/*
    * Copyright 2006-2013 the original author or authors.
    *
    * 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 org.springframework.batch.core.listener;
  
  import java.util.Iterator;
  import java.util.List;
  
  import org.springframework.batch.core.ItemProcessListener;
  import org.springframework.core.Ordered;
  
  /**
   * @author Dave Syer
   *
   */
  public class CompositeItemProcessListener<T, S> implements ItemProcessListener<T, S> {
  
  	private OrderedComposite<ItemProcessListener<? super T, ? super S>> listeners = new OrderedComposite<ItemProcessListener<? super T, ? super S>>();
  
  	/**
  	 * Public setter for the listeners.
  	 *
  	 * @param itemReadListeners
  	 */
  	public void setListeners(List<? extends ItemProcessListener<? super T, ? super S>> itemReadListeners) {
  		this.listeners.setItems(itemReadListeners);
  	}
  
  	/**
  	 * Register additional listener.
  	 *
  	 * @param itemReaderListener
  	 */
  	public void register(ItemProcessListener<? super T, ? super S> itemReaderListener) {
  		listeners.add(itemReaderListener);
  	}
  
  	/**
  	 * Call the registered listeners in reverse order, respecting and
  	 * prioritising those that implement {@link Ordered}.
  	 * @see org.springframework.batch.core.ItemProcessListener#afterProcess(java.lang.Object,
  	 * java.lang.Object)
  	 */
  	@Override
  	public void afterProcess(T item, S result) {
  		for (Iterator<ItemProcessListener<? super T, ? super S>> iterator = listeners.reverse(); iterator.hasNext();) {
  			ItemProcessListener<? super T, ? super S> listener = iterator.next();
  			listener.afterProcess(item, result);
  		}
  	}
  
  	/**
  	 * Call the registered listeners in order, respecting and prioritising those
  	 * that implement {@link Ordered}.
  	 * @see org.springframework.batch.core.ItemProcessListener#beforeProcess(java.lang.Object)
  	 */
  	@Override
  	public void beforeProcess(T item) {
  		for (Iterator<ItemProcessListener<? super T, ? super S>> iterator = listeners.iterator(); iterator.hasNext();) {
  			ItemProcessListener<? super T, ? super S> listener = iterator.next();
  			listener.beforeProcess(item);
  		}
  	}
  
  	/**
  	 * Call the registered listeners in reverse order, respecting and
  	 * prioritising those that implement {@link Ordered}.
  	 * @see org.springframework.batch.core.ItemProcessListener#onProcessError(java.lang.Object,
  	 * java.lang.Exception)
  	 */
  	@Override
  	public void onProcessError(T item, Exception e) {
  		for (Iterator<ItemProcessListener<? super T, ? super S>> iterator = listeners.reverse(); iterator.hasNext();) {
  			ItemProcessListener<? super T, ? super S> listener = iterator.next();
  			listener.onProcessError(item, e);
  		}
  	}
  
  }