/*
 * IronJacamar, a Java EE Connector Architecture implementation
 * Copyright 2015, Red Hat Inc, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the Eclipse Public License 1.0 as
 * published by the Free Software Foundation.
 *
 * 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 Eclipse
 * Public License for more details.
 *
 * You should have received a copy of the Eclipse 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.ironjacamar.core.naming;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.NameNotFoundException;
import javax.naming.NamingException;

import org.jboss.logging.Logger;

/**
 * A static utility class for common JNDI operations.
 *
 * @author sstark@redhat.com
 * @author abrock@redhat.com
 */
@SuppressWarnings("unchecked")
class Util
{
   private static final Logger log = Logger.getLogger(Util.class);

   /**
    * Create a subcontext including any intermediate contexts.
    * @param ctx the parent JNDI Context under which value will be bound
    * @param name the name relative to ctx of the subcontext.
    * @return The new or existing JNDI subcontext
    * @throws NamingException on any JNDI failure
    */
   private static Context createSubcontext(Context ctx, Name name) throws NamingException
   {
      Context subctx = ctx;
      for (int pos = 0; pos < name.size(); pos++)
      {
         String ctxName = name.get(pos);
         try
         {
            subctx = (Context) ctx.lookup(ctxName);
         }
         catch (NameNotFoundException e)
         {
            subctx = ctx.createSubcontext(ctxName);
         }
         // The current subctx will be the ctx for the next name component
         ctx = subctx;
      }
      return subctx;
   }

   /**
    * Bind val to name in ctx, and make sure that all intermediate contexts exist
    * @param ctx the parent JNDI Context under which value will be bound
    * @param name the name relative to ctx where value will be bound
    * @param value the value to bind.
    * @throws NamingException for any error
    */
   public static void bind(Context ctx, String name, Object value) throws NamingException
   {
      Name n = ctx.getNameParser("").parse(name);
      bind(ctx, n, value);
   }

   /**
    * Bind val to name in ctx, and make sure that all intermediate contexts exist
    * @param ctx the parent JNDI Context under which value will be bound
    * @param name the name relative to ctx where value will be bound
    * @param value the value to bind.
    * @throws NamingException for any error
    */
   private static void bind(Context ctx, Name name, Object value) throws NamingException
   {
      int size = name.size();
      String atom = name.get(size - 1);
      Context parentCtx = createSubcontext(ctx, name.getPrefix(size - 1));
      parentCtx.bind(atom, value);
   }

   /**
    * Unbinds a name from ctx, and removes parents if they are empty
    * @param ctx the parent JNDI Context under which the name will be unbound
    * @param name The name to unbind
    * @throws NamingException for any error
    */
   public static void unbind(Context ctx, String name) throws NamingException
   {
      unbind(ctx, ctx.getNameParser("").parse(name));
   }

   /** 
    * Unbinds a name from ctx, and removes parents if they are empty
    * @param ctx the parent JNDI Context under which the name will be unbound
    * @param name The name to unbind
    * @throws NamingException for any error
    */
   private static void unbind(Context ctx, Name name) throws NamingException
   {
      ctx.unbind(name); //unbind the end node in the name
      int sz = name.size();
      // walk the tree backwards, stopping at the domain
      while (--sz > 0)
      {
         Name pname = name.getPrefix(sz);
         try
         {
            ctx.destroySubcontext(pname);
         }
         catch (NamingException e)
         {
            log.tracef("Unable to remove context: %s (%s)", pname, e);
            break;
         }
      }
   }
}