/*
    * Copyright 2006-2007 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.repeat.context;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.springframework.batch.repeat.RepeatContext;
  
  public class RepeatContextSupport extends SynchronizedAttributeAccessor implements RepeatContext {
  
  	private RepeatContext parent;
  
  	private int count;
  
  	private volatile boolean completeOnly;
  
  	private volatile boolean terminateOnly;
  
  	private Map<String, Set<Runnable>> callbacks = new HashMap<String, Set<Runnable>>();
  
  	/**
  	 * Constructor for {@link RepeatContextSupport}. The parent can be null, but
  	 * should be set to the enclosing repeat context if there is one, e.g. if
  	 * this context is an inner loop.
  	 * @param parent
  	 */
  	public RepeatContextSupport(RepeatContext parent) {
  		super();
  		this.parent = parent;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.springframework.batch.repeat.RepeatContext#isCompleteOnly()
  	 */
      @Override
  	public boolean isCompleteOnly() {
  		return completeOnly;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.springframework.batch.repeat.RepeatContext#setCompleteOnly()
  	 */
      @Override
  	public void setCompleteOnly() {
  		completeOnly = true;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.springframework.batch.repeat.RepeatContext#isTerminateOnly()
  	 */
      @Override
  	public boolean isTerminateOnly() {
  		return terminateOnly;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.springframework.batch.repeat.RepeatContext#setTerminateOnly()
  	 */
      @Override
  	public void setTerminateOnly() {
  		terminateOnly = true;
  		setCompleteOnly();
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.springframework.batch.repeat.RepeatContext#getParent()
  	 */
      @Override
  	public RepeatContext getParent() {
  		return parent;
 	}
 
 	/**
 	 * Used by clients to increment the started count.
 	 */
 	public synchronized void increment() {
 		count++;
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see org.springframework.batch.repeat.RepeatContext#getStartedCount()
 	 */
     @Override
 	public synchronized int getStartedCount() {
 		return count;
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see
 	 * org.springframework.batch.repeat.RepeatContext#registerDestructionCallback
 	 * (java.lang.String, java.lang.Runnable)
 	 */
     @Override
 	public void registerDestructionCallback(String name, Runnable callback) {
 		synchronized (callbacks) {
 			Set<Runnable> set = callbacks.get(name);
 			if (set == null) {
 				set = new HashSet<Runnable>();
 				callbacks.put(name, set);
 			}
 			set.add(callback);
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see org.springframework.batch.repeat.RepeatContext#close()
 	 */
     @Override
 	public void close() {
 
 		List<RuntimeException> errors = new ArrayList<RuntimeException>();
 
 		Set<Map.Entry<String, Set<Runnable>>> copy;
 
 		synchronized (callbacks) {
 			copy = new HashSet<Map.Entry<String, Set<Runnable>>>(callbacks.entrySet());
 		}
 
 		for (Map.Entry<String, Set<Runnable>> entry : copy) {
 
 			for (Runnable callback : entry.getValue()) {
 				/*
 				 * Potentially we could check here if there is an attribute with
 				 * the given name - if it has been removed, maybe the callback
 				 * is invalid. On the other hand it is less surprising for the
 				 * callback register if it is always executed.
 				 */
 				if (callback != null) {
 					/*
 					 * The documentation of the interface says that these
 					 * callbacks must not throw exceptions, but we don't trust
 					 * them necessarily...
 					 */
 					try {
 						callback.run();
 					}
 					catch (RuntimeException t) {
 						errors.add(t);
 					}
 				}
 			}
 		}
 
 		if (errors.isEmpty()) {
 			return;
 		}
 
 		throw (RuntimeException) errors.get(0);
 	}
 
 }