/*
 * Directory Lookup Service *
 * author: Florida Estrella
*/

package com.c2kernel.lookup;

import java.util.Enumeration;
import java.util.StringTokenizer;

import com.c2kernel.common.ObjectAlreadyExistsException;
import com.c2kernel.common.ObjectCannotBeUpdated;
import com.c2kernel.common.ObjectNotFoundException;
import com.c2kernel.entity.TraceableEntity;
import com.c2kernel.entity.agent.ActiveEntity;
import com.c2kernel.entity.proxy.EntityProxyManager;
import com.c2kernel.entity.proxy.ProxyMessage;
import com.c2kernel.process.Gateway;
import com.c2kernel.utils.Logger;
import com.c2kernel.utils.Resource;
import com.novell.ldap.*;

/**
 * The LDAPLookup object, statically accessible through the Gateway, manages 
 * the LDAP connection for the cristal process. It provides:
 * <ul>
 * <li>Authentication - returning an AgentProxy object if a user has logged in
 * <li>System key generation - through the NextKeyManager
 * <li>Agent and Role lookup/modification - through the RoleManager
 * <li>
 * @version $Revision: 1.113 $ $Date: 2006/03/03 13:52:21 $
 * @author  $Author: abranson $
 */

public class LDAPLookup 

{
    private LDAPConnection mLDAPConn;
    private LDAPProperties mLDAPProps;
    private NextKeyManager mNextKeyManager;
    private LDAPPropertyManager mPropManager;
    private LDAPRoleManager mRoleManager;
    
    

    /**
     * Creates a new LDAPLookup manager with the properties supplied. 
     * This should be only done by the Gateway during initialisation.
     * 
     * @param props The LDAP properties object that extracts LDAP connection properties from the global c2kprops
     */
    public LDAPLookup(LDAPProperties props) throws LDAPException
    {
        Logger.msg(8,"LDAPLookup - initialising.");
        
        mLDAPProps = props;
        
        mLDAPConn = createConnection(mLDAPProps);
        
        Path.mGlobalPath=props.mGlobalPath;
        Path.mRootPath=props.mRootPath;
        Path.mLocalPath=props.mLocalPath;
        
        EntityPath.mTypeRoot = "cn=entity,"+props.mLocalPath;
        DomainPath.mTypeRoot = "cn=domain,"+props.mLocalPath;
        
        mNextKeyManager = new NextKeyManager(this, "cn=last,"+EntityPath.mTypeRoot);
        Logger.debug("LDAP.useOldProps="+Gateway.getProperty("LDAP.useOldProps", "false"));
        if (Gateway.getProperty("LDAP.useOldProps", "false").equals("true")) {
        	Logger.debug("Using Kernel 2.1 LDAP Property Format");
        	mPropManager = new LegacyLDAPPropertyManager(this);
        }
        else {
        	Logger.debug("Using Kernel 2.2 LDAP Property Format");
        	mPropManager = new LDAPPropertyManager(this);
        }
        mRoleManager = new LDAPRoleManager(this, "cn=agent,"+DomainPath.mTypeRoot, EntityPath.mTypeRoot);

    }
    
    /**
     * Utility method to connect to an LDAP server  
     * @param lp LDAP properties to connect with
     * @return a novell LDAPConnection object
     * @throws LDAPException when the connection was unsuccessful
     */
    public static LDAPConnection createConnection(LDAPProperties lp) throws LDAPException {
        LDAPConnection ld = new LDAPConnection();

        Logger.msg(3, "LDAPLookup - connecting to " + lp.mHost);
        ld.connect(lp.mHost, Integer.valueOf(lp.mPort).intValue());

        Logger.msg(3, "LDAPLookup - authenticating user:" + lp.mUser);
        ld.bind( LDAPConnection.LDAP_V3, lp.mUser,
                 String.valueOf(lp.mPassword).getBytes());                 

        Logger.msg(3, "LDAPLookup - authentication successful");
        LDAPSearchConstraints searchCons = new LDAPSearchConstraints();
        searchCons.setMaxResults(0);
        ld.setConstraints(searchCons);
        
        return ld;
    }

    /**
     * Gets the entity key generator, used to get a unique system key for new entities.
     * @return the global NextKeyManager
     */
    public NextKeyManager getNextKeyManager()
    {
        return mNextKeyManager;
    }
    
