatment for each codes.
                         * By adding some offset number for them, we
                         * can process them as the same way of that of
                         * extended IBM chars.
                         */
                        if ((int)ileft > 0) {
                                if (ISSJKANJI2(*ip)) {
                                        unsigned short dest;
                                        dest = (ic << 8);
                                        GET(ic);
                                        dest += ic;
                                        if ((0xed40 <= dest) &&
                                                (dest <= 0xeffc)) {
                                                REMAP_NEC(dest);
                                                if (dest == 0xffff) {
                                                        goto ill_ibm;
                                                }
                                        }
                                        if ((dest == 0xfa54) ||
                                                (dest == 0xfa5b)) {
                                                CHECK2BIG(EUCW1,2);
                                                if (dest == 0xfa54) {
                                                        PUT(0xa2);
                                                        PUT(0xcc);
                                                } else {
                                                        PUT(0xa2);
                                                        PUT(0xe8);
                                                }
                                                continue;
                                        }
                                        CHECK2BIG((SS3W + EUCW3),2);
                                        dest = dest - 0xfa40 -
                                                (((dest>>8) - 0xfa) * 0x40);
                                        dest = sjtoibmext[dest];
                                        if (dest == 0xffff) {
                                                /*
                                                 * Illegal code points
                                                 * in IBM-EXT area.
                                                 */
ill_ibm:
                                                UNGET();
                                                UNGET();
                                                errno = EILSEQ;
                                                retval = (size_t)ERR_RETURN;
                                                goto ret;
                                        }
                                        PUT(SS3);
                                        PUT((dest>>8) & 0xff);
                                        PUT(dest & 0xff);
                                        continue;
                                } else {        /* 2nd byte is illegal */
                                        UNGET();
                                        errno = EILSEQ;
                                        retval = (size_t)ERR_RETURN;
                                        goto ret;
                                }
                        } else {                /* input fragment of Kanji */
                                UNGET();
                                errno = EINVAL;
                                retval = (size_t)ERR_RETURN;
                                goto ret;
                        }
                } else if ((0xeb <= ic) && (ic <= 0xec)) {
                /*
                 * Based on the draft convention of OSF-JVC CDEWG,
                 * characters in this area will be mapped to
                 * "CHIKAN-MOJI." (convertible character)
                 * So far, we'll use (0x222e) for it.
                 */
                        if ((int)ileft > 0) {
                                if (ISSJKANJI2(*ip)) {
                                        CHECK2BIG(EUCW1,1);
                                        GET(ic); /* Dummy */
                                        PUT((EGETA>>8) & 0xff);
                                        PUT(EGETA & 0xff);
                                        continue;
                                } else {        /* 2nd byte is illegal */
                                        UNGET();
                                        errno = EILSEQ;
                                        retval = (size_t)ERR_RETURN;
                                        goto ret;
                                }
                        } else {                /* input fragment of Kanji */
                                UNGET();
                                errno = EINVAL;
                                retval = (size_t)ERR_RETURN;
                                goto ret;
                        }
                } else {                        /* 1st byte is illegal */
                        UNGET();
                        errno = EILSEQ;
                        retval = (size_t)ERR_RETURN;
                        goto ret;
                }
        }
        retval = ileft;
ret:
        *inbuf = (char *)ip;
        *inbytesleft = ileft;
        *outbuf = (char *)op;
        *outbytesleft = oleft;

        return (retval);
}