/*
 * Copyright 2009-2012 by The Regents of the University of California
 * 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 from
 * 
 *     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 edu.uci.ics.asterix.installer.command;

import java.io.File;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;

import org.kohsuke.args4j.Option;

import edu.uci.ics.asterix.event.schema.cluster.Cluster;
import edu.uci.ics.asterix.event.schema.cluster.MasterNode;
import edu.uci.ics.asterix.event.schema.cluster.Node;
import edu.uci.ics.asterix.installer.driver.InstallerDriver;
import edu.uci.ics.asterix.installer.schema.conf.Configuration;
import edu.uci.ics.asterix.installer.schema.conf.Zookeeper;

public class ValidateCommand extends AbstractCommand {

	private static final String OK = " [" + "OK" + "]";
	private static final String ERROR = " [" + "ERROR" + "]";
	private static final String WARNING = " [" + "WARNING" + "]";

	@Override
	protected void execCommand() throws Exception {
		ValidateConfig vConfig = (ValidateConfig) config;
		logValidationResult("Environment", validateEnvironment());
		if (((ValidateConfig) config).cluster != null) {
			logValidationResult("Cluster configuration",
					validateCluster(vConfig.cluster));
		} else {
			logValidationResult("Installer Configuration",
					validateConfiguration());
		}
	}

	private void logValidationResult(String prefix, boolean isValid) {
		if (!isValid) {
			LOGGER.fatal(prefix + ERROR);
		} else {
			LOGGER.info(prefix + OK);
		}
	}

	@Override
	protected CommandConfig getCommandConfig() {
		return new ValidateConfig();
	}

	@Override
	protected String getUsageDescription() {
		return "\nValidate the installer's configuration or a cluster configuration"
				+ "\nUsage"
				+ "\nFor validating the installer configuration"
				+ "\nuse managix validate"
				+ "\n\nFor validating a cluster configuration"
				+ "\nuse managix validate -c <path to the cluster configuration file>";
	}

	public boolean validateEnvironment() throws Exception {
		boolean valid = true;
		String managixHome = System.getenv(InstallerDriver.ENV_MANAGIX_HOME);
		if (managixHome == null) {
			valid = false;
			LOGGER.fatal(InstallerDriver.ENV_MANAGIX_HOME + " not set " + ERROR);
		} else {
			File home = new File(managixHome);
			if (!home.exists()) {
				valid = false;
				LOGGER.fatal(InstallerDriver.ENV_MANAGIX_HOME + ": "
						+ home.getAbsolutePath() + " does not exist!" + ERROR);
			}
		}
		return valid;

	}

	public boolean validateCluster(String clusterPath) throws Exception {
		boolean valid = true;
		Cluster cluster = null;
		File f = new File(clusterPath);
		if (!f.exists() || !f.isFile()) {
			LOGGER.error(" Invalid path " + f.getAbsolutePath() + ERROR);
			valid = false;
		} else {
			JAXBContext ctx = JAXBContext.newInstance(Cluster.class);
			Unmarshaller unmarshaller = ctx.createUnmarshaller();
			cluster = (Cluster) unmarshaller.unmarshal(new File(clusterPath));
			validateClusterProperties(cluster);

			Set<String> servers = new HashSet<String>();
			Set<String> serverIds = new HashSet<String>();
			servers.add(cluster.getMasterNode().getClusterIp());
			serverIds.add(cluster.getMasterNode().getId());

			MasterNode masterNode = cluster.getMasterNode();
			Node master = new Node(masterNode.getId(),
					masterNode.getClusterIp(), masterNode.getJavaOpts(),
					masterNode.getJavaHome(), masterNode.getLogdir(), null,
					null, null);

			valid = valid & validateNodeConfiguration(master, cluster);

			for (Node node : cluster.getNode()) {
				servers.add(node.getClusterIp());
				if (serverIds.contains(node.getId())) {
					valid = false;
					LOGGER.error("Duplicate node id :" + node.getId() + ERROR);
				} else {
					valid = valid & validateNodeConfiguration(node, cluster);
				}
			}
		}

		return valid;
	}

	private void validateClusterProperties(Cluster cluster) {
		List<String> tempDirs = new ArrayList<String>();
		if (cluster.getLogdir() != null
				&& checkTemporaryPath(cluster.getLogdir())) {
			tempDirs.add("Log directory: " + cluster.getLogdir());
		}
		if (cluster.getIodevices() != null
				&& checkTemporaryPath(cluster.getIodevices())) {
			tempDirs.add("IO Device: " + cluster.getIodevices());
		}

		if (tempDirs.size() > 0) {
			StringBuffer msg = new StringBuffer();
			msg.append("The following paths are subject to be cleaned up by OS");
			for (String tempDir : tempDirs) {
				msg.append("\n" + tempDir + WARNING);
			}
			LOGGER.warn(msg);
		}

