/*
 * 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 IMessageConveyor based on resource bundles. 

 See also getMessage(Enum, Object...) for details. 
Author:
Ceki Gülcü/**
 * 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 Locale associated with this instance. 
Params:
locale – the Locale which this conveyor targets/**
   * 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).

 The name of the resource bundle is defined via the BaseName annotation whereas the locale is specified in this MessageConveyor instance's constructor. 
Params:
key – an enum instance used as message key/**
   * 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());
  }
}