/*
**  L2 - OSSP Logging Library
**  Copyright (c) 2001 The OSSP Project (http://www.ossp.org/)
**  Copyright (c) 2001 Cable & Wireless Deutschland (http://www.cw.com/de/)
**
**  This file is part of OSSP L2, a flexible logging library which
**  can be found at http://www.ossp.com/pkg/l2/.
**
**  Permission to use, copy, modify, and distribute this software for
**  any purpose with or without fee is hereby granted, provided that
**  the above copyright notice and this permission notice appear in all
**  copies.
**
**  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 AUTHORS AND COPYRIGHT HOLDERS AND THEIR
**  CONTRIBUTORS 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.
**
**  l2_channel.c: channel handling
**
*/

#include "l2.h"
#include "l2_p.h"

l2_channel_t *l2_channel_create(l2_handler_t *h)
{
    l2_channel_t *ch;

    if (h == NULL)
        return NULL;
    if ((ch = (l2_channel_t *)malloc(sizeof(l2_channel_t))) == NULL)
        return NULL;
    ch->below              = NULL;
    ch->context.vp         = NULL;
    ch->handler.create     = h->create;
    ch->handler.configure  = h->configure;
    ch->handler.open       = h->open;
    ch->handler.write      = h->write;
    ch->handler.flush      = h->flush;
    ch->handler.close      = h->close;
    ch->handler.destroy    = h->destroy;
    if (ch->handler.create(&ch->context) == L2_ERROR) {
        free(ch);
        return NULL;
    }
    return ch;
}

l2_channel_t *l2_channel_stack(l2_channel_t *ch1, l2_channel_t *ch2)
{
    if (ch1 == NULL || ch2 == NULL)
        return NULL;
    ch2->below = ch1;
    return ch2;
}

int l2_channel_configure(l2_channel_t *ch, const char *fmt, ...)
{
    int rv;
    va_list ap;

    if (ch == NULL || fmt == NULL)
        return L2_ERROR;
    va_start(ap, fmt);
    rv = ch->handler.configure(&ch->context, fmt, ap);
    va_end(ap);
    return rv;
}

int l2_channel_open(l2_channel_t *ch)
{
    if (ch == NULL)
        return L2_ERROR;
    while (ch != NULL && ch->handler.open == NULL)
        ch = ch->below;
    if (ch == NULL)
        return L2_ERROR;
    return ch->handler.open(&ch->context, ch->below);
}

int l2_channel_write(l2_channel_t *ch, const char *buf, size_t bufsize)
{
    if (ch == NULL || buf == NULL || bufsize <= 0)
        return L2_ERROR;
    while (ch != NULL && ch->handler.write == NULL)
        ch = ch->below;
    if (ch == NULL)
        return L2_ERROR;
    return ch->handler.write(&ch->context, ch->below, buf, bufsize);
}

int l2_channel_flush(l2_channel_t *ch)
{
    if (ch == NULL)
        return L2_ERROR;
    while (ch != NULL && ch->handler.flush == NULL)
        ch = ch->below;
    if (ch == NULL)
        return L2_ERROR;
    return ch->handler.flush(&ch->context, ch->below);
}

int l2_channel_close(l2_channel_t *ch)
{
    if (ch == NULL)
        return L2_ERROR;
    while (ch != NULL && ch->handler.close == NULL)
        ch = ch->below;
    if (ch == NULL)
        return L2_ERROR;
    return ch->handler.close(&ch->context, ch->below);
}

int l2_channel_destroy(l2_channel_t *ch)
{
    int rv = L2_OK;

    if (ch == NULL)
        return L2_ERROR;
    while (ch != NULL && ch->handler.destroy == NULL)
        ch = ch->below;
    if (ch != NULL)
        rv = ch->handler.destroy(&ch->context);
    free(ch);
    return rv;
}