/*

 * Copyright (c) 2014 Eejya Singh

 *

 * 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

 * STL subtitles format demuxer

 * @see https://documentation.apple.com/en/dvdstudiopro/usermanual/index.html#chapter=19%26section=13%26tasks=true

 */

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#include "subtitles.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/avstring.h"

typedef struct {

    FFDemuxSubtitlesQueue q;

} STLContext;

static int stl_probe(const AVProbeData *p)

{

    char c;

    const unsigned char *ptr = p->buf;

    if (AV_RB24(ptr) == 0xEFBBBF)

        ptr += 3;  /* skip UTF-8 BOM */

    while (*ptr == '\r' || *ptr == '\n' || *ptr == '$' || !strncmp(ptr, "//" , 2))

        ptr += ff_subtitles_next_line(ptr);

    if (sscanf(ptr, "%*d:%*d:%*d:%*d , %*d:%*d:%*d:%*d , %c", &c) == 1)

        return AVPROBE_SCORE_MAX;

    return 0;

}

static int64_t get_pts(char **buf, int *duration)

{

    int hh1, mm1, ss1, ms1;

    int hh2, mm2, ss2, ms2;

    int len = 0;

    if (sscanf(*buf, "%2d:%2d:%2d:%2d , %2d:%2d:%2d:%2d , %n",

                &hh1, &mm1, &ss1, &ms1,

                &hh2, &mm2, &ss2, &ms2, &len) >= 8 && len > 0) {

        int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;

        int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;

        *duration = end - start;

        *buf += len;

        return start;

    }

    return AV_NOPTS_VALUE;

}

static int stl_read_header(AVFormatContext *s)

{

    STLContext *stl = s->priv_data;

    AVStream *st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 64, 1, 100);

    st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;

    st->codecpar->codec_id   = AV_CODEC_ID_STL;

    while (!avio_feof(s->pb)) {

        char line[4096];

        char *p = line;

        const int64_t pos = avio_tell(s->pb);

        int len = ff_get_line(s->pb, line, sizeof(line));

        int64_t pts_start;

        int duration;

        if (!len)

            break;

        line[strcspn(line, "\r\n")] = 0;

        pts_start = get_pts(&p , &duration);

        if (pts_start != AV_NOPTS_VALUE) {

            AVPacket *sub;

            sub = ff_subtitles_queue_insert(&stl->q, p, strlen(p), 0);

            if (!sub)

                return AVERROR(ENOMEM);

            sub->pos = pos;

            sub->pts = pts_start;

            sub->duration = duration;

        }

    }

    ff_subtitles_queue_finalize(s, &stl->q);

    return 0;

}

const FFInputFormat ff_stl_demuxer = {

    .p.name         = "stl",

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

    .p.extensions   = "stl",

    .priv_data_size = sizeof(STLContext),

    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,

    .read_probe     = stl_probe,

    .read_header    = stl_read_header,

    .read_packet    = ff_subtitles_read_packet,

    .read_seek2     = ff_subtitles_read_seek,

    .read_close     = ff_subtitles_read_close,

};