package envoy.server.processors;

import java.util.logging.Logger;

import envoy.data.User.UserStatus;
import envoy.event.UserStatusChange;
import envoy.server.data.*;
import envoy.server.net.ObjectWriteProxy;
import envoy.util.EnvoyLog;

/**
 * This processor handles incoming {@link UserStatusChange}.
 *
 * @author Leon Hofmeister
 * @since Envoy Server Standalone v0.1-alpha
 */
public final class UserStatusChangeProcessor implements ObjectProcessor<UserStatusChange> {

	private static ObjectWriteProxy writeProxy;

	private static final PersistenceManager	persistenceManager	= PersistenceManager.getInstance();
	private static final Logger				logger				= EnvoyLog.getLogger(UserStatusChangeProcessor.class);

	@Override
	public void process(UserStatusChange input, long socketID, ObjectWriteProxy writeProxy) {
		// new status should not equal old status
		if (input.get().equals(persistenceManager.getUserByID(input.getID()).getStatus())) {
			logger.warning("Received an unnecessary UserStatusChange");
			return;
		}
		updateUserStatus(input);
	}

	/**
	 * Sets the {@link UserStatus} for a given user. Both offline contacts and
	 * currently online contacts are notified.
	 *
	 * @param user the {@link UserStatusChange} that signals the change
	 * @since Envoy Server Standalone v0.1-alpha
	 */

	public static void updateUserStatus(User user) {

		// Handling for newly logged in clients
		persistenceManager.updateContact(user);

		// Handling for contacts that are already online
		writeProxy.writeToOnlineContacts(user.getContacts(), new UserStatusChange(user.getID(), user.getStatus()));
	}

	/**
	 * @param evt the {@link UserStatusChange}
	 * @since Envoy Server Standalone v0.1-alpha
	 */
	public static void updateUserStatus(UserStatusChange evt) { updateUserStatus(persistenceManager.getUserByID(evt.getID())); }

	/**
	 * This method is only called by the LoginCredentialProcessor because every
	 * user needs to login (open a socket) before changing his status.
	 * Needed to ensure propagation of events because an uninitialized writeProxy
	 * would cause problems.
	 *
	 * @param writeProxy the writeProxy that is used to send objects back to clients
	 * @since Envoy Server Standalone v0.1-alpha
	 */
	public static void setWriteProxy(ObjectWriteProxy writeProxy) { UserStatusChangeProcessor.writeProxy = writeProxy; }
	// TODO may cause an problem if two clients log in at the same time.
	// Change Needed.
}