package org.apache.turbine.services.localization;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.text.MessageFormat;
  import java.util.HashMap;
  import java.util.Locale;
  import java.util.Map;
  import java.util.MissingResourceException;
  import java.util.ResourceBundle;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.apache.commons.configuration.Configuration;
  
  import org.apache.commons.lang.StringUtils;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.turbine.Turbine;
  import org.apache.turbine.services.InitializationException;
  import org.apache.turbine.services.TurbineBaseService;
  import org.apache.turbine.util.RunData;
  
  /***
   * <p>This class is the single point of access to all localization
   * resources.  It caches different ResourceBundles for different
   * Locales.</p>
   *
   * <p>Usage example:</p>
   *
   * <blockquote><code><pre>
   * LocalizationService ls = (LocalizationService) TurbineServices
   *     .getInstance().getService(LocalizationService.SERVICE_NAME);
   * </pre></code></blockquote>
   *
   * <p>Then call one of four methods to retrieve a ResourceBundle:
   *
   * <ul>
   * <li>getBundle("MyBundleName")</li>
   * <li>getBundle("MyBundleName", httpAcceptLanguageHeader)</li>
   * <li>etBundle("MyBundleName", HttpServletRequest)</li>
   * <li>getBundle("MyBundleName", Locale)</li>
   * <li>etc.</li>
   * </ul></p>
   *
   * @author <a href="mailto:jm@mediaphil.de">Jonas Maurus</a>
   * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
   * @author <a href="mailto:novalidemail@foo.com">Frank Y. Kim</a>
   * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
   * @author <a href="mailto:leonardr@collab.net">Leonard Richardson</a>
   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
   * @version $Id: TurbineLocalizationService.java 534527 2007-05-02 16:10:59Z tv $
   */
  public class TurbineLocalizationService
          extends TurbineBaseService
          implements LocalizationService
  {
      /*** Logging */
      private static Log log = LogFactory.getLog(TurbineLocalizationService.class);
  
      /***
       * The value to pass to <code>MessageFormat</code> if a
       * <code>null</code> reference is passed to <code>format()</code>.
       */
      private static final Object[] NO_ARGS = new Object[0];
  
      /***
       * Bundle name keys a Map of the ResourceBundles in this
       * service (which is in turn keyed by Locale).
       * Key=bundle name
       * Value=Hashtable containing ResourceBundles keyed by Locale.
       */
      private Map bundles = null;
  
      /***
       * The list of default bundles to search.
       */
      private String[] bundleNames = null;
  
      /***
      * The name of the default locale to use (includes language and
      * country).
      */
     private Locale defaultLocale = null;
 
     /*** The name of the default language to use. */
     private String defaultLanguage = null;
 
     /*** The name of the default country to use. */
     private String defaultCountry = null;
 
     /***
      * Constructor.
      */
     public TurbineLocalizationService()
     {
         bundles = new HashMap();
     }
 
     /***
      * Called the first time the Service is used.
      */
     public void init()
             throws InitializationException
     {
         Configuration conf = Turbine.getConfiguration();
 
         initBundleNames(null);
 
         Locale jvmDefault = Locale.getDefault();
 
         defaultLanguage = conf.getString("locale.default.language",
                 jvmDefault.getLanguage()).trim();
         defaultCountry = conf.getString("locale.default.country",
                 jvmDefault.getCountry()).trim();
 
         defaultLocale = new Locale(defaultLanguage, defaultCountry);
         setInit(true);
     }
 
     /***
      * Initialize list of default bundle names.
      *
      * @param ignored Ignored.
      */
     protected void initBundleNames(String[] ignored)
     {
         Configuration conf = Turbine.getConfiguration();
         bundleNames = conf.getStringArray("locale.default.bundles");
         String name = conf.getString("locale.default.bundle");
 
         if (name != null && name.length() > 0)
         {
             // Using old-style single bundle name property.
             if (bundleNames == null || bundleNames.length <= 0)
             {
                 bundleNames = new String[] {name};
             }
             else
             {
                 // Prepend "default" bundle name.
                 String[] array = new String[bundleNames.length + 1];
                 array[0] = name;
                 System.arraycopy(bundleNames, 0, array, 1, bundleNames.length);
                 bundleNames = array;
             }
         }
         if (bundleNames == null)
         {
             bundleNames = new String[0];
         }
     }
 
     /***
      * Retrieves the default language (specified in the config file).
      */
     public String getDefaultLanguage()
     {
         return defaultLanguage;
     }
 
