/*

 * Copyright (c) 2012 Clément Bœsch

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * SAMI subtitle demuxer

 * @see http://msdn.microsoft.com/en-us/library/ms971327.aspx

 */

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#include "subtitles.h"

#include "libavutil/avstring.h"

#include "libavutil/bprint.h"

typedef struct {

    FFDemuxSubtitlesQueue q;

} SAMIContext;

static int sami_probe(const AVProbeData *p)

{

    char buf[6];

    FFTextReader tr;

    ff_text_init_buf(&tr, p->buf, p->buf_size);

    ff_text_read(&tr, buf, sizeof(buf));

    return !strncmp(buf, "<SAMI>", 6) ? AVPROBE_SCORE_MAX : 0;

}

static int sami_read_header(AVFormatContext *s)

{

    SAMIContext *sami = s->priv_data;

    AVStream *st = avformat_new_stream(s, NULL);

    AVBPrint buf, hdr_buf;

    char c = 0;

    int res = 0, got_first_sync_point = 0;

    FFTextReader tr;

    ff_text_init_avio(s, &tr, s->pb);

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 64, 1, 1000);

    st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;

    st->codecpar->codec_id   = AV_CODEC_ID_SAMI;

    av_bprint_init(&buf,     0, AV_BPRINT_SIZE_UNLIMITED);

    av_bprint_init(&hdr_buf, 0, AV_BPRINT_SIZE_UNLIMITED);

    while (!ff_text_eof(&tr)) {

        AVPacket *sub;

        const int64_t pos = ff_text_pos(&tr) - (c != 0);

        int is_sync, is_body, n = ff_smil_extract_next_text_chunk(&tr, &buf, &c);

        if (n < 0) {

            res = n;

            goto end;

        }

        if (n == 0)

            break;

        is_body = !av_strncasecmp(buf.str, "</BODY", 6);

        if (is_body) {

             av_bprint_clear(&buf);

             break;

        }

        is_sync = !av_strncasecmp(buf.str, "<SYNC", 5);

        if (is_sync)

            got_first_sync_point = 1;

        if (!got_first_sync_point) {

            av_bprintf(&hdr_buf, "%s", buf.str);

        } else {

            sub = ff_subtitles_queue_insert_bprint(&sami->q, &buf, !is_sync);

            if (!sub) {

                res = AVERROR(ENOMEM);

                av_bprint_finalize(&hdr_buf, NULL);

                goto end;

            }

            if (is_sync) {

                const char *p = ff_smil_get_attr_ptr(buf.str, "Start");

                sub->pos      = pos;

                sub->pts      = p ? strtol(p, NULL, 10) : 0;

                if (sub->pts <= INT64_MIN/2 || sub->pts >= INT64_MAX/2) {

                    res = AVERROR_PATCHWELCOME;

                    av_bprint_finalize(&hdr_buf, NULL);

                    goto end;

                }

                sub->duration = -1;

            }

        }

        av_bprint_clear(&buf);

    }

    res = ff_bprint_to_codecpar_extradata(st->codecpar, &hdr_buf);

    if (res < 0)

        goto end;

    ff_subtitles_queue_finalize(s, &sami->q);

end:

    av_bprint_finalize(&buf, NULL);

    return res;

}

const FFInputFormat ff_sami_demuxer = {

    .p.name         = "sami",

    .p.long_name    = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),

    .p.extensions   = "smi,sami",

    .priv_data_size = sizeof(SAMIContext),

    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,

    .read_probe     = sami_probe,

    .read_header    = sami_read_header,

    .read_packet    = ff_subtitles_read_packet,

    .read_seek2     = ff_subtitles_read_seek,

    .read_close     = ff_subtitles_read_close,

};