package thrift;

import org.apache.log4j.Logger;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;
import org.openslx.imagemaster.thrift.iface.ImageServer;
import org.openslx.sat.thrift.iface.Server;

public class ThriftManager {

	private final static Logger LOGGER = Logger.getLogger(ThriftManager.class);
	
	/** 
	 * Public variables to represent client types
	 * TODO: Public needed?
	 */
	public static enum ClientType {
		MASTER, SATELLITE
	}
	/**
	 * Private singleton instances of itself and the satellite/master clients
	 */
	private static ThreadLocal<ThriftManager> _instance = null;
	private static ThreadLocal<Server.Client> _satClient = new ThreadLocal<>();
	private static ThreadLocal<ImageServer.Client> _masterClient = new ThreadLocal<>();
	
	/**
	 * Private members for master connection information
	 */
	private static final String MASTERSERVER_IP = "132.230.4.16";
	private static final int 		MASTERSERVER_PORT = 9090;
	private static final int 		MASTERSERVER_TIMEOUT = 30000;
	
	
	/**
	 * Private members for satellite connection information
	 */
	private static String 			SATELLITE_IP = null;
	private static final int 		SATELLITE_PORT = 9090;
	private static final int 		SATELLITE_TIMEOUT = 10000;
	
	/**
	 * Protected constructor to avoid external instantiation 
	 */
	protected ThriftManager() {
		if (_instance.get() == null) {
			_instance.set(new ThriftManager());
		}
		if (_instance.get() == null) {
			// something very wrong...
			LOGGER.error("Could not initialize Thrift Manager, this should not happen. Contact a developper.");
			// TODO handle: exit? message box?
		}
	}
	
	/**
	 * Initialise the client of type 'type' with give ip, port and timeout.
	 * 
	 * @param type type of the client. Valid are 'MASTER' or 'SATELLITE'
	 * @param ip ip of the server to connect to
	 * @param port port of the server to connect to
	 * @param timeout timeout of the connection in milliseconds
	 * @return true if initializing the client worked, false otherwise
	 */
	private static boolean init(ClientType type, String ip, int port, int timeout) {

		/*
		 * Master Connection
		 */
		if (type == ClientType.MASTER) {
			TTransport transport = 
					new TFramedTransport(new TSocket(MASTERSERVER_IP, MASTERSERVER_PORT, MASTERSERVER_TIMEOUT));
			try {
				transport.open();
			} catch (TTransportException e) {
				LOGGER.error("Could not open transport to thrift's server with IP: " + MASTERSERVER_IP);
				return false;
			}
			final TProtocol protocol = new TBinaryProtocol(transport);
			// now we are ready to create the client, according to ClientType!
			_masterClient.set(new ImageServer.Client(protocol));
			LOGGER.info("Masterserver '" + MASTERSERVER_IP + "' reachable. Client initialised.");
		}
		/*
		 * Satellite Connection
		 */
		if (type == ClientType.SATELLITE) {
			// first check if we have a sat ip
			if (SATELLITE_IP == null) {
				LOGGER.error("Satellite ip adress was not set prior to getting the sat client. Use setSatellite(<ip>).");
				return false;
			}
			// ok lets do it
			TTransport transport = 
					new TSocket(SATELLITE_IP, SATELLITE_PORT, SATELLITE_TIMEOUT);
			try {
				transport.open();
			} catch (TTransportException e) {
				LOGGER.error("Could not open transport to thrift's server with IP: " + SATELLITE_IP);
				return false;
			}
			final TProtocol protocol = new TBinaryProtocol(transport);
			// now we are ready to create the client, according to ClientType!
			_satClient.set(new Server.Client(protocol));
		}
		return true;
	}
	/**
	 * Sets the IP of the satellite to connect to
	 * @param ip the ip of the satellite as String
	 * @return true if setting the ip worked, false otherwise
	 */
	public static boolean setSatellite(String ip) {
		if (ip.isEmpty()) {
			LOGGER.error("Given IP for satellite is empty.");
			return false;
		}
		SATELLITE_IP = ip;
		return true;
	}
	/** 
	 * Returns the singleton client of the thrift connection to the satellite
	 * @return the thrift client to the satellite server
	 */
	public static Server.Client getSatClient() {
			if (_satClient.get() == null) {
				init(ClientType.SATELLITE, SATELLITE_IP, SATELLITE_PORT, SATELLITE_TIMEOUT);
			}
			if (_satClient.get() == null) {
				LOGGER.error("Satelite client still null. Initialisation must have failed. Contact developper.");
				return null;
			}
			return _satClient.get();
	}
	
	/**
	 * Returns the singleton client of the master thrift connection
	 * @return the thrift client to the master server
	 */
	public static ImageServer.Client getMasterClient() {
		if (_masterClient.get() == null) {
			LOGGER.debug("Initialising master thrift client...");
			init(ClientType.MASTER, MASTERSERVER_IP, MASTERSERVER_PORT, MASTERSERVER_TIMEOUT);
		}
		if (_masterClient.get() == null) {
			LOGGER.error("Satellite client still null. Initialisation must have failed. Contact developper.");
			return null;
		}
		return _masterClient.get();
	}
}