/*
  * 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
  * AQTitle subtitles format demuxer
  *
  * @see http://web.archive.org/web/20070210095721/http://www.volny.cz/aberka/czech/aqt.html
  * @see https://trac.annodex.net/wiki/AQTitle
  */
 
 #include "avformat.h"
 #include "internal.h"
 #include "subtitles.h"
 #include "libavutil/opt.h"
 
 typedef struct {
     const AVClass *class;
     FFDemuxSubtitlesQueue q;
     AVRational frame_rate;
 } AQTitleContext;
 
 static int aqt_probe(AVProbeData *p)
 {
     int frame;
     const char *ptr = p->buf;
 
     if (sscanf(ptr, "-->> %d", &frame) == 1)

         return AVPROBE_SCORE_EXTENSION;

     return 0;
 }
 
 static int aqt_read_header(AVFormatContext *s)
 {
     AQTitleContext *aqt = s->priv_data;
     AVStream *st = avformat_new_stream(s, NULL);
     int new_event = 1;
     int64_t pos = 0, frame = AV_NOPTS_VALUE;
     AVPacket *sub = NULL;
 
     if (!st)
         return AVERROR(ENOMEM);
     avpriv_set_pts_info(st, 64, aqt->frame_rate.den, aqt->frame_rate.num);
     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
     st->codec->codec_id   = AV_CODEC_ID_TEXT;
 
     while (!url_feof(s->pb)) {
         char line[4096];
         int len = ff_get_line(s->pb, line, sizeof(line));
 
         if (!len)
             break;
 
         line[strcspn(line, "\r\n")] = 0;
 

         if (sscanf(line, "-->> %"SCNd64, &frame) == 1) {

             new_event = 1;
             pos = avio_tell(s->pb);
             if (sub) {
                 sub->duration = frame - sub->pts;
                 sub = NULL;
             }
         } else if (*line) {
             if (!new_event) {
                 sub = ff_subtitles_queue_insert(&aqt->q, "\n", 1, 1);
                 if (!sub)
                     return AVERROR(ENOMEM);
             }
             sub = ff_subtitles_queue_insert(&aqt->q, line, strlen(line), !new_event);
             if (!sub)
                 return AVERROR(ENOMEM);
             if (new_event) {
                 sub->pts = frame;
                 sub->duration = -1;
                 sub->pos = pos;
             }
             new_event = 0;
         }
     }
 
     ff_subtitles_queue_finalize(&aqt->q);
     return 0;
 }
 
 static int aqt_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     AQTitleContext *aqt = s->priv_data;
     return ff_subtitles_queue_read_packet(&aqt->q, pkt);
 }
 
 static int aqt_read_seek(AVFormatContext *s, int stream_index,
                          int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 {
     AQTitleContext *aqt = s->priv_data;
     return ff_subtitles_queue_seek(&aqt->q, s, stream_index,
                                    min_ts, ts, max_ts, flags);
 }
 
 static int aqt_read_close(AVFormatContext *s)
 {
     AQTitleContext *aqt = s->priv_data;
     ff_subtitles_queue_clean(&aqt->q);
     return 0;
 }
 
 #define OFFSET(x) offsetof(AQTitleContext, x)
 #define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM
 static const AVOption aqt_options[] = {
     { "subfps", "set the movie frame rate", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=25}, 0, INT_MAX, SD },
     { NULL }
 };
 
 static const AVClass aqt_class = {
     .class_name = "aqtdec",
     .item_name  = av_default_item_name,
     .option     = aqt_options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 AVInputFormat ff_aqtitle_demuxer = {
     .name           = "aqtitle",
     .long_name      = NULL_IF_CONFIG_SMALL("AQTitle subtitles"),
     .priv_data_size = sizeof(AQTitleContext),
     .read_probe     = aqt_probe,
     .read_header    = aqt_read_header,
     .read_packet    = aqt_read_packet,
     .read_seek2     = aqt_read_seek,
     .read_close     = aqt_read_close,
     .extensions     = "aqt",
     .priv_class     = &aqt_class,
 };