     /***
      * Retrieves the default country (specified in the config file).
      */
     public String getDefaultCountry()
     {
         return defaultCountry;
     }
 
     /***
      * Retrieves the name of the default bundle (as specified in the
      * config file).
      * @see org.apache.turbine.services.localization.LocalizationService#getDefaultBundleName()
      */
     public String getDefaultBundleName()
     {
         return (bundleNames.length > 0 ? bundleNames[0] : "");
     }
 
     /***
      * @see org.apache.turbine.services.localization.LocalizationService#getBundleNames()
      */
     public String[] getBundleNames()
     {
         return (String []) bundleNames.clone();
     }
 
     /***
      * This method returns a ResourceBundle given the bundle name
      * "DEFAULT" and the default Locale information supplied in
      * TurbineProperties.
      *
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle()
     {
         return getBundle(getDefaultBundleName(), (Locale) null);
     }
 
     /***
      * This method returns a ResourceBundle given the bundle name and
      * the default Locale information supplied in TurbineProperties.
      *
      * @param bundleName Name of bundle.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(String bundleName)
     {
         return getBundle(bundleName, (Locale) null);
     }
 
     /***
      * This method returns a ResourceBundle given the bundle name and
      * the Locale information supplied in the HTTP "Accept-Language"
      * header.
      *
      * @param bundleName Name of bundle.
      * @param languageHeader A String with the language header.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(String bundleName, String languageHeader)
     {
         return getBundle(bundleName, getLocale(languageHeader));
     }
 
     /***
      * This method returns a ResourceBundle given the Locale
      * information supplied in the HTTP "Accept-Language" header which
      * is stored in HttpServletRequest.
      *
      * @param req HttpServletRequest.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(HttpServletRequest req)
     {
         return getBundle(getDefaultBundleName(), getLocale(req));
     }
 
     /***
      * This method returns a ResourceBundle given the bundle name and
      * the Locale information supplied in the HTTP "Accept-Language"
      * header which is stored in HttpServletRequest.
      *
      * @param bundleName Name of the bundle to use if the request's
      * locale cannot be resolved.
      * @param req HttpServletRequest.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(String bundleName, HttpServletRequest req)
     {
         return getBundle(bundleName, getLocale(req));
     }
 
     /***
      * This method returns a ResourceBundle given the Locale
      * information supplied in the HTTP "Accept-Language" header which
      * is stored in RunData.
      *
      * @param data Turbine information.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(RunData data)
     {
         return getBundle(getDefaultBundleName(), getLocale(data.getRequest()));
     }
 
     /***
      * This method returns a ResourceBundle given the bundle name and
      * the Locale information supplied in the HTTP "Accept-Language"
      * header which is stored in RunData.
      *
      * @param bundleName Name of bundle.
      * @param data Turbine information.
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(String bundleName, RunData data)
     {
         return getBundle(bundleName, getLocale(data.getRequest()));
     }
 
     /***
      * This method returns a ResourceBundle for the given bundle name
      * and the given Locale.
      *
      * @param bundleName Name of bundle (or <code>null</code> for the
      * default bundle).
      * @param locale The locale (or <code>null</code> for the locale
      * indicated by the default language and country).
      * @return A localized ResourceBundle.
      */
     public ResourceBundle getBundle(String bundleName, Locale locale)
     {
         // Assure usable inputs.
         bundleName = (StringUtils.isEmpty(bundleName) ? getDefaultBundleName() : bundleName.trim());
         if (locale == null)
         {
             locale = getLocale((String) null);
         }
 
         // Find/retrieve/cache bundle.
         ResourceBundle rb = null;
         Map bundlesByLocale = (Map) bundles.get(bundleName);
         if (bundlesByLocale != null)
         {
             // Cache of bundles by locale for the named bundle exists.
             // Check the cache for a bundle corresponding to locale.
             rb = (ResourceBundle) bundlesByLocale.get(locale);
 
             if (rb == null)
             {
                 // Not yet cached.
                 rb = cacheBundle(bundleName, locale);
             }
         }
         else
         {
             rb = cacheBundle(bundleName, locale);
         }
         return rb;
     }
 
