/*
  * 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 "internal.h"
 #include "subtitles.h"

 #include "libavcodec/internal.h"

 #include "libavutil/avstring.h"
 #include "libavutil/bprint.h"
 #include "libavutil/intreadwrite.h"
 
 typedef struct {
     FFDemuxSubtitlesQueue q;
 } SAMIContext;
 
 static int sami_probe(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)
             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(&sami->q, buf.str, buf.len, !is_sync);
             if (!sub) {
                 res = AVERROR(ENOMEM);
                 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;
                 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;
 }
 
 static int sami_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     SAMIContext *sami = s->priv_data;
     return ff_subtitles_queue_read_packet(&sami->q, pkt);
 }
 

 static int sami_read_seek(AVFormatContext *s, int stream_index,
                           int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 {
     SAMIContext *sami = s->priv_data;
     return ff_subtitles_queue_seek(&sami->q, s, stream_index,
                                    min_ts, ts, max_ts, flags);
 }
 

 static int sami_read_close(AVFormatContext *s)
 {
     SAMIContext *sami = s->priv_data;
     ff_subtitles_queue_clean(&sami->q);
     return 0;
 }
 
 AVInputFormat ff_sami_demuxer = {
     .name           = "sami",
     .long_name      = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
     .priv_data_size = sizeof(SAMIContext),
     .read_probe     = sami_probe,
     .read_header    = sami_read_header,
     .read_packet    = sami_read_packet,

     .read_seek2     = sami_read_seek,

     .read_close     = sami_read_close,
     .extensions     = "smi,sami",
 };