/**
 * 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.activemq.security;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import javax.naming.Binding;
import javax.naming.Context;
import javax.naming.InvalidNameException;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.naming.event.EventDirContext;
import javax.naming.event.NamespaceChangeListener;
import javax.naming.event.NamingEvent;
import javax.naming.event.NamingExceptionEvent;
import javax.naming.event.ObjectChangeListener;
import javax.naming.ldap.LdapName;
import javax.naming.ldap.Rdn;

import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQQueue;
import org.apache.activemq.command.ActiveMQTopic;
import org.apache.activemq.filter.DestinationMapEntry;
import org.apache.activemq.jaas.UserPrincipal;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SimpleCachedLDAPAuthorizationMap implements AuthorizationMap {

    private static final Logger LOG = LoggerFactory.getLogger(SimpleCachedLDAPAuthorizationMap.class);

    // Configuration Options
    private final String initialContextFactory = "com.sun.jndi.ldap.LdapCtxFactory";
    private String connectionURL = "ldap://localhost:1024";
    private String connectionUsername = "uid=admin,ou=system";
    private String connectionPassword;
    private String connectionProtocol = "s";
    private String authentication = "simple";

    private int queuePrefixLength = 4;
    private int topicPrefixLength = 4;
    private int tempPrefixLength = 4;

    private String queueSearchBase = "ou=Queue,ou=Destination,ou=ActiveMQ,ou=system";
    private String topicSearchBase = "ou=Topic,ou=Destination,ou=ActiveMQ,ou=system";
    private String tempSearchBase = "ou=Temp,ou=Destination,ou=ActiveMQ,ou=system";

    private String permissionGroupMemberAttribute = "member";

    private String adminPermissionGroupSearchFilter = "(cn=Admin)";
    private String readPermissionGroupSearchFilter = "(cn=Read)";
    private String writePermissionGroupSearchFilter = "(cn=Write)";

    private boolean legacyGroupMapping = true;
    private String groupObjectClass = "groupOfNames";
    private String userObjectClass = "person";
    private String groupNameAttribute = "cn";
    private String userNameAttribute = "uid";

    private int refreshInterval = -1;
    private boolean refreshDisabled = false;

    protected String groupClass = DefaultAuthorizationMap.DEFAULT_GROUP_CLASS;

    // Internal State
    private long lastUpdated = -1;

    private static String ANY_DESCENDANT = "\\$";

    protected DirContext context;
    private EventDirContext eventContext;

    private final AtomicReference<DefaultAuthorizationMap> map =
        new AtomicReference<DefaultAuthorizationMap>(new DefaultAuthorizationMap());
    private final ThreadPoolExecutor updaterService;

    protected Map<ActiveMQDestination, AuthorizationEntry> entries =
        new ConcurrentHashMap<ActiveMQDestination, AuthorizationEntry>();

    public SimpleCachedLDAPAuthorizationMap() {
        // Allow for only a couple outstanding update request, they can be slow so we
        // don't want a bunch to pile up for no reason.
        updaterService = new ThreadPoolExecutor(0, 1, 60, TimeUnit.SECONDS,
            new LinkedBlockingQueue<Runnable>(2),
            new ThreadFactory() {

                @Override
                public Thread newThread(Runnable r) {
                    return new Thread(r, "SimpleCachedLDAPAuthorizationMap update thread");
                }
            });
        updaterService.setRejectedExecutionHandler(new ThreadPoolExecutor.DiscardPolicy());
    }

    protected DirContext createContext() throws NamingException {
        Hashtable<String, String> env = new Hashtable<String, String>();
        env.put(Context.INITIAL_CONTEXT_FACTORY, initialContextFactory);
        if (connectionUsername != null && !"".equals(connectionUsername)) {
            env.put(Context.SECURITY_PRINCIPAL, connectionUsername);
        } else {
            throw new NamingException("Empty username is not allowed");
        }
        if (connectionPassword != null && !"".equals(connectionPassword)) {
            env.put(Context.SECURITY_CREDENTIALS, connectionPassword);
        } else {
            throw new NamingException("Empty password is not allowed");
        }
        env.put(Context.SECURITY_PROTOCOL, connectionProtocol);
        env.put(Context.PROVIDER_URL, connectionURL);
        env.put(Context.SECURITY_AUTHENTICATION, authentication);
        return new InitialDirContext(env);
    }

    protected boolean isContextAlive() {
        boolean alive = false;
        if (context != null) {
            try {
                context.getAttributes("");
                alive = true;
            } catch (Exception e) {
            }
        }
        return alive;
    }

