/*
    * 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.taglib.core;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Enumeration;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.MissingResourceException;
  import java.util.ResourceBundle;
  import java.util.Set;
  
  import javax.faces.component.UIViewRoot;
  import javax.faces.context.FacesContext;
  import javax.faces.webapp.UIComponentTag;
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.tagext.Tag;
  import javax.servlet.jsp.tagext.TagSupport;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  /**
   * Loads a resource bundle and saves it as a variable in the request scope.
   * 
   * Unless otherwise specified, all attributes accept static values or EL expressions.
   * 
   * @JSFJspTag
   *   name="f:loadBundle"
   *   bodyContent="empty"
   *
   * @author Manfred Geiler (latest modification by $Author: skitching $)
   * @version $Revision: 673803 $ $Date: 2008-07-03 16:07:46 -0500 (Thu, 03 Jul 2008) $
   */
  public class LoadBundleTag
          extends TagSupport
  {
   /*
   * TODO:
   * We should find a way to save loaded bundles in the state, because otherwise
   * on the next request the bundle map will not be present before the render phase
   * and value bindings that reference to the bundle will always log annoying
   * "Variable 'xxx' could not be resolved" error messages.
   */
      
      private static final long serialVersionUID = -8892145684062838928L;
  
      private static final Log log = LogFactory.getLog(LoadBundleTag.class);
  
      private String _basename;
      private String _var;
  
      /**
       * The base name of the resource bundle.
       * 
       * @JSFJspAttribute
       *   required="true"
       */
      public void setBasename(String basename)
      {
          _basename = basename;
      }
  
      /**
       * The name of the variable in request scope that the resources
       * are saved to.  This must be a static value.
       *  
       * @JSFJspAttribute
       *   required="true"
       */
      public void setVar(String var)
      {
          _var = var;
      }
  
      public int doStartTag() throws JspException
      {
          FacesContext facesContext = FacesContext.getCurrentInstance();
          if (facesContext == null)
          {
              throw new JspException("No faces context?!");
         }
 
         try
         {
             resolveBundle(getBasename(facesContext));
         }
         catch(IllegalStateException ex)
         {
             throw new JspException(ex);
         }
 
         return Tag.SKIP_BODY;
     }
 
     private String getBasename(FacesContext facesContext) {
         String basename = null;
 
         if (_basename!=null) {
             if (UIComponentTag.isValueReference(_basename)) {
                 basename = (String)facesContext.getApplication().createValueBinding(_basename).getValue(facesContext);
             } else {
                 basename = _basename;
             }
         }
         return basename;
     }
 
     /**
      * This method is copied over to org.apache.myfaces.custom.loadbundle.LoadBundle.
      * If you change anything here, think about changing it there as well.
      *
      * @param resolvedBasename
      */
     private void resolveBundle(String resolvedBasename) {
         //ATTENTION: read comment above before changing this!
         FacesContext facesContext = FacesContext.getCurrentInstance();
 
         UIViewRoot viewRoot = facesContext.getViewRoot();
         if (viewRoot == null)
         {
             throw new IllegalStateException("No view root! LoadBundle must be nested inside <f:view> action.");
         }
 
         Locale locale = viewRoot.getLocale();
         if (locale == null)
         {
             locale = facesContext.getApplication().getDefaultLocale();
         }
 
         final ResourceBundle bundle;
         try
         {
             bundle = ResourceBundle.getBundle(resolvedBasename,
                                               locale,
                                               Thread.currentThread().getContextClassLoader());
 
             facesContext.getExternalContext().getRequestMap().put(_var,
                                                                   new BundleMap(bundle));
 
         }
         catch (MissingResourceException e)
         {
             log.error("Resource bundle '" + resolvedBasename + "' could not be found.",e);
         }
         //ATTENTION: read comment above before changing this!
     }
 
 
     /**
      * This class is copied over to org.apache.myfaces.custom.loadbundle.LoadBundle.
      * If you change anything here, think about changing it there as well.
      *
      */
     private static class BundleMap implements Map
     {
         //ATTENTION: read javadoc
         private ResourceBundle _bundle;
         private List _values;
 
         public BundleMap(ResourceBundle bundle)
         {
             _bundle = bundle;
         }
 
         //Optimized methods
 
         public Object get(Object key)
         {
             try {
                 return _bundle.getObject(key.toString());
             } catch (Exception e) {
                 return "MISSING: " + key + " :MISSING";
             }
         }
 
         public boolean isEmpty()
         {
             return !_bundle.getKeys().hasMoreElements();
         }
 
         public boolean containsKey(Object key)
         {
             try {
                 return _bundle.getObject(key.toString()) != null;
             } catch (MissingResourceException e) {
                 return false;
             }
         }
 
 
         //Unoptimized methods
 
         public Collection values()
         {
             if (_values == null)
             {
                 _values = new ArrayList();
                 for (Enumeration enumer = _bundle.getKeys(); enumer.hasMoreElements(); )
                 {
                     String v = _bundle.getString((String)enumer.nextElement());
                     _values.add(v);
                 }
             }
             return _values;
         }
 
         public int size()
         {
             return values().size();
         }
 
         public boolean containsValue(Object value)
         {
             return values().contains(value);
         }
 
         public Set entrySet()
         {
             Set set = new HashSet();
             for (Enumeration enumer = _bundle.getKeys(); enumer.hasMoreElements(); )
             {
                 final String k = (String)enumer.nextElement();
                 set.add(new Map.Entry() {
                     public Object getKey()
                     {
                         return k;
                     }
 
                     public Object getValue()
                     {
                         return _bundle.getObject(k);
                     }
 
                     public Object setValue(Object value)
                     {
                         throw new UnsupportedOperationException(this.getClass().getName() + " UnsupportedOperationException");
                     }
                 });
             }
             return set;
         }
 
         public Set keySet()
         {
             Set set = new HashSet();
             for (Enumeration enumer = _bundle.getKeys(); enumer.hasMoreElements(); )
             {
                 set.add(enumer.nextElement());
             }
             return set;
         }
         //ATTENTION: read javadoc
 
 
         //Unsupported methods
 
         public Object remove(Object key)
         {
             throw new UnsupportedOperationException(this.getClass().getName() + " UnsupportedOperationException");
         }
 
         public void putAll(Map t)
         {
             throw new UnsupportedOperationException(this.getClass().getName() + " UnsupportedOperationException");
         }
 
         public Object put(Object key, Object value)
         {
             throw new UnsupportedOperationException(this.getClass().getName() + " UnsupportedOperationException");
         }
 
         public void clear()
         {
             throw new UnsupportedOperationException(this.getClass().getName() + " UnsupportedOperationException");
         }
         //ATTENTION: read javadoc
     }
 
 }