/**
 * Copyright 2013-2015 Seagate Technology LLC.
 *
 * This Source Code Form is subject to the terms of the Mozilla
 * Public License, v. 2.0. If a copy of the MPL was not
 * distributed with this file, You can obtain one at
 * https://mozilla.org/MP:/2.0/.
 * 
 * This program is distributed in the hope that it will be useful,
 * but is provided AS-IS, WITHOUT ANY WARRANTY; including without 
 * the implied warranty of MERCHANTABILITY, NON-INFRINGEMENT or 
 * FITNESS FOR A PARTICULAR PURPOSE. See the Mozilla Public 
 * License for more details.
 *
 * See www.openkinetic.org for more project information
 */
package com.seagate.kinetic.client.internal;

import kinetic.client.CallbackResult;

import com.seagate.kinetic.common.lib.KineticMessage;

/**
 * Java API Asynchronous callback result implementation.
 *
 * @author chiaming yang
 *
 * @param <T>
 *            callback result type.
 */
public class AsyncCallbackResult<T> implements CallbackResult<T> {

	// request message
	private KineticMessage request = null;

	// response message
	private KineticMessage response = null;

	// callback result
	private T result;

	/**
	 * default constructor.
	 */
	public AsyncCallbackResult() {
		;
	}

	/**
	 * Construct a new instance of asynchronous call back result with the
	 * specified parameters.
	 *
	 * @param request
	 *            the associated request object.
	 * @param response
	 *            the associated response object
	 * @param result
	 *            the associated call back result.
	 */
	public AsyncCallbackResult(KineticMessage request, KineticMessage response,
			T result) {
		this.request = request;
		this.response = response;
		this.result = result;
	}

	/**
	 * Set request instance.
	 *
	 * @param request
	 *            the request object for the asynchronous operation.
	 */
	public void setRequestMessage(KineticMessage request) {
		this.request = request;
	}

	/**
	 * Set response object.
	 *
	 * @param response
	 *            the response object for the asynchronous operation.
	 */
	public void setResponseMessage(KineticMessage response) {
		this.response = response;
	}

	/**
	 * Set the result object.
	 *
	 * @param result
	 *            the result object for the asynchronous operation.
	 */
	public void setResult(T result) {
		this.result = result;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public KineticMessage getRequestMessage() {
		return this.request;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public KineticMessage getResponseMessage() {
		return this.response;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public T getResult() {
		return result;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public byte[] getRequestKey() {

		// check if request message is present
		if (this.request == null) {
			throw new NullPointerException("request message cannot be null.");
		}

		// return the key field of the request message.
		return this.request.getCommand().getBody().getKeyValue()
				.getKey()
				.toByteArray();
	}

}