    /**
     * Returns the existing open context or creates a new one and registers listeners for push notifications if such an
     * update style is enabled. This implementation should not be invoked concurrently.
     *
     * @return the current context
     *
     * @throws NamingException
     *             if there is an error setting things up
     */
    protected DirContext open() throws NamingException {
        if (isContextAlive()) {
            return context;
        }

        try {
            context = createContext();
            if (refreshInterval == -1 && !refreshDisabled) {
                eventContext = ((EventDirContext) context.lookup(""));

                final SearchControls constraints = new SearchControls();
                constraints.setSearchScope(SearchControls.SUBTREE_SCOPE);

                // Listeners for Queue policy //

                // Listeners for each type of permission
                for (PermissionType permissionType : PermissionType.values()) {
                    eventContext.addNamingListener(queueSearchBase, getFilterForPermissionType(permissionType), constraints,
                        this.new CachedLDAPAuthorizationMapNamespaceChangeListener(DestinationType.QUEUE, permissionType));
                }
                // Listener for changes to the destination pattern entry itself and not a permission entry.
                eventContext.addNamingListener(queueSearchBase, "cn=*", new SearchControls(), this.new CachedLDAPAuthorizationMapNamespaceChangeListener(
                    DestinationType.QUEUE, null));

                // Listeners for Topic policy //

                // Listeners for each type of permission
                for (PermissionType permissionType : PermissionType.values()) {
                    eventContext.addNamingListener(topicSearchBase, getFilterForPermissionType(permissionType), constraints,
                        this.new CachedLDAPAuthorizationMapNamespaceChangeListener(DestinationType.TOPIC, permissionType));
                }
                // Listener for changes to the destination pattern entry itself and not a permission entry.
                eventContext.addNamingListener(topicSearchBase, "cn=*", new SearchControls(), this.new CachedLDAPAuthorizationMapNamespaceChangeListener(
                    DestinationType.TOPIC, null));

                // Listeners for Temp policy //

                // Listeners for each type of permission
                for (PermissionType permissionType : PermissionType.values()) {
                    eventContext.addNamingListener(tempSearchBase, getFilterForPermissionType(permissionType), constraints,
                        this.new CachedLDAPAuthorizationMapNamespaceChangeListener(DestinationType.TEMP, permissionType));
                }

            }
        } catch (NamingException e) {
            context = null;
            throw e;
        }

        return context;
    }

    /**
     * Queries the directory and initializes the policy based on the data in the directory. This implementation should
     * not be invoked concurrently.
     *
     * @throws Exception
     *             if there is an unrecoverable error processing the directory contents
     */
    @SuppressWarnings("rawtypes")
    protected synchronized void query() throws Exception {
        DirContext currentContext = open();
        entries.clear();

        final SearchControls constraints = new SearchControls();
        constraints.setSearchScope(SearchControls.SUBTREE_SCOPE);

        DefaultAuthorizationMap newMap = new DefaultAuthorizationMap();
        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(newMap,
                    currentContext.search(queueSearchBase, getFilterForPermissionType(permissionType),
                    constraints), DestinationType.QUEUE, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '{}' with filter '{}'", new Object[]{ queueSearchBase, getFilterForPermissionType(permissionType) }, e);
            }
        }

        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(newMap,
                    currentContext.search(topicSearchBase, getFilterForPermissionType(permissionType),
                    constraints), DestinationType.TOPIC, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '{}' with filter '{}'", new Object[]{ topicSearchBase, getFilterForPermissionType(permissionType) }, e);
            }
        }

        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(newMap,
                    currentContext.search(tempSearchBase, getFilterForPermissionType(permissionType),
                    constraints), DestinationType.TEMP, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '{}' with filter '{}'", new Object[]{ tempSearchBase, getFilterForPermissionType(permissionType) }, e);
            }
        }

        // Create and swap in the new instance with updated LDAP data.
        newMap.setAuthorizationEntries(new ArrayList<DestinationMapEntry>(entries.values()));
        newMap.setGroupClass(groupClass);
        this.map.set(newMap);

        updated();
    }

    /**
     * Processes results from a directory query in the context of a given destination type and permission type. This
     * implementation should not be invoked concurrently.
     *
     * @param results
     *            the results to process
     * @param destinationType
     *            the type of the destination for which the directory results apply
     * @param permissionType
     *            the type of the permission for which the directory results apply
     *
     * @throws Exception
     *             if there is an error processing the results
     */
    protected void processQueryResults(DefaultAuthorizationMap map, NamingEnumeration<SearchResult> results, DestinationType destinationType, PermissionType permissionType)
        throws Exception {

        while (results.hasMore()) {
            SearchResult result = results.next();
            AuthorizationEntry entry = null;

            try {
                entry = getEntry(map, new LdapName(result.getNameInNamespace()), destinationType);
            } catch (Exception e) {
                LOG.error("Policy not applied!  Error parsing authorization policy entry under {}", result.getNameInNamespace(), e);
                continue;
            }

            applyACL(entry, result, permissionType);
        }
    }

    /**
     * Marks the time at which the authorization state was last refreshed. Relevant for synchronous
     * policy updates. This implementation should not be invoked concurrently.
     */
    protected void updated() {
        lastUpdated = System.currentTimeMillis();
    }

