/*
    * Copyright (c) 2009 QOS.ch All rights reserved.
    * 
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
    * in the Software without restriction, including without limitation the rights
    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    * copies of the Software, and to permit persons to whom the Software is
    * furnished to do so, subject to the following conditions:
   * 
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS  IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  package ch.qos.cal10n;
  
  import java.text.MessageFormat;
  import java.util.Locale;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import ch.qos.cal10n.util.AnnotationExtractorViaEnumClass;
  import ch.qos.cal10n.util.CAL10NBundle;
  import ch.qos.cal10n.util.CAL10NBundleFinderByClassloader;
  
  /**
   * The default implementation for {@link IMessageConveyor} based on resource
   * bundles.
   * <p/>
   * <p/>
   * See also {@link #getMessage(Enum, Object...)} for details.
   *
   * @author Ceki G&uuml;lc&uuml;
   */
  public class MessageConveyor implements IMessageConveyor {
  
    final Locale locale;
  
    final Map<String, CAL10NBundle> cache = new ConcurrentHashMap<String, CAL10NBundle>();
  
    /**
     * The {@link Locale} associated with this instance.
     *
     * @param locale the Locale which this conveyor targets
     */
    public MessageConveyor(Locale locale) {
      this.locale = locale;
    }
  
    /**
     * Given an enum as key, find the resource bundle corresponding to this locale and return
     * the message corresponding to the key passed as parameter (internationalized per this locale).
     * <p/>
     * <p/>
     * The name of the resource bundle is defined via the {@link BaseName}
     * annotation whereas the locale is specified in this MessageConveyor
     * instance's constructor.
     *
     * @param key an enum instance used as message key
     */
    public <E extends Enum<?>> String getMessage(E key, Object... args)
            throws MessageConveyorException {
  
      Class<? extends Enum<?>> declaringClass = key.getDeclaringClass();
  
      String declaringClassName = declaringClass.getName();
      CAL10NBundle rb = cache.get(declaringClassName);
      if (rb == null || rb.hasChanged()) {
        rb = lookupResourceBundleByEnumClassAndLocale(declaringClass);
        cache.put(declaringClassName, rb);
      }
  
      String keyAsStr = key.toString();
      String value = rb.getString(keyAsStr);
      if (value == null) {
        return "No key found for " + keyAsStr;
      } else {
        if (args == null || args.length == 0) {
          return value;
        } else {
          return MessageFormat.format(value, args);
        }
      }
    }
  
    private <E extends Enum<?>> CAL10NBundle lookupResourceBundleByEnumClassAndLocale(Class<E> declaringClass)
            throws MessageConveyorException {
  
      AnnotationExtractorViaEnumClass annotationExtractor = new AnnotationExtractorViaEnumClass(declaringClass);
      // basename is declared via an annotation on the declaringClass
      String baseName = annotationExtractor.getBaseName();
     if (baseName == null) {
       throw new MessageConveyorException(
               "Missing @BaseName annotation in enum type ["
                       + declaringClass.getName() + "]. See also "
                       + CAL10NConstants.MISSING_BN_ANNOTATION_URL);
     }
 
     String charset = annotationExtractor.extractCharset(locale);
     // use the declaring class' loader instead of
     // this.getClass().getClassLoader()
     // see also http://jira.qos.ch/browse/CAL-8
     CAL10NBundleFinderByClassloader cal10NBundleFinderByClassloader = new CAL10NBundleFinderByClassloader(declaringClass.getClassLoader());
     CAL10NBundle rb = cal10NBundleFinderByClassloader.getBundle(
             baseName, locale, charset);
 
     if (rb == null) {
       throw new MessageConveyorException(
               "Failed to locate resource bundle [" + baseName
                       + "] for locale [" + locale + "] for enum type ["
                       + declaringClass.getName() + "]");
     }
     return rb;
   }
 
   public String getMessage(MessageParameterObj mpo)
           throws MessageConveyorException {
     if (mpo == null) {
       throw new IllegalArgumentException(
               "MessageParameterObj argumument cannot be null");
     }
     return getMessage(mpo.getKey(), mpo.getArgs());
   }
 }