/**
 * 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 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.GroupPrincipal;
import org.apache.activemq.jaas.UserPrincipal;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;

import javax.naming.Binding;
import javax.naming.Context;
import javax.naming.InvalidNameException;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.*;
import javax.naming.event.*;
import javax.naming.ldap.LdapName;
import javax.naming.ldap.Rdn;

import java.util.*;

/**
 * A {@link DefaultAuthorizationMap} implementation which uses LDAP to initialize and update authorization
 * policy.
 *
 * @org.apache.xbean.XBean
 */
public class CachedLDAPAuthorizationMap extends DefaultAuthorizationMap implements InitializingBean, DisposableBean {

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

    // Configuration Options
    private String initialContextFactory = "com.sun.jndi.ldap.LdapCtxFactory";
    private String connectionURL = "ldap://localhost:1024";
    private String connectionUsername = "uid=admin,ou=system";
    private String connectionPassword = "secret";
    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;
    
    // Internal State
    private long lastUpdated;

    private static String ANY_DESCENDANT = "\\$";

    protected DirContext context;
    private EventDirContext eventContext;
    
    protected HashMap<ActiveMQDestination, AuthorizationEntry> entries = 
            new HashMap<ActiveMQDestination, AuthorizationEntry>();

    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);
        }
        if (connectionPassword != null || !"".equals(connectionPassword)) {
            env.put(Context.SECURITY_CREDENTIALS, connectionPassword);
        }
        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 void query() throws Exception {
        DirContext currentContext = open();
    
        final SearchControls constraints = new SearchControls();
        constraints.setSearchScope(SearchControls.SUBTREE_SCOPE);
       
        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(
                        currentContext.search(queueSearchBase, getFilterForPermissionType(permissionType), constraints),
                        DestinationType.QUEUE, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '" + queueSearchBase + "' with filter '" 
                        + getFilterForPermissionType(permissionType) + "'", e);
            }
        }
        
        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(
                        currentContext.search(topicSearchBase, getFilterForPermissionType(permissionType), constraints),
                        DestinationType.TOPIC, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '" + topicSearchBase + "' with filter '" 
                        + getFilterForPermissionType(permissionType) + "'", e);
            }
        }
        
        for (PermissionType permissionType : PermissionType.values()) {
            try {
                processQueryResults(
                        currentContext.search(tempSearchBase, getFilterForPermissionType(permissionType), constraints),
                        DestinationType.TEMP, permissionType);
            } catch (Exception e) {
                LOG.error("Policy not applied!.  Error processing policy under '" + tempSearchBase + "' with filter '" 
                        + getFilterForPermissionType(permissionType) + "'", e);
            }
        }
        
        setEntries(new ArrayList<DestinationMapEntry>(entries.values()));
        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(NamingEnumeration<SearchResult> results,
            DestinationType destinationType, PermissionType permissionType) throws Exception {
        
        while (results.hasMore()) {
            SearchResult result = results.next();
            AuthorizationEntry entry = null;
            
            try {
                entry = getEntry(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 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(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 = getTempDestinationAuthorizationEntry();
                if (entry == null) {
                    entry = new TempDestinationAuthorizationEntry();
                    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 " + memberDn
                                    + " in policy entry "
                                    + 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 "
                                    + memberDn
                                    + "does not have name attribute "
                                    + groupNameAttribute + " under entry " + 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 "
                                    + memberDn + " does not have name attribute "
                                    + userNameAttribute + " under entry " + 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 "
                        + memberDn + " under entry " + result.getNameInNamespace());
            } else if (principalName != null){
                if (group && !user) {
                    members.add(new GroupPrincipal(principalName));
                } 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 (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;
                }
            }
            reset();
            setTempDestinationAuthorizationEntry(null);
            entries.clear();

            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 synchronous refresh capabilities if so configured before delegating to the super implementation,
     * and otherwise simply delegates to the super implementation.
     */
    @Override
    protected synchronized Set<AuthorizationEntry> getAllEntries(ActiveMQDestination destination) {
        checkForUpdates();
        return super.getAllEntries(destination);
    }
    
    /**
     * 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 synchronized Set<Object> getTempDestinationAdminACLs() {
        checkForUpdates();
        return transcribeSet(super.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.
     */
    public synchronized Set<Object> getTempDestinationReadACLs() {
        checkForUpdates();
        return transcribeSet(super.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.
     */
    public synchronized Set<Object> getTempDestinationWriteACLs() {
        checkForUpdates();
        return transcribeSet(super.getTempDestinationWriteACLs());
    }
    
    /**
     * Provides synchronized access to the admin ACLs for the destinations as 
     * {@link AuthorizationEntry} is not setup for concurrent access.
     */
    public synchronized Set<Object> getAdminACLs(ActiveMQDestination destination) {
        return super.getAdminACLs(destination);
    }

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

    /**
     * Provides synchronized access to the write ACLs for the destinations as 
     * {@link AuthorizationEntry} is not setup for concurrent access.
     */
    public synchronized Set<Object> getWriteACLs(ActiveMQDestination destination) {
        checkForUpdates();
        return super.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 synchronized void objectAdded(NamingEvent namingEvent, DestinationType destinationType,
            PermissionType permissionType) {
        LOG.debug("Adding object: " + namingEvent.getNewBinding());
        SearchResult result = (SearchResult) namingEvent.getNewBinding();
        
        try {
            LdapName name = new LdapName(result.getName());
            
            AuthorizationEntry entry = getEntry(name, destinationType);
               
            applyACL(entry, result, permissionType);
            if (!(entry instanceof TempDestinationAuthorizationEntry)) {
                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 synchronized void objectRemoved(NamingEvent namingEvent, DestinationType destinationType,
            PermissionType permissionType) {
        LOG.debug("Removing object: " + namingEvent.getOldBinding());
        Binding result = namingEvent.getOldBinding();
        
        try {
            LdapName name = new LdapName(result.getName());
            
            AuthorizationEntry entry = getEntry(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 synchronized void objectRenamed(NamingEvent namingEvent, DestinationType destinationType,
            PermissionType permissionType) {
        Binding oldBinding = namingEvent.getOldBinding();
        Binding newBinding = namingEvent.getNewBinding();
        LOG.debug("Renaming object: " + oldBinding + " to " + 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 "
                            + oldBinding.getName() + " to " + newBinding.getName()
                            + ".  Could not determine permission type of new object.");
                }
                
            } 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);
                        put(newDest, entry);
                        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 "
                    + oldBinding.getName() + " to " + newBinding.getName(), e);
        } catch (Exception e) {
            LOG.error("Policy not applied!  Error processing object rename for rename of "
                    + oldBinding.getName() + " to " + 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 synchronized void objectChanged(NamingEvent namingEvent,
            DestinationType destinationType, PermissionType permissionType) {
        LOG.debug("Changing object " + namingEvent.getOldBinding() + " to " + 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
    
    @Override
    public void afterPropertiesSet() throws Exception {
        query();
    }
    
    @Override
    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;
    }
    
    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) {
            CachedLDAPAuthorizationMap.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) {
                CachedLDAPAuthorizationMap.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) {
                CachedLDAPAuthorizationMap.this.objectRemoved(evt, destinationType, permissionType);
            }
        }

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