/*
    * Copyright 2016 The Lannister Project
    * 
    * 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 net.anyflow.lannister.cluster;
  
  import java.util.Date;
  import java.util.Map;
  import java.util.UUID;
  
  import com.google.common.collect.Maps;
  import com.hazelcast.core.ITopic;
  import com.hazelcast.core.Message;
  import com.hazelcast.core.MessageListener;
  import com.hazelcast.monitor.LocalTopicStats;
  
  import io.netty.util.concurrent.GlobalEventExecutor;
  
  public class SingleTopic<E> implements ITopic<E> {
  
  	private final String name;
  	private final Map<String, MessageListener<E>> messageListeners;
  
  	public SingleTopic(String name) {
  		this.name = name;
  		this.messageListeners = Maps.newConcurrentMap();
  	}
  
  	@Override
  	public void destroy() {
  		// DO NOTHING
  	}
  
  	@Override
  	public String getName() {
  		return name;
  	}
  
  	@Override
  	public void publish(E message) {
  		final Date now = new Date();
  
  		GlobalEventExecutor.INSTANCE.execute(() -> {
  			Message<E> msg = new Message<E>(name, message, now.getTime(), null);
  			messageListeners.values().forEach(c -> c.onMessage(msg));
  		});
  	}
  
  	@Override
  	public String addMessageListener(MessageListener<E> listener) {
  		UUID ret = UUID.randomUUID();
  
  		messageListeners.put(ret.toString(), listener);
  
  		return ret.toString();
  	}
  
  	@Override
  	public boolean removeMessageListener(String registrationId) {
  		return messageListeners.remove(registrationId) != null;
  	}
  
  	@Override
  	public String getPartitionKey() {
  		throw new Error("The method should not be called");
  	}
  
  	@Override
  	public String getServiceName() {
  		throw new Error("The method should not be called");
  	}
  
  	@Override
  	public LocalTopicStats getLocalTopicStats() {
  		throw new Error("The method should not be called");
  	}
  }