/*
    * 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.
   */
  package org.apache.myfaces.commons.util;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import javax.el.ValueExpression;
  import javax.faces.FactoryFinder;
  import javax.faces.application.Application;
  import javax.faces.application.ApplicationFactory;
  import javax.faces.application.FacesMessage;
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import java.text.MessageFormat;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.ResourceBundle;
  
  /**
   * Utility class to support multilingual FacesMessages using ResourceBundles.
   * Standard messages are stored at <code>DEFAULT_BUNDLE</code>.<br>
   * The summary of the message is stored at the requested key value. The detail
   * of the message is stored at &lt;messageId&gt;_detail.
   *
   * @see FacesMessage
   * @see java.util.ResourceBundle
   *
   * @author Thomas Spiegl (latest modification by $Author: lu4242 $)
   * @author Manfred Geiler
   * @author Sean Schofield
   * @author Stpehan Strittmatter
   * @version $Revision: 1003673 $ $Date: 2010-10-01 17:11:09 -0500 (Fri, 01 Oct 2010) $
   */
  public final class MessageUtils
  {
    /** Utility class, do not instatiate */
      private MessageUtils()
      {
          // nope
      }
  
      /** Default bundle for messages (<code>org.apache.myfaces.commons.Messages</code>) */ 
      private static final String DEFAULT_BUNDLE = "org.apache.myfaces.commons.Messages";//javax.faces.Messages
  
      /** Suffix for message details (<code>_detail</code>)*/
      private static final String DETAIL_SUFFIX = "_detail";
      private static Log log = LogFactory.getLog(MessageUtils.class);
  
      /**
       * @param severity serverity of message
       * @param messageId id of message
       * @param arg arument of message
       *
       * @return generated FacesMessage
       */
      public static FacesMessage getMessage(FacesMessage.Severity severity,
                                            String messageId,
                                            Object arg)
      {
          return getMessage(severity,
                            messageId,
                            new Object[]{arg},
                            FacesContext.getCurrentInstance());
      }
      
      public static FacesMessage getMessage(String bundleBaseName, 
              FacesMessage.Severity severity,
              String messageId,
              Object arg)
      {
          return getMessage(bundleBaseName,
                            severity,
                            messageId,
                            new Object[]{arg},
                            FacesContext.getCurrentInstance());
      }
  
      /**
       * @param severity serverity of message
       * @param messageId id of message
       * @param args aruments of message
       *
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(FacesMessage.Severity severity,
                                           String messageId,
                                           Object[] args)
     {
         return getMessage(severity,
                           messageId,
                           args,
                           FacesContext.getCurrentInstance());
     }
     
     public static FacesMessage getMessage(String bundleBaseName, 
             FacesMessage.Severity severity,
             String messageId,
             Object[] args)
     {
         return getMessage(bundleBaseName,
                           severity,
                           messageId,
                           args,
                           FacesContext.getCurrentInstance());
     }    
 
     public static FacesMessage getMessage(FacesMessage.Severity severity,
                                           String messageId,
                                           Object[] args,
                                           FacesContext facesContext)
     {
         FacesMessage message = getMessage(facesContext, messageId, args);
         message.setSeverity(severity);
 
         return message;
     }
 
     public static FacesMessage getMessage(String bundleBaseName,
             FacesMessage.Severity severity,
             String messageId,
             Object[] args,
             FacesContext facesContext)
     {
         FacesMessage message = getMessage(bundleBaseName, facesContext, messageId, args);
         message.setSeverity(severity);
         
         return message;
     }
 
     public static void addMessage(FacesMessage.Severity severity,
                                   String messageId,
                                   Object[] args)
     {
         addMessage(severity, messageId, args, null, FacesContext.getCurrentInstance());
     }
 
     public static void addMessage(String bundleBaseName, 
             FacesMessage.Severity severity,
             String messageId,
             Object[] args)
     {
         addMessage(bundleBaseName, severity, messageId, args, null, FacesContext.getCurrentInstance());
     }
 
     public static void addMessage(FacesMessage.Severity severity,
                                   String messageId,
                                   Object[] args,
                                   FacesContext facesContext)
     {
         addMessage(severity, messageId, args, null, facesContext);
     }
 
