/**
 *        CloudGraph Community Edition (CE) License
 * 
 * This is a community release of CloudGraph, a dual-license suite of
 * Service Data Object (SDO) 2.1 services designed for relational and 
 * big-table style "cloud" databases, such as HBase and others. 
 * This particular copy of the software is released under the 
 * version 2 of the GNU General Public License. CloudGraph was developed by 
 * TerraMeta Software, Inc.
 * 
 * Copyright (c) 2013, TerraMeta Software, Inc. All rights reserved.
 * 
 * General License information can be found below.
 * 
 * This distribution may include materials developed by third
 * parties. For license and attribution notices for these
 * materials, please refer to the documentation that accompanies
 * this distribution (see the "Licenses for Third-Party Components"
 * appendix) or view the online documentation at 
 * <http://cloudgraph.org/licenses/>. 
 */
package org.cloudgraph.state;

import java.io.InputStream;
import java.io.OutputStream;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.plasma.common.bind.ValidatingUnmarshaler;
import org.xml.sax.SAXException;

/**
 * State JAXB Binding delegate. It is crucial that this binding be cached by
 * service implementations at the appropriate level to 1.) guarantee
 * thread safety (this class is NOT thread safe) and 2.) re-use the
 * underlying JAXB context and parsed schema instance(s) across as many
 * requests as possible.   
 *  
 * @author Scott Cinnamond
 * @since 0.5.2
 */
public class StateValidatingDataBinding implements ValidatingDataBinding {

    private static Log log = LogFactory.getLog(StateValidatingDataBinding.class);
    public static String FILENAME_SCHEMA_CHAIN_ROOT = "cloudgraph-state.xsd";

    public static Class<?> RESOURCE_CLASS = StateValidatingDataBinding.class;

    private ValidatingUnmarshaler unmarshaler;

    public static Class<?>[] FACTORIES = { org.cloudgraph.state.ObjectFactory.class, };
        
    public StateValidatingDataBinding()
            throws JAXBException, SAXException {
        log.info("loading schema chain...(note: this is expensive - cache this binding where possible)");
        InputStream stream = RESOURCE_CLASS.getResourceAsStream(FILENAME_SCHEMA_CHAIN_ROOT);
        if (stream == null)
            stream = RESOURCE_CLASS.getClassLoader().getResourceAsStream(FILENAME_SCHEMA_CHAIN_ROOT);
        if (stream == null)
            throw new StateException("could not find configuration file schema resource '" 
                    + FILENAME_SCHEMA_CHAIN_ROOT 
                    + "' on the current classpath");        
        this.unmarshaler = new ValidatingUnmarshaler(stream, 
        	JAXBContext.newInstance(FACTORIES), 
        	new StateValidationEventHandler());
    }

    public Class<?>[] getObjectFactories() {
        return FACTORIES;
    }

    /* (non-Javadoc)
	 * @see org.cloudgraph.state.ValidatingDataBinding#marshal(java.lang.Object)
	 */
    @Override
	public String marshal(Object root) throws JAXBException {
    	
        return unmarshaler.marshal(root);
    }

    /* (non-Javadoc)
	 * @see org.cloudgraph.state.ValidatingDataBinding#marshal(java.lang.Object, java.io.OutputStream)
	 */
    @Override
	public void marshal(Object root, OutputStream stream) throws JAXBException {
        unmarshaler.marshal(root, stream);
    }
    
    /* (non-Javadoc)
	 * @see org.cloudgraph.state.ValidatingDataBinding#marshal(java.lang.Object, java.io.OutputStream, boolean)
	 */
    @Override
	public void marshal(Object root, OutputStream stream, boolean formattedOutput) throws JAXBException
    {
    	unmarshaler.marshal(root, stream, formattedOutput);
    }
    
    /* (non-Javadoc)
	 * @see org.cloudgraph.state.ValidatingDataBinding#validate(java.lang.String)
	 */
    @Override
	public Object validate(String xml) throws JAXBException {
        return unmarshaler.validate(xml);
    }

    /* (non-Javadoc)
	 * @see org.cloudgraph.state.ValidatingDataBinding#validate(java.io.InputStream)
	 */
    @Override
	public Object validate(InputStream stream) throws JAXBException {
        return unmarshaler.validate(stream);
    }
}