/*
    * 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.plugin;
  
  public class DefaultSubscribeEventListener implements SubscribeEventListener {
  	@SuppressWarnings("unused")
  	private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory
  			.getLogger(DefaultSubscribeEventListener.class);
  
  	public static final DefaultSubscribeEventListener SHARED = new DefaultSubscribeEventListener();
  
  	@Override
  	public Plugin clone() {
  		return this;
  	}
  
  	@Override
  	public boolean allowSubscribe(SubscribeEventArgs args) {
  		return args.cleanSession()
  				|| args.topicSubscriptions().stream().filter(ts -> ts.topicFilter().startsWith("$SYS")).count() <= 0;
  	}
  }