    /**
     * Gets the property manager, that is used to read and write cristal properties to the LDAP store.
     * @return Returns the global LDAPPropertyManager.
     */
    public LDAPPropertyManager getPropManager() {
        return mPropManager;
    }
    /**
     * Gets the role manager, that is used to add and remove roles and agents.
     * @return Returns the mRoleManager.
     */
    public LDAPRoleManager getRoleManager() {
        return mRoleManager;
    }    

    /**
     * Returns the current LDAP connection, and attempts to reconnect if it has been closed.
     * @return
     */
    protected LDAPConnection getConnection() 
    { 
        if (!mLDAPConn.isConnected()) {
            Logger.warning("LDAPLookup - lost connection to LDAP server. Attempting to reconnect.");
            try {
                mLDAPConn = createConnection(mLDAPProps);
            } catch (LDAPException ex) { }
        }
        return mLDAPConn; 
    }
    
    /**
     * Disconnects the connection with the LDAP server during shutdown
     */
    public void disconnect() {
        Logger.msg(1, "LDAP Lookup: Shutting down LDAP connection.");
        if (mLDAPConn != null) {
            try {
                mLDAPConn.disconnect();
            } catch (LDAPException e) {
                Logger.error(e);
            }
            mLDAPConn = null;
        }
    }

   /** 
    * Attempts to resolve the CORBA object for a Path, either directly or through an alias.
    * @param path the path to resolve
    * @return the CORBA object
    * @throws ObjectNotFoundException When the path does not exist
    */
    public org.omg.CORBA.Object getIOR(Path path)
    throws ObjectNotFoundException
    {
        return resolveObject(path.getFullDN());
    }

    /**
     * Attempts to resolve the CORBA object from the IOR attribute of a DN, either directly or through an alias
     * @param dn The String dn
     * @throws ObjectNotFoundException when the dn or aliased dn does not exist
     */
    private org.omg.CORBA.Object resolveObject(String dn)
        throws ObjectNotFoundException
    {
        Logger.msg(8,"LDAPLookup.resolveObject("+dn+")");
        LDAPEntry anEntry = LDAPLookupUtils.getEntry(getConnection(),dn,LDAPSearchConstraints.DEREF_NEVER);
        if (anEntry != null)
        {
            String iorString;
            try {
                iorString = LDAPLookupUtils.getFirstAttributeValue(anEntry, "ior");
                org.omg.CORBA.Object ior=Gateway.getORB().string_to_object(iorString);
                if (ior!=null)
                    return ior;
                else
                    throw new ObjectNotFoundException("LDAPLookup.resolveObject() - " + dn + " has no IOR", "");
            } catch (ObjectNotFoundException ex) {
                return resolveObject(LDAPLookupUtils.getFirstAttributeValue(anEntry,"aliasedObjectName"));
            }
        }
        else
            throw new ObjectNotFoundException("LDAPLookup.resolveObject() LDAP node " + dn + " is not in LDAP or has no IOR.", "");
    }

    /**
     * 
     * @param domPath
     * @return
     * @throws InvalidEntityPathException
     * @throws ObjectNotFoundException
     */
    protected EntityPath resolvePath(DomainPath domPath) 
        throws InvalidEntityPathException, ObjectNotFoundException {
        EntityPath referencedPath = null;
        LDAPEntry domEntry = LDAPLookupUtils.getEntry(getConnection(), domPath
                .getFullDN(), LDAPSearchConstraints.DEREF_ALWAYS);
        String entityKey = LDAPLookupUtils.getFirstAttributeValue(domEntry,
                "intsyskey");
        Logger.msg(7, "DomainPath " + domPath + " is a reference to "
                + entityKey);
        String objClass = LDAPLookupUtils.getFirstAttributeValue(domEntry,
                "objectClass");
        if (objClass.equals("cristalagent"))
            referencedPath = new AgentPath(Integer.parseInt(entityKey));
        else
            referencedPath = new EntityPath(Integer.parseInt(entityKey));

        return referencedPath;
    }
    

    public LDAPEntry add(Path path)
        throws ObjectCannotBeUpdated, ObjectAlreadyExistsException
    {
        String root = path.getRoot();
        try {
            checkLDAPContext(path);
            LDAPAttributeSet attrSet = path.createAttributeSet();
            LDAPEntry newEntry = new LDAPEntry(path.getFullDN(),attrSet);
            LDAPLookupUtils.addEntry(getConnection(),newEntry);
            if (path instanceof DomainPath)
                EntityProxyManager.sendProxyEvent(new ProxyMessage(ProxyMessage.NA, path.toString(), ProxyMessage.ADDED));
            return newEntry;
        } catch (LDAPException ex) {
            if (ex.getResultCode() == LDAPException.ENTRY_ALREADY_EXISTS)
                throw new ObjectAlreadyExistsException(ex.getLDAPErrorMessage(), "");
            else
                throw new ObjectCannotBeUpdated(ex.getLDAPErrorMessage(), "");
        }
     }

