/*
 * Copyright (c) 1999, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.jndi.ldap.obj;

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.spi.DirObjectFactory;

import org.glassfish.jndi.toolkit.corba.CorbaUtils;
import org.omg.CORBA.ORB;

/**
  * A DirObjectFactory that returns a omg.org.CORBA.Object when given
  * attributes that contain the objectclass "corbaObject".
  * The form of <tt>getObjectInstance()</tt> that does not accept an
  * <tt>Attributes</tt> parameter always return null because using it
  * would impose too much overhead (incurs an extra search each time).
  * The caller should always use the form of <tt>getObjectInstance()</tt>
  * that accepts an <tt>Attributes</tt> parameter. This is the case if
  * the service provider uses <tt>DirectoryManager</tt>.
  *<p>
  * The LDAP schema for CORBA objects is:
  *<blockquote>
  * objectClass: top, corbaObject, corbaContainer
  * corbaIor: IOR of CORBA object
  *</blockquote>
  *
  * @author Rosanna Lee
  */
public class AttrsToCorba implements DirObjectFactory {
    public AttrsToCorba() {
    }

    /**
      * Returns a CORBA object if attributes represents a "corbaObject".
      * <p>
      * If <tt>attrs</tt>'s <tt>objectclass</tt> attribute has the value
      * "corbaObject" or "corbaobject", this factory will use the directory
      * entry's "corbaIor" attribute to get the stringified IOR, which is then
      * converted into a CORBA object. The "corbaIor" attribute is obtained
      * from <tt>attrs</tt>, and if not available from there, from the directory
      * using the <tt>DirContext</tt>, <tt>orig</tt>.
      *
      * @param orig The non-null DirContext object representing the directory entry;
      *     If not a DirContext, return null.
      * @param name Ignored
      * @param ctx  Ignored
      * @param env The possibly null environment properties. The caller can pass
      *        the ORB to use (via the <tt>java.naming.corba.orb</tt> property)
      *        or pass properties like the applet and the org.omg.CORBA.*
      *        properties for creating the ORB. If none of these is available,
      *     a default (static) ORB is used.
      * @param attrs The possibly null attributes containing at least the
      *        directory entry's <tt>objectclass</tt> attribute.
      * @return The CORBA object represented by the directory entry; null if
      *     the entry does not represent a CORBA object.
      * @exception NamingException If an error is encountered while getting the
      *     corbaIor attribute using <tt>orig</tt>.
      * @exception Exception If an error occurred while converting the IOR to
      *     a CORBA object or using the ORB.
      */
    @Override
    public Object getObjectInstance(Object orig, Name name, Context ctx, Hashtable env, Attributes attrs)
        throws Exception {
        Attribute oc;
        if (attrs != null
            && (oc = attrs.get("objectclass")) != null
            && (oc.contains("corbaObject") || oc.contains("corbaobject"))
            && orig instanceof DirContext) {

        // See if IOR already available
        Attribute iorAttr = attrs.get("corbaIor");

        if (iorAttr == null) {
            // have to get from directory
            attrs = ((DirContext)orig).getAttributes("",
            new String[]{"corbaIor"});
            iorAttr = attrs.get("corbaIor");
        }

        String ior = null;
        if (iorAttr != null && (ior = (String)iorAttr.get()) != null) {

            // Use ORB supplied or default ORB
            ORB orb = (env != null) ?
            (ORB)env.get("java.naming.corba.orb") : null;
            if (orb == null) {
            orb = getDefaultOrb(env);
            }

            // Convert IOR to Object
            return orb.string_to_object(ior);
        }

        // %%% else should we indicate any error or just ignore
        }

        // depend on
        return null;
    }

    /**
     * Always returns null.
     * @param orig Ignored
     * @param name Ignored
     * @param ctx Ignored
     * @param env Ignored
     * @return null
     * @exception Exception Never thrown
     */
    @Override
    public Object getObjectInstance(Object orig, Name name, Context ctx, Hashtable env) throws Exception {
        // Too expensive if we must fetch attributes each time,
        // effectively doubling all calls
        return null;
    }

    //private static ORB defaultOrb = null;

    /**
     * Return default ORB.
     * The ORB is used for turning a stringified IOR into an Object.
     *
     * @param env The possibly null environment properties. The caller can pass
     *         the ORB to use (via the <tt>java.naming.corba.orb</tt> property)
     *         or pass properties like the applet and the org.omg.CORBA.*
     *         properties for creating the ORB.
     * @return A non-null ORB.
     */
    private static ORB getDefaultOrb(Hashtable env) {
        return CorbaUtils.getOrb(null, -1, env);
    }
}