     /***
      * Caches the named bundle for fast lookups.  This operation is
      * relatively expesive in terms of memory use, but is optimized
      * for run-time speed in the usual case.
      *
      * @exception MissingResourceException Bundle not found.
      */
     private synchronized ResourceBundle cacheBundle(String bundleName,
                                                     Locale locale)
         throws MissingResourceException
     {
         Map bundlesByLocale = (HashMap) bundles.get(bundleName);
         ResourceBundle rb = (bundlesByLocale == null ? null :
                              (ResourceBundle) bundlesByLocale.get(locale));
 
         if (rb == null)
         {
             bundlesByLocale = (bundlesByLocale == null ? new HashMap(3) :
                                new HashMap(bundlesByLocale));
             try
             {
                 rb = ResourceBundle.getBundle(bundleName, locale);
             }
             catch (MissingResourceException e)
             {
                 rb = findBundleByLocale(bundleName, locale, bundlesByLocale);
                 if (rb == null)
                 {
                     throw (MissingResourceException) e.fillInStackTrace();
                 }
             }
 
             if (rb != null)
             {
                 // Cache bundle.
                 bundlesByLocale.put(rb.getLocale(), rb);
 
                 Map bundlesByName = new HashMap(bundles);
                 bundlesByName.put(bundleName, bundlesByLocale);
                 this.bundles = bundlesByName;
             }
         }
         return rb;
     }
 
     /***
      * <p>Retrieves the bundle most closely matching first against the
      * supplied inputs, then against the defaults.</p>
      *
      * <p>Use case: some clients send a HTTP Accept-Language header
      * with a value of only the language to use
      * (i.e. "Accept-Language: en"), and neglect to include a country.
      * When there is no bundle for the requested language, this method
      * can be called to try the default country (checking internally
      * to assure the requested criteria matches the default to avoid
      * disconnects between language and country).</p>
      *
      * <p>Since we're really just guessing at possible bundles to use,
      * we don't ever throw <code>MissingResourceException</code>.</p>
      */
     private ResourceBundle findBundleByLocale(String bundleName, Locale locale,
                                               Map bundlesByLocale)
     {
         ResourceBundle rb = null;
         if (!StringUtils.isNotEmpty(locale.getCountry()) &&
              defaultLanguage.equals(locale.getLanguage()))
         {
             /*
              *              log.debug("Requested language '" + locale.getLanguage() +
              *              "' matches default: Attempting to guess bundle " +
              *              "using default country '" + defaultCountry + '\'');
              */
             Locale withDefaultCountry = new Locale(locale.getLanguage(),
                                                    defaultCountry);
             rb = (ResourceBundle) bundlesByLocale.get(withDefaultCountry);
             if (rb == null)
             {
                 rb = getBundleIgnoreException(bundleName, withDefaultCountry);
             }
         }
         else if (!StringUtils.isNotEmpty(locale.getLanguage()) &&
                   defaultCountry.equals(locale.getCountry()))
         {
             Locale withDefaultLanguage = new Locale(defaultLanguage,
                                                     locale.getCountry());
             rb = (ResourceBundle) bundlesByLocale.get(withDefaultLanguage);
             if (rb == null)
             {
                 rb = getBundleIgnoreException(bundleName, withDefaultLanguage);
             }
         }
 
         if (rb == null && !defaultLocale.equals(locale))
         {
             rb = getBundleIgnoreException(bundleName, defaultLocale);
         }
 
         return rb;
     }
 
     /***
      * Retrieves the bundle using the
      * <code>ResourceBundle.getBundle(String, Locale)</code> method,
      * returning <code>null</code> instead of throwing
      * <code>MissingResourceException</code>.
      */
     private ResourceBundle getBundleIgnoreException(String bundleName,
                                                           Locale locale)
     {
         try
         {
             return ResourceBundle.getBundle(bundleName, locale);
         }
         catch (MissingResourceException ignored)
         {
             return null;
         }
     }
 
     /***
      * This method sets the name of the first bundle in the search
      * list (the "default" bundle).
      *
      * @param defaultBundle Name of default bundle.
      */
     public void setBundle(String defaultBundle)
     {
         if (bundleNames.length > 0)
         {
             bundleNames[0] = defaultBundle;
         }
         else
         {
             synchronized (this)
             {
                 if (bundleNames.length <= 0)
                 {
                     bundleNames = new String[] {defaultBundle};
                 }
             }
         }
     }
 
     /***
      * @see org.apache.turbine.services.localization.LocalizationService#getLocale(HttpServletRequest)
      */
     public final Locale getLocale(HttpServletRequest req)
     {
         return getLocale(req.getHeader(ACCEPT_LANGUAGE));
     }
 
     /***
      * @see org.apache.turbine.services.localization.LocalizationService#getLocale(String)
      */
     public Locale getLocale(String header)
     {
         if (!StringUtils.isEmpty(header))
         {
             LocaleTokenizer tok = new LocaleTokenizer(header);
             if (tok.hasNext())
             {
                 return (Locale) tok.next();
             }
         }
 
