/*
 * AnimalXmlSerializer.java
 *
 * Created on: 08-Apr-2010
 *
 */

package netukar.animalia.rest.xml;

import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import netukar.animalia.Animal;
import netukar.animalia.rest.AnimalSerializer;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 *
 * @author Radovan Netuka
 */
public class AnimalXmlSerializer implements AnimalSerializer {

    private Animal animal;


    /**
     * Creates a new instance of AnimalXmlSerializer.
     */
    public AnimalXmlSerializer() {

    }


    public void setAnimal(Animal animal) {
        if (animal == null) {
            throw new IllegalArgumentException("Parameter animal cannot be null");
        }
        this.animal = animal;
    }
    
    @Override
    public String toString() {
        if (animal == null) {
            throw new IllegalStateException("No animal has been set");
        }
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.newDocument();

            Element animalElement = document.createElement("animal");
            document.appendChild(animalElement);

            Element genus = document.createElement("genus");
            genus.setTextContent(animal.getGenus());
            animalElement.appendChild(genus);

            Element species = document.createElement("species");
            species.setTextContent(animal.getSpecies());
            animalElement.appendChild(species);

            Transformer transformer = TransformerFactory.newInstance().newTransformer();
            transformer.setOutputProperty(OutputKeys.METHOD, "xml");
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");

            StringWriter writer = new StringWriter();
            StreamResult result = new StreamResult(writer);
            DOMSource source = new DOMSource(document);
            transformer.transform(source, result);

            return writer.toString();
        }
        catch (ParserConfigurationException ex) {
            throw new RuntimeException(ex);
        }
        catch (TransformerConfigurationException ex) {
            throw new RuntimeException(ex);
        }
        catch (TransformerException ex) {
            throw new RuntimeException(ex);
        }
    }

}