package envoy.server.processors;

import static envoy.data.Message.MessageStatus.READ;

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

import envoy.data.Message.MessageStatus;
import envoy.event.*;
import envoy.util.EnvoyLog;

import envoy.server.data.*;
import envoy.server.net.*;
import envoy.server.util.UserAuthenticationUtil;

/**
 * @author Maximilian Käfer
 * @since Envoy Server Standalone v0.1-beta
 */
public final class GroupMessageStatusChangeProcessor
	implements ObjectProcessor<GroupMessageStatusChange> {

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

	@Override
	public void process(GroupMessageStatusChange statusChange, long socketID,
		ObjectWriteProxy writeProxy) {

		// Check whether the message has the expected parameters
		if (!UserAuthenticationUtil.isExpectedUser(statusChange.getMemberID(), socketID)) {
			logger.log(Level.INFO,
				"Received a group message with invalid parameters");
			return;
		}
		
		GroupMessage gmsg = (GroupMessage) persistenceManager.getMessageByID(statusChange.getID());
		if (gmsg == null)
			return;

		// Any other status than READ is not supposed to be sent to the server
		if (statusChange.get() != MessageStatus.READ) {
			logger.log(Level.WARNING, "Invalid " + statusChange);
			return;
		}

		// Apply the status change
		gmsg.getMemberMessageStatus().replace(statusChange.getMemberID(), statusChange.get());
		gmsg.setLastStatusChangeDate(Instant.now());

		// Notifying the other members about the status change
		final var userID = connectionManager.getUserIDBySocketID(socketID);
		gmsg.getMemberMessageStatus()
			.keySet()
			.stream()
			.filter(k -> userID != k)
			.filter(connectionManager::isOnline)
			.forEach(k -> writeProxy.write(connectionManager.getSocketID(k), statusChange));

		// Increment overall status to READ if necessary
		if (Collections.min(gmsg.getMemberMessageStatus().values()) == READ) {
			gmsg.read();

			// Notify online members about the status change
			writeProxy.writeToOnlineContacts(gmsg.getRecipient().getContacts(),
				new MessageStatusChange(gmsg.getID(), gmsg.getStatus(), Instant.now()));
		}
		persistenceManager.updateMessage(gmsg);
	}
}