     public static void addMessage(String bundleBaseName, 
             FacesMessage.Severity severity,
             String messageId,
             Object[] args,
             FacesContext facesContext)
     {
         addMessage(bundleBaseName, severity, messageId, args, null, facesContext);
     }
 
     public static void addMessage(FacesMessage.Severity severity,
                                   String messageId,
                                   Object[] args,
                                   String forClientId)
     {
         addMessage(severity, messageId, args, forClientId, FacesContext.getCurrentInstance());
     }
 
     public static void addMessage(String bundleBaseName,
             FacesMessage.Severity severity,
             String messageId,
             Object[] args,
             String forClientId)
     {
         addMessage(bundleBaseName, severity, messageId, args, forClientId, FacesContext.getCurrentInstance());
     }
 
     public static void addMessage(FacesMessage.Severity severity,
                                   String messageId,
                                   Object[] args,
                                   String forClientId,
                                   FacesContext facesContext)
     {
         if(log.isTraceEnabled()) {
           log.trace("adding message " + messageId + " for clientId " + forClientId);
         }
         facesContext.addMessage(forClientId,
                                 getMessage(severity, messageId, args, facesContext));
     }
 
     public static void addMessage(String bundleBaseName,
             FacesMessage.Severity severity,
             String messageId,
             Object[] args,
             String forClientId,
             FacesContext facesContext)
     {
         if(log.isTraceEnabled()) {
         log.trace("adding message " + messageId + " for clientId " + forClientId);
         }
         facesContext.addMessage(forClientId,
                   getMessage(bundleBaseName, severity, messageId, args, facesContext));
     }
 
     /**
      * Uses <code>MessageFormat</code> and the supplied parameters to fill in the param placeholders in the String.
      *
      * @param locale The <code>Locale</code> to use when performing the substitution.
      * @param msgtext The original parameterized String.
      * @param params The params to fill in the String with.
      * @return The updated String.
      */
     public static String substituteParams(Locale locale, String msgtext, Object params[])
     {
         String localizedStr = null;
         if(params == null || msgtext == null)
             return msgtext;
         StringBuffer b = new StringBuffer(100);
         MessageFormat mf = new MessageFormat(msgtext);
         if(locale != null)
         {
             mf.setLocale(locale);
             b.append(mf.format(((Object) (params))));
             localizedStr = b.toString();
         }
         return localizedStr;
     }
 
     public static FacesMessage getMessage(String messageId, Object params[])
     {
         Locale locale = getCurrentLocale();
         return getMessage(locale, messageId, params);
     }
 
     public static FacesMessage getMessageFromBundle(String bundleBaseName, String messageId, Object params[])
     {
         Locale locale = null;
         FacesContext context = FacesContext.getCurrentInstance();
         if(context != null && context.getViewRoot() != null)
         {
             locale = context.getViewRoot().getLocale();
             if(locale == null)
                 locale = Locale.getDefault();
         } else
         {
             locale = Locale.getDefault();
         }
         return getMessageFromBundle(bundleBaseName, context , locale, messageId, params);
     }
 
     public static FacesMessage getMessage(Locale locale, String messageId, Object params[])
     {
         String summary = null;
         String detail = null;
         String bundleName = getApplication().getMessageBundle();
         ResourceBundle bundle = null;
 
         if (bundleName != null)
         {
             try
             {
                 bundle = ResourceBundle.getBundle(bundleName, locale, getCurrentLoader(bundleName));
                 summary = bundle.getString(messageId);
             }
             catch (MissingResourceException e) {
                 // NoOp
             }
         }
 
         if (summary == null)
         {
             try
             {
                 bundle = ResourceBundle.getBundle(DEFAULT_BUNDLE, locale, getCurrentLoader(DEFAULT_BUNDLE));
                 if(bundle == null)
                 {
                     throw new NullPointerException();
                 }
                 summary = bundle.getString(messageId);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
         }
 