    /**
     * Retrieves or creates the {@link AuthorizationEntry} that corresponds to the DN in {@code dn}. This implementation
     * should not be invoked concurrently.
     *
     * @param map
     *            the DefaultAuthorizationMap to operate on.
     * @param dn
     *            the DN representing the policy entry in the directory
     * @param destinationType
     *            the type of the destination to get/create the entry for
     *
     * @return the corresponding authorization entry for the DN
     *
     * @throws IllegalArgumentException
     *             if destination type is not one of {@link DestinationType#QUEUE}, {@link DestinationType#TOPIC},
     *             {@link DestinationType#TEMP} or if the policy entry DN is malformed
     */
    protected AuthorizationEntry getEntry(DefaultAuthorizationMap map, LdapName dn, DestinationType destinationType) {
        AuthorizationEntry entry = null;
        switch (destinationType) {
            case TEMP:
                // handle temp entry
                if (dn.size() != getPrefixLengthForDestinationType(destinationType) + 1) {
                    // handle unknown entry
                    throw new IllegalArgumentException("Malformed policy structure for a temporary destination "
                        + "policy entry.  The permission group entries should be immediately below the " + "temporary policy base DN.");
                }
                entry = map.getTempDestinationAuthorizationEntry();
                if (entry == null) {
                    entry = new TempDestinationAuthorizationEntry();
                    map.setTempDestinationAuthorizationEntry((TempDestinationAuthorizationEntry) entry);
                }

                break;

            case QUEUE:
            case TOPIC:
                // handle regular destinations
                if (dn.size() != getPrefixLengthForDestinationType(destinationType) + 2) {
                    throw new IllegalArgumentException("Malformed policy structure for a queue or topic destination "
                        + "policy entry.  The destination pattern and permission group entries should be " + "nested below the queue or topic policy base DN.");
                }

                ActiveMQDestination dest = formatDestination(dn, destinationType);

                if (dest != null) {
                    entry = entries.get(dest);
                    if (entry == null) {
                        entry = new AuthorizationEntry();
                        entry.setDestination(dest);
                        entries.put(dest, entry);
                    }
                }

                break;
            default:
                // handle unknown entry
                throw new IllegalArgumentException("Unknown destination type " + destinationType);
        }

        return entry;
    }

    /**
     * Applies the policy from the directory to the given entry within the context of the provided permission type.
     *
     * @param entry
     *            the policy entry to apply the policy to
     * @param result
     *            the results from the directory to apply to the policy entry
     * @param permissionType
     *            the permission type of the data in the directory
     *
     * @throws NamingException
     *             if there is an error applying the ACL
     */
    protected void applyACL(AuthorizationEntry entry, SearchResult result, PermissionType permissionType) throws NamingException {

        // Find members
        Attribute memberAttribute = result.getAttributes().get(permissionGroupMemberAttribute);
        NamingEnumeration<?> memberAttributeEnum = memberAttribute.getAll();

        HashSet<Object> members = new HashSet<Object>();

        while (memberAttributeEnum.hasMoreElements()) {
            String memberDn = (String) memberAttributeEnum.nextElement();
            boolean group = false;
            boolean user = false;
            String principalName = null;

            if (!legacyGroupMapping) {
                // Lookup of member to determine principal type (group or user) and name.
                Attributes memberAttributes;
                try {
                    memberAttributes = context.getAttributes(memberDn, new String[] { "objectClass", groupNameAttribute, userNameAttribute });
                } catch (NamingException e) {
                    LOG.error("Policy not applied! Unknown member {} in policy entry {}", new Object[]{ memberDn, result.getNameInNamespace() }, e);
                    continue;
                }

                Attribute memberEntryObjectClassAttribute = memberAttributes.get("objectClass");
                NamingEnumeration<?> memberEntryObjectClassAttributeEnum = memberEntryObjectClassAttribute.getAll();

                while (memberEntryObjectClassAttributeEnum.hasMoreElements()) {
                    String objectClass = (String) memberEntryObjectClassAttributeEnum.nextElement();

                    if (objectClass.equalsIgnoreCase(groupObjectClass)) {
                        group = true;
                        Attribute name = memberAttributes.get(groupNameAttribute);
                        if (name == null) {
                            LOG.error("Policy not applied! Group {} does not have name attribute {} under entry {}", new Object[]{ memberDn, groupNameAttribute, result.getNameInNamespace() });
                            break;
                        }

                        principalName = (String) name.get();
                    }

                    if (objectClass.equalsIgnoreCase(userObjectClass)) {
                        user = true;
                        Attribute name = memberAttributes.get(userNameAttribute);
                        if (name == null) {
                            LOG.error("Policy not applied! User {} does not have name attribute {} under entry {}", new Object[]{ memberDn, userNameAttribute, result.getNameInNamespace() });
                            break;
                        }

