package application;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.file.Paths;
import java.util.Locale;
import java.util.ResourceBundle;

/***********************************************************************
 * アプリケーションの言語を切り替える（シングルトン）
 */
public class ApplicationLanguage {
	private Locale locale = null;
	private ResourceBundle resBundle = null;

	private static ApplicationLanguage instance = null;

	private final static String RESOURCE_PATH = "resources/locales/";

	public final static String JP = "ja";
	public final static String EN = "en";

	/***********************************************************************
	/***********************************************************************
	 * [ *constructor ]
	/***********************************************************************
	 * 
	 * @return
	 */
	private ApplicationLanguage() {
		this.locale = Locale.getDefault();
		setLocaleLanguage(this.locale.getLanguage());
	}

	/***********************************************************************
	/***********************************************************************
	 * [ *public static ]
	/***********************************************************************
	 * 
	 */
	public static ApplicationLanguage getInstance() {
		if (instance == null) instance = new ApplicationLanguage();
		return instance;
	}

	/***********************************************************************
	/***********************************************************************
	 * [ *public ]
	 /***********************************************************************
	 * ローカルの .properties から言語情報を切り替え. 
	 * @param language 変更先の言語
	 */
	public void setLocaleLanguage(final String language) {
		URL resURL = null;
		try {
			File resDir = Paths.get(RESOURCE_PATH).toFile();		// for Eclipse project
			resURL = resDir.toURI().toURL();
		} catch (MalformedURLException e) {
			e.printStackTrace();
		}
//		resURL = this.getClass().getClassLoader().getResource(RESOURCE_PATH);	// for executable jar
		URLClassLoader urlLoader = new URLClassLoader(new URL[] { resURL });
		this.resBundle = ResourceBundle.getBundle(language, this.locale, urlLoader);
		
//		// Another approach.
//		properties = new Properties();
//		try {
//			properties.load(Main.class.getClassLoader().getResourceAsStream(RESOURCE_PATH + language + ".properties"));
//		} catch (IOException e) {
//			return;
//		}
	}

	/***********************************************************************
	 * オプション名に対応した名前を返す. 
	 * @param propName 取得したいプロパティの名前
	 */
	public String getOptionByPropName(final String propName) {
//		return properties.getProperty(propName);
		return this.resBundle.getString(propName);
	}
}