/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2011, Geomatys
 *
 *    This library 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 library 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.
 */
package org.geotoolkit.csw.xml;

import java.io.File;
import java.io.InputStream;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.logging.Level;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.Source;

import org.apache.sis.util.logging.Logging;
import org.apache.sis.xml.MarshallerPool;

import org.opengis.metadata.citation.OnlineResource;

import org.w3c.dom.Node;
import org.xml.sax.InputSource;

/**
 * Utility class to unmarshall CSW capabilities object
 *
 * @author Mehdi Sidhoum (Geomatys)
 * @module
 */
public class CSWBindingUtilities {

    /**
     * Returns {@link AbstractCapabilities} object as a result of unmarshalling
     * from source object.
     *
     * @param source Object to unmarshal XML data from.
     * @return {@link AbstractCapabilities} instance which is the unmarshall result.
     * @throws JAXBException If any unexpected errors occur while unmarshalling.
     */
    public static AbstractCapabilities unmarshall(final Object source) throws JAXBException {

        MarshallerPool selectedPool = CSWMarshallerPool.getInstance();
        Unmarshaller unMarshaller = selectedPool.acquireUnmarshaller();
        AbstractCapabilities c = (AbstractCapabilities) unmarshall(source, unMarshaller);
        selectedPool.recycle(unMarshaller);
        return c;
    }

    /**
     * Unmarshal XML data from the specified source and return the resulting content tree.
     *
     * @param source object to unmarshall
     * @param unMarshaller {@link Unmarshaller} instance
     * @return the newly created root object of the java content tree.
     * @throws JAXBException  If any unexpected errors occur while unmarshalling
     * @throws IllegalArgumentException  If source object is not a valid class
     */
    private static final Object unmarshall(final Object source, final Unmarshaller unMarshaller)
            throws JAXBException, IllegalArgumentException {
        if (source instanceof File) {
            return unMarshaller.unmarshal((File) source);
        } else if (source instanceof InputSource) {
            return unMarshaller.unmarshal((InputSource) source);
        } else if (source instanceof InputStream) {
            return unMarshaller.unmarshal((InputStream) source);
        } else if (source instanceof Node) {
            return unMarshaller.unmarshal((Node) source);
        } else if (source instanceof Reader) {
            return unMarshaller.unmarshal((Reader) source);
        } else if (source instanceof Source) {
            return unMarshaller.unmarshal((Source) source);
        } else if (source instanceof URL) {
            return unMarshaller.unmarshal((URL) source);
        } else if (source instanceof XMLEventReader) {
            return unMarshaller.unmarshal((XMLEventReader) source);
        } else if (source instanceof XMLStreamReader) {
            return unMarshaller.unmarshal((XMLStreamReader) source);
        } else if (source instanceof OnlineResource) {
            final OnlineResource online = (OnlineResource) source;
            try {
                final URL url = online.getLinkage().toURL();
                return unMarshaller.unmarshal(url);
            } catch (MalformedURLException ex) {
                Logging.getLogger("org.geotoolkit.csw.xml").log(Level.WARNING, null, ex);
                return null;
            }

        } else {
            throw new IllegalArgumentException("Source object is not a valid class :" + source.getClass());
        }

    }
}