/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.apache.synapse.config.xml.endpoints;

import org.apache.axiom.om.OMAttribute;
import org.apache.axiom.om.OMElement;
import org.apache.synapse.SynapseConstants;
import org.apache.synapse.commons.util.PropertyHelper;
import org.apache.synapse.config.xml.XMLConfigConstants;
import org.apache.synapse.endpoints.ClassEndpoint;
import org.apache.synapse.endpoints.Endpoint;

import javax.xml.namespace.QName;
import java.lang.reflect.InvocationTargetException;
import java.util.Iterator;
import java.util.Properties;

/**
 * This EndpointFactory will be used as an extension point for defining Endpoints externally.
 * <p/>
 * The endpoint configuration will look similar to the one shown below;
 * <p/>
 * <endpoint name="testEndpoint">
 * <class name="org.apache.synapse.ext.endpoints.TestEndpoint">
 * <parameter/>*
 * </class>
 * </endpoint>
 */
public class ClassEndpointFactory extends EndpointFactory {
	
	    private static ClassEndpointFactory instance = new ClassEndpointFactory();
	    public static final QName CLASS_QNAME = new QName(SynapseConstants.SYNAPSE_NAMESPACE,
	                                                      "class");
	    public static final QName NAME_QNAME = new QName("name");
	    public static final QName PARAMETER_QNAME = new QName("parameter");
	
	    private ClassEndpointFactory() {
	    }
	
	    public static ClassEndpointFactory getInstance() {
	        return instance;
	    }
	
	    protected Endpoint createEndpoint(OMElement epConfig,
	                                      boolean anonymousEndpoint,
	                                      Properties properties) {
	    	
	    	ClassEndpoint clazzEndpoint = new ClassEndpoint();
	    	OMAttribute endpointName =  epConfig.getAttribute(new QName(XMLConfigConstants.NULL_NAMESPACE,
		                                                   "name"));

			if (endpointName != null) {
				clazzEndpoint.setName(endpointName.getAttributeValue());
			}
			
	        OMElement classElement =  epConfig.getFirstChildWithName(CLASS_QNAME);
	        if (classElement == null) {
	            return null;
	        }
	
	        String nameAttr = classElement.getAttributeValue(NAME_QNAME);
	        if (nameAttr == null) {
	            return null;
	        }
	
	        Endpoint endpoint = null;
	        try {
	            Class clazz = Class.forName(nameAttr);
	            endpoint = (Endpoint) clazz.newInstance();
	            for (Iterator iter = classElement.getChildrenWithName(PARAMETER_QNAME);
	                 iter.hasNext(); ) {
	                OMElement paramEle = (OMElement) iter.next();
	                setParameter(endpoint, paramEle,clazzEndpoint);
	            }
	        } catch (Exception e) {
	            handleException("Cannot create class endpoint", e);
	        }
	        clazzEndpoint.setClassEndpoint(endpoint);
	        return clazzEndpoint;
	    }
	
	    private void setParameter(Endpoint endpoint, OMElement paramEle,ClassEndpoint clazzEndpoint) throws IllegalAccessException,
	                                                                            InvocationTargetException,
	                                                                            NoSuchMethodException {
	        String name = paramEle.getAttributeValue(new QName("name"));
	        String value = paramEle.getText();
	        if (name !=null) {
	            PropertyHelper.setInstanceProperty(name, value, endpoint);
	            clazzEndpoint.setParameters(name, value);
            }
	    }
}