package javax.megaco.message.descriptor;



import java.io.Serializable;



import javax.megaco.CommandEvent;

import javax.megaco.ParameterNotSetException;

import javax.megaco.message.CommandReq;

import javax.megaco.message.CommandResp;

import javax.megaco.message.Descriptor;

import javax.megaco.message.DescriptorType;

import javax.megaco.pkg.PkgItemParam;

import javax.megaco.pkg.GenericPkg.GenSigComplEvent;

import javax.megaco.pkg.ToneGenPkg.ToneGenParamInd;

import javax.megaco.pkg.ToneGenPkg.ToneGenParamTl;

import javax.megaco.pkg.ToneGenPkg.ToneGenPlayToneSignal;



/**

 * The class extends JAIN MEGACO Descriptor. This class describes the stream

 * descriptor. The SDP information set within the local and remote descriptor

 * for this class is outside the scope of JAIN MEGACO. It is defined in

 * javax.sdp.

 */

public class StreamDescriptor extends Descriptor implements Serializable {



	private MediaStreamParam mediaStreamParam = null;

	private Integer streamId = null;



	/**

	 * Constructs a Stream Descriptor object. This extends the Descriptor class.

	 * It defines the Stream descriptor of the Megaco which contains the stream

	 * id and stream parameter. Multiple of these can be set in the media

	 * descriptor.

	 */

	public StreamDescriptor() {

		super();

		super.descriptorId = DescriptorType.M_STREAM_DESC;

	}



	/**

	 * This method cannot be overridden by the derived class. This method

	 * returns that the descriptor identifier is of type descriptor Stream. This

	 * method overrides the corresponding method of the base class Descriptor.

	 * 

	 * @return descriptorId - Returns an integer value that identifies this

	 *         stream object as the type of stream descriptor. It returns that

	 *         it is Stream Descriptor i.e., M_STREAM_DESC.

	 */

	public int getDescriptorId() {

		return super.descriptorId;

	}



	/**

	 * This method gets the Stream parameter for the stream descriptor. This can

	 * be used to get the local descriptor, remote descriptor and the local

	 * control descriptor.

	 * 

	 * @return Returns the object reference of type stream parameter.

	 */

	public final MediaStreamParam getMediaStreamParam() {



		return this.mediaStreamParam;

	}



	/**

	 * This method sets the stream parameter.

	 * 

	 * @param streamParam

	 *            - Sets the stream parameter consisiting of atleast one of

	 *            local descriptor, local control and remote descriptor.

	 * @throws IllegalArgumentException

	 *             if the parameters set for the stream parameter are such that

	 *             the Stream Descriptor cannot be encoded.

	 */

	public final void setMediaStreamParam(MediaStreamParam streamParam) throws IllegalArgumentException {

		// FIXME: add error checks



		if (streamParam == null) {

			throw new IllegalArgumentException("MediaStreamParam must not be null");

		}



		this.mediaStreamParam = streamParam;

	}



	/**

	 * The method can be used to get stream id in the stream descriptor. This

	 * method should be invoked after verifying that the port number is present

	 * using method isStreamIdPresent().

	 * 

	 * @return streamId - The integer value of the stream id shall be returned.

	 * @throws javax.megaco.ParameterNotSetException

	 *             - Thrown if streamId has not been set.

	 */

	public int getStreamId() throws javax.megaco.ParameterNotSetException {

		if (this.streamId == null) {

			throw new ParameterNotSetException();

		}



		return this.streamId.intValue();

	}



	/**

	 * The method can be used to set stream id in the stream descriptor.

	 * 

	 * @param streamId

	 *            - The integer value of the stream id shall be set.

	 * @throws IllegalArgumentException

	 *             - Thrown if streamId is set with an invalid value.

	 */

	public void setStreamId(int streamId) throws IllegalArgumentException {

		if (streamId <= 0) {

			throw new IllegalArgumentException("StreanId must not be less or equal to zero");

		}



		this.streamId = new Integer(streamId);

	}



	/**

	 * This method is used for checking if the Stream Id is present for this

	 * descriptor or not.

	 * 

	 * @return

	 */

	public boolean isStreamIdPresent() {

		

		

		

		return this.streamId != null;

	}



}