                        principalName = (String) name.get();
                    }
                }

            } else {
                group = true;
                principalName = memberDn.replaceAll("(cn|CN)=", "");
            }

            if ((!group && !user) || (group && user)) {
                LOG.error("Policy not applied! Can't determine type of member {} under entry {}", memberDn, result.getNameInNamespace());
            } else if (principalName != null) {
                DefaultAuthorizationMap map = this.map.get();
                if (group && !user) {
                    try {
                        members.add(DefaultAuthorizationMap.createGroupPrincipal(principalName, map.getGroupClass()));
                    } catch (Exception e) {
                        NamingException ne = new NamingException(
                            "Can't create a group " + principalName + " of class " + map.getGroupClass());
                        ne.initCause(e);
                        throw ne;
                    }
                } else if (!group && user) {
                    members.add(new UserPrincipal(principalName));
                }
            }
        }

        try {
            applyAcl(entry, permissionType, members);
        } catch (Exception e) {
            LOG.error("Policy not applied! Error adding principals to ACL under {}", result.getNameInNamespace(), e);
        }
    }

    /**
     * Applies policy to the entry given the actual principals that will be applied to the policy entry.
     *
     * @param entry
     *            the policy entry to which the policy should be applied
     * @param permissionType
     *            the type of the permission that the policy will be applied to
     * @param acls
     *            the principals that represent the actual policy
     *
     * @throw IllegalArgumentException if {@code permissionType} is unsupported
     */
    protected void applyAcl(AuthorizationEntry entry, PermissionType permissionType, Set<Object> acls) {

        switch (permissionType) {
            case READ:
                entry.setReadACLs(acls);
                break;
            case WRITE:
                entry.setWriteACLs(acls);
                break;
            case ADMIN:
                entry.setAdminACLs(acls);
                break;
            default:
                throw new IllegalArgumentException("Unknown permission " + permissionType + ".");
        }
    }

    /**
     * Parses a DN into the equivalent {@link ActiveMQDestination}. The default implementation expects a format of
     * cn=<PERMISSION_NAME>,ou=<DESTINATION_PATTERN>,.... or ou=<DESTINATION_PATTERN>,.... for permission and
     * destination entries, respectively. For example {@code cn=admin,ou=$,ou=...} or {@code ou=$,ou=...}.
     *
     * @param dn
     *            the DN to parse
     * @param destinationType
     *            the type of the destination that we are parsing
     *
     * @return the destination that the DN represents
     *
     * @throws IllegalArgumentException
     *             if {@code destinationType} is {@link DestinationType#TEMP} or if the format of {@code dn} is
     *             incorrect for for a topic or queue
     *
     * @see #formatDestination(Rdn, DestinationType)
     */
    protected ActiveMQDestination formatDestination(LdapName dn, DestinationType destinationType) {
        ActiveMQDestination destination = null;

        switch (destinationType) {
            case QUEUE:
            case TOPIC:
                // There exists a need to deal with both names representing a permission or simply a
                // destination. As such, we need to determine the proper RDN to work with based
                // on the destination type and the DN size.
                if (dn.size() == (getPrefixLengthForDestinationType(destinationType) + 2)) {
                    destination = formatDestination(dn.getRdn(dn.size() - 2), destinationType);
                } else if (dn.size() == (getPrefixLengthForDestinationType(destinationType) + 1)) {
                    destination = formatDestination(dn.getRdn(dn.size() - 1), destinationType);
                } else {
                    throw new IllegalArgumentException("Malformed DN for representing a permission or destination entry.");
                }
                break;
            default:
                throw new IllegalArgumentException("Cannot format destination for destination type " + destinationType);
        }

        return destination;
    }

    /**
     * Parses RDN values representing the destination name/pattern and destination type into the equivalent
     * {@link ActiveMQDestination}.
     *
     * @param destinationName
     *            the RDN representing the name or pattern for the destination
     * @param destinationType
     *            the type of the destination
     *
     * @return the destination that the RDN represent
     *
     * @throws IllegalArgumentException
     *             if {@code destinationType} is not one of {@link DestinationType#TOPIC} or
     *             {@link DestinationType#QUEUE}.
     *
     * @see #formatDestinationName(Rdn)
     * @see #formatDestination(LdapName, DestinationType)
     */
    protected ActiveMQDestination formatDestination(Rdn destinationName, DestinationType destinationType) {
        ActiveMQDestination dest = null;

        switch (destinationType) {
            case QUEUE:
                dest = new ActiveMQQueue(formatDestinationName(destinationName));
                break;
            case TOPIC:
                dest = new ActiveMQTopic(formatDestinationName(destinationName));
                break;
            default:
                throw new IllegalArgumentException("Unknown destination type: " + destinationType);
        }

        return dest;
    }

    /**
     * Parses the RDN representing a destination name/pattern into the standard string representation of the
     * name/pattern. This implementation does not care about the type of the RDN such that the RDN could be a CN or OU.
     *
     * @param destinationName
     *            the RDN representing the name or pattern for the destination
     *
     * @see #formatDestination(Rdn, Rdn)
     */
    protected String formatDestinationName(Rdn destinationName) {
        return destinationName.getValue().toString().replaceAll(ANY_DESCENDANT, ">");
    }

