package org.jaudiotagger.audio.asf.io;

 import java.io.IOException;

 import java.io.InputStream;

 import org.jaudiotagger.audio.asf.data.Chunk;

 import org.jaudiotagger.audio.asf.data.GUID;

 /**

  * A ChunkReader provides methods for reading an ASF chunk.<br>

  * 

  * @author Christian Laireiter

  */

 public interface ChunkReader

 {

     /**

      * Tells whether the reader can fail to return a valid chunk.<br>

      * The current Use would be a modified version of {@link StreamChunkReader}, which

      * is configured to only manage audio streams. However, the primary GUID for

      * audio and video streams is the same. So if a stream shows itself to

      * be a video stream, the reader would return <code>null</code>.<br> 

      * 

      * @return <code>true</code>, if further analysis of the chunk can show,

      *  that the reader is not applicable, despite the header GUID 

      *  {@linkplain #getApplyingId() identification} told it can handle the chunk. 

      */

     public boolean canFail();

     /**

      * Returns the GUID identifying the type of chunk, this reader will parse.<br>

      * 

      * @return the GUID identifying the type of chunk, this reader will parse.<br>

      */

     public GUID getApplyingId();

     /**

      * Parses the chunk.

      * 

      * @param guid the GUID of the chunks header, which is about to be read.  

      * @param stream source to read chunk from.<br> No  {@link GUID} is expected at the currents stream position. 

      *               The length of the chunk is about to follow. 

      * @param streamPosition the position in stream, the chunk starts.<br>

      * @return the read chunk. (Mostly a subclass of {@link Chunk}).<br>

      * @throws IOException On I/O Errors.

      */

     public Chunk read(GUID guid, InputStream stream, long streamPosition) throws IOException;

 }