// derived from org.gagravarr.opus.OpusFile
/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.gagravarr.ogg.*;
import org.gagravarr.ogg.audio.*;

sclass OpusFromStream implements OggAudioStream, OggAudioHeaders, Closeable {
  private OggFile ogg;
  private OggPacketReader r;
  private int sid = -1;

  private OpusInfo info;
  private OpusTags tags;

  public OpusFile(File f) throws IOException, FileNotFoundException {
      this(new OggFile(new FileInputStream(f)));
  }
  
  /**
   * Opens the given file for reading
   */
  public OpusFile(OggFile ogg) throws IOException {
      this(ogg.getPacketReader());
      this.ogg = ogg;
  }
  /**
   * Loads a Opus File from the given packet reader.
   */
  public OpusFile(OggPacketReader r) throws IOException { 
      this.r = r;

      OggPacket p = null;
      while( (p = r.getNextPacket()) != null ) {
          if (p.isBeginningOfStream() && p.getData().length > 10) {
              if (OpusPacketFactory.isOpusStream(p)) {
                  sid = p.getSid();
                  break;
              }
          }
      }
      if (sid == -1) {
          throw new IllegalArgumentException("Supplied File is not Opus");
      }

      // First two packets are required to be info then tags
      info = (OpusInfo)OpusPacketFactory.create( p );
      tags = (OpusTags)OpusPacketFactory.create( r.getNextPacketWithSid(sid) );

      // Everything else should be audio data
  }

  public OpusAudioData getNextAudioPacket() throws IOException {
      OggPacket p = null;
      OpusPacket op = null;
      while( (p = r.getNextPacketWithSid(sid)) != null ) {
          op = OpusPacketFactory.create(p);
          if(op instanceof OpusAudioData) {
              return (OpusAudioData)op;
          } else {
              System.err.println("Skipping non audio packet " + op + " mid audio stream");
          }
      }
      return null;
  }

  /**
   * Skips the audio data to the next packet with a granule
   *  of at least the given granule position.
   * Note that skipping backwards is not currently supported!
   */
  public void skipToGranule(long granulePosition) throws IOException {
      r.skipToGranulePosition(sid, granulePosition);
  }

  /**
   * Returns the Ogg Stream ID
   */
  public int getSid() {
      return sid;
  }

  /**
   * This is an Opus file
   */
  public OggStreamType getType() {
      return OggStreamIdentifier.OPUS_AUDIO;
  }

  public OpusInfo getInfo() {
      return info;
  }
  public OpusTags getTags() {
      return tags;
  }
  
  /**
   * Opus doesn't have setup headers, so this is always null
   */
  public OggAudioSetupHeader getSetup() {
      return null;
  }

  public void close() throws IOException {
    dispose r;
    dispose ogg;
  }
}