/* Icecast
 *
 * This program is distributed under the GNU General Public License, version 2.
 * A copy of this license is included with this source.
 *
 * Copyright 2000-2004, Jack Moffitt <jack@xiph.org,
 *                      Michael Smith <msmith@xiph.org>,
 *                      oddsock <oddsock@xiph.org>,
 *                      Karl Heyes <karl@xiph.org>
 *                      and others (see AUTHORS for details).
 * Copyright 2014-2018, Philipp "ph3-der-loewe" Schafft <lion@lion.leolix.org>,
 */


/* Ogg codec handler for skeleton logical streams */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <string.h>
#include <ogg/ogg.h>

#include "refbuf.h"
#include "format_ogg.h"
#include "format_skeleton.h"
#include "client.h"
#include "stats.h"

#define CATMODULE "format-skeleton"
#include "logging.h"


static void skeleton_codec_free (ogg_state_t *ogg_info, ogg_codec_t *codec)
{
    ICECAST_LOG_DEBUG("freeing skeleton codec");
    ogg_stream_clear (&codec->os);
    free (codec);
}


/* skeleton pages are not rebuilt, so here we just for headers and then
 * pass them straight through to the the queue
 */
static refbuf_t *process_skeleton_page (ogg_state_t *ogg_info, ogg_codec_t *codec, ogg_page *page, format_plugin_t *plugin)
{
    ogg_packet packet;

    if (ogg_stream_pagein (&codec->os, page) < 0)
    {
        ogg_info->error = 1;
        return NULL;
    }

    while (ogg_stream_packetout (&codec->os, &packet) > 0)
    {
        codec->headers++;
    }

    /* all skeleon packets are headers */
    format_ogg_attach_header (ogg_info, page);
    return NULL;
}


/* Check if specified BOS page is the start of a skeleton stream and
 * if so, create a codec structure for handling it
 */
ogg_codec_t *initial_skeleton_page (format_plugin_t *plugin, ogg_page *page)
{
    ogg_state_t *ogg_info = plugin->_state;
    ogg_codec_t *codec = calloc (1, sizeof (ogg_codec_t));
    ogg_packet packet;

    ogg_stream_init (&codec->os, ogg_page_serialno (page));
    ogg_stream_pagein (&codec->os, page);

    ogg_stream_packetout (&codec->os, &packet);

    ICECAST_LOG_DEBUG("checking for skeleton codec");

    if ((packet.bytes<8) || memcmp(packet.packet, "fishead\0", 8))
    {
        ogg_stream_clear (&codec->os);
        free (codec);
        return NULL;
    }

    ICECAST_LOG_INFO("seen initial skeleton header");
    codec->process_page = process_skeleton_page;
    codec->codec_free = skeleton_codec_free;
    codec->headers = 1;
    codec->name = "Skeleton";

    format_ogg_attach_header(ogg_info, page);
    return codec;
}

