/*

 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

package com.sun.jndi.ldap;

import javax.naming.*;

import javax.naming.directory.*;

import javax.naming.event.*;

import javax.naming.ldap.*;

import javax.naming.ldap.LdapName;

import java.util.Vector;

import com.sun.jndi.toolkit.ctx.Continuation;

/**

  * Gathers information to generate events by using the Persistent Search

  * control.

  *<p>

  * This class maintains a list of listeners all interested in the same

  * "search" request. It creates a thread that does the persistent search

  * and blocks, collecting the results of the search.

  * For each result that it receives from the search, it fires the

  * corresponding event to its listeners. If an exception is encountered,

  * it fires a NamingExceptionEvent.

  *

  * @author Rosanna Lee

  */

final class NamingEventNotifier implements Runnable {

    private final static boolean debug = false;

    private Vector<NamingListener> namingListeners;

    private Thread worker;

    private LdapCtx context;

    private EventContext eventSrc;

    private EventSupport support;

    private NamingEnumeration<SearchResult> results;

    // package private; used by EventSupport to remove it

    NotifierArgs info;

    NamingEventNotifier(EventSupport support, LdapCtx ctx, NotifierArgs info,

        NamingListener firstListener) throws NamingException {

        this.info = info;

        this.support = support;

        Control psearch;

        try {

            psearch = new PersistentSearchControl(

                info.mask,

                true /* no info about original entry(s) */,

                true /* additional info about changes */,

                Control.CRITICAL);

        } catch (java.io.IOException e) {

            NamingException ne = new NamingException(

                "Problem creating persistent search control");

            ne.setRootCause(e);

            throw ne;

        }

        // Add psearch control to existing list

        context = (LdapCtx)ctx.newInstance(new Control[]{psearch});

        eventSrc = ctx;

        namingListeners = new Vector<>();

        namingListeners.addElement(firstListener);

        worker = Obj.helper.createThread(this);

        worker.setDaemon(true);  // not a user thread

        worker.start();

    }

    // package private; used by EventSupport; namingListener already synchronized

    void addNamingListener(NamingListener l) {

        namingListeners.addElement(l);

    }

    // package private; used by EventSupport; namingListener already synchronized

    void removeNamingListener(NamingListener l) {

        namingListeners.removeElement(l);

    }

    // package private; used by EventSupport; namingListener already synchronized

    boolean hasNamingListeners() {

        return namingListeners.size() > 0;

    }

    /**

     * Execute "persistent search".

     * For each result, create the appropriate NamingEvent and

     * queue to be dispatched to listeners.

     */

    public void run() {

        try {

            Continuation cont = new Continuation();

            cont.setError(this, info.name);

            Name nm = (info.name == null || info.name.equals("")) ?

                new CompositeName() : new CompositeName().add(info.name);

            results = context.searchAux(nm, info.filter, info.controls,

                true, false, cont);

            // Change root of search results so that it will generate

            // names relative to the event context instead of that

            // named by nm

            ((LdapSearchEnumeration)(NamingEnumeration)results)

                    .setStartName(context.currentParsedDN);

            SearchResult si;

            Control[] respctls;

            EntryChangeResponseControl ec;

            long changeNum;

            while (results.hasMore()) {

                si = results.next();

                respctls = (si instanceof HasControls) ?

                    ((HasControls) si).getControls() : null;

                if (debug) {

                    System.err.println("notifier: " + si);

                    System.err.println("respCtls: " + respctls);

                }

                // Just process ECs; ignore all the rest

                if (respctls != null) {

                    for (int i = 0; i < respctls.length; i++) {

                        // %%% Should be checking OID instead of class

                        // %%% in case using someone else's  EC ctl

                        if (respctls[i] instanceof EntryChangeResponseControl) {

                            ec = (EntryChangeResponseControl)respctls[i];

                            changeNum = ec.getChangeNumber();

                            switch (ec.getChangeType()) {

                            case EntryChangeResponseControl.ADD:

                                fireObjectAdded(si, changeNum);

                                break;

