/*
    * 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.message;
  
  import com.google.common.collect.Maps;
  
  import net.anyflow.lannister.cluster.ClusterDataFactory;
  import net.anyflow.lannister.cluster.Map;
  
  public class MessageReferenceCounts {
  	private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(MessageReferenceCounts.class);
  
  	public static final MessageReferenceCounts INSTANCE = new MessageReferenceCounts();
  
  	private final Map<String, Integer> data; // key : message.key()
  
  	private MessageReferenceCounts() {
  		this.data = ClusterDataFactory.INSTANCE.createMap("MessagesReferenceCounts_data");
  	}
  
  	public java.util.Map<String, Integer> data() {
  		java.util.Map<String, Integer> ret = Maps.newHashMap();
  		data.keySet().stream().forEach(k -> ret.put(k, data.get(k)));
  
  		return ret;
  	}
  
  	public void retain(String messageKey) {
  		Integer count = data.get(messageKey);
  		if (count == null) {
  			count = 0;
  		}
  
  		data.put(messageKey, ++count);
  		logger.debug("RETAINed message reference [count={}, messageKey={}]", count, messageKey);
  	}
  
  	public void release(String messageKey) {
  		Integer count = data.get(messageKey);
  		if (count == null) { return; }
  
  		if (count <= 0) {
  			logger.error("Invalid Message reference Found![key={}, count={}]", messageKey, count);
  			return;
  		}
  		else if (count == 1) {
  			data.remove(messageKey);
  			logger.debug("REMOVEed Message reference [key={}]", messageKey);
  
  			Message.NEXUS.remove(messageKey);
  		}
  		else {
  			data.put(messageKey, --count);
  			logger.debug("RELEASEed Message reference [key={}, count={}]", messageKey, count);
  		}
  	}
  
  	public int size() {
  		return data.size();
  	}
  }