/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * The contents of this file are subject to the terms of the Liferay Enterprise
 * Subscription License ("License"). You may not use this file except in
 * compliance with the License. You can obtain a copy of the License by
 * contacting Liferay, Inc. See the License for the specific language governing
 * permissions and limitations under the License, including but not limited to
 * distribution rights of the Software.
 *
 *
 *
 */

package com.liferay.portal.kernel.messaging.config;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.messaging.Destination;
import com.liferay.portal.kernel.messaging.DestinationConfiguration;
import com.liferay.portal.kernel.messaging.DestinationEventListener;
import com.liferay.portal.kernel.messaging.DestinationFactory;
import com.liferay.portal.kernel.messaging.DestinationFactoryUtil;
import com.liferay.portal.kernel.messaging.MessageBus;
import com.liferay.portal.kernel.messaging.MessageBusEventListener;
import com.liferay.portal.kernel.messaging.MessageListener;
import com.liferay.portal.kernel.security.pacl.permission.PortalMessageBusPermission;
import com.liferay.portal.kernel.servlet.ServletContextClassLoaderPool;
import com.liferay.portal.kernel.util.StringBundler;
import com.liferay.registry.Filter;
import com.liferay.registry.Registry;
import com.liferay.registry.RegistryUtil;
import com.liferay.registry.ServiceReference;
import com.liferay.registry.ServiceRegistrar;
import com.liferay.registry.dependency.ServiceDependencyListener;
import com.liferay.registry.dependency.ServiceDependencyManager;

import java.lang.reflect.Method;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * @author Michael C. Han
 */
public abstract class AbstractMessagingConfigurator
	implements MessagingConfigurator {

	public void afterPropertiesSet() {
		final ServiceDependencyManager serviceDependencyManager =
			new ServiceDependencyManager();

		serviceDependencyManager.addServiceDependencyListener(
			new ServiceDependencyListener() {

				@Override
				public void dependenciesFulfilled() {
					Registry registry = RegistryUtil.getRegistry();

					_serviceReference = registry.getServiceReference(
						MessageBus.class);

					_messageBus = registry.getService(_serviceReference);

					initialize();
				}

				@Override
				public void destroy() {
					if (_serviceReference != null) {
						Registry registry = RegistryUtil.getRegistry();

						registry.ungetService(_serviceReference);
					}
				}

				private ServiceReference<MessageBus> _serviceReference;

			});

		serviceDependencyManager.registerDependencies(
			DestinationFactory.class, MessageBus.class);
	}

	@Override
	public void connect() {
		Registry registry = RegistryUtil.getRegistry();

		_messageListenerServiceRegistrar = registry.getServiceRegistrar(
			MessageListener.class);

		Thread currentThread = Thread.currentThread();

		ClassLoader contextClassLoader = currentThread.getContextClassLoader();

		try {
			ClassLoader operatingClassLoader = getOperatingClassloader();

			currentThread.setContextClassLoader(operatingClassLoader);

			for (Map.Entry<String, List<MessageListener>> messageListeners :
					_messageListeners.entrySet()) {

				String destinationName = messageListeners.getKey();

				ServiceDependencyManager serviceDependencyManager =
					new ServiceDependencyManager();

				serviceDependencyManager.addServiceDependencyListener(
					new DestinationServiceDependencyListener(
						destinationName, messageListeners.getValue()));

				Filter filter = registry.getFilter(
					StringBundler.concat(
						"(&(destination.name=", destinationName,
						")(objectClass=", Destination.class.getName(), "))"));

				serviceDependencyManager.registerDependencies(filter);
			}
		}
		finally {
			currentThread.setContextClassLoader(contextClassLoader);
		}
	}

	@Override
	public void destroy() {
		if (_messageListenerServiceRegistrar != null) {
			_messageListenerServiceRegistrar.destroy();
		}

		if (_destinationEventListenerServiceRegistrar != null) {
			_destinationEventListenerServiceRegistrar.destroy();
		}

		if (_destinationServiceRegistrar != null) {
			_destinationServiceRegistrar.destroy();
		}

		if (_messageBusEventListenerServiceRegistrar != null) {
			_messageBusEventListenerServiceRegistrar.destroy();
		}