	}

	private boolean validateNodeConfiguration(Node node, Cluster cluster) {
		boolean valid = true;
		valid = checkNodeReachability(node.getClusterIp());
		if (node.getJavaHome() == null || node.getJavaHome().length() == 0) {
			if (cluster.getJavaHome() == null
					|| cluster.getJavaHome().length() == 0) {
				valid = false;
				LOGGER.fatal("java_home not defined at cluster/node level for node: "
						+ node.getId() + ERROR);
			}
		}

		if (node.getLogdir() == null || node.getLogdir().length() == 0) {
			if (cluster.getLogdir() == null
					|| cluster.getLogdir().length() == 0) {
				valid = false;
				LOGGER.fatal("log_dir not defined at cluster/node level for node: "
						+ node.getId() + ERROR);
			}
		}

		if (node.getStore() == null || node.getStore().length() == 0) {
			if (!cluster.getMasterNode().getId().equals(node.getId())
					&& (cluster.getStore() == null || cluster.getStore()
							.length() == 0)) {
				valid = false;
				LOGGER.fatal("store not defined at cluster/node level for node: "
						+ node.getId() + ERROR);
			}
		}

		if (node.getIodevices() == null || node.getIodevices().length() == 0) {
			if (!cluster.getMasterNode().getId().equals(node.getId())
					&& (cluster.getIodevices() == null || cluster
							.getIodevices().length() == 0)) {
				valid = false;
				LOGGER.fatal("iodevice(s) not defined at cluster/node level for node: "
						+ node.getId() + ERROR);
			}
		}

		return valid;
	}

	private boolean checkTemporaryPath(String logdir) {
		return logdir.startsWith("/tmp/");

	}

	public boolean validateConfiguration() throws Exception {
		String managixHome = System.getenv(InstallerDriver.ENV_MANAGIX_HOME);
		File configFile = new File(managixHome + File.separator
				+ InstallerDriver.MANAGIX_CONF_XML);
		JAXBContext configCtx = JAXBContext.newInstance(Configuration.class);
		Unmarshaller unmarshaller = configCtx.createUnmarshaller();
		Configuration conf = (Configuration) unmarshaller.unmarshal(configFile);
		return validateZookeeperConfiguration(conf);
	}

	private boolean validateZookeeperConfiguration(Configuration conf)
			throws Exception {
		boolean valid = true;
		Zookeeper zk = conf.getZookeeper();

		if (zk.getHomeDir() == null || zk.getHomeDir().length() == 0) {
			valid = false;
			LOGGER.fatal("Zookeeper home dir not configured" + ERROR);
		} else if (checkTemporaryPath(zk.getHomeDir())) {
			LOGGER.warn("Zookeeper home dir is subject to be cleaned up by OS"
					+ WARNING);
		}

		if (zk.getServers().getServer().isEmpty()) {
			valid = false;
			LOGGER.fatal("Zookeeper servers not configured" + ERROR);
		}

		boolean validEnsemble = true;
		for (String server : zk.getServers().getServer()) {
			validEnsemble = validEnsemble && checkNodeReachability(server);
		}

		return valid;
	}

	private boolean checkNodeReachability(String server) {
		boolean reachable = true;
		try {
			InetAddress address = InetAddress.getByName(server);
			if (!address.isReachable(1000)) {
				LOGGER.fatal("\n" + "Server: " + server + " unreachable"
						+ ERROR);
				reachable = false;
			}
		} catch (Exception e) {
			reachable = false;
			LOGGER.fatal("\n" + "Server: " + server + " Invalid address"
					+ ERROR);
		}
		return reachable;
	}

}

class ValidateConfig extends CommandConfig {

	@Option(name = "-c", required = false, usage = "Path to the cluster configuration xml")
	public String cluster;

}