/*

  * 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.el.unified.resolver;

 import java.beans.FeatureDescriptor;

 import java.util.ArrayList;

 import java.util.Iterator;

 import java.util.Map;

 import java.util.ResourceBundle;

 import javax.el.ELContext;

 import javax.el.ELException;

 import javax.el.ELResolver;

 import javax.el.PropertyNotFoundException;

 import javax.el.PropertyNotWritableException;

 import javax.faces.application.Application;

 import javax.faces.context.FacesContext;

 import org.apache.myfaces.config.RuntimeConfig;

 /**

  * See JSF 1.2 spec section 5.6.1.4

  *

  * @author Stan Silvert

  */

 public final class ResourceBundleResolver extends ELResolver {

     /**

      * RuntimeConfig is instantiated once per servlet and never changes--we can

      * safely cache it

      */

     private RuntimeConfig runtimeConfig;

     /** Creates a new instance of ResourceBundleResolver */

     public ResourceBundleResolver() {

     }

     public void setValue(final ELContext context, final Object base, final Object property, final Object value)

         throws NullPointerException, PropertyNotFoundException, PropertyNotWritableException, ELException {

         if ((base == null) && (property == null)) throw new PropertyNotFoundException();

         if (!(property instanceof String)) return;

         final ResourceBundle bundle = getResourceBundle(context, (String)property);

         if (bundle != null) {

             throw new PropertyNotWritableException("ResourceBundles are read-only");

         }

     }

     public boolean isReadOnly(final ELContext context, final Object base, final Object property)

         throws NullPointerException, PropertyNotFoundException, ELException {

         if (base != null) return false;

         if (property == null) throw new PropertyNotFoundException();

         if (!(property instanceof String)) return false;

         final ResourceBundle bundle = getResourceBundle(context, (String)property);

         if (bundle != null) {

             context.setPropertyResolved(true);

             return true;

         }

         return false;

     }

     public Object getValue(final ELContext context, final Object base, final Object property)

         throws NullPointerException, PropertyNotFoundException, ELException {

         if (base != null) return null;

         if (property == null) throw new PropertyNotFoundException();

         if (!(property instanceof String)) return null;

         final ResourceBundle bundle = getResourceBundle(context, (String)property);

         if (bundle != null) {

             context.setPropertyResolved(true);

             return bundle;

         }

         return null;

     }

     public Class<?> getType(final ELContext context, final Object base, final Object property)

         throws NullPointerException, PropertyNotFoundException, ELException {

         if (base != null) return null;

         if (property == null) throw new PropertyNotFoundException();

         if (!(property instanceof String)) return null;

         final ResourceBundle bundle = getResourceBundle(context, (String)property);

         if (bundle != null) {

             context.setPropertyResolved(true);

             return ResourceBundle.class;

         }

         return null;

     }

     public Iterator<FeatureDescriptor> getFeatureDescriptors(final ELContext context, final Object base) {

         if (base != null) return null;

         final ArrayList<FeatureDescriptor> descriptors = new ArrayList<FeatureDescriptor>();

         final Map<String, org.apache.myfaces.config.impl.digester.elements.ResourceBundle> resourceBundles = runtimeConfig(context).getResourceBundles();

         for (org.apache.myfaces.config.impl.digester.elements.ResourceBundle resourceBundle : resourceBundles.values()) {

             descriptors.add(makeDescriptor(resourceBundle));

         }

         return descriptors.iterator();

     }

     public Class<?> getCommonPropertyType(final ELContext context, final Object base) {

         if (base != null) return null;

         return String.class;

     }

     // get the FacesContext from the ELContext

     private static FacesContext facesContext(final ELContext context) {

         return (FacesContext)context.getContext(FacesContext.class);

     }

     private static ResourceBundle getResourceBundle(final ELContext context, final String property) {

         final FacesContext facesContext = facesContext(context);

         if (facesContext != null) {

             final Application application = facesContext.getApplication();

             return application.getResourceBundle(facesContext, property);

         }

         return null;

     }

     protected RuntimeConfig runtimeConfig(ELContext context) {

         final FacesContext facesContext = facesContext(context);

         // application-level singleton - we can safely cache this

         if (this.runtimeConfig == null) {

             this.runtimeConfig = RuntimeConfig.getCurrentInstance(facesContext.getExternalContext());

         }

         return runtimeConfig;

     }

     private static FeatureDescriptor makeDescriptor(org.apache.myfaces.config.impl.digester.elements.ResourceBundle bundle) {

         final FeatureDescriptor fd = new FeatureDescriptor();

         fd.setValue(ELResolver.RESOLVABLE_AT_DESIGN_TIME, Boolean.TRUE);

         fd.setName(bundle.getVar());

         fd.setDisplayName(bundle.getDisplayName());

         fd.setValue(ELResolver.TYPE, ResourceBundle.class);

         fd.setShortDescription("");

         fd.setExpert(false);

         fd.setHidden(false);

         fd.setPreferred(true);

         return fd;

     }

 }