// ========================================================================
   // Copyright (c) 2008-2009 Mort Bay Consulting Pty. Ltd.
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
   // The Apache License v2.0 is available at
  // http://www.opensource.org/licenses/apache2.0.php
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.plus.jndi;
  
  
  
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import javax.naming.Binding;
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.naming.Name;
  import javax.naming.NameNotFoundException;
  import javax.naming.NameParser;
  import javax.naming.NamingEnumeration;
  import javax.naming.NamingException;
  
  import org.eclipse.jetty.util.log.Log;
  
  
  public class NamingEntryUtil
  {
   
      
      /**
       * Link a name in a webapp's java:/comp/evn namespace to a pre-existing
       * resource. The pre-existing resource can be either in the webapp's
       * naming environment, or in the container's naming environment. Webapp's 
       * environment takes precedence over the server's namespace.
       *
       * @param scope the scope of the lookup
       * @param asName the name to bind as
       * @param mappedName the name from the environment to link to asName
       * @throws NamingException
       */
      public static boolean bindToENC (Object scope, String asName, String mappedName)
      throws NamingException
      {  
          if (asName==null||asName.trim().equals(""))
              throw new NamingException ("No name for NamingEntry");
  
          if (mappedName==null || "".equals(mappedName))
              mappedName=asName;
          
          NamingEntry entry = lookupNamingEntry (scope, mappedName);
          if (entry == null)
              return false;
          
          entry.bindToENC(asName);
          return true;
       }
  
      
      
   
  
      /**
       * Find a NamingEntry in the given scope.
       * 
       * @param scope
       * @param jndiName
       * @return the naming entry for the given scope
       * @throws NamingException
       */
      public static NamingEntry lookupNamingEntry (Object scope, String jndiName)
      throws NamingException
      {
          NamingEntry entry = null;
          try
          {         
              Name scopeName = getNameForScope(scope);
              InitialContext ic = new InitialContext();   
              NameParser parser = ic.getNameParser("");
              Name namingEntryName = makeNamingEntryName(parser, jndiName);  
              scopeName.addAll(namingEntryName);           
              entry =  (NamingEntry)ic.lookup(scopeName);
          }
          catch (NameNotFoundException ee)
          {
          }
  
          return entry;
      }
      
      
      public static Object lookup (Object scope, String jndiName)
     throws NamingException
     {
         Object o = null;
                 
             Name scopeName = getNameForScope(scope);
             InitialContext ic = new InitialContext();   
             NameParser parser = ic.getNameParser("");          
             scopeName.addAll(parser.parse(jndiName));           
             return ic.lookup(scopeName);
     }
 
     
     /** 
      * Get all NameEntries of a certain type in the given naming
      * environment scope (server-wide names or context-specific names)
      * 
      * @param scope 
      * @param clazz the type of the entry
      * @return all NameEntries of a certain type in the given naming environment scope (server-wide names or context-specific names)
      * @throws NamingException
      */
     public static List lookupNamingEntries (Object scope, Class clazz)
     throws NamingException
     { 
         try
         {
             Context scopeContext = getContextForScope(scope);
             Context namingEntriesContext = (Context)scopeContext.lookup(NamingEntry.__contextName);
             ArrayList list = new ArrayList();
             lookupNamingEntries(list, namingEntriesContext, clazz);
             return list;
         }
         catch (NameNotFoundException e)
         {
             return Collections.EMPTY_LIST;
         }
     }
     
     
     public static Name makeNamingEntryName (NameParser parser, NamingEntry namingEntry)
     throws NamingException
     {
         return makeNamingEntryName(parser, (namingEntry==null?null:namingEntry.getJndiName()));
     }
     
     public static Name makeNamingEntryName (NameParser parser, String jndiName)
     throws NamingException
     {
         if (jndiName==null)
             return null;
         
         if (parser==null)
         {
             InitialContext ic = new InitialContext();
             parser = ic.getNameParser("");
         }
         
         Name name = parser.parse("");
         name.add(NamingEntry.__contextName);
         name.addAll(parser.parse(jndiName));
         return name;
     }
     
 
     public static Name getNameForScope (Object scope)
     {
         try
         {
             InitialContext ic = new InitialContext();
             NameParser parser = ic.getNameParser("");
             Name name = parser.parse("");
             if (scope != null)
             {
                 name.add(canonicalizeScope(scope));
             }  
             return name;
         }
         catch (NamingException e)
         {
             Log.warn(e);
             return null;
         }
     }
 
     public static Context getContextForScope(Object scope)
     throws NamingException
     {
 
         InitialContext ic = new InitialContext();
         NameParser parser = ic.getNameParser("");
         Name name = parser.parse("");
         if (scope != null)
         {
             name.add(canonicalizeScope(scope));
         }  
         return (Context)ic.lookup(name);
     }
     
     public static Context getContextForNamingEntries (Object scope)
     throws NamingException
     {
         Context scopeContext = getContextForScope(scope);
         return (Context)scopeContext.lookup(NamingEntry.__contextName);
     }
 
     /**
      * Build up a list of NamingEntry objects that are of a specific type.
      * 
      * @param list
      * @param context
      * @param clazz
      * @return
      * @throws NamingException
      */
     private static List lookupNamingEntries (List list, Context context, Class clazz)
     throws NamingException
     {
         try
         {
             NamingEnumeration nenum = context.listBindings("");
             while (nenum.hasMoreElements())
             {
                 Binding binding = (Binding)nenum.next();
                 if (binding.getObject() instanceof Context)
                     lookupNamingEntries (list, (Context)binding.getObject(), clazz);
                 else if (clazz.isInstance(binding.getObject()))
                   list.add(binding.getObject());
             }
         }
         catch (NameNotFoundException e)
         {
             Log.debug("No entries of type "+clazz.getName()+" in context="+context);
         }
 
         return list;
     }
 
     private static String canonicalizeScope(Object scope)
     {
         if (scope==null)
             return "";
 
         String str = scope.getClass().getName()+"@"+scope.hashCode();
         str=str.replace('/', '_').replace(' ', '_');
         return str;
     }
 }