		_destinationConfigurations.clear();
		_destinationEventListeners.clear();
		_messageListeners.clear();

		for (Destination destination : _destinations) {
			destination.destroy();
		}

		_destinations.clear();
		_messageBusEventListeners.clear();

		ClassLoader operatingClassLoader = getOperatingClassloader();

		String servletContextName =
			ServletContextClassLoaderPool.getServletContextName(
				operatingClassLoader);

 		if (servletContextName != null) {
			MessagingConfiguratorRegistry.unregisterMessagingConfigurator(
				servletContextName, this);
 		}
	}

	@Override
	public void disconnect() {
		for (Map.Entry<String, List<MessageListener>> messageListeners :
				_messageListeners.entrySet()) {

			String destinationName = messageListeners.getKey();

			for (MessageListener messageListener :
					messageListeners.getValue()) {

				_messageBus.unregisterMessageListener(
					destinationName, messageListener);
			}
		}
	}

	@Override
	public void setDestinationConfigurations(
		Set<DestinationConfiguration> destinationConfigurations) {

		_destinationConfigurations.addAll(destinationConfigurations);
	}

	@Override
	public void setDestinationEventListeners(
		Map<String, List<DestinationEventListener>> destinationEventListeners) {

		_destinationEventListeners.putAll(destinationEventListeners);
	}

	@Override
	public void setDestinations(List<Destination> destinations) {
		_destinations.addAll(destinations);
	}

	@Override
	public void setMessageBusEventListeners(
		List<MessageBusEventListener> messageBusEventListeners) {

		_messageBusEventListeners.addAll(messageBusEventListeners);
	}

	@Override
	public void setMessageListeners(
		Map<String, List<MessageListener>> messageListeners) {

		for (List<MessageListener> messageListenersList :
				messageListeners.values()) {

			for (MessageListener messageListener : messageListenersList) {
				Class<?> messageListenerClass = messageListener.getClass();

				try {
					Method setMessageBusMethod = messageListenerClass.getMethod(
						"setMessageBus", MessageBus.class);

					setMessageBusMethod.setAccessible(true);

					setMessageBusMethod.invoke(messageListener, _messageBus);

					continue;
				}
				catch (Exception e) {
				}

				try {
					Method setMessageBusMethod =
						messageListenerClass.getDeclaredMethod(
							"setMessageBus", MessageBus.class);

					setMessageBusMethod.setAccessible(true);

					setMessageBusMethod.invoke(messageListener, _messageBus);
				}
				catch (Exception e) {
				}
			}
		}

		_messageListeners.putAll(messageListeners);
	}

	/**
	 * @param      replacementDestinations
	 * @deprecated As of Wilberforce (7.0.x), replaced by {@link
	 *             #setDestinations(List)}
	 */
	@Deprecated
	@Override
	public void setReplacementDestinations(
		List<Destination> replacementDestinations) {

		_destinations.addAll(replacementDestinations);
	}

	protected abstract ClassLoader getOperatingClassloader();

	protected void initialize() {
		Thread currentThread = Thread.currentThread();

		ClassLoader contextClassLoader = currentThread.getContextClassLoader();

		ClassLoader operatingClassLoader = getOperatingClassloader();

		if (contextClassLoader == operatingClassLoader) {
			_portalMessagingConfigurator = true;
		}

		registerMessageBusEventListeners();

		registerDestinations();

		registerDestinationEventListeners();

		connect();

		String servletContextName =
			ServletContextClassLoaderPool.getServletContextName(
				operatingClassLoader);

		if (servletContextName != null) {
			MessagingConfiguratorRegistry.unregisterMessagingConfigurator(
				servletContextName, this);
		}
	}

	protected void registerDestinationEventListeners() {
		if (_destinationEventListeners.isEmpty()) {
			return;
		}

		Registry registry = RegistryUtil.getRegistry();

		_destinationEventListenerServiceRegistrar =
			registry.getServiceRegistrar(DestinationEventListener.class);

		for (final Map.Entry<String, List<DestinationEventListener>> entry :
				_destinationEventListeners.entrySet()) {

			final String destinationName = entry.getKey();

			ServiceDependencyManager serviceDependencyManager =
				new ServiceDependencyManager();

			serviceDependencyManager.addServiceDependencyListener(
				new ServiceDependencyListener() {

