/*
 * This is eMonocot, a global online biodiversity information resource.
 *
 * Copyright © 2011–2015 The Board of Trustees of the Royal Botanic Gardens, Kew and The University of Oxford
 *
 * eMonocot is free software: you can redistribute it and/or modify it under the terms of the
 * GNU Affero General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * eMonocot is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * The complete text of the GNU Affero General Public License is in the source repository as the file
 * ‘COPYING’.  It is also available from <http://www.gnu.org/licenses/>.
 */
package org.emonocot.harvest.integration;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.integration.Message;
import org.springframework.integration.message.GenericMessage;
import org.springframework.integration.splitter.AbstractMessageSplitter;

/**
 * @author jk00kg
 *
 */
public class HeaderCollectionSplitter extends AbstractMessageSplitter {

	/**
	 * There is the strong and unverified assumption that this key has a Itrable header value
	 */
	private String requestKey;

	/**
	 *
	 */
	private String responseKey;

	/**
	 * @param requestKey the requestKey to set
	 */
	public void setRequestKey(String requestKey) {
		this.requestKey = requestKey;
	}

	/**
	 * @param responseKey the responseKey to set
	 */
	public void setResponseKey(String responseKey) {
		this.responseKey = responseKey;
	}

	/*
	 * Splits a 'request' message, preserving the payload and all headers other than that named by the requestKey.
	 * A message header containing the object from the Iterable can be added to a header on the 'response' message by setting the responseKey
	 * @return A list of messages, one for each of the objects in the specified message header
	 */
	@Override
	protected List<Message<Object>> splitMessage(Message<?> message) {
		List<Message<Object>> split = new ArrayList<Message<Object>>();
		Message<Object> m;
		for(Object o : (Iterable) message.getHeaders().get(requestKey)) {
			Map<String, Object> newHeaders = new HashMap<String, Object>();
			newHeaders.putAll(message.getHeaders());
			if(responseKey != null) {
				newHeaders.put(responseKey, o);
			}
			m = new GenericMessage<Object>(message.getPayload(), newHeaders);
			split.add(m);
		}
		return split;
	}

}