/*
 * Copyright (c) 2006 Stiftung Deutsches Elektronen-Synchroton,
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS.
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE.
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION,
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */

package org.csstudio.dal.proxy;

import org.csstudio.dal.RemoteException;
import org.csstudio.dal.Request;
import org.csstudio.dal.ResponseListener;

/**
 * Proxy for commands. Same interface is used for synchronous and asynchronous
 * commands.
 *
 * @author Igor Kriznar (igor.kriznarATcosylab.com)
 *
 */
public interface CommandProxy{
	/**
	 * The name of the command within parent context.
	 *
	 * @return the name
	 */
	public String getName();

	/**
	 * Executes command syncrhonously. Thread calling this method is
	 * blocked until  execution is finished.
	 *
	 * @return returned valune, <code>null</code> if non exists
	 *
	 * @throws RemoteException if executions fails
	 */
	public Object execute(Object... parameters) throws RemoteException;

	/**
	 * Returns input parameter types.
	 *
	 * @return array of types
	 */
	public Class[] getParameterTypes();

	/**
	 * Returned type, may be <code>null</code> if no value is returned.
	 *
	 * @return return type or <code>null</code>
	 */
	public Class getReturnedType();

	/**
	 * Returns <code>true</code> if this command can be executed
	 * asynchronously.
	 *
	 * @return <code>true</code> if this command can be executed asynchronously
	 */
	public boolean isAsynchronous();

	/**
	 * Asynchronously executes command.
	 *
	 * @param callback a callback which receives response notification
	 *
	 * @return request object which identifies responses
	 *
	 * @throws RemoteException if remote operation fails
	 */
	public <T> Request<T> execute(ResponseListener<T> callback, Object... parameters) throws RemoteException;
	
}