/*
    * 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.custom.selectOneLanguage;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Set;
  import java.util.TreeMap;
  
  import javax.faces.component.UISelectItems;
  import javax.faces.component.UIViewRoot;
  import javax.faces.context.FacesContext;
  import javax.faces.model.SelectItem;
  
  import org.apache.myfaces.component.html.ext.HtmlSelectOneMenu;
  import org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils;
  
  /**
   * A localized list of languages choose box. The value binds to the 
   * language ISO 639 code (lowercase). This is the same code as 
   * for java.util.Locale.getLanguage(). The official codes 
   * list is available here : 
   * 
   * http://www.loc.gov/standards/iso639-2/englangn.html 
   * 
   * Unless otherwise specified, all attributes accept static values or EL expressions.
   * 
   * @JSFComponent
   *   name = "t:selectOneLanguage"
   *   class = "org.apache.myfaces.custom.selectOneLanguage.SelectOneLanguage"
   *   tagClass = "org.apache.myfaces.custom.selectOneLanguage.SelectOneLanguageTag"
   * @since 1.1.7
   * @author Sylvain Vieujot (latest modification by $Author: lu4242 $)
   * @version $Revision: 691856 $ $Date: 2008-09-03 21:40:30 -0500 (Wed, 03 Sep 2008) $
   */
  public abstract class AbstractSelectOneLanguage extends HtmlSelectOneMenu {
      public static final String COMPONENT_TYPE = "org.apache.myfaces.SelectOneLanguage";
      private static final String DEFAULT_RENDERER_TYPE = "org.apache.myfaces.SelectOneLanguageRenderer";
  
      private Integer _maxLength = null;
      
      private String _emptySelection = null;
  
      public AbstractSelectOneLanguage() {
          setRendererType(DEFAULT_RENDERER_TYPE);
      }
  
      /**
       * Integer equals to the maximum number of characters in the language name.
       * 
       * @JSFProperty
       */
      public abstract Integer getMaxLength();
      
      /**
       * Label and value to be used when displaying an empty selection
       * 
       * @JSFProperty
       */
      public abstract String getEmptySelection();
  
      private Set getFilterSet(){
          List selectItems = RendererUtils.getSelectItemList( this );
          Set set = new HashSet( selectItems.size() );
  
          for (Iterator i = selectItems.iterator(); i.hasNext(); )
              set.add( ((SelectItem)i.next()).getValue().toString().toLowerCase() );
  
          return set;
      }
  
      protected List getLanguagesChoicesAsSelectItemList(){
          //return RendererUtils.getSelectItemList(component);
  
          Set filterSet = getFilterSet();
  
          String[] availableLanguages = Locale.getISOLanguages();
  
          Locale currentLocale;
  
         FacesContext facesContext = FacesContext.getCurrentInstance();
         UIViewRoot viewRoot = facesContext.getViewRoot();
         if( viewRoot != null )
             currentLocale = viewRoot.getLocale();
         else
             currentLocale = facesContext.getApplication().getDefaultLocale();
 
 
         TreeMap map = new TreeMap();
         // TreeMap is sorted according to the keys' natural order
 
         for(int i=0; i<availableLanguages.length; i++){
             String languageCode = availableLanguages[i];
             if( ! filterSet.isEmpty() && ! filterSet.contains(languageCode))
                 continue;
             Locale tmp = new Locale(languageCode);
             map.put(tmp.getDisplayLanguage(currentLocale), languageCode);
         }
 
         List languagesSelectItems = new ArrayList( map.size() );
         if(getEmptySelection() != null)
             languagesSelectItems.add(new SelectItem("", getEmptySelection()));
 
         Integer maxLength = getMaxLength();
         int maxDescriptionLength = maxLength==null ? Integer.MAX_VALUE : maxLength.intValue();
         if( maxDescriptionLength < 5 )
             maxDescriptionLength = 5;
 
         for(Iterator i = map.keySet().iterator(); i.hasNext(); ){
             String languageName = (String) i.next();
             String languageCode = (String) map.get( languageName );
             String label;
             if( languageName.length() <= maxDescriptionLength )
                 label = languageName;
             else
                 label = languageName.substring(0, maxDescriptionLength-3)+"...";
 
             languagesSelectItems.add( new SelectItem(languageCode, label) );
         }
 
         return languagesSelectItems;
     }
 
     protected void validateValue(FacesContext context, Object value) {
         UISelectItems selectItems = new UISelectItems();
         selectItems.setTransient(true);
         selectItems.setValue(getLanguagesChoicesAsSelectItemList());
         getChildren().add(selectItems);
         
         super.validateValue(context,value);
     }
 }