    //deletes a node
    //throws LDAPexception if node cannot be deleted (eg node is not a leaf)
    public void delete(Path path) throws ObjectCannotBeUpdated
    {
        try {
            LDAPLookupUtils.delete(getConnection(),path.getDN()+Path.mLocalPath);
        } catch (LDAPException ex) {
            throw new ObjectCannotBeUpdated(ex.getLDAPErrorMessage(), "");
        }
        if (path instanceof DomainPath) {
            EntityProxyManager.sendProxyEvent(new ProxyMessage(ProxyMessage.NA, path.toString(), ProxyMessage.DELETED));
        }
    }
    
	//change specs, add boolean alias leaf context
    protected void checkLDAPContext(Path path)
    throws LDAPException
    {
        String dn = path.getFullDN();
        if (!LDAPLookupUtils.exists(getConnection(),dn))
        {
            String listDN[] = path.getPath();
            String name = "cn="+ path.getRoot() + "," + Path.mLocalPath;
            int i=0;
            while (i<listDN.length-1)
            {
                name= "cn="+listDN[i]+","+name;
                if (!LDAPLookupUtils.exists(getConnection(),name))
                {
                    try
                    {
                        //create cristalcontext
                        Logger.msg(8,"LDAPLookup::addLDAPContext() context added " + name);
                        LDAPLookupUtils.createCristalContext(getConnection(), name);
                    }
                    catch (Exception ex)
                    {
                        Logger.error("LDAPLookup::addContext() " + ex);
                    }
                }
                i++;
            }
        }
    }
    public void createBootTree()
    {
        Logger.msg(8,"Initializing LDAP Boot tree");
        
        //create org
        LDAPLookupUtils.createOrganizationContext(getConnection(), Path.mGlobalPath);
        //create root
        LDAPLookupUtils.createCristalContext(getConnection(), Path.mRootPath);
        //create local
        LDAPLookupUtils.createCristalContext(getConnection(), Path.mLocalPath);
    }
    
    public void install() throws LDAPException
    {
        createBootTree();
        initTree( Resource.getTextResource("boot/LDAPboot.txt"));
    }
    
    public void initTree(String bootFile)
    {
        Logger.msg(8,"Verifying Cristal LDAP roots");
        StringTokenizer strTokenizer = new StringTokenizer(bootFile, "\n\r");
        while (strTokenizer.hasMoreTokens())
        {
            String line = strTokenizer.nextToken();
            Logger.msg(8,"Checking " + line+Path.mLocalPath);
            LDAPLookupUtils.createCristalContext(getConnection(), line+Path.mLocalPath);
        }
        
    }   
    
 	//typically search for cn=barcode
    public Enumeration search(Path start, String filter)
    {
    	Logger.msg(8,"LDAPLookup::search() From " + start.getDN() + " for cn=" + filter );
        return search(start.getFullDN(),"cn="+LDAPLookupUtils.escapeSearchFilter(filter));
    }
    
    protected Enumeration search(String startDN, int scope, String filter, LDAPSearchConstraints searchCons)
    {        
        Logger.msg(8,"Searching for "+filter+" in "+startDN);
        searchCons.setMaxResults(0);
        String[] attr = { LDAPConnection.ALL_USER_ATTRS };  
        try
        {
            LDAPSearchResults res = getConnection().search(LDAPLookupUtils.escapeDN(startDN),scope,
            		filter,attr,false,searchCons);
            return new LDAPPathSet(res);
        }
        catch (LDAPException ex)
        {
            Logger.error("LDAPException::LDAPLookup::search() " + ex.toString());
            return new LDAPPathSet();
        }
    }    
    //typically search for (any filter combination)
    public Enumeration search(String startDN,String filter)
    {
        LDAPSearchConstraints searchCons = new LDAPSearchConstraints();
        searchCons.setBatchSize(0);
        searchCons.setDereference(LDAPSearchConstraints.DEREF_NEVER);
        return search(startDN,LDAPConnection.SCOPE_SUB,filter,searchCons);
    }

