package org.opendaylight.mwtn.base.database;

import static org.elasticsearch.node.NodeBuilder.nodeBuilder;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.DatagramSocket;
import java.net.ServerSocket;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.node.Node;
import org.opendaylight.mwtn.base.internalTypes.Resources;
import org.opendaylight.mwtn.config.impl.AkkaConfig;
import org.opendaylight.mwtn.config.impl.AkkaConfig.ClusterNodeInfo;
import org.opendaylight.mwtn.config.impl.EsConfig;
import org.opendaylight.mwtn.config.impl.GeoConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HtDatabaseNode implements AutoCloseable {



	private static final Logger LOGGER = LoggerFactory.getLogger(HtDatabaseNode.class);
	private static final String DBCONFIGFILENAME = "etc/elasticsearch.yml";
	private static int MIN_PORT_NUMBER = 1024;
	private static int MAX_PORT_NUMBER = 65535;
	private static int ES_PORT = 9200;
	private static int DELAYSECONDS = 30;

	private static String pluginFolder="etc/elasticsearch-plugins";

	private static HtDatabaseNode oneNode = null;
	/**
	 *
	 */
	private static Integer initializedTarget = 0;
	private static Integer initializedReached = 0;

	private final Node node;

	private HtDatabaseNode() {
		LOGGER.debug("Start elasticsearch service");
		node = nodeBuilder().settings(Settings.builder().put("path.home", "etc").put("path.conf", "etc")).node();
		LOGGER.info("Starting Database service. Wait {} s", DELAYSECONDS);
		// Wait for green status but only wait for 2 seconds
		ClusterHealthResponse nodeStatus = node.client().admin().cluster().prepareHealth().setWaitForYellowStatus()
				.setTimeout(TimeValue.timeValueSeconds(DELAYSECONDS)).get();

		LOGGER.debug("Elasticsearch service started with status {}", nodeStatus.toString());
	}

	/**
	 * Close node
	 */
	@Override
	public void close() {
		node.close();
		oneNode = null; //Release the one instance that was started !
	}

	public Boolean getInitialized() {
		synchronized (initializedReached) {
			return initializedTarget != 0 && initializedReached == initializedTarget;
		}
	}

	public void setInitializedReached() {
		synchronized (initializedReached) {
			HtDatabaseNode.initializedReached++;
		}
	}

	public void setInitializedTarget() {
		synchronized (initializedTarget) {
			HtDatabaseNode.initializedTarget++;
		}
	}

	public Client getClient() {
		return node.client();
	}


	/* ---------------------------------------
	 * Static functions below
	 */


	private static void extractZip(String zipFile, String outputFolder) {

		byte[] buffer = new byte[1024];

		try {

			// create output directory is not exists
			File folder = new File(outputFolder);
			if (!folder.exists()) {
				folder.mkdir();
			}

			// get the zip file content
			ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFile));
			// get the zipped file list entry
			ZipEntry ze = zis.getNextEntry();

			while (ze != null) {

				String fileName = ze.getName();

				File newFile = new File(outputFolder + File.separator + fileName);
				System.out.println("file unzip : " + newFile.getAbsoluteFile());
				if(ze.isDirectory())
				{
					newFile.mkdir();
				}
				else
				{

					// create all non exists folders
					// else you will hit FileNotFoundException for compressed folder
					new File(newFile.getParent()).mkdirs();

					FileOutputStream fos = new FileOutputStream(newFile);

					int len;
					while ((len = zis.read(buffer)) > 0) {
						fos.write(buffer, 0, len);
					}

					fos.close();
				}
				ze = zis.getNextEntry();
			}

			zis.closeEntry();
			zis.close();
		} catch (IOException ex) {
			LOGGER.warn("problem extracting " + zipFile + " to " + outputFolder);
		}
	}

	// Visibility package for test purpose
	static void checkorcreateplugins(String pluginFolder) {
		File f = new File(pluginFolder);
		String tmpFilename = pluginFolder + "/tmp.zip";
		if (!f.exists())
			f.mkdir();

		f = new File(pluginFolder + "/head");
		File tmpFile = new File(tmpFilename);
		if (!f.exists()) {
			LOGGER.debug("extracting head plugin");
			if (Resources.extractFileTo("/elasticsearch/plugins/head.zip", tmpFile)) {
				extractZip(tmpFile.getAbsolutePath(), pluginFolder);
			} else
				LOGGER.debug("problem extracting plugin res");
		}
		f = new File(pluginFolder + "/delete-by-query");
		if (!f.exists()) {
			LOGGER.debug("extracting head delete-by-query plugin");
			if (Resources.extractFileTo("/elasticsearch/plugins/delete-by-query.zip", tmpFile)) {
				extractZip(tmpFile.getAbsolutePath(), pluginFolder);
			} else
				LOGGER.debug("problem extracting plugin res");
		}
		if(tmpFile.exists())
			tmpFile.delete();

