envoy/server/src/main/java/envoy/server/processors/UserOperationProcessor.java

package envoy.server.processors;

import java.time.Instant;
import java.util.logging.*;

import envoy.event.ElementOperation;
import envoy.event.contact.UserOperation;
import envoy.util.EnvoyLog;

import envoy.server.data.PersistenceManager;
import envoy.server.net.*;

/**
 * @author Kai S. K. Engelbart
 * @since Envoy Server Standalone v0.1-alpha
 */
public final class UserOperationProcessor implements ObjectProcessor<UserOperation> {

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

	@Override
	public void process(UserOperation evt, long socketID, ObjectWriteProxy writeProxy) {
		final long	userID		= ConnectionManager.getInstance().getUserIDBySocketID(socketID);
		final long	contactID	= evt.get().getID();
		final var	recipient	= persistenceManager.getUserByID(contactID);

		// TODO: Inform the sender if the requested contact has already been deleted
		if (recipient == null)
			return;

		final var sender = persistenceManager.getUserByID(userID);
		switch (evt.getOperationType()) {
			case ADD:
				logger.log(Level.FINE,
					String.format("Adding %s to the contact list of user %d.", evt.get(), userID));
				persistenceManager.addContactBidirectional(userID, contactID);

				// Notify the contact if online
				if (connectionManager.isOnline(contactID))
					writeProxy.write(connectionManager.getSocketID(contactID),
						new UserOperation(sender.toCommon(), ElementOperation.ADD));
				break;
			case REMOVE:

				// Remove the relationships and notify sender if he logs in using another
				// LocalDB
				persistenceManager.removeContactBidirectional(userID, contactID);
				sender.setLatestContactDeletion(Instant.now());

				// Notify the removed contact on next startup(s) of this deletion
				recipient.setLatestContactDeletion(Instant.now());

				// Notify the removed contact if online
				if (connectionManager.isOnline(contactID))
					writeProxy.write(connectionManager.getSocketID(contactID),
						new UserOperation(sender.toCommon(), ElementOperation.REMOVE));
				break;
		}
	}
}