/*
 * 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) 1994 by Sun Microsystems, Inc.
 */


#include <stdlib.h>
#include <errno.h>
#include "ktable.h"
#include "utf_johap.h"


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

void* _icv_open()
{
        _conv_desc* cd = (_conv_desc*)malloc(sizeof(_conv_desc));

        if (cd == (_conv_desc*)NULL)
        {
                errno = ENOMEM;
                return((void*)-1);
        }

        RESET_CONV_DESC();

        return((void*)cd);
}  /* end of int _icv_open(). */


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

void _icv_close(_conv_desc* cd)
{
        if (!cd)
                errno = EBADF;
        else
                free((void*)cd);
}  /* end of void _icv_close(_conv_desc*). */


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

size_t _icv_iconv(_conv_desc* 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)
        {
                errno = EBADF;
                return((size_t)-1);
        }

        if (!inbuf || !(*inbuf))
        {
                RESET_CONV_DESC();
                return((size_t)0);
        }

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

        while (ib < ibtail)
        {
                if (!(*ib & 0x80))              /* 7 bits */
                {
                        PROCESS_PRIOR_CVC();

                        if (ob >= obtail)
                        {
                                errno = E2BIG;
                                ret_val = (size_t)-1;
                                break;
                        }
                        *ob++ = *ib++;
                }
                else if ((*ib & 0xF0) == 0xE0)  /* 16 bits */
                {
                        unsigned long   utf;

                        if ((ibtail - ib) < 3)
                        {
                                errno = EINVAL;
                                ret_val = (size_t)-1;
                                break;
                        }

                        utf = ((unsigned long)(*ib) << 16) |
                              ((unsigned long)(*(ib + 1)) << 8) |
                              (unsigned long)(*(ib + 2));
                        if (utf == 0xE1859F ||
                            (utf >= 0xE18480 && utf <= 0xE18492))  /* Ci */
                        {
                                PROCESS_PRIOR_CVC();

                                cd->ci = (utf == 0xE1859F) ? CVC_FILL
                                                           : utf - 0xE18480;
                                cd->prev_state = CI;
                        }
                        else if (utf == 0xE185A0 ||
                                 (utf >= 0xE185A1 && utf <= 0xE185B5))  /* V */
                        {
                                if (cd->prev_state != E && cd->prev_state != CI)
                                        PROCESS_PRIOR_CVC();

                                cd->v = (utf == 0xE185A0) ? CVC_FILL
                                                          : utf - 0xE185A1;
                                cd->prev_state = V;
                        }
                        else if ((utf >= 0xE186A8 && utf <= 0xE186BF) ||
                                 (utf >= 0xE18780 && utf <= 0xE18782))  /* Cf */
                        {
                                if (cd->prev_state != E && cd->prev_state != V)
                                        PROCESS_PRIOR_CVC();

                                cd->cf = utf - ((utf >= 0xE18780) ? 0xE18766
                                                                 : 0xE186A6);
                                cd->prev_state = CF;

                                PROCESS_PRIOR_CVC();
                        }
                        else
                        {
                                PROCESS_PRIOR_CVC();

                                /* Let's assume the code is non-identical. */
                                if ((obtail - ob) < 2)
                                {
                                        errno = E2BIG;
                                        ret_val = (size_t)-1;
                                        break;
                                }
                                *ob++ = NON_IDENTICAL;
                                *ob++ = NON_IDENTICAL;
                                ret_val += 2;
                        }
                        ib += 3;
                }
                else  /* 11, 21, 26 & 31 bits codes won't be able to convert. */
                {
                        short int offset;

                        PROCESS_PRIOR_CVC();

                        if ((*ib & 0xE0) == 0xC0)  /* 11 */
                                offset = 2;
                        else if ((*ib & 0xF0) == 0xE0)  /* 16 */
                                offset = 3;
                        else if ((*ib & 0xF8) == 0xF0)  /* 21 */
                                offset = 4;
                        else if ((*ib & 0xFC) == 0xF8)  /* 26 */
                                offset = 5;
                        else if ((*ib & 0xFE) == 0xFC)  /* 31 */
                                offset = 6;
                        else  /* Illegal sequence. */
                                offset = 1;

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

                        /* Let's assume the code is non-identical. */
                        offset = (offset > 2) ? 2 : 1;
                        if ((obtail - ob) < offset)
                        {
                                errno = E2BIG;
                                ret_val = (size_t)-1;
                                break;
                        }
                        *ob++ = NON_IDENTICAL;
                        if (offset > 1)
                                *ob++ = NON_IDENTICAL;
                        ret_val += offset;
                }
        }

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

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