/**
 *
 */
package de.intevation.gnv.artifacts.ressource;

import java.util.MissingResourceException;
import java.util.ResourceBundle;

import org.apache.log4j.Logger;

import de.intevation.artifacts.PreferredLocale;

/**
 * @author Tim Englich <tim.englich@intevation.de>
 * 
 */
public class RessourceFactory {

    /**
     * the logger, used to log exceptions and additonaly information
     */
    private static Logger log = Logger.getLogger(RessourceFactory.class);

    /**
     * The singleton Instance of this Factory.
     */
    private static RessourceFactory instance = null;

    private static String RESSOURCE_BASE_ID = "artifact.ressource.dir";

    private static String ressourceName = "artifactMessages";
    private static String DEFAULT_DIR = "lang";

    private String ressourceDir = null;

    /**
     * Basic-Constructor of this Class
     */
    private RessourceFactory() {
        super();
        ressourceDir = System.getProperty(RESSOURCE_BASE_ID, DEFAULT_DIR);
    }

    /**
     * This Method provides an singleton Instance of this Class.
     * 
     * @return an singleton Instance of this Class
     */
    public static synchronized RessourceFactory getInstance() {
        if (instance == null) {
            instance = new RessourceFactory();
        }
        return instance;
    }

    /**
     * Deliveres the translated Value for an Key to an given Language
     * 
     * @param locale
     *            The choosen locale
     * @param key
     *            the key
     * @param defaultValue
     *            the Value that should be returned.
     * @return the translated Value
     */
    public String getRessource(PreferredLocale[] preferredLocales, String key,
                               String defaultValue) {
        if (key == null || preferredLocales.length == 0) {
            return defaultValue;
        }

        try {
            ResourceBundle rb = ResourceBundle.getBundle(ressourceDir + "/"
                                                         + ressourceName,
                    preferredLocales[0].getLocale());

            return rb.getString(key);
        } catch (MissingResourceException mre) {
            log.warn(mre.getLocalizedMessage());
            return defaultValue;
        }
    }
}