    /**
     * Transcribes an existing set into a new set. Used to make defensive copies for concurrent access.
     *
     * @param source
     *            the source set or {@code null}
     *
     * @return a new set containing the same elements as {@code source} or {@code null} if {@code source} is
     *         {@code null}
     */
    protected <T> Set<T> transcribeSet(Set<T> source) {
        if (source != null) {
            return new HashSet<T>(source);
        } else {
            return null;
        }
    }

    /**
     * Returns the filter string for the given permission type.
     *
     * @throws IllegalArgumentException
     *             if {@code permissionType} is not supported
     *
     * @see #setAdminPermissionGroupSearchFilter(String)
     * @see #setReadPermissionGroupSearchFilter(String)
     * @see #setWritePermissionGroupSearchFilter(String)
     */
    protected String getFilterForPermissionType(PermissionType permissionType) {
        String filter = null;

        switch (permissionType) {
            case ADMIN:
                filter = adminPermissionGroupSearchFilter;
                break;
            case READ:
                filter = readPermissionGroupSearchFilter;
                break;
            case WRITE:
                filter = writePermissionGroupSearchFilter;
                break;
            default:
                throw new IllegalArgumentException("Unknown permission type " + permissionType);
        }

        return filter;
    }

    /**
     * Returns the DN prefix size based on the given destination type.
     *
     * @throws IllegalArgumentException
     *             if {@code destinationType} is not supported
     *
     * @see #setQueueSearchBase(String)
     * @see #setTopicSearchBase(String)
     * @see #setTempSearchBase(String)
     */
    protected int getPrefixLengthForDestinationType(DestinationType destinationType) {
        int filter = 0;

        switch (destinationType) {
            case QUEUE:
                filter = queuePrefixLength;
                break;
            case TOPIC:
                filter = topicPrefixLength;
                break;
            case TEMP:
                filter = tempPrefixLength;
                break;
            default:
                throw new IllegalArgumentException("Unknown permission type " + destinationType);
        }

        return filter;
    }

    /**
     * Performs a check for updates from the server in the event that synchronous updates are enabled and are the
     * refresh interval has elapsed.
     */
    protected void checkForUpdates() {
        if (lastUpdated == -1) {
            //ACL's have never been queried, but we need them NOW as we're being asked for them. 
            try {
                query();
                return;
            } catch (Exception e) {
                LOG.error("Error updating authorization map.  Partial policy may be applied until the next successful update.", e);
            }
        }

        if (context != null && refreshDisabled) {
            return;
        }
        
        if (context == null || (!refreshDisabled && (refreshInterval != -1 && System.currentTimeMillis() >= lastUpdated + refreshInterval))) {
            this.updaterService.execute(new Runnable() {
                @Override
                public void run() {

                    // Check again in case of stacked update request.
                    if (context == null || (!refreshDisabled &&
                        (refreshInterval != -1 && System.currentTimeMillis() >= lastUpdated + refreshInterval))) {

                        if (!isContextAlive()) {
                            try {
                                context = createContext();
                            } catch (NamingException ne) {
                                // LDAP is down, use already cached values
                                return;
                            }
                        }

                        LOG.debug("Updating authorization map!");
                        try {
                            query();
                        } catch (Exception e) {
                            LOG.error("Error updating authorization map.  Partial policy may be applied until the next successful update.", e);
                        }
                    }
                }
            });
        }
    }

    // Authorization Map

    /**
     * Provides synchronized and defensive access to the admin ACLs for temp destinations as the super implementation
     * returns live copies of the ACLs and {@link AuthorizationEntry} is not setup for concurrent access.
     */
    @Override
    public Set<Object> getTempDestinationAdminACLs() {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return transcribeSet(map.getTempDestinationAdminACLs());
    }

    /**
     * Provides synchronized and defensive access to the read ACLs for temp destinations as the super implementation
     * returns live copies of the ACLs and {@link AuthorizationEntry} is not setup for concurrent access.
     */
    @Override
    public Set<Object> getTempDestinationReadACLs() {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return transcribeSet(map.getTempDestinationReadACLs());
    }

    /**
     * Provides synchronized and defensive access to the write ACLs for temp destinations as the super implementation
     * returns live copies of the ACLs and {@link AuthorizationEntry} is not setup for concurrent access.
     */
    @Override
    public Set<Object> getTempDestinationWriteACLs() {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return transcribeSet(map.getTempDestinationWriteACLs());
    }