	}

	/**
	 * Checks to see if a specific port is available.
	 *
	 * @param port
	 *            the port to check for availability
	 */
	private static boolean isPortAvailable(int port) {
		if (port < MIN_PORT_NUMBER || port > MAX_PORT_NUMBER) {
			throw new IllegalArgumentException("Invalid start port: " + port);
		}

		ServerSocket ss = null;
		DatagramSocket ds = null;
		try {
			ss = new ServerSocket(port);
			ss.setReuseAddress(true);
			ds = new DatagramSocket(port);
			ds.setReuseAddress(true);
			return true;
		} catch (IOException e) {
		} finally {
			if (ds != null) {
				ds.close();
			}

			if (ss != null) {
				try {
					ss.close();
				} catch (IOException e) {
					/* should not be thrown */
				}
			}
		}

		return false;
	}

	private static void checkorcreateConfigFile(EsConfig config, AkkaConfig akkaConfig,GeoConfig geoConfig) {
		File f = new File(DBCONFIGFILENAME);
		if (!f.exists()) {
			LOGGER.debug("no " + DBCONFIGFILENAME + " found - extracting from resources");
			if (Resources.extractFileTo("/elasticsearch/elasticsearch.yml", f)) {
				// replace template values
				LOGGER.debug("replace template values with config:" + config);
				Charset charset = StandardCharsets.UTF_8;
				try {
					Path p = f.toPath();
					String hostName = "0.0.0.0"; //Default as initialisation value
					if(akkaConfig!=null && akkaConfig.isCluster())
					{
						LOGGER.debug("cluster configuration found");
						hostName=akkaConfig.getClusterConfig().getHostName(hostName);
						String clusterDBName=akkaConfig.getClusterConfig().getDBClusterName(null);
						String nodeName=String.format("node%d.%s",akkaConfig.getClusterConfig().getRoleMemberIndex(),clusterDBName);
						if(clusterDBName!=null)
						{
							config.setCluster(clusterDBName);
							config.setNode(nodeName);
							LOGGER.info("set db name to "+clusterDBName+" nodename="+nodeName );
						}
						else
							LOGGER.warn("unable to set correct db clustername");
					}
					String content = new String(Files.readAllBytes(p), charset);
					content = content.replaceAll("\\$clustername", config.getCluster()).replaceAll("\\$nodename",
							config.getNode()).replaceAll("\\$hostname", hostName);

					//add cluster configuration
					if(akkaConfig!=null && akkaConfig.isCluster())
					{
						List<ClusterNodeInfo> seedNodes=akkaConfig.getClusterConfig().getSeedNodes();
						String nodesJSONString="[\""+seedNodes.get(0).getRemoteAddress()+"\"";
						for(int i=1;i<seedNodes.size();i++)
							nodesJSONString+=",\""+seedNodes.get(i).getRemoteAddress()+"\"";
						nodesJSONString+="]";
						content+=System.lineSeparator()+String.format("discovery.zen.ping.unicast.hosts: %s",nodesJSONString);

						if(geoConfig!=null)
						{
							LOGGER.debug("adding zone configuration");
							content+=System.lineSeparator()+String.format("cluster.routing.allocation.awareness.force.zone.values: zone1,zone2");
							content+=System.lineSeparator()+String.format("cluster.routing.allocation.awareness.attributes: zone");
							if(geoConfig.isPrimary(akkaConfig.getClusterConfig().getRoleMember()))
							{
								content+=System.lineSeparator()+String.format("node.zone: zone1");
								LOGGER.debug("setting zone to zone1");
							}
							else
							{
								content+=System.lineSeparator()+String.format("node.zone: zone2");
								LOGGER.debug("setting zone to zone2");
							}
						}
					}
					Files.write(p, content.getBytes(charset));
				} catch (IOException e) {
					LOGGER.warn("problem replacing values in file: " + e.getMessage());

				}
			} else {
				LOGGER.warn("problem writing database.yml to etc folder from res");
			}
		}
	}

	/**
	 * Start as singleton
	 * @return the node
	 */
	public static HtDatabaseNode start(EsConfig config) throws IllegalStateException {
		return start(config,null,null);
	}

	public static HtDatabaseNode start(EsConfig config, AkkaConfig akkaConfig,GeoConfig geoConfig) {
		if (isPortAvailable(ES_PORT)) {
			LOGGER.info("ES Port not in use. Start internal ES.");
			if (oneNode == null) {
				checkorcreateplugins(pluginFolder);
				checkorcreateConfigFile(config,akkaConfig,geoConfig);
				oneNode = new HtDatabaseNode();
			} else
				throw new IllegalStateException("Database is already started, but can only be started once. Stop here.");
		} else {
			LOGGER.info("ES Port in use. External ES used.");
		}

		return oneNode;
	}

}