/*
    * 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.resource;
  
  import java.io.InputStream;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.Set;
  
  import javax.faces.context.FacesContext;
  import org.apache.myfaces.shared.resource.ResourceLoader;
  import org.apache.myfaces.shared.resource.ResourceMeta;
  import org.apache.myfaces.shared.resource.ResourceMetaImpl;
  
  /**
   * A resource loader implementation which loads resources from the webapp root.
   * It uses the methods on ExternalContext for handle resources.
   * 
   */
  public class RootExternalContextResourceLoader extends ResourceLoader
  {
  
      public RootExternalContextResourceLoader()
      {
          super("");
      }
  
      protected Set<String> getResourcePaths(String path)
      {
          if (path.startsWith("/"))
          {
              return FacesContext.getCurrentInstance().getExternalContext().getResourcePaths(path);
          }
          else
          {
              return FacesContext.getCurrentInstance().getExternalContext().getResourcePaths('/' + path);
          }
      }
  
      @Override
      public String getResourceVersion(String path)
      {
          return null;
      }
  
      @Override
      public String getLibraryVersion(String path)
      {
          return null;
      }
  
      //@Override
      public URL getResourceURL(String resourceId)
      {
          try
          {
              if (resourceId.startsWith("/"))
              {
                  return FacesContext.getCurrentInstance().getExternalContext().getResource(
                      resourceId);
              }
              else
              {
                  return FacesContext.getCurrentInstance().getExternalContext().getResource(
                      '/' + resourceId);
              }
          }
          catch (MalformedURLException e)
          {
              return null;
          }
      }
      
      @Override
      public URL getResourceURL(ResourceMeta resourceMeta)
      {
          if (resourceMeta.getLocalePrefix() != null)
          {
              // the webapp root folder cannot be localized, 
              // but if the resource lives in /contracts/[contract-name] it can be.
              return null;
          }
          return getResourceURL(resourceMeta.getResourceIdentifier());
     }
 
     @Override
     public InputStream getResourceInputStream(ResourceMeta resourceMeta)
     {
         return FacesContext.getCurrentInstance().getExternalContext().getResourceAsStream(
             '/' + resourceMeta.getResourceIdentifier());
     }
 
     @Override
     public ResourceMeta createResourceMeta(String prefix, String libraryName, String libraryVersion,
                                            String resourceName, String resourceVersion)
     {
         return new ResourceMetaImpl(prefix, libraryName, libraryVersion, resourceName, resourceVersion);
     }
 
     @Override
     public boolean libraryExists(String libraryName)
     {
         //No library can be created in root resolver
         return false;
     }
 }