    /**
     * Provides synchronized access to the admin ACLs for the destinations as {@link AuthorizationEntry}
     * is not setup for concurrent access.
     */
    @Override
    public Set<Object> getAdminACLs(ActiveMQDestination destination) {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return map.getAdminACLs(destination);
    }

    /**
     * Provides synchronized access to the read ACLs for the destinations as {@link AuthorizationEntry} is not setup for
     * concurrent access.
     */
    @Override
    public Set<Object> getReadACLs(ActiveMQDestination destination) {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return map.getReadACLs(destination);
    }

    /**
     * Provides synchronized access to the write ACLs for the destinations as {@link AuthorizationEntry} is not setup
     * for concurrent access.
     */
    @Override
    public Set<Object> getWriteACLs(ActiveMQDestination destination) {
        checkForUpdates();
        DefaultAuthorizationMap map = this.map.get();
        return map.getWriteACLs(destination);
    }

    /**
     * Handler for new policy entries in the directory.
     *
     * @param namingEvent
     *            the new entry event that occurred
     * @param destinationType
     *            the type of the destination to which the event applies
     * @param permissionType
     *            the permission type to which the event applies
     */
    public void objectAdded(NamingEvent namingEvent, DestinationType destinationType, PermissionType permissionType) {
        LOG.debug("Adding object: {}", namingEvent.getNewBinding());
        SearchResult result = (SearchResult) namingEvent.getNewBinding();

        try {
            DefaultAuthorizationMap map = this.map.get();
            LdapName name = new LdapName(result.getName());
            AuthorizationEntry entry = getEntry(map, name, destinationType);

            applyACL(entry, result, permissionType);
            if (!(entry instanceof TempDestinationAuthorizationEntry)) {
                map.put(entry.getDestination(), entry);
            }
        } catch (InvalidNameException e) {
            LOG.error("Policy not applied!  Error parsing DN for addition of {}", result.getName(), e);
        } catch (Exception e) {
            LOG.error("Policy not applied!  Error processing object addition for addition of {}", result.getName(), e);
        }
    }

    /**
     * Handler for removed policy entries in the directory.
     *
     * @param namingEvent
     *            the removed entry event that occurred
     * @param destinationType
     *            the type of the destination to which the event applies
     * @param permissionType
     *            the permission type to which the event applies
     */
    public void objectRemoved(NamingEvent namingEvent, DestinationType destinationType, PermissionType permissionType) {
        LOG.debug("Removing object: {}", namingEvent.getOldBinding());
        Binding result = namingEvent.getOldBinding();

        try {
            DefaultAuthorizationMap map = this.map.get();
            LdapName name = new LdapName(result.getName());
            AuthorizationEntry entry = getEntry(map, name, destinationType);
            applyAcl(entry, permissionType, new HashSet<Object>());
        } catch (InvalidNameException e) {
            LOG.error("Policy not applied!  Error parsing DN for object removal for removal of {}", result.getName(), e);
        } catch (Exception e) {
            LOG.error("Policy not applied!  Error processing object removal for removal of {}", result.getName(), e);
        }
    }

    /**
     * Handler for renamed policy entries in the directory. This handler deals with the renaming of destination entries
     * as well as permission entries. If the permission type is not null, it is assumed that we are dealing with the
     * renaming of a permission entry. Otherwise, it is assumed that we are dealing with the renaming of a destination
     * entry.
     *
     * @param namingEvent
     *            the renaming entry event that occurred
     * @param destinationType
     *            the type of the destination to which the event applies
     * @param permissionType
     *            the permission type to which the event applies
     */
    public void objectRenamed(NamingEvent namingEvent, DestinationType destinationType, PermissionType permissionType) {
        Binding oldBinding = namingEvent.getOldBinding();
        Binding newBinding = namingEvent.getNewBinding();
        LOG.debug("Renaming object: {} to {}", oldBinding, newBinding);

        try {
            LdapName oldName = new LdapName(oldBinding.getName());
            ActiveMQDestination oldDest = formatDestination(oldName, destinationType);

            LdapName newName = new LdapName(newBinding.getName());
            ActiveMQDestination newDest = formatDestination(newName, destinationType);

            if (permissionType != null) {
                // Handle the case where a permission entry is being renamed.
                objectRemoved(namingEvent, destinationType, permissionType);

