/*
    * 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.shared.resource;
  
  import java.io.IOException;
  import java.net.JarURLConnection;
  import java.net.URL;
  import java.net.URLConnection;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.Locale;
  import java.util.TimeZone;
  import org.apache.myfaces.shared.util.StringUtils;
  
  public class ResourceLoaderUtils
  {
      // TODO: In tomcat and jetty it is implemented a Flyweight pattern when converting
      // date headers. For now it is better keep this stuff simple.
      private static final String HTTP_RESPONSE_DATE_HEADER =
          "EEE, dd MMM yyyy HH:mm:ss zzz";
      
      private static final String[] HTTP_REQUEST_DATE_HEADER = {
              "EEE, dd MMM yyyy HH:mm:ss zzz", "EEEEEE, dd-MMM-yy HH:mm:ss zzz",
              "EEE MMMM d HH:mm:ss yyyy" };
      
      private static final TimeZone GMT = TimeZone.getTimeZone("GMT");
  
      public static String formatDateHeader(long value)
      {
          SimpleDateFormat format = new SimpleDateFormat(
                  HTTP_RESPONSE_DATE_HEADER,
                  Locale.US);
          format.setTimeZone(GMT);
          return format.format(new Date(value));
      }
      
      public static Long parseDateHeader(String value)
      {
          Date date = null;
          for (int i = 0; (date == null) && (i < HTTP_REQUEST_DATE_HEADER.length); i++)
          {
              try
              {
                  SimpleDateFormat format = new SimpleDateFormat(
                          HTTP_REQUEST_DATE_HEADER[i], Locale.US);
                  format.setTimeZone(GMT);
                  date = format.parse(value);
              }
              catch (ParseException e)
              {
                  // all fine
              }
          }
          if (date == null)
          {
              return null;
          }
          return Long.valueOf(date.getTime());
      }
      
      //Taken from trinidad URLUtils
      public static long getResourceLastModified(URL url) throws IOException
      {
          return getResourceLastModified(url.openConnection());
      }
  
      //Taken from trinidad URLUtils
      public static long getResourceLastModified(URLConnection connection) throws IOException
      {
          long modified;
          if (connection instanceof JarURLConnection)
          {
              // The following hack is required to work-around a JDK bug.
              // getLastModified() on a JAR entry URL delegates to the actual JAR file
              // rather than the JAR entry.
              // This opens internally, and does not close, an input stream to the JAR
              // file.
              // In turn, you cannot close it by yourself, because it's internal.
              // The work-around is to get the modification date of the JAR file
              // manually,
              // and then close that connection again.
  
             URL jarFileUrl = ((JarURLConnection) connection).getJarFileURL();
             URLConnection jarFileConnection = jarFileUrl.openConnection();
 
             try
             {
                 modified = jarFileConnection.getLastModified();
             }
             finally
             {
                 try
                 {
                     jarFileConnection.getInputStream().close();
                 }
                 catch (Exception exception)
                 {
                     // Ignored
                 }
             }
         }
         else
         {
             modified = connection.getLastModified();
         }
 
         return modified;
     }
     
     public static int getDepth(String path)
     {
         int depth = 0;
         String [] paths = StringUtils.splitShortString(path, '/');
         if (paths == null)
         {
             return 0;
         }
         for (String p : paths)
         {
             if (p != null && p.length() > 0)
             {
                 depth++;
             }
         }
         return depth;
     }
 
     public static boolean isDirectory(String path)
     {
         return path.startsWith("/") && path.endsWith("/");
     }
     
 }