/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.jbpm.jpdl.internal.convert.action;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.jbpm.jpdl.internal.convert.node.NodeConverterTypes;

/**
 * This originates from jbpm3 code base
 * It reads the "META-INF/action.converter.types.xml" configuration to load the class to convert 
 * Action elements
 */

public class ActionConverterTypes {

	public static Set<Class<? extends Action>> getActionTypes() {
		return actionNames.keySet();
	}

	public static Set<String> getActionNames() {
		return actionTypes.keySet();
	}

	public static Class<? extends Action> getActionType(String name) {
		return actionTypes.get(name);
	}

	public static String getActionName(Class<? extends Action> type) {
		return actionNames.get(type);
	}

	public static boolean hasActionName(String name) {
		return actionTypes.containsKey(name);
	}

	private static SAXReader reader = new SAXReader();
	static final Log log = LogFactory.getLog(ActionConverterTypes.class);
	static Map<String, Class<? extends Action>> actionTypes = initialiseActionTypes();
	static Map<Class<? extends Action>, String> actionNames = NodeConverterTypes.createInverseMapping(actionTypes);

	static Map<String, Class<? extends Action>> initialiseActionTypes() {
		Map<String, Class<? extends Action>> types = new HashMap<String, Class<? extends Action>>();

		InputStream actionTypesStream = ActionConverterTypes.class
				.getClassLoader().getResourceAsStream(
						"action.converter.types.xml");

		Element actionTypesElement = null;
		try {
			actionTypesElement = reader.read(actionTypesStream)
					.getRootElement();
		} catch (DocumentException e1) {
			log.error("Failed to parse the action.converter.types.xml", e1);
		}

		Iterator<?> actionTypeIterator = actionTypesElement
				.elementIterator("action-type");
		while (actionTypeIterator.hasNext()) {
			Element actionTypeElement = (Element) actionTypeIterator.next();

			String elementTag = actionTypeElement.attributeValue("element");
			String className = actionTypeElement.attributeValue("class");
			try {
				Class<?> actionClass = ActionConverterTypes.class.forName(className);
				types.put(elementTag, actionClass.asSubclass(Action.class));

			} catch (Exception e) {
				// NOTE that Error's are not caught because that might halt the
				// JVM and mask the original Error.
				if (log.isDebugEnabled()) {
					log.debug("action '" + elementTag
							+ "' will not be available. class '" + className
							+ "' couldn't be loaded");
				}
			}
		}
		return types;
	}

}