                SearchControls controls = new SearchControls();
                controls.setSearchScope(SearchControls.OBJECT_SCOPE);

                boolean matchedToType = false;

                for (PermissionType newPermissionType : PermissionType.values()) {
                    NamingEnumeration<SearchResult> results = context.search(newName, getFilterForPermissionType(newPermissionType), controls);

                    if (results.hasMore()) {
                        objectAdded(namingEvent, destinationType, newPermissionType);
                        matchedToType = true;
                        break;
                    }
                }

                if (!matchedToType) {
                    LOG.error("Policy not applied!  Error processing object rename for rename of {} to {}. Could not determine permission type of new object.", oldBinding.getName(), newBinding.getName());
                }
            } else {
                // Handle the case where a destination entry is being renamed.
                if (oldDest != null && newDest != null) {
                    AuthorizationEntry entry = entries.remove(oldDest);
                    if (entry != null) {
                        entry.setDestination(newDest);
                        DefaultAuthorizationMap map = this.map.get();
                        map.put(newDest, entry);
                        map.remove(oldDest, entry);
                        entries.put(newDest, entry);
                    } else {
                        LOG.warn("No authorization entry for {}", oldDest);
                    }
                }
            }
        } catch (InvalidNameException e) {
            LOG.error("Policy not applied!  Error parsing DN for object rename for rename of {} to {}", new Object[]{ oldBinding.getName(), newBinding.getName() }, e);
        } catch (Exception e) {
            LOG.error("Policy not applied!  Error processing object rename for rename of {} to {}", new Object[]{ oldBinding.getName(), newBinding.getName() }, e);
        }
    }

    /**
     * Handler for changed policy entries in the directory.
     *
     * @param namingEvent
     *            the changed entry event that occurred
     * @param destinationType
     *            the type of the destination to which the event applies
     * @param permissionType
     *            the permission type to which the event applies
     */
    public void objectChanged(NamingEvent namingEvent, DestinationType destinationType, PermissionType permissionType) {
        LOG.debug("Changing object {} to {}", namingEvent.getOldBinding(), namingEvent.getNewBinding());
        objectRemoved(namingEvent, destinationType, permissionType);
        objectAdded(namingEvent, destinationType, permissionType);
    }

    /**
     * Handler for exception events from the registry.
     *
     * @param namingExceptionEvent
     *            the exception event
     */
    public void namingExceptionThrown(NamingExceptionEvent namingExceptionEvent) {
        context = null;
        LOG.error("Caught unexpected exception.", namingExceptionEvent.getException());
    }

    // Init / Destroy
    public void afterPropertiesSet() throws Exception {
        query();
    }

    public void destroy() throws Exception {
        if (eventContext != null) {
            eventContext.close();
            eventContext = null;
        }

        if (context != null) {
            context.close();
            context = null;
        }
    }

    // Getters and Setters

    public String getConnectionURL() {
        return connectionURL;
    }

    public void setConnectionURL(String connectionURL) {
        this.connectionURL = connectionURL;
    }

    public String getConnectionUsername() {
        return connectionUsername;
    }

    public void setConnectionUsername(String connectionUsername) {
        this.connectionUsername = connectionUsername;
    }

    public String getConnectionPassword() {
        return connectionPassword;
    }

    public void setConnectionPassword(String connectionPassword) {
        this.connectionPassword = connectionPassword;
    }

    public String getConnectionProtocol() {
        return connectionProtocol;
    }

    public void setConnectionProtocol(String connectionProtocol) {
        this.connectionProtocol = connectionProtocol;
    }

    public String getAuthentication() {
        return authentication;
    }

    public void setAuthentication(String authentication) {
        this.authentication = authentication;
    }

    public String getQueueSearchBase() {
        return queueSearchBase;
    }

    public void setQueueSearchBase(String queueSearchBase) {
        try {
            LdapName baseName = new LdapName(queueSearchBase);
            queuePrefixLength = baseName.size();
            this.queueSearchBase = queueSearchBase;
        } catch (InvalidNameException e) {
            throw new IllegalArgumentException("Invalid base DN value " + queueSearchBase, e);
        }
    }

    public String getTopicSearchBase() {
        return topicSearchBase;
    }

    public void setTopicSearchBase(String topicSearchBase) {
        try {
            LdapName baseName = new LdapName(topicSearchBase);
            topicPrefixLength = baseName.size();
            this.topicSearchBase = topicSearchBase;
        } catch (InvalidNameException e) {
            throw new IllegalArgumentException("Invalid base DN value " + topicSearchBase, e);
        }
    }

    public String getTempSearchBase() {
        return tempSearchBase;
    }

    public void setTempSearchBase(String tempSearchBase) {
        try {
            LdapName baseName = new LdapName(tempSearchBase);
            tempPrefixLength = baseName.size();
            this.tempSearchBase = tempSearchBase;
        } catch (InvalidNameException e) {
            throw new IllegalArgumentException("Invalid base DN value " + tempSearchBase, e);
        }
    }

    public String getPermissionGroupMemberAttribute() {
        return permissionGroupMemberAttribute;
    }

    public void setPermissionGroupMemberAttribute(String permissionGroupMemberAttribute) {
        this.permissionGroupMemberAttribute = permissionGroupMemberAttribute;
    }

    public String getAdminPermissionGroupSearchFilter() {
        return adminPermissionGroupSearchFilter;
    }

