/*
 * _hz.c: the HZ codec (RFC1843)
 *
 * Copyright (C) 2003 Hye-Shik Chang <perky@FreeBSD.org>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: _hz.c,v 1.1.1.1 2003/09/24 17:44:47 perky Exp $
 */

#include "codeccommon.h"

ENCMAP(gbcommon)
DECMAP(gb2312)

#define HAVE_ENCODER_INIT
ENCODER_INIT(hz)
{
    state->i = 0;
    return 0;
}

#define HAVE_ENCODER_RESET
ENCODER_RESET(hz)
{
    if (state->i != 0) {
        WRITE2('~', '}')
        state->i = 0;
        NEXT_OUT(2)
    }
    return 0;
}

ENCODER(hz)
{
    while (inleft > 0) {
        Py_UNICODE  c = IN1;
        DBCHAR      code;

        if (c < 0x80) {
            if (state->i == 0) {
                WRITE1(c)
                NEXT(1, 1)
            } else {
                WRITE3('~', '}', c)
                NEXT(1, 3)
                state->i = 0;
            }
            continue;
        }

        UCS4INVALID(c)

        TRYMAP_ENC(gbcommon, code, c);
        else return 1;

        if (code & 0x8000) /* MSB set: GBK */
            return 1;

        if (state->i == 0) {
            WRITE4('~', '{', code >> 8, code & 0xff)
            NEXT(1, 4)
            state->i = 1;
        } else {
            WRITE2(code >> 8, code & 0xff)
            NEXT(1, 2)
        }
    }

    return 0;
}

#define HAVE_DECODER_INIT
DECODER_INIT(hz)
{
    state->i = 0;
    return 0;
}

#define HAVE_DECODER_RESET
DECODER_RESET(hz)
{
    state->i = 0;
    return 0;
}

DECODER(hz)
{
    while (inleft > 0) {
        unsigned char    c = IN1;

        if (c == '~') {
            unsigned char    c2 = IN2;

            RESERVE_INBUF(2)
            if (c2 == '~') {
                WRITE1('~')
                NEXT(2, 1)
                continue;
            } else if (c2 == '{' && state->i == 0)
                state->i = 1; /* set GB */
            else if (c2 == '}' && state->i == 1)
                state->i = 0; /* set ASCII */
            else if (c2 == '\n')
                ; /* line-continuation */
            else
                return 2;
            NEXT(2, 0);
            continue;
        }

        if (c & 0x80)
            return 1;

        if (state->i == 0) { /* ASCII mode */
            WRITE1(c)
            NEXT(1, 1)
        } else { /* GB mode */
            RESERVE_INBUF(2)
            RESERVE_OUTBUF(1)
            TRYMAP_DEC(gb2312, **outbuf, c, IN2) {
                NEXT(2, 1)
            } else
                return 2;
        }
    }

    return 0;
}

#include "codecentry.h"
BEGIN_CODEC_REGISTRY(hz)
    MAPOPEN(zh_CN)
        IMPORTMAP_DEC(gb2312)
        IMPORTMAP_ENC(gbcommon)
    MAPCLOSE()
END_CODEC_REGISTRY(hz)

/*
 * ex: ts=8 sts=4 et
 */