    public Enumeration searchEntities(Path start) {
        LDAPSearchConstraints searchCons = new LDAPSearchConstraints();
        searchCons.setBatchSize(0);
        searchCons.setDereference(LDAPSearchConstraints.DEREF_SEARCHING);
        return search(start.getFullDN(), LDAPConnection.SCOPE_SUB, "objectClass=cristalentity", searchCons);
    }
    
    public Enumeration searchAliases(DomainPath start) {
        LDAPSearchConstraints searchCons = new LDAPSearchConstraints();
        searchCons.setBatchSize(0);
        searchCons.setDereference(LDAPSearchConstraints.DEREF_NEVER);
        return search(start.getFullDN(), LDAPConnection.SCOPE_SUB, "objectClass=aliasObject", searchCons);
    }

    public boolean exists(Path path) {
        return LDAPLookupUtils.exists(getConnection(), path.getFullDN());
    }
    
    public Class getEntityClass(Path path) throws ObjectNotFoundException {
        String[] attr = { LDAPConnection.ALL_USER_ATTRS };
        try {
            LDAPEntry anEntry=getConnection().read(path.getDN()+Path.mLocalPath,attr);
            String type = LDAPLookupUtils.getFirstAttributeValue(anEntry, "objectClass");
            if (type.equals("cristalentity"))
                return TraceableEntity.class;
            else if (type.equals("cristalagent"))
                return ActiveEntity.class;
            else
                throw new ObjectNotFoundException("Not an entity", "");
               
        } catch (LDAPException ex) {
            if (ex.getResultCode() == LDAPException.NO_SUCH_OBJECT)
                throw new ObjectNotFoundException("Entity does not exist", "");
            Logger.error(ex);
            throw new ObjectNotFoundException("Error getting entity class", "");
        }
    }
    
    /** converts an LDAPentry to a Path object
     *  Note that the search producing the entry should have retrieved the attrs
     *  'ior' and 'uniquemember'
     * @throws ObjectNotFoundException
     * @throws ObjectNotFoundException
     */
    protected Path nodeToPath(LDAPEntry entry) throws InvalidEntityPathException, ObjectNotFoundException
    {
        String dn = entry.getDN();
    	
        // extract syskey
        int entityKey = -1;
        try {
            String entityKeyStr = LDAPLookupUtils.getFirstAttributeValue(entry,"intsyskey");
            entityKey = Integer.parseInt(entityKeyStr);
        } catch (Exception e) { }
        
        // extract IOR
        org.omg.CORBA.Object ior = null;
        try {
            String stringIOR = LDAPLookupUtils.getFirstAttributeValue(entry,"ior");
            ior = Gateway.getORB().string_to_object(stringIOR);
        } catch (ObjectNotFoundException e2) { }

        /* Find the right path class */
        Path thisPath;
        if (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","cristalagent"))
        { //cristalagent
            String agentID = LDAPLookupUtils.getFirstAttributeValue(entry,"uid");
            thisPath = new AgentPath(entityKey, agentID);
        }
        
        else if (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","cristalrole"))
        { //cristalrole
            thisPath = new RolePath(LDAPDN.explodeDN(dn,true)[0], 
                    LDAPLookupUtils.getFirstAttributeValue(entry, "jobList").equals("TRUE"));
        }
        else if (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","aliasObject") ||
                (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","cristalcontext") && dn.endsWith(DomainPath.mTypeRoot)))
        {
            DomainPath domainPath = new DomainPath();
            domainPath.setDN(dn);
            thisPath = domainPath;        	
        }
        else if (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","cristalentity") ||
                (LDAPLookupUtils.existsAttributeValue(entry,"objectclass","cristalcontext") && dn.endsWith(EntityPath.mTypeRoot)))
        {
            if(dn.endsWith(EntityPath.mTypeRoot)) {
                EntityPath entityPath;
                if (entityKey != -1)
                    entityPath = new EntityPath(entityKey);
                else {
                    entityPath = new EntityPath();
                    entityPath.setDN(dn);
                }
                thisPath = entityPath;
            }
            else
                throw new ObjectNotFoundException("Entity found outside entity tree");
        }
        else
        {
			throw new ObjectNotFoundException("Unrecognised LDAP entry. Not a cristal entry");
        }               
        
        //set IOR if we have one
        if (ior!=null) thisPath.setIOR(ior);
        return thisPath;
    }
}