/*
 * Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hazelcast.map.impl.querycache;

import com.hazelcast.map.impl.ListenerAdapter;
import com.hazelcast.map.listener.MapListener;
import com.hazelcast.spi.EventFilter;


/**
 * Event service abstraction to allow different type of implementations
 * on query cache subscriber and query cache publisher sides. Runs locally on query-cache
 * subscriber side which may be node or client. Responsible for registering/removing listeners
 * and publishing events locally etc.
 *
 * @param <E> type of event to be published.
 */
public interface QueryCacheEventService<E> {

    /**
     * Publishes query-cache events locally.
     *
     * @param mapName   underlying map name of query cache.
     * @param cacheName name of the query cache.
     * @param event     event to publish.
     * @param orderKey  use same order key for events which are required to be ordered.
     */
    void publish(String mapName, String cacheName, E event, int orderKey);

    /**
     * Adds the listener to listen underlying IMap on all nodes.
     *
     * @param mapName         underlying map name of query cache.
     * @param cacheName       name of the query cache.
     * @param listenerAdapter listener adapter for the query-cache.
     * @return id of registered event listener
     */
    String listenPublisher(String mapName, String cacheName, ListenerAdapter listenerAdapter);

    /**
     * Removes listener from underlying IMap
     *
     * @param mapName    underlying map name which query cache listens.
     * @param listenerId id of registered listener
     * @return {@code true} if listener is de-registered, {@code false} otherwise.
     */
    boolean removePublisherListener(String mapName, String listenerId);

    /**
     * Adds a user-defined listener to a query-cache. This listener is registered as a local listener
     * on subscriber side.
     *
     * @param mapName   underlying IMap name of query-cache.
     * @param cacheName name of the query-cache.
     * @param listener  listener for receiving events.
     * @return id of registered event listener
     */
    String addListener(String mapName, String cacheName, MapListener listener);

    /**
     * Adds a user-defined listener to a query-cache. This listener is registered as a local listener
     * on subscriber side.
     *
     * @param mapName   underlying IMap name of query-cache.
     * @param cacheName name of the query-cache.
     * @param listener  listener for receiving events.
     * @param filter    used to filter events.
     * @return id of registered event listener
     */
    String addListener(String mapName, String cacheName, MapListener listener, EventFilter filter);

    /**
     * Removes listener from this event service.
     *
     * @param mapName   underlying IMap name of query-cache.
     * @param cacheName name of the query cache.
     * @param id        id of listener.
     * @return {@code true} if listener is removed successfully, {@code false} otherwise.
     */
    boolean removeListener(String mapName, String cacheName, String id);

    /**
     * Returns {@code true} if this query-cache has at least one registered listener otherwise returns {@code false}.
     *
     * @param mapName   underlying IMap name of query-cache.
     * @param cacheName name of the query-cache.
     * @return {@code true} if this query-cache has at least one registered listener otherwise returns {@code false}.
     */
    boolean hasListener(String mapName, String cacheName);

    /**
     * Only sends events which wrap data to be put in a query cache.
     *
     * @param name      listener name.
     * @param eventData the event data.
     * @param orderKey  the order key for the event.
     */
    void sendEventToSubscriber(String name, Object eventData, int orderKey);
}