/* ======================================================================
The Bodington System Software License, Version 1.0
  
Copyright (c) 2001 The University of Leeds.  All rights reserved.
  
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

1.  Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

2.  Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

3.  The end-user documentation included with the redistribution, if any,
must include the following acknowledgement:  "This product includes
software developed by the University of Leeds
(http://www.bodington.org/)."  Alternately, this acknowledgement may
appear in the software itself, if and wherever such third-party
acknowledgements normally appear.

4.  The names "Bodington", "Nathan Bodington", "Bodington System",
"Bodington Open Source Project", and "The University of Leeds" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
d.gardner@leeds.ac.uk.

5.  The name "Bodington" may not appear in the name of products derived
from this software without prior written permission of the University of
Leeds.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO,  TITLE,  THE IMPLIED WARRANTIES 
OF QUALITY  AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO 
EVENT SHALL THE UNIVERSITY OF LEEDS OR ITS CONTRIBUTORS BE LIABLE FOR 
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
POSSIBILITY OF SUCH DAMAGE.
=========================================================

This software was originally created by the University of Leeds and may contain voluntary 
contributions from others.  For more information on the Bodington Open Source Project, please 
see http://bodington.org/

====================================================================== */

package org.bodington.server;

import java.security.cert.X509Certificate;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;

import org.apache.log4j.Logger;
import org.bodington.database.PrimaryKey;
import org.bodington.server.realm.AuthenticationException;
import org.bodington.server.realm.Authenticator;
import org.bodington.server.realm.User;
import org.bodington.server.realm.UserX509;
import org.bodington.server.resources.Resource;
import org.bodington.server.resources.ResourceSummary;
import org.bodington.server.resources.ResourceTree;
import org.bodington.server.resources.ResourceTreeManager;
import org.bodington.text.Metadatum;

/**
 * This class has the idea if a session has been authenticated.
 * @author Jon Maber
 */
public class NavigationSessionImpl extends ReusableResourceSession implements NavigationSession 
	{
    
    private static Logger log = Logger.getLogger(NavigationSessionImpl.class);
	Authenticator authenticator = null;
	String authenticator_alias = null;
	    
	public NavigationSessionImpl()
		{
		super();
		}
    
	private Authenticator getAuthenticator( String alias )
	throws BuildingServerException
	{
	    authenticator = null;
	    String property_name = "authenticator.alias." + alias;
	    String class_name = BuildingContext.getProperty( property_name );
	    
	    if ( class_name == null )
		throw new BuildingServerException( "Unknown authenticator alias." );
	    
	    try
	    {
		Class authenticator_class;
		authenticator_class = Class.forName( class_name );
		authenticator = (Authenticator)authenticator_class.newInstance();
		authenticator_alias = alias;
		return authenticator;
		
	    }
	    catch ( ClassNotFoundException cnfe )
	    {
		authenticator = null;
		log.error( cnfe.getMessage(), cnfe );
		throw new BuildingServerException( "Unable to find the authentication code." );
	    }
	    catch ( InstantiationException ie )
	    {
		authenticator = null;
		log.error( ie.getMessage(), ie );
		throw new BuildingServerException( "Unable to create an authentication object." );
	    }
	    catch ( IllegalAccessException iae )
	    {
		authenticator = null;
		log.error( iae.getMessage(), iae );
		throw new BuildingServerException( "Unable to create an authentication object." );
	    }
	}
		
	public void clearAuthenticationCredentials()
		throws BuildingServerException
	{
	    authenticator = null;
	}
	
	public void setAuthenticationCredentials( Properties credentials, String alias )
		throws BuildingServerException
	{
	    try
	    {
		getAuthenticator( alias );
		authenticator.setAuthenticationCredentials( credentials );
	    }
	    catch ( AuthenticationException authe )
	    {
		authenticator = null;
		authenticator_alias = null;
		log.error( authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
	    
	}

        public void setClientX509( X509Certificate cert )
        throws BuildingServerException
        {
	    try
	    {
		InternalX509Authenticator int_authenticator = new InternalX509Authenticator();
		authenticator = int_authenticator;
                authenticator_alias = "_internal_x509_authenticator";
                int_authenticator.setClientX509( cert );
	    }
	    catch ( AuthenticationException authe )
	    {
		authenticator = null;
		authenticator_alias = null;
		log.error( authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
            
