/*
 * 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.implementation.data;

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.tuscany.sca.assembly.AssemblyFactory;
import org.apache.tuscany.sca.assembly.xml.Constants;
import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
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.data.engine.ConnectionInfoArtifactProcessor;
import org.apache.tuscany.sca.data.engine.config.ConnectionInfo;
import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceFactory;
import org.apache.tuscany.sca.monitor.Monitor;


/**
 * Implements a StAX artifact processor for DATA implementations.
 * 
 * The artifact processor is responsible for processing <implementation.data>
 * elements in SCA assembly XML composite files and populating the DATA
 * implementation model, resolving its references to other artifacts in the SCA
 * contribution, and optionally write the model back to SCA assembly XML.
 * 
 * @version $Rev$ $Date$
 */
public class DATAImplementationProcessor implements StAXArtifactProcessor<DATAImplementation> {
    protected static final QName IMPLEMENTATION_DATA_XML = new QName(Constants.SCA10_TUSCANY_NS, "implementation.data.xml");
    
    private DATAImplementationFactory dataFactory;
    private Monitor monitor;
    private StAXArtifactProcessor<ConnectionInfo> connectionInfoProcessor;
    
    public DATAImplementationProcessor(ModelFactoryExtensionPoint modelFactories, Monitor monitor) {
        AssemblyFactory assemblyFactory = modelFactories.getFactory(AssemblyFactory.class);
        JavaInterfaceFactory javaFactory = modelFactories.getFactory(JavaInterfaceFactory.class);
        this.monitor = monitor;
        this.dataFactory = new DATAImplementationFactory(assemblyFactory, javaFactory);        
        this.connectionInfoProcessor = new ConnectionInfoArtifactProcessor(modelFactories, this.monitor);        
    }

    public QName getArtifactType() {
        // Returns the qname of the XML element processed by this processor
        return IMPLEMENTATION_DATA_XML;
    }

    public Class<DATAImplementation> getModelType() {
        // Returns the type of model processed by this processor
        return DATAImplementation.class;
    }

    /*
     * <component name="CompanyDataComponent">
     *   <implementation.data.xml>
     *      <connectionInfo>
     *         <connectionProperties 
     *          driverClass="org.apache.derby.jdbc.EmbeddedDriver" 
     *          databaseURL="jdbc:derby:target/test-classes/dastest; create = true" 
     *          loginTimeout="600000"/>
     *      </connectionInfo>
     *   </implementation.data>
     * </component>
     */
    public DATAImplementation read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
        assert IMPLEMENTATION_DATA_XML.equals(reader.getName());

        // Read an <implementation.data.xml> element

        // Create an initialize the DAS implementation model
        DATAImplementation implementation = dataFactory.createDASImplementation();

        while (true) {
            int event = reader.next();
            switch (event) {

            case START_ELEMENT:
                if (ConnectionInfoArtifactProcessor.CONNECTION_INFO.equals(reader.getName())) {
                    
                    // Read connection info
                    ConnectionInfo connectionInfo = (ConnectionInfo) connectionInfoProcessor.read(reader);
                    implementation.setConnectionInfo(connectionInfo);
                }
                break;
            case XMLStreamConstants.END_ELEMENT:
                if (IMPLEMENTATION_DATA_XML.equals(reader.getName())) {
                    return implementation;
                }                    
                break;
            }
        }

    }

    public void resolve(DATAImplementation impl, ModelResolver resolver) throws ContributionResolveException {
    }

    public void write(DATAImplementation implementation, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
        writer.writeStartElement(IMPLEMENTATION_DATA_XML.getNamespaceURI(), IMPLEMENTATION_DATA_XML.getLocalPart());
                
        if (implementation.getConnectionInfo() != null) { 
            connectionInfoProcessor.write(implementation.getConnectionInfo(), writer);
        }
        
        writer.writeEndElement();
    }
}