         if(summary == null)
         {
             summary = messageId;
         }
 
         if (bundle == null)
         {
             throw new NullPointerException(
                 "Unable to locate ResourceBundle: bundle is null");
         }
         if (params != null && locale != null)
         {
             try
             {
                 detail = bundle.getString(messageId + DETAIL_SUFFIX);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
             return new ParametrizableFacesMessage(summary, detail, params, locale);
         }
         else
         {
             summary = substituteParams(locale, summary, params);
             try
             {
                 detail = substituteParams(locale,
                     bundle.getString(messageId + DETAIL_SUFFIX), params);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
             return new FacesMessage(summary, detail);
         }
     }
     
     public static FacesMessage getMessageFromBundle(String bundleBaseName, FacesContext context, Locale locale, String messageId, Object params[])
     {
         String summary = null;
         String detail = null;
         String bundleName = context.getApplication().getMessageBundle();
         ResourceBundle bundle = null;
 
         if (bundleName != null)
         {
             try
             {
                 bundle = ResourceBundle.getBundle(bundleName, locale, getCurrentLoader(bundleName));
                 summary = bundle.getString(messageId);
             }
             catch (MissingResourceException e) {
                 // NoOp
             }
         }
 
         if (summary == null)
         {
             try
             {
                 bundle = ResourceBundle.getBundle(bundleBaseName, locale, getCurrentLoader(bundleBaseName));
                 if(bundle == null)
                 {
                     throw new NullPointerException();
                 }
                 summary = bundle.getString(messageId);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
         }
         
         if (summary == null)
         {
             try
             {
                 bundle = ResourceBundle.getBundle(DEFAULT_BUNDLE, locale, getCurrentLoader(DEFAULT_BUNDLE));
                 if(bundle == null)
                 {
                     throw new NullPointerException();
                 }
                 summary = bundle.getString(messageId);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
         }
 
         if(summary == null)
         {
             summary = messageId;
         }
 
         if (bundle == null)
         {
             throw new NullPointerException(
                 "Unable to locate ResourceBundle: bundle is null");
         }
         
         if (params != null && locale != null)
         {
             try
             {
                 detail = bundle.getString(messageId + DETAIL_SUFFIX);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
             return new ParametrizableFacesMessage(summary, detail, params, locale);
         }
         else
         {
             summary = substituteParams(locale, summary, params);
             try
             {
                 detail = substituteParams(locale,
                     bundle.getString(messageId + DETAIL_SUFFIX), params);
             }
             catch(MissingResourceException e) {
                 // NoOp
             }
             return new FacesMessage(summary, detail);
         }
     }
 
     /**
      *  Retrieve the message from a specific bundle. It does not look on application message bundle
      * or default message bundle. If it is required to look on those bundles use getMessageFromBundle instead
      * 
      * @param bundleBaseName baseName of ResourceBundle to load localized messages
      * @param messageId id of message
      * @param params parameters to set at localized message
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(String bundleBaseName, String messageId, Object params[])
     {
         return getMessage(bundleBaseName, getCurrentLocale(), messageId, params);
     }
     
     /**
      * 
      * @return  currently applicable Locale for this request.
      */
     public static Locale getCurrentLocale() {
         return getCurrentLocale(FacesContext.getCurrentInstance());
     }
     
     public static Locale getCurrentLocale(FacesContext context) {
         Locale locale;
         if(context != null && context.getViewRoot() != null)
         {
             locale = context.getViewRoot().getLocale();
             if(locale == null)
                 locale = Locale.getDefault();
         }
         else
         {
             locale = Locale.getDefault();
         }
         
         return locale;
     }
 
     /**
      * @param severity severity of message
      * @param bundleBaseName baseName of ResourceBundle to load localized messages
      * @param messageId id of message
      * @param params parameters to set at localized message
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(FacesMessage.Severity severity, String bundleBaseName, String messageId, Object params[])
     {
       FacesMessage msg = getMessage(bundleBaseName, messageId, params);
       msg.setSeverity(severity);
 
       return msg;
     }
 
     /**
      *  Retrieve the message from a specific bundle. It does not look on application message bundle
      * or default message bundle. If it is required to look on those bundles use getMessageFromBundle instead
      * 
      * @param bundleBaseName baseName of ResourceBundle to load localized messages
      * @param locale current locale
      * @param messageId id of message
      * @param params parameters to set at localized message
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(String bundleBaseName, Locale locale, String messageId, Object params[])
     {
       if (bundleBaseName == null)
       {
           throw new NullPointerException(
               "Unable to locate ResourceBundle: bundle is null");
       }
 