					@Override
					public void dependenciesFulfilled() {
						Map<String, Object> properties = new HashMap<>();

						properties.put("destination.name", destinationName);

						for (DestinationEventListener destinationEventListener :
								entry.getValue()) {

							_destinationEventListenerServiceRegistrar.
								registerService(
									DestinationEventListener.class,
									destinationEventListener, properties);
						}
					}

					@Override
					public void destroy() {
					}

				});

			Filter filter = registry.getFilter(
				StringBundler.concat(
					"(&(destination.name=", destinationName, ")(objectClass=",
					Destination.class.getName(), "))"));

			serviceDependencyManager.registerDependencies(filter);
		}
	}

	protected void registerDestinations() {
		for (DestinationConfiguration destinationConfiguration :
				_destinationConfigurations) {

			try {
				PortalMessageBusPermission.checkListen(
					destinationConfiguration.getDestinationName());
			}
			catch (SecurityException se) {
				if (_log.isInfoEnabled()) {
					_log.info(
						"Rejecting destination " +
							destinationConfiguration.getDestinationName());
				}

				continue;
			}

			_destinations.add(
				DestinationFactoryUtil.createDestination(
					destinationConfiguration));
		}

		if (_destinations.isEmpty()) {
			return;
		}

		Registry registry = RegistryUtil.getRegistry();

		_destinationServiceRegistrar = registry.getServiceRegistrar(
			Destination.class);

		for (Destination destination : _destinations) {
			String destinationName = destination.getName();

			try {
				PortalMessageBusPermission.checkListen(destinationName);
			}
			catch (SecurityException se) {
				if (_log.isInfoEnabled()) {
					_log.info("Rejecting destination " + destinationName);
				}

				continue;
			}

			Map<String, Object> properties = new HashMap<>();

			properties.put("destination.name", destinationName);

			_destinationServiceRegistrar.registerService(
				Destination.class, destination, properties);
		}
	}

	protected void registerMessageBusEventListeners() {
		if (_messageBusEventListeners.isEmpty()) {
			return;
		}

		Registry registry = RegistryUtil.getRegistry();

		_messageBusEventListenerServiceRegistrar = registry.getServiceRegistrar(
			MessageBusEventListener.class);

		for (MessageBusEventListener messageBusEventListener :
				_messageBusEventListeners) {

			_messageBusEventListenerServiceRegistrar.registerService(
				MessageBusEventListener.class, messageBusEventListener);
		}
	}

	private static final Log _log = LogFactoryUtil.getLog(
		AbstractMessagingConfigurator.class);

	private final Set<DestinationConfiguration> _destinationConfigurations =
		new HashSet<>();
	private final Map<String, List<DestinationEventListener>>
		_destinationEventListeners = new HashMap<>();
	private ServiceRegistrar<DestinationEventListener>
		_destinationEventListenerServiceRegistrar;
	private final List<Destination> _destinations = new ArrayList<>();
	private ServiceRegistrar<Destination> _destinationServiceRegistrar;
	private volatile MessageBus _messageBus;
	private final List<MessageBusEventListener> _messageBusEventListeners =
		new ArrayList<>();
	private ServiceRegistrar<MessageBusEventListener>
		_messageBusEventListenerServiceRegistrar;
	private final Map<String, List<MessageListener>> _messageListeners =
		new HashMap<>();
	private ServiceRegistrar<MessageListener> _messageListenerServiceRegistrar;
	private boolean _portalMessagingConfigurator;

	private class DestinationServiceDependencyListener
		implements ServiceDependencyListener {

		public DestinationServiceDependencyListener(
			String destinationName, List<MessageListener> messageListeners) {

			_destinationName = destinationName;
			_messageListeners = messageListeners;
		}

		@Override
		public void dependenciesFulfilled() {
			ClassLoader operatingClassLoader = getOperatingClassloader();

			Map<String, Object> properties = new HashMap<>();

			properties.put("destination.name", _destinationName);
			properties.put(
				"message.listener.operating.class.loader",
				operatingClassLoader);

			for (MessageListener messageListener : _messageListeners) {
				_messageListenerServiceRegistrar.registerService(
					MessageListener.class, messageListener, properties);
			}
		}

		@Override
		public void destroy() {
		}

		private final String _destinationName;
		private final List<MessageListener> _messageListeners;

	}

}