package geniusweb.profilesserver;

import java.lang.management.ManagementFactory;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Set;

import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.Query;

import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * A central class containing the constants/configuration of the server.
 * 
 * <b> This class should is private to the server and should not be used by
 * others. However servers that derive from this server can completely override
 * this class to change the constants/configuration</b>
 */
public class Constants {
	private static transient ObjectMapper jackson; // cache
	private static transient String hostport = ""; // cache

	/**
	 * 
	 * @return the object mapper, so that we can extend the objectmapper (with
	 *         custom classes) centrally. Also allows us to cache the objectmapper
	 */
	public static ObjectMapper getJackson() {
		if (jackson == null) {
			jackson = new ObjectMapper();
		}
		return jackson;
	}

	/**
	 * 
	 * @return a string like "127.0.1.1:8080" containing the server address on which
	 *         this service is running.
	 * @throws UnknownHostException         if we can not get the host ip
	 * @throws MalformedObjectNameException if we can not get the host ip
	 */
	public static String getIpAddressAndPort() throws UnknownHostException, MalformedObjectNameException {
		synchronized (hostport) {
			if (hostport.isEmpty()) {
				MBeanServer beanServer = ManagementFactory.getPlatformMBeanServer();

				Set<ObjectName> objectNames = beanServer.queryNames(new ObjectName("*:type=Connector,*"),
						Query.match(Query.attr("protocol"), Query.value("HTTP/1.1")));

				String host = InetAddress.getLocalHost().getHostAddress();
				String port = objectNames.iterator().next().getKeyProperty("port");

				hostport = host + ":" + port;
			}
			return hostport;
		}

	}
}