/* 
 * Copyright (c) 2006 Stiftung Deutsches Elektronen-Synchroton, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
package org.csstudio.sds.internal.persistence;

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

import org.jdom.Element;

/**
 * Persistence handler for the property type <code>sds.map</code>.
 * 
 * @author Kai Meyer
 * 
 */
public final class StringMapPropertyPersistenceHandler extends
		AbstractPropertyPersistenceHandler {

	/**
	 * XML tag name <code>map</code>.
	 */
	public static final String XML_ELEMENT_MAP = "map"; //$NON-NLS-1$

	/**
	 * XML tag name <code>mapEntry</code>.
	 */
	public static final String XML_ELEMENT_MAP_ENTRY = "mapEntry"; //$NON-NLS-1$

	/**
	 * XML attribute name <code>name</code>.
	 */
	public static final String XML_ATTRIBUTE_NAME = "name"; //$NON-NLS-1$

	/**
	 * XML attribute name <code>value</code>.
	 */
	public static final String XML_ATTRIBUTE_VALUE = "value"; //$NON-NLS-1$

	/**
	 * {@inheritDoc}
	 */
	@SuppressWarnings("unchecked")
	@Override
	public void writeProperty(final Element domElement,
			final Object propertyValue) {
		Map<String, String> aliases = (Map<String, String>) propertyValue;
		List<String> aliasKeys = new ArrayList<String>(aliases.keySet());
		Collections.sort(aliasKeys);

		Element mapElement = new Element(XML_ELEMENT_MAP);
		for (String key : aliasKeys) {
			Element mapEntryElement = new Element(XML_ELEMENT_MAP_ENTRY);
			mapEntryElement.setAttribute(XML_ATTRIBUTE_NAME, key); //$NON-NLS-1$
			mapEntryElement.setAttribute(XML_ATTRIBUTE_VALUE, aliases.get(key)); //$NON-NLS-1$
			mapElement.addContent(mapEntryElement);
		}

		domElement.addContent(mapElement);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Object readProperty(final Element domElement) {
		Element mapElement = domElement.getChild(XML_ELEMENT_MAP);

		Map<String, String> result = new HashMap<String, String>();

		for (Object o : mapElement.getChildren(XML_ELEMENT_MAP_ENTRY)) {
			Element mapEntryElement = (Element) o;

			String name = mapEntryElement.getAttributeValue(XML_ATTRIBUTE_NAME);
			String value = mapEntryElement.getAttributeValue(XML_ATTRIBUTE_VALUE);

			result.put(name, value);
		}

		return result;
	}
}