/**
 * 
 */
package cz.cuni.mff.peckam.java.origamist.services;

import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URL;

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

import cz.cuni.mff.peckam.java.origamist.exceptions.UnsupportedDataFormatException;
import cz.cuni.mff.peckam.java.origamist.files.Listing;
import cz.cuni.mff.peckam.java.origamist.files.ObjectFactory;
import cz.cuni.mff.peckam.java.origamist.jaxb.BindingsController;
import cz.cuni.mff.peckam.java.origamist.jaxb.BindingsManager;
import cz.cuni.mff.peckam.java.origamist.services.interfaces.ListingHandler;
import cz.cuni.mff.peckam.java.origamist.utils.URIAdapter;

/**
 * Handles loading and exporting a listing.xml file using JAXB.
 * 
 * @author Martin Pecka
 */
public class JAXBListingHandler extends Service implements ListingHandler
{

    /** The namespace of the newest schema. */
    public static final String LATEST_SCHEMA_NAMESPACE = "http://www.mff.cuni.cz/~peckam/java/origamist/files/v1";

    /** The listing to return. */
    protected Listing          listing                 = null;

    @Override
    public void export(Listing listing, File file) throws IOException, MarshalException, JAXBException
    {
        export(listing, file, null, null);
    }

    @Override
    public void export(Listing listing, File file, URI relativeBase, URI currentBase) throws IOException,
            MarshalException, JAXBException
    {
        if (!file.exists())
            file.createNewFile();
        if (!file.isFile())
            throw new IOException("Cannot save listing.xml in a directory or a non-file object: "
                    + file.getAbsolutePath() + ".");

        JAXBContext context = JAXBContext.newInstance("cz.cuni.mff.peckam.java.origamist.files.jaxb", getClass()
                .getClassLoader());
        Marshaller m = context.createMarshaller();

        // enable indenting and newline generation
        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        // make URLs in the listing relative to the location we save the listing to
        m.setAdapter(new URIAdapter());
        m.getAdapter(URIAdapter.class).setCurrentBase(currentBase);
        if (relativeBase == null) {
            m.getAdapter(URIAdapter.class).setRelativeBase(file.getParentFile().toURI());
        } else {
            m.getAdapter(URIAdapter.class).setRelativeBase(relativeBase);
        }

        // do the Java class->XML conversion
        m.marshal(new ObjectFactory().createListing(listing), file);
    }

    @Override
    public Listing load(final URL path) throws IOException, UnsupportedDataFormatException
    {
        try {
            BindingsManager manager = ServiceLocator.get(BindingsManager.class);
            BindingsController<Listing> controller = new BindingsController<Listing>(manager, LATEST_SCHEMA_NAMESPACE);
            return controller.unmarshal(new InputStreamReader(path.openStream(), "UTF8"));
        } catch (JAXBException e) {
            throw new UnsupportedDataFormatException();
        }
    }
}