/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.services.i18n;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.PropertyResourceBundle;
  import java.util.ResourceBundle;
  import java.util.ResourceBundle.Control;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mycore.common.config.MCRComponent;
  import org.mycore.common.config.MCRConfigurationInputStream;
  import org.mycore.datamodel.language.MCRLanguageFactory;
  
  import com.google.common.collect.Lists;
  
  /**
   * A {@link Control} that stacks ResourceBundles of {@link MCRComponent}.
   * 
   * @author Thomas Scheffler (yagee)
   * @since 2014.04
   */
  public class MCRCombinedResourceBundleControl extends Control {
      private static Logger LOGGER = LogManager.getLogger(MCRCombinedResourceBundleControl.class);
  
      private Locale defaultLocale = MCRLanguageFactory.instance().getDefaultLanguage().getLocale();
  
      private static final ResourceBundle.Control CONTROL_HELPER = new ResourceBundle.Control() {
      };
  
      @Override
      public ResourceBundle newBundle(String baseName, Locale locale, String format, ClassLoader loader, boolean reload)
          throws IllegalAccessException, InstantiationException, IOException {
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug("New bundle: {}, locale {}", baseName, locale);
          }
          if (locale.equals(Locale.ROOT)) {
              //MCR-1064 fallback should be default language, if property key does not exist
              locale = defaultLocale;
          }
          String bundleName = baseName.substring(baseName.indexOf(':') + 1);
          String filename = CONTROL_HELPER.toBundleName(bundleName, locale) + ".properties";
          try (MCRConfigurationInputStream propertyStream = new MCRConfigurationInputStream(filename)) {
              if (propertyStream.isEmpty()) {
                  String className = bundleName + "_" + locale;
                  throw new MissingResourceException(
                      "Can't find bundle for base name " + baseName + ", locale " + locale, className, "");
              }
              return new PropertyResourceBundle(propertyStream);
          }
      }
  
      @Override
      public List<String> getFormats(String baseName) {
          return Lists.newArrayList("mycore");
      }
  
      @Override
      public Locale getFallbackLocale(String baseName, Locale locale) {
          return defaultLocale.equals(locale) ? null : defaultLocale;
      }
  
      @Override
      public long getTimeToLive(String baseName, Locale locale) {
          //JAR files never change in runtime
          return Long.MAX_VALUE;
      }
  
      @Override
      public boolean needsReload(String baseName, Locale locale, String format, ClassLoader loader,
          ResourceBundle bundle, long loadTime) {
          //JAR files never change in runtime
          return false;
      }
  
  }