/*
 * 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.tuscany.sca.policy.xml.ws;

import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNamespace;
import org.apache.neethi.PolicyEngine;
import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
import org.apache.tuscany.sca.contribution.processor.BaseStAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
import org.apache.tuscany.sca.contribution.service.ContributionReadException;
import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
import org.apache.tuscany.sca.monitor.Monitor;
import org.apache.tuscany.sca.policy.xml.PolicyConstants;


/**
 * Processor for handling xml models of PolicySet definitions
 *
 * @version $Rev$ $Date$
 */
public class WSPolicyProcessor extends BaseStAXArtifactProcessor implements StAXArtifactProcessor<org.apache.neethi.Policy>, PolicyConstants {
	public final static String WS_POLICY_NS = "http://schemas.xmlsoap.org/ws/2004/09/policy";
	public final static String WS_POLICY = "Policy";
	
    public final static QName WS_POLICY_QNAME =new QName(WS_POLICY_NS, WS_POLICY);

    public WSPolicyProcessor() {
    	//System.out.println(">>>Initializing WSPolicyProcessor");
    }
    
    public WSPolicyProcessor(ModelFactoryExtensionPoint modelFactories, Monitor monitor) {
    	//System.out.println(">>>Initializing WSPolicyProcessor");
    }
    
    public QName getArtifactType() {
        return WS_POLICY_QNAME;
    }
    
    public Class<org.apache.neethi.Policy> getModelType() {
        return org.apache.neethi.Policy.class;
    }

    public org.apache.neethi.Policy read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
		org.apache.neethi.Policy wsPolicy = null;

		int event = reader.getEventType();
		if (event == START_ELEMENT) {
			QName name = reader.getName();
			if (WS_POLICY_QNAME.equals(name)) {
				OMElement policyElement = loadElement(reader);
				wsPolicy = PolicyEngine.getPolicy(policyElement);
			}
		}
		return wsPolicy;
    }
        
    public void write(org.apache.neethi.Policy wsPolicy, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {

        // Write an <sca:policySet>
        writer.writeStartElement(WS_POLICY_NS, WS_POLICY);
       
        //FIXME write proper ws-policy stuff here
       
        writer.writeEndElement();
    }

    public void resolve(org.apache.neethi.Policy wsPolicy, ModelResolver resolver) throws ContributionResolveException {

    }   

       
    private OMElement loadElement(XMLStreamReader reader) throws XMLStreamException {
        OMFactory fac = OMAbstractFactory.getOMFactory();
        OMElement head = fac.createOMElement(reader.getName());
        OMElement current = head;
        
        while (true) {
            switch (reader.next()) {
                case XMLStreamConstants.START_ELEMENT:
                    QName name = reader.getName();
                    OMElement child = fac.createOMElement(name, current);

                    int count = reader.getNamespaceCount();
                    for (int i = 0; i < count; i++) {
                        String prefix = reader.getNamespacePrefix(i);
                        String ns = reader.getNamespaceURI(i);
                        child.declareNamespace(ns, prefix);
                    }

                    if(!"".equals(name.getNamespaceURI())) {
                        child.declareNamespace(name.getNamespaceURI(), name.getPrefix());
                    }

                    // add the attributes for this element
                    count = reader.getAttributeCount();
                    for (int i = 0; i < count; i++) {
                        OMNamespace omNs = null;
                        String ns = reader.getAttributeNamespace(i);
                        String prefix = reader.getAttributePrefix(i);
                        String qname = reader.getAttributeLocalName(i);
                        String value = reader.getAttributeValue(i);
                        
                        if ( ns != null ) {
                            omNs = fac.createOMNamespace(ns, prefix);
                        }
                            
                        child.addAttribute(qname, value, omNs);
                        if (ns != null) {
                            child.declareNamespace(ns, prefix);
                        }
                    }
                    current = child;
                    break;
                case XMLStreamConstants.CDATA:
                    fac.createOMText(current, reader.getText());
                    break;
                case XMLStreamConstants.CHARACTERS:
                    fac.createOMText(current, reader.getText());
                    break;
                case XMLStreamConstants.END_ELEMENT:
                    if ( current == head ) {
                        return head;
                    } else {
                        current = (OMElement)current.getParent();
                    }
            }
        }
    }
    

 }