                            case EntryChangeResponseControl.DELETE:

                                fireObjectRemoved(si, changeNum);

                                break;

                            case EntryChangeResponseControl.MODIFY:

                                fireObjectChanged(si, changeNum);

                                break;

                            case EntryChangeResponseControl.RENAME:

                                fireObjectRenamed(si, ec.getPreviousDN(),

                                    changeNum);

                                break;

                            }

                        }

                        break;

                    }

                }

            }

        } catch (InterruptedNamingException e) {

            if (debug) System.err.println("NamingEventNotifier Interrupted");

        } catch (NamingException e) {

            // Fire event to notify NamingExceptionEvent listeners

            fireNamingException(e);

            // This notifier is no longer valid

            support.removeDeadNotifier(info);

        } finally {

            cleanup();

        }

        if (debug) System.err.println("NamingEventNotifier finished");

    }

    private void cleanup() {

        if (debug) System.err.println("NamingEventNotifier cleanup");

        try {

            if (results != null) {

                if (debug) System.err.println("NamingEventNotifier enum closing");

                results.close(); // this will abandon the search

                results = null;

            }

            if (context != null) {

                if (debug) System.err.println("NamingEventNotifier ctx closing");

                context.close();

                context = null;

            }

        } catch (NamingException e) {}

    }

    /**

     * Stop the dispatcher so we can be destroyed.

     * package private; used by EventSupport

     */

    void stop() {

        if (debug) System.err.println("NamingEventNotifier being stopping");

        if (worker != null) {

            worker.interrupt(); // kill our thread

            worker = null;

        }

    }

    /**

     * Fire an "object added" event to registered NamingListeners.

     */

    private void fireObjectAdded(Binding newBd, long changeID) {

        if (namingListeners == null || namingListeners.size() == 0)

            return;

        NamingEvent e = new NamingEvent(eventSrc, NamingEvent.OBJECT_ADDED,

            newBd, null, changeID);

        support.queueEvent(e, namingListeners);

    }

    /**

     * Fire an "object removed" event to registered NamingListeners.

     */

    private void fireObjectRemoved(Binding oldBd, long changeID) {

        if (namingListeners == null || namingListeners.size() == 0)

            return;

        NamingEvent e = new NamingEvent(eventSrc, NamingEvent.OBJECT_REMOVED,

            null, oldBd, changeID);

        support.queueEvent(e, namingListeners);

    }

    /**

     * Fires an "object changed" event to registered NamingListeners.

     */

    private void fireObjectChanged(Binding newBd, long changeID) {

        if (namingListeners == null || namingListeners.size() == 0)

            return;

        // Name hasn't changed; construct old binding using name from new binding

        Binding oldBd = new Binding(newBd.getName(), null, newBd.isRelative());

        NamingEvent e = new NamingEvent(

            eventSrc, NamingEvent.OBJECT_CHANGED, newBd, oldBd, changeID);

        support.queueEvent(e, namingListeners);

    }

    /**

     * Fires an "object renamed" to registered NamingListeners.

     */

    private void fireObjectRenamed(Binding newBd, String oldDN, long changeID) {

        if (namingListeners == null || namingListeners.size() == 0)

            return;

        Binding oldBd = null;

        try {

            LdapName dn = new LdapName(oldDN);

            if (dn.startsWith(context.currentParsedDN)) {

                String relDN = dn.getSuffix(context.currentParsedDN.size()).toString();

                oldBd = new Binding(relDN, null);

            }

        } catch (NamingException e) {}

        if (oldBd == null) {

            oldBd = new Binding(oldDN, null, false /* not relative name */);

        }

        NamingEvent e = new NamingEvent(

            eventSrc, NamingEvent.OBJECT_RENAMED, newBd, oldBd, changeID);

        support.queueEvent(e, namingListeners);

    }

    private void fireNamingException(NamingException e) {

        if (namingListeners == null || namingListeners.size() == 0)

            return;

        NamingExceptionEvent evt = new NamingExceptionEvent(eventSrc, e);

        support.queueEvent(evt, namingListeners);

    }

}