/*
  * 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 "internal.h"
 #include "subtitles.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/avstring.h"
 
 typedef struct {
     FFDemuxSubtitlesQueue q;
 } STLContext;
 
 static int stl_probe(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;
 }
 static int stl_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     STLContext *stl = s->priv_data;
     return ff_subtitles_queue_read_packet(&stl->q, pkt);
 }
 
 static int stl_read_seek(AVFormatContext *s, int stream_index,
                              int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 {
     STLContext *stl = s->priv_data;
     return ff_subtitles_queue_seek(&stl->q, s, stream_index,
                                    min_ts, ts, max_ts, flags);
 }
 
 static int stl_read_close(AVFormatContext *s)
 {
     STLContext *stl = s->priv_data;
     ff_subtitles_queue_clean(&stl->q);
     return 0;
 }
 
 AVInputFormat ff_stl_demuxer = {
     .name           = "stl",
     .long_name      = NULL_IF_CONFIG_SMALL("Spruce subtitle format"),
     .priv_data_size = sizeof(STLContext),
     .read_probe     = stl_probe,
     .read_header    = stl_read_header,
     .read_packet    = stl_read_packet,
     .read_seek2     = stl_read_seek,
     .read_close     = stl_read_close,
     .extensions     = "stl",
 };