/*
 * 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 1997-2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


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

#ifdef RFC1468_MODE
#define JFP_U2E_ICONV_RFC1468
#else
#define JFP_U2E_ICONV
#endif
#include "jfp_ucs2_to_euc16.h"

#define DEF_SINGLE      '?'

/*
 * struct _cv_state; to keep status
 */
struct _icv_state {
        int     _st_cset;
};

void *
_icv_open(void)
{
        struct _icv_state *st;

        if ((st = (struct _icv_state *)
                malloc(sizeof (struct _icv_state))) == NULL)
                return ((void *)-1);

        st->_st_cset = CS_0;

        return (st);
}

void
_icv_close(void *cd)
{
        if (cd == NULL) {
                errno = EBADF;
        } else {
                free(cd);
        }
        return;
}

size_t
_icv_iconv(void *cd, char **inbuf, size_t *inbytesleft,
                                char **outbuf, size_t *outbytesleft)
{
        unsigned char   ic;
        size_t          rv = (size_t)0;
        unsigned int    ucs4;
        unsigned short  euc16;

        struct _icv_state       *st = (struct _icv_state *)cd;
        int                     cset;

        unsigned char   *ip;
        size_t          ileft;
        char            *op;
        size_t          oleft;

        /*
         * If inbuf and/or *inbuf are NULL, reset conversion descriptor
         * and put escape sequence if needed.
         */
        if ((inbuf == NULL) || (*inbuf == NULL)) {
                if (st->_st_cset != CS_0) {
                        if ((outbuf != NULL) && (*outbuf != NULL)
                                        && (outbytesleft != NULL)) {
                                op = (char *)*outbuf;
                                oleft = *outbytesleft;
                                NPUT(ESC, "RESET-SEQ-ESC");
                                NPUT(SBTOG0_1, "RESET-SEQ-1");
                                NPUT(F_X0201_RM, "RESET-SEQ-2");
                                *outbuf = (char *)op;
                                *outbytesleft = oleft;
                        }
                        st->_st_cset = CS_0;
                }
                return ((size_t)0);
        }

        cset = st->_st_cset;

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

        while (ileft != 0) {
                if (utf8_ucs(&ucs4, &ip, &ileft) == (size_t)-1) {
                        /* errno has been set in utf8_ucs() */
                        rv = (size_t)-1;
                        goto ret;
                }

                if (ucs4 > 0xffff) {
                        /* non-BMP */
                        if (cset != CS_0) {
                                NPUT(ESC, "CS0-SEQ-ESC");
                                NPUT(SBTOG0_1, "CS0-SEQ-1");
                                NPUT(F_X0201_RM, "CS0-SEQ-2");
                                cset = CS_0;
                        }
                        ic = (unsigned char)DEF_SINGLE;
                        NPUT(ic, "DEF for non-BMP(replaced)");
                } else {
                        euc16 = _jfp_ucs2_to_euc16((unsigned short)ucs4);

                        switch (euc16 & 0x8080) {
                        case 0x0000:    /* CS0 */
                                if (cset != CS_0) {
                                        NPUT(ESC, "CS0-SEQ-ESC");
                                        NPUT(SBTOG0_1, "CS0-SEQ-1");
                                        NPUT(F_X0201_RM, "CS0-SEQ-2");
                                        cset = CS_0;
                                }
                                ic = (unsigned char)euc16;
                                NPUT(ic, "CS0-1");
                                break;
                        case 0x8080:    /* CS1 */
                                if (cset != CS_1) {
                                        NPUT(ESC, "CS1-SEQ-ESC");
                                        NPUT(MBTOG0_1, "CS1-SEQ-1");
                                        NPUT(F_X0208_83_90, "CS1-SEQ-2");
                                        cset = CS_1;
                                }
                                ic = (unsigned char)((euc16 >> 8) & CMASK);
                                NPUT(ic, "CS1-1");
                                ic = (unsigned char)(euc16 & CMASK);
                                NPUT(ic, "CS1-2");
                                break;
                        case 0x0080:    /* CS2 */
#ifdef  RFC1468_MODE    /* Substitute JIS X 0208 for JIS X 0201 Katakana */
                                if (cset != CS_1) {
                                        NPUT(ESC, "CS2-SEQ-ESC(fullsized)");
                                        NPUT(MBTOG0_1, "CS2-SEQ-1(fullsized)");
                                        NPUT(F_X0208_83_90,
                                                "CS2-SEQ-2(fullsized)");
                                        cset = CS_1;
                                }
                                euc16 = halfkana2zenkakuj[euc16 - 0xa1];
                                ic = (unsigned char)((euc16 >> 8) & CMASK);
                                NPUT(ic, "CS2-1(fullsized)");
                                ic = (unsigned char)(euc16 & CMASK);
                                NPUT(ic, "CS2-2(fullsized)");
#else   /* ISO-2022-JP.UIOSF */
                                if (cset != CS_2) {
                                        NPUT(ESC, "CS2-SEQ-ESC");
                                        NPUT(SBTOG0_1, "CS2-SEQ-1");
                                        NPUT(F_X0201_KN, "CS2-SEQ-2");
                                        cset = CS_2;
                                }
                                ic = (unsigned char)euc16;
                                NPUT(ic & CMASK, "CS2-1");
#endif  /* RFC1468_MODE */
                                break;
                        case 0x8000:    /* CS3 */
                                if (cset != CS_3) {
                                        NPUT(ESC, "CS3-SEQ-ESC");
                                        NPUT(MBTOG0_1, "CS3-SEQ-1");
                                        NPUT(MBTOG0_2, "CS3-SEQ-2");
                                        NPUT(F_X0212_90, "CS3-SEQ-3");
                                        cset = CS_3;
                                }
                                ic = (unsigned char)((euc16 >> 8) & CMASK);
                                NPUT(ic, "CS3-1");
                                ic = (unsigned char)(euc16 & CMASK);
                                NPUT(ic, "CS3-2");
                                break;
                        }
                }

                /*
                 * One character successfully converted so update
                 * values outside of this function's stack.
                 */
                *inbuf = (char *)ip;
                *inbytesleft = ileft;
                *outbuf = op;
                *outbytesleft = oleft;

                st->_st_cset = cset;
        }

ret:

#if     defined(DEBUG)
        if (rv == (size_t)-1) {
                fprintf(stderr, "DEBUG: errno=%d: %s\n", errno, debugmsg);
        }
#endif  /* DEBUG */

        /*
         * Return value for successful return is not defined by XPG
         * so return same as *inbytesleft as existing codes do.
         */
        return ((rv == (size_t)-1) ? rv : *inbytesleft);
}