         // Couldn't parse locale.
         return defaultLocale;
     }
 
     /***
      * @exception MissingResourceException Specified key cannot be matched.
      * @see org.apache.turbine.services.localization.LocalizationService#getString(String, Locale, String)
      */
     public String getString(String bundleName, Locale locale, String key)
     {
         String value = null;
 
         if (locale == null)
         {
             locale = getLocale((String) null);
         }
 
         // Look for text in requested bundle.
         ResourceBundle rb = getBundle(bundleName, locale);
         value = getStringOrNull(rb, key);
 
         // Look for text in list of default bundles.
         if (value == null && bundleNames.length > 0)
         {
             String name;
             for (int i = 0; i < bundleNames.length; i++)
             {
                 name = bundleNames[i];
                 //System.out.println("getString(): name=" + name +
                 //                   ", locale=" + locale + ", i=" + i);
                 if (!name.equals(bundleName))
                 {
                     rb = getBundle(name, locale);
                     value = getStringOrNull(rb, key);
                     if (value != null)
                     {
                         locale = rb.getLocale();
                         break;
                     }
                 }
             }
         }
 
         if (value == null)
         {
             String loc = locale.toString();
             String mesg = LocalizationService.SERVICE_NAME +
                 " noticed missing resource: " +
                 "bundleName=" + bundleName + ", locale=" + loc +
                 ", key=" + key;
             log.debug(mesg);
             // Text not found in requested or default bundles.
             throw new MissingResourceException(mesg, bundleName, key);
         }
 
         return value;
     }
 
     /***
      * Gets localized text from a bundle if it's there.  Otherwise,
      * returns <code>null</code> (ignoring a possible
      * <code>MissingResourceException</code>).
      */
     protected final String getStringOrNull(ResourceBundle rb, String key)
     {
         if (rb != null)
         {
             try
             {
                 return rb.getString(key);
             }
             catch (MissingResourceException ignored)
             {
             }
         }
         return null;
     }
 
     /***
      * Formats a localized value using the provided object.
      *
      * @param bundleName The bundle in which to look for the localizable text.
      * @param locale The locale for which to format the text.
      * @param key The identifier for the localized text to retrieve,
      * @param arg1 The object to use as {0} when formatting the localized text.
      * @return Formatted localized text.
      * @see #format(String, Locale, String, Object[])
      */
     public String format(String bundleName, Locale locale,
                          String key, Object arg1)
     {
         return format(bundleName, locale, key, new Object[] { arg1 });
     }
 
     /***
      * Formats a localized value using the provided objects.
      *
      * @param bundleName The bundle in which to look for the localizable text.
      * @param locale The locale for which to format the text.
      * @param key The identifier for the localized text to retrieve,
      * @param arg1 The object to use as {0} when formatting the localized text.
      * @param arg2 The object to use as {1} when formatting the localized text.
      * @return Formatted localized text.
      * @see #format(String, Locale, String, Object[])
      */
     public String format(String bundleName, Locale locale,
                          String key, Object arg1, Object arg2)
     {
         return format(bundleName, locale, key, new Object[] { arg1, arg2 });
     }
 
     /***
      * Looks up the value for <code>key</code> in the
      * <code>ResourceBundle</code> referenced by
      * <code>bundleName</code>, then formats that value for the
      * specified <code>Locale</code> using <code>args</code>.
      *
      * @param bundleName The bundle in which to look for the localizable text.
      * @param locale The locale for which to format the text.
      * @param key The identifier for the localized text to retrieve,
      * @param args The objects to use when formatting the localized text.
      *
      * @return Localized, formatted text identified by
      * <code>key</code>.
      */
     public String format(String bundleName, Locale locale,
                          String key, Object[] args)
     {
         if (locale == null)
         {
             // When formatting Date objects and such, MessageFormat
             // cannot have a null Locale.
             locale = getLocale((String) null);
         }
         String value = getString(bundleName, locale, key);
         if (args == null)
         {
             args = NO_ARGS;
         }
         // FIXME: after switching to JDK 1.4, it will be possible to clean
         // this up by providing the Locale along with the string in the
         // constructor to MessageFormat.  Until 1.4, the following workaround
         // is required for constructing the format with the appropriate locale:
         MessageFormat messageFormat = new MessageFormat("");
         messageFormat.setLocale(locale);
         messageFormat.applyPattern(value);
         return messageFormat.format(args);
     }
 }