        }
	
	public boolean isAuthenticated()
		throws BuildingServerException
	{
	    try
	    {
		if ( authenticator == null )
		    return false;
		return authenticator.isAuthenticated();
	    }
	    catch ( AuthenticationException authe )
	    {
		log.error( authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
	}

	public boolean isAnonymous()
		throws BuildingServerException
	{
	    try
	    {
		if ( authenticator == null )
		    return false;
		return authenticator.isAnonymous();
	    }
	    catch ( AuthenticationException authe )
	    {		
		log.error(authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
	}
	
	public String getAuthenticationError()
		throws BuildingServerException
	{
	    try
	    {
		if ( authenticator == null )
		    return null;
		return authenticator.getAuthenticationError();
	    }
	    catch ( AuthenticationException authe )
	    {
		log.error( authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
	}
	
	public PrimaryKey getAuthenticatedUserId()
		throws BuildingServerException
	{
	    try
	    {
		if ( authenticator == null )
		    return null;
		return authenticator.getAuthenticatedUserId();
	    }
	    catch ( AuthenticationException authe )
	    {
		log.error( authe.getMessage(), authe );
		throw new BuildingServerException( "Technical problem authenticating credentials." );
	    }
	}
	
	public User getAuthenticatedUser()
		throws BuildingServerException
	{
	    PrimaryKey user_id = getAuthenticatedUserId();
	    return User.findUser( user_id );
	}
	
	public String getAuthenticatorAlias()
		throws BuildingServerException
	{
	    return authenticator_alias;
	}

	public synchronized String currentUserName()
		throws BuildingServerException
		{
			User user = getAuthenticatedUser();
			if ( user == null )
				return "null";
			return user.getName();	
		}
		
	public synchronized ResourceSummary getRootSummary()
		throws BuildingServerException
		{
			ResourceTree tree = ResourceTreeManager.getInstance();
			Resource r =  tree.findRootResource();
			if ( r == null )
				return null;
				
			ResourceSummary summary;
			
			summary = new ResourceSummary();
			summary.setResourceId( r.getResourceId() );
			summary.setHttpFacilityNo( r.getHttpFacilityNo() );
			summary.setName( r.getName() );
			summary.setTitle( r.getTitle() );
			summary.setDescription( r.getDescription() );
			summary.setIntroduction( r.getIntroduction() );
			
			return summary;
		}

		
	public synchronized Vector childSummaries( PrimaryKey r_id )
		throws BuildingServerException
		{
			
			Vector list = new Vector( 10, 10 );

			if ( r_id == null )
				throw new BuildingServerException( "No resource has been selected - can't supply any information." );
			Resource resource = Resource.findResource( r_id );
			if ( resource == null )
				throw new BuildingServerException( "Specified resource couldn't be found." );
				
			
			Enumeration enumeration = resource.findChildren();
			Resource r;
			ResourceSummary summary;
			while ( enumeration.hasMoreElements() )
				{
				r = (Resource)enumeration.nextElement();
				summary = new ResourceSummary();
				summary.setResourceId( r.getResourceId() );
				summary.setHttpFacilityNo( r.getHttpFacilityNo() );
				summary.setName( r.getName() );
				summary.setTitle( r.getTitle() );
				summary.setDescription( r.getDescription() );
				summary.setIntroduction( r.getIntroduction() );
				list.addElement( summary );
				}
			
			return list;

		}
		
		
	public Resource findResource( PrimaryKey resource_id )
		throws BuildingServerException
	    {
		if ( resource_id == null )
		    return null;
		return Resource.findResource( resource_id );
	    }
	    
	public PrimaryKey findResourceId( String[] names )
		throws BuildingServerException
	    {
		ResourceTree tree = ResourceTreeManager.getInstance();
		Resource r;
		if ( names==null || names.length == 0 )
		    r = tree.findResource( "/" );
		else
		    r = tree.findResource( names );
		if ( r==null )
		    return null;
		return r.getResourceId();
	    }

	    
	public String getUserPreferredStyleSheet()
		throws BuildingServerException
	{
	    User user = (User)BuildingContext.getContext().getUser();
	    String stylefile = "standard.css";
	    Metadatum metadatum = Metadatum.findMetadatumByIdAndName( user.getUserId(), "preference.stylesheet" );
	    if ( metadatum != null )
	    {
		stylefile=metadatum.getValue();
	    }
	    return stylefile;
	}
	    
	
	public String getUserProperty( String name )
		throws BuildingServerException
	{
	    String value=null;
	    User user = (User)BuildingContext.getContext().getUser();
	    Metadatum metadatum = Metadatum.findMetadatumByIdAndName( user.getUserId(), name );
	    if ( metadatum != null )
	    {
		value=metadatum.getValue();
	    }
	    return value;
	}
	
	public void setUserProperty( String name, String value )
		throws BuildingServerException
	{
	    if ( name == null )
		throw new BuildingServerException( "Null property name not allowed." );
	    
	    User user = (User)BuildingContext.getContext().getUser();
	