    public void setAdminPermissionGroupSearchFilter(String adminPermissionGroupSearchFilter) {
        this.adminPermissionGroupSearchFilter = adminPermissionGroupSearchFilter;
    }

    public String getReadPermissionGroupSearchFilter() {
        return readPermissionGroupSearchFilter;
    }

    public void setReadPermissionGroupSearchFilter(String readPermissionGroupSearchFilter) {
        this.readPermissionGroupSearchFilter = readPermissionGroupSearchFilter;
    }

    public String getWritePermissionGroupSearchFilter() {
        return writePermissionGroupSearchFilter;
    }

    public void setWritePermissionGroupSearchFilter(String writePermissionGroupSearchFilter) {
        this.writePermissionGroupSearchFilter = writePermissionGroupSearchFilter;
    }

    public boolean isLegacyGroupMapping() {
        return legacyGroupMapping;
    }

    public void setLegacyGroupMapping(boolean legacyGroupMapping) {
        this.legacyGroupMapping = legacyGroupMapping;
    }

    public String getGroupObjectClass() {
        return groupObjectClass;
    }

    public void setGroupObjectClass(String groupObjectClass) {
        this.groupObjectClass = groupObjectClass;
    }

    public String getUserObjectClass() {
        return userObjectClass;
    }

    public void setUserObjectClass(String userObjectClass) {
        this.userObjectClass = userObjectClass;
    }

    public String getGroupNameAttribute() {
        return groupNameAttribute;
    }

    public void setGroupNameAttribute(String groupNameAttribute) {
        this.groupNameAttribute = groupNameAttribute;
    }

    public String getUserNameAttribute() {
        return userNameAttribute;
    }

    public void setUserNameAttribute(String userNameAttribute) {
        this.userNameAttribute = userNameAttribute;
    }

    public boolean isRefreshDisabled() {
        return refreshDisabled;
    }

    public void setRefreshDisabled(boolean refreshDisabled) {
        this.refreshDisabled = refreshDisabled;
    }

    public int getRefreshInterval() {
        return refreshInterval;
    }

    public void setRefreshInterval(int refreshInterval) {
        this.refreshInterval = refreshInterval;
    }

    public String getGroupClass() {
        return groupClass;
    }

    public void setGroupClass(String groupClass) {
        this.groupClass = groupClass;
        map.get().setGroupClass(groupClass);
    }

    protected static enum DestinationType {
        QUEUE, TOPIC, TEMP;
    }

    protected static enum PermissionType {
        READ, WRITE, ADMIN;
    }

    /**
     * Listener implementation for directory changes that maps change events to destination types.
     */
    protected class CachedLDAPAuthorizationMapNamespaceChangeListener implements NamespaceChangeListener, ObjectChangeListener {

        private final DestinationType destinationType;
        private final PermissionType permissionType;

        /**
         * Creates a new listener. If {@code permissionType} is {@code null}, add and remove events are ignored as they
         * do not directly affect policy state. This configuration is used when listening for changes on entries that
         * represent destination patterns and not for entries that represent permissions.
         *
         * @param destinationType
         *            the type of the destination being listened for
         * @param permissionType
         *            the optional permission type being listened for
         */
        public CachedLDAPAuthorizationMapNamespaceChangeListener(DestinationType destinationType, PermissionType permissionType) {
            this.destinationType = destinationType;
            this.permissionType = permissionType;
        }

        @Override
        public void namingExceptionThrown(NamingExceptionEvent evt) {
            SimpleCachedLDAPAuthorizationMap.this.namingExceptionThrown(evt);
        }

        @Override
        public void objectAdded(NamingEvent evt) {
            // This test is a hack to work around the fact that Apache DS 2.0 seems to trigger notifications
            // for the entire sub-tree even when one-level is the selected search scope.
            if (permissionType != null) {
                SimpleCachedLDAPAuthorizationMap.this.objectAdded(evt, destinationType, permissionType);
            }
        }

        @Override
        public void objectRemoved(NamingEvent evt) {
            // This test is a hack to work around the fact that Apache DS 2.0 seems to trigger notifications
            // for the entire sub-tree even when one-level is the selected search scope.
            if (permissionType != null) {
                SimpleCachedLDAPAuthorizationMap.this.objectRemoved(evt, destinationType, permissionType);
            }
        }

        @Override
        public void objectRenamed(NamingEvent evt) {
            SimpleCachedLDAPAuthorizationMap.this.objectRenamed(evt, destinationType, permissionType);
        }

        @Override
        public void objectChanged(NamingEvent evt) {
            // This test is a hack to work around the fact that Apache DS 2.0 seems to trigger notifications
            // for the entire sub-tree even when one-level is the selected search scope.
            if (permissionType != null) {
                SimpleCachedLDAPAuthorizationMap.this.objectChanged(evt, destinationType, permissionType);
            }
        }
    }
}