       ResourceBundle bundle = ResourceBundle.getBundle(bundleBaseName, locale);
 
       return getMessage(bundle, messageId, params);
     }
     /**
      * @param bundle ResourceBundle to load localized messages
      * @param messageId id of message
      * @param params parameters to set at localized message
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(ResourceBundle bundle, String messageId, Object params[])
     {
 
       String summary = null;
       String detail = null;
 
       try
       {
           summary = bundle.getString(messageId);
       }
       catch (MissingResourceException e) {
         // NoOp
       }
 
 
       if(summary == null)
       {
           summary = messageId;
       }
 
       summary = substituteParams(bundle.getLocale(), summary, params);
 
       try
       {
           detail = substituteParams(bundle.getLocale(),
               bundle.getString(messageId + DETAIL_SUFFIX), params);
       }
       catch(MissingResourceException e) {
         // NoOp
       }
 
       return new FacesMessage(summary, detail);
     }
 
     /**
      *
      * @param context
      * @param messageId
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(FacesContext context, String messageId)
     {
         return getMessage(context, messageId, ((Object []) (null)));
     }
     
     public static FacesMessage getMessage(String bundleBaseName, FacesContext context, String messageId)
     {
         return getMessage(bundleBaseName, context, messageId, ((Object []) (null)));
     }
 
     /**
      *
      * @param context
      * @param messageId
      * @param params
      * @return generated FacesMessage
      */
     public static FacesMessage getMessage(FacesContext context, String messageId, Object params[])
     {
         if(context == null || messageId == null)
             throw new NullPointerException(" context " + context + " messageId " + messageId);
         Locale locale = getCurrentLocale(context);
         if(null == locale)
             throw new NullPointerException(" locale " + locale);
         FacesMessage message = getMessage(locale, messageId, params);
         if(message != null)
         {
             return message;
         } else
         {
             // TODO /FIX:  Note that this has fallback behavior to default Locale for message,
             // but similar behavior above does not.  The methods should probably behave
             locale = Locale.getDefault();
             return getMessage(locale, messageId, params);
         }
     }
     
     public static FacesMessage getMessage(String bundleBaseName, FacesContext context, String messageId, Object params[])
     {
         if(context == null || messageId == null)
             throw new NullPointerException(" context " + context + " messageId " + messageId);
         Locale locale = getCurrentLocale(context);
         if(null == locale)
             throw new NullPointerException(" locale " + locale);
         FacesMessage message = getMessageFromBundle(bundleBaseName, context, locale, messageId, params);
         if(message != null)
         {
             return message;
         } else
         {
             // TODO /FIX:  Note that this has fallback behavior to default Locale for message,
             // but similar behavior above does not.  The methods should probably behave
             locale = Locale.getDefault();
             return getMessageFromBundle(bundleBaseName, context, locale, messageId, params);
         }
     }
     
     public static Object getLabel(FacesContext facesContext, UIComponent component) {
         Object label = component.getAttributes().get("label");
         if(label != null)
             return label;
         
         ValueExpression expression = component.getValueExpression("label");
         if(expression != null)
             return expression;
         
         //If no label is not specified, use clientId
         return component.getClientId( facesContext );
     }
 
     private static Application getApplication()
     {
         FacesContext context = FacesContext.getCurrentInstance();
         if(context != null)
         {
             return context.getApplication();
         } else
         {
             ApplicationFactory afactory = (ApplicationFactory)FactoryFinder.getFactory("javax.faces.application.ApplicationFactory");
             return afactory.getApplication();
         }
     }
     
     private static ClassLoader getCurrentLoader(Object defaultObject)
     {
         ClassLoader loader = Thread.currentThread().getContextClassLoader();
         if(loader == null)
         {
             loader = defaultObject.getClass().getClassLoader();
         }
         return loader;
     }
     
 }