/*
 * 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 (c) 1995 by Sun Microsystems, Inc.
 * All Rights Reserved.
 */


#include <errno.h>
#include "ktable.h"
#include "hangulcode.h"

static unsigned short _johap92_to_wansung(unsigned short code);

/****  _ I C V _ O P E N  ****/

void* _icv_open()
{
        return((void*)MAGIC_NUMBER);
}  /* end of void* _icv_open(). */


/****  _ I C V _ C L O S E  ****/

void _icv_close(int* cd)
{
        if (!cd || cd != (int*)MAGIC_NUMBER)
                errno = EBADF;
}  /* end of void _icv_close(int*). */


/****  _ I C V _ I C O N V  ****/

size_t _icv_iconv(int* cd, char** inbuf, size_t* inbufleft,
                        char** outbuf, size_t* outbufleft)
{
        size_t          ret_val = 0;
        unsigned char*  ib;
        unsigned char*  ob;
        unsigned char*  ibtail;
        unsigned char*  obtail;

        if (!cd || cd != (int*)MAGIC_NUMBER)
        {
                errno = EBADF;
                return((size_t)-1);
        }

        if (!inbuf || !(*inbuf))
                return((size_t)0);

        ib = (unsigned char*)*inbuf;
        ob = (unsigned char*)*outbuf;
        ibtail = ib + *inbufleft;
        obtail = ob + *outbufleft;

        while (ib < ibtail)
        {
                if (!(*ib & 0x80))
                {
                        if (ob >= obtail)
                        {
                                errno = E2BIG;
                                ret_val = (size_t)-1;
                                break;
                        }
                        *ob++ = *ib++;
                }
                else
                {
                        unsigned short  result;

                        if ((ibtail - ib) < 2)
                        {
                                errno = EINVAL;
                                ret_val = (size_t)-1;
                                break;
                        }

                        result = _johap92_to_wansung((unsigned short)(*ib)<<8 |
                                        (unsigned short)(*(ib + 1)));
                        if (result != FAILED && result != ILLEGAL_SEQ)
                        {
                                if ((obtail - ob) < 2)
                                {
                                        errno = E2BIG;
                                        ret_val = (size_t)-1;
                                        break;
                                }
                                *ob++ = (unsigned char)(result >> 8);
                                *ob++ = (unsigned char)(result & 0xFF);
                        }
                        else
                        {
                                errno = EILSEQ;
                                ret_val = (size_t)-1;
                                break;
                        }
                        ib += 2;
                }
        }

        *inbuf = (char*)ib;
        *inbufleft = ibtail - ib;
        *outbuf = (char*)ob;
        *outbufleft = obtail - ob;

        return(ret_val);
}  /* end of size_t _icv_iconv(int*, char**, size_t*, char**, size_t*). */


/**** _ J O H A P 9 2 _ T O _ W A N S U N G ****/

static unsigned short _johap92_to_wansung(unsigned short code)
{
        short   ci, v, cf;
        short   mask;
        int     disp, i;
        int     ch1, ch2;
        long    cfbit;

        ch1 = code >> 8;
        ch2 = code & 0xff;

        if ((ch1 >= 0x84 && ch1 <= 0xd3) && ((ch2 >= 0x41 && ch2 <= 0x7e) ||
            (ch2 >= 0x81 && ch2 <= 0xfe)))  /* Hangul */
        {
                ci = CHOSUNG(code) - 0x02;
                v = JOONGSUNG(code) - ((unsigned short)(JOONGSUNG(code) - 2) /
                        8 * 2 + 3);
                cf = JONGSUNG(code) - (unsigned short)JONGSUNG(code) / 18;

                if (v < 0)
                        return(0xA4A0 + Y19_32[CHOSUNG(code) - 1]);
                if (ci < 0)
                {
                        if (cf <= 1)
                                return(0xA4BF + v);
                        return(ILLEGAL_SEQ);
                }

                for (cfbit = cmp_bitmap[ci][v], disp = 0, i = 0; i < cf; i++)
                {
                        if (cfbit & BIT_MASK)
                                disp++;
                        cfbit >>= 1;
                }

                if (!(cfbit & BIT_MASK))
                        return(ILLEGAL_SEQ);

                code = cmp_srchtbl[ci][v] + disp;
                mask = cmp_srchtbl[ci][v] & 0xff;
                if ((mask + disp) > 0xfe)
                        code += SKIP;

                return(code);
        }
        else if ((ch2 >= 0x31 && ch2 <= 0x7e) || (ch2 >= 0x91 && ch2 <= 0xfe))
        {
                if (ch1 >= 0xe0 && ch1 <= 0xf9)  /* Hanja */
                {
                        code = (0xca + (ch1 - 0xe0) * 2 + ch2 / 0xa1) << 8;
                        return(code | ((ch2 > 0xa0) ? ch2
                                : ch2 + 0x70 - ((ch2 / 0x91) * 0x12)));
                }
                else if (ch1 >= 0xd9 && ch1 <= 0xde)  /* Graphic characters */
                {
                        code = (0xa1 + (ch1 - 0xd9) * 2 + ch2 / 0xa1) << 8;
                        return(code | ((ch2 > 0xa0) ? ch2
                                : ch2 + 0x70 - ((ch2 / 0x91) * 0x12)));
                }
                else if (ch1 == 0xd8)  /* User definable characters */
                        return((ch2 > 0xa0) ? 0xfe00 | ch2 : 0xc900
                                        | (ch2 + 0x70 - ((ch2 / 0x91) * 0x12)));
        }

        return(FAILED);
}  /* end og static unsigned short _johap92_to_wansung(unsigned short). */