/**

  * Distribution License:

  * JSword is free software; you can redistribute it and/or modify it under

  * the terms of the GNU Lesser General Public License, version 2.1 or later

  * as published by the Free Software Foundation. This program 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.

  *

  * The License is available on the internet at:

  *      http://www.gnu.org/copyleft/lgpl.html

  * or by writing to:

  *      Free Software Foundation, Inc.

  *      59 Temple Place - Suite 330

  *      Boston, MA 02111-1307, USA

  *

  * © CrossWire Bible Society, 2005 - 2016

  *

  */

 package org.crosswire.common.util;

 import java.io.IOException;

 import java.net.URL;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.Locale;

 import java.util.Map;

 import java.util.MissingResourceException;

 import java.util.ResourceBundle;

 import java.util.Set;

 import org.crosswire.jsword.book.Books;

 import org.crosswire.jsword.internationalisation.LocaleProviderManager;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A utility class that converts bcp-47 codes as supported by {@link Language} to their

  * localized language name.

  * 

  * @see gnu.lgpl.License The GNU Lesser General Public License for details.

  * @author DM Smith

  */

 public final class Languages {

     /**

      * Make the class a true utility class by having a private constructor.

      */

     private Languages() {

     }

     /**

      * Get the language name for the BCP-47 specification of the language.

      * 

      * @param code the BCP-47 specification for the language

      * @return the name of the language

      */

     public static String getName(String code) {

         // Returning the code is the fallback for lookup

         String name = code;

         try {

             ResourceBundle langs = getLocalisedCommonLanguages();

             if (langs != null) {

                 name = langs.getString(code);

             }

         } catch (MissingResourceException e) {

             // This is allowed

         }

         return name;

     }

     /**

      * Gets the localised common languages. Caching here, is done to prevent extra logging 

      * happening every time we miss the iso639 ResourceBundle

      * and end up having to lookup the iso639full

      * 

      * @return the localised common languages

      */

     private static ResourceBundle getLocalisedCommonLanguages() {

         Locale locale = LocaleProviderManager.getLocale();

         ResourceBundle langs = localisedCommonLanguages.get(locale);

         if (langs == null) {

             synchronized (Languages.class) {

                 langs = localisedCommonLanguages.get(locale);

                 if (langs == null) {

                     langs = initLanguages(locale);

                     if (langs != null) {

                         localisedCommonLanguages.put(locale, langs);

                     }

                 }

             }

         }

         return langs;

     }

     private static ResourceBundle initLanguages(Locale locale) {

         try {

             return ResourceBundle.getBundle("iso639", locale, CWClassLoader.instance());

         } catch (MissingResourceException e) {

             log.info("Unable to find language in iso639 bundle", e);

         }

         return null;

     }

     /**

      * Provide a fallback lookup against a huge list of all languages.

      * The basic list has a few hundred languages. The full list has

      * over 7000. As a fallback, this file is not internationalized.

      */

     public static final class AllLanguages {

         /**

          * This is a singleton class. Do not allow construction.

          */

         private AllLanguages() { }

         /**

          * Get the language name for the code. If the language name is not known

          * then return the code.

          * 

          * @param languageCode the language code

          * @return the name for the language.

          */

         public static String getName(String languageCode) {

             if (instance != null) {

                 String name = instance.get(languageCode);

                 if (name != null) {

                     return name;

                 }

             }

             return languageCode;

         }

         /**

          * Do lazy loading of the huge file of languages.

          * Note: It is OK for it not to be present.

          */

         private static PropertyMap instance;

         static {

             try {

                 instance = ResourceUtil.getProperties("iso639full");

                 log.debug("Loading iso639full.properties file");

             } catch (IOException e) {

                 log.info("Unable to load iso639full.properties", e);

             }

         }

     }

     /**

      * Provide a fallback lookup against a huge list of all languages.

      * The basic list has a few hundred languages. The full list has

      * over 7000. As a fallback, this file is not internationalized.

      */

     public static final class RtoL {

         /**

          * This is a singleton class. Do not allow construction.

          */

         private RtoL() { }

         /**

          * Determine whether this language is a Left-to-Right or a Right-to-Left

          * language. If the language has a script, it is used for the determination.

          * Otherwise, check the language.

          * <p>

          * Note: This is problematic. Languages do not have direction.

          * Scripts do. Further, there are over 7000 living languages, many of which

          * are written in Right-to-Left scripts and are not listed here.

          * </p>

          * 

          * @param script the iso15924 script code, must be in Title case

          * @param lang the iso639 language code, must be lower case

          * @return true if the language is Right-to-Left

          */

         public static boolean isRtoL(String script, String lang) {

             if (script != null) {

                 return rtol.contains(script);

             }

             if (lang != null) {

                 return rtol.contains(lang);

             }

             return false;

         }

         /**

          * Do lazy loading of the huge file of languages.

          * Note: It is OK for it not to be present.

          */

         private static Set rtol = new HashSet();

         /**

          * load RtoL data

          */

         static {

             try {

                 URL index = ResourceUtil.getResource(Translations.class, "rtol.txt");

                 String[] list = NetUtil.listByIndexFile(NetUtil.toURI(index));

                 log.debug("Loading iso639full.properties file");

                 for (int i = 0; i < list.length; i++) {

                     rtol.add(list[i]);

                 }

             } catch (IOException ex) {

                 log.info("Unable to load rtol.txt", ex);

             }

         }

     }

     private static Map<Locale, ResourceBundle> localisedCommonLanguages = new HashMap<Locale, ResourceBundle>();

     /**

      * The log stream

      */

     protected static final Logger log = LoggerFactory.getLogger(Books.class);

 }