/*
 * 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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * In this program, we assume that each table entry provided will contain
 * a valid UCS character, an illegal character, or, a replacement character.
 * In other words, it is table provider's responsibility to provide
 * an appropriate mapping for each single byte character in the table since
 * the program in this file will not do any special checking on the table
 * component values.
 *
 * This particular file is to cover conversions from various single byte
 * codesets to UCS-2, UCS-2BE, UCS-2LE, UCS-4, UCS-4BE, UCS-4LE, UTF-16,
 * UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, and UTF-32LE.
 */


#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/isa_defs.h>
#include "sb_to_ucs.h"


void *
_icv_open()
{
        ucs_state_t *cd = (ucs_state_t *)calloc(1, sizeof(ucs_state_t));

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

#if defined(UTF_16BE) || defined(UCS_2BE) || defined(UCS_4BE) || \
        defined(UTF_32BE)
        cd->little_endian = false;
        cd->bom_written = true;
#elif defined(UTF_16LE) || defined(UCS_2LE) || defined(UCS_4LE) || \
        defined(UTF_32LE)
        cd->little_endian = true;
        cd->bom_written = true;
#elif defined(_LITTLE_ENDIAN)
        cd->little_endian = true;
#endif

        return((void *)cd);
}


void
_icv_close(ucs_state_t *cd)
{
        if (! cd)
                errno = EBADF;
        else
                free((void *)cd);
}


size_t
_icv_iconv(ucs_state_t *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;
        unsigned int u4;
#if defined(UTF_16) || defined(UTF_16BE) || defined(UTF_16LE)
        unsigned int u4_2;
#endif
        signed char obsz;


        if (! cd) {
                errno = EBADF;
                return((size_t)-1);
        }

        if (!inbuf || !(*inbuf)) {
#if defined(UCS_2) || defined(UCS_4) || defined(UTF_16) || defined(UTF_32)
                cd->bom_written = false;
#endif
                return((size_t)0);
        }

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

        while (ib < ibtail) {
                u4 = sb_u4_tbl[*ib].u8;
#if defined(UTF_16) || defined(UTF_16BE) || defined(UTF_16LE)
                u4_2 = 0;
#endif

                if (sb_u4_tbl[*ib].size == ICV_TYPE_ILLEGAL_CHAR) {
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                }

                obsz = (cd->bom_written) ? ICV_FETCH_UCS_SIZE :
                        ICV_FETCH_UCS_SIZE_TWO;
#if defined(UCS_2) || defined(UCS_2BE) || defined(UCS_2LE)
                if (u4 > 0x00ffff) {
                        u4 = ICV_CHAR_UCS2_REPLACEMENT;
                        ret_val++;
                }
#elif defined(UTF_16) || defined(UTF_16BE) || defined(UTF_16LE)
                if (u4 > 0x00ffff && u4 < 0x110000) {
                        u4_2 = ((u4 - 0x010000) % 0x400) + 0x00dc00;
                        u4   = ((u4 - 0x010000) / 0x400) + 0x00d800;
                        obsz += 2;
                } else if (u4 > 0x10ffff) {
                        u4 = ICV_CHAR_UCS2_REPLACEMENT;
                        ret_val++;
                }
#elif defined(UTF_32) || defined(UTF_32BE) || defined(UTF_32LE)
                if (u4 > 0x10ffff) {
                        u4 = ICV_CHAR_UCS2_REPLACEMENT;
                        ret_val++;
                }
#elif defined(UCS_4) || defined(UCS_4BE) || defined(UCS_4LE)
                /* do nothing */
#else
#error  "Fatal: one of the UCS macros need to be defined."
#endif

                /*
                 * The target values in the conversion tables are in UCS-4
                 * without BOM and so the max target value possible would be
                 * U+7FFFFFFF.
                 */
                if (u4 == 0x00fffe || u4 == 0x00ffff || u4 > 0x7fffffff ||
                    (u4 >= 0x00d800 && u4 <= 0x00dfff)) {
                        /*
                         * if conversion table is right, this should not
                         * happen.
                         */
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                }

                if ((obtail - ob) < obsz) {
                        errno = E2BIG;
                        ret_val = (size_t)-1;
                        break;
                }

                if (cd->little_endian) {
                        if (! cd->bom_written) {
                                *ob++ = (uchar_t)0xff;
                                *ob++ = (uchar_t)0xfe;
#if defined(UCS_4) || defined(UCS_4BE) || defined(UCS_4LE) || \
        defined(UTF_32) || defined(UTF_32BE) || defined(UTF_32LE)
                                *(ushort_t *)ob = (ushort_t)0;
                                ob += 2;
#endif
                                cd->bom_written = true;
                        }
                        *ob++ = (uchar_t)(u4 & 0xff);
                        *ob++ = (uchar_t)((u4 >> 8) & 0xff);
#if defined(UCS_4) || defined(UCS_4BE) || defined(UCS_4LE) || \
        defined(UTF_32) || defined(UTF_32BE) || defined(UTF_32LE)
                        *ob++ = (uchar_t)((u4 >> 16) & 0xff);
                        *ob++ = (uchar_t)((u4 >> 24) & 0xff);
#elif defined(UTF_16) || defined(UTF_16BE) || defined(UTF_16LE)
                        if (u4_2) {
                                *ob++ = (uchar_t)(u4_2 & 0xff);
                                *ob++ = (uchar_t)((u4_2 >> 8) & 0xff);
                        }
#endif
                } else {
                        if (! cd->bom_written) {
#if defined(UCS_4) || defined(UCS_4BE) || defined(UCS_4LE) || \
        defined(UTF_32) || defined(UTF_32BE) || defined(UTF_32LE)
                                *(ushort_t *)ob = (ushort_t)0;
                                ob += 2;
#endif
                                *ob++ = (uchar_t)0xfe;
                                *ob++ = (uchar_t)0xff;
                                cd->bom_written = true;
                        }
#if defined(UCS_4) || defined(UCS_4BE) || defined(UCS_4LE) || \
        defined(UTF_32) || defined(UTF_32BE) || defined(UTF_32LE)
                        *ob++ = (uchar_t)((u4 >> 24) & 0xff);
                        *ob++ = (uchar_t)((u4 >> 16) & 0xff);
#endif
                        *ob++ = (uchar_t)((u4 >> 8) & 0xff);
                        *ob++ = (uchar_t)(u4 & 0xff);
#if defined(UTF_16) || defined(UTF_16BE) || defined(UTF_16LE)
                        if (u4_2) {
                                *ob++ = (uchar_t)((u4_2 >> 8) & 0xff);
                                *ob++ = (uchar_t)(u4_2 & 0xff);
                        }
#endif
                }
                ib++;
        }

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

        return(ret_val);
}