/*******************************************************************************
 * Copyright (c) 2011 GigaSpaces Technologies Ltd. All rights reserved
 *
 * 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.
 *******************************************************************************/
package org.cloudifysource.usm.liveness;

import java.util.List;
import java.util.Map;

import org.cloudifysource.domain.context.ServiceContext;
import org.cloudifysource.dsl.utils.ServiceUtils;
import org.cloudifysource.usm.Plugin;
import org.cloudifysource.usm.UniversalServiceManagerBean;
import org.cloudifysource.usm.events.AbstractUSMEventListener;
import org.cloudifysource.usm.events.EventResult;
import org.cloudifysource.usm.events.PreStartListener;
import org.cloudifysource.usm.events.StartReason;

/**
 * PortLivenessDetector class is responsible for verifying that the process has finished loading by checking whether the
 * ports opened by the process are indeed open. the application ports to check are defined in the configuration file.
 * 
 * There are 2 ways of using the PortLiveness. 1. The first is by adding a plugin to the DSL in the following manner:
 * plugins ([ plugin { name "portLiveness" className "org.cloudifysource.usm.liveness.PortLivenessDetector" config ([
 * "Port" : [39000,38999,38998], "TimeoutInSeconds" : 30, "Host" : "127.0.0.1" ]) },
 * 
 * plugin{...
 * 
 * 2. By adding the following closures to the Service Groovy file in the following manner:
 * 
 * * Add the following command to the preStart Closure(Not a mandatory check):
 * ServiceUtils.arePortsFree([23894,34,3243], "127.0.0.1") //to see that the ports are available before process starts.
 * 
 * * Add the following closure to the lifecycle closure: startDetection
 * {ServiceUtils.waitForPortToOpen([23894,34,3243],"127.0.0.1", 60)} //to see that the process has started and is using
 * these ports.
 * 
 * @author adaml
 * 
 */
public class PortLivenessDetector extends AbstractUSMEventListener implements LivenessDetector, Plugin,
		PreStartListener {

	private static final java.util.logging.Logger logger = java.util.logging.Logger
			.getLogger(PortLivenessDetector.class.getName());
	private static final String PORT_KEY = "Port";
	// Injected values
	private List<Integer> portList;

	@SuppressWarnings("unchecked")
	@Override
	public void setConfig(final Map<String, Object> config) {
		this.portList = (List<Integer>) config.get(PORT_KEY);
		if (this.portList == null) {
			throw new IllegalArgumentException("Parameter portList of Plugin " + this.getClass().getName()
					+ " is mandatory");
		}
	}

	/**
	 * Checks if a set of ports is open (i.e. you can connect to them).
	 * 
	 * @return true if all ports in the list are open, false if any one of them is not. 
	 */
	@Override
	public boolean isProcessAlive() {
		logger.info("Testing if the following ports are open: " + this.portList.toString());
		return ServiceUtils.arePortsOccupied(this.portList);
	}

	@Override
	public void init(final UniversalServiceManagerBean usm) {

	}

	@Override
	public int getOrder() {
		return 5;
	}

	/**
	 * Verifies that the ports are not in use before the service starts.
	 * 
	 * @param reason
	 *            the start reason.
	 * @return the event result.
	 */
	@Override
	public EventResult onPreStart(final StartReason reason) {
		for (final Integer port : this.portList) {

			if (ServiceUtils.isPortOccupied(port)) {
				throw new IllegalStateException("The Port Liveness Detector found that port " + port
						+ " is IN USE before the process was launched!");

			}
		}

		return EventResult.SUCCESS;
	}

	@Override
	public void setServiceContext(final ServiceContext context) {
		// ignore
	}
}