/**
 * Copyright (C) 2009 eXo Platform SAS.
 * 
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.exoplatform.resolver;

import org.exoplatform.services.log.ExoLogger;
import org.exoplatform.services.log.Log;

import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * This class is an aggregation of ResourceResolver object and extends itself the ResourceResover class.
 * 
 * Hence every call to this ResourceResolver will in fact be delegated to one of the resolver it aggregates.
 * 
 * Created by The eXo Platform SAS
 * Oct 24, 2006
 */
public class ApplicationResourceResolver extends ResourceResolver
{

   protected static Log log = ExoLogger.getLogger("portal:ApplicationResourceResolver");

   private Map<String, ResourceResolver> resolvers_ = new HashMap<String, ResourceResolver>();

   /**
    * There are by default 2 resolvers already aggregated: 
    *  1) FileResourceResolver
    *  2) ClasspathResourceResolver
    */
   public ApplicationResourceResolver()
   {
      addResourceResolver(new FileResourceResolver());
      addResourceResolver(new ClasspathResourceResolver());
   }

   public ResourceResolver getResourceResolverByScheme(String scheme)
   {
      return resolvers_.get(scheme);
   }

   public ResourceResolver getResourceResolver(String url)
   {
      String scheme = "app:";
      int index = url.indexOf(":");
      if (index > 0)
         scheme = url.substring(0, index + 1);
      if (log.isDebugEnabled())
         log.debug("Try to extract resource resolver for the url: " + url);
      return resolvers_.get(scheme);
   }

   public void addResourceResolver(ResourceResolver resolver)
   {
      if (log.isDebugEnabled())
         log.debug("Add a resource resolver for the scheme: " + resolver.getResourceScheme());
      resolvers_.put(resolver.getResourceScheme(), resolver);
   }

   public URL getResource(String url) throws Exception
   {
      return getResourceResolver(url).getResource(url);
   }

   public InputStream getInputStream(String url) throws Exception
   {
      return getResourceResolver(url).getInputStream(url);
   }

   public List<URL> getResources(String url) throws Exception
   {
      return getResourceResolver(url).getResources(url);
   }

   public List<InputStream> getInputStreams(String url) throws Exception
   {
      return getResourceResolver(url).getInputStreams(url);
   }

   public boolean isModified(String url, long lastAccess)
   {
      return getResourceResolver(url).isModified(url, lastAccess);
   }

   public boolean isResolvable(String url)
   {
      return getResourceResolver(url) != null;
   }

   public String getResourceIdPrefix()
   {
      return Integer.toString(hashCode());
   }

   public String createResourceId(String url)
   {
      return hashCode() + ":" + url;
   }

   public String getResourceScheme()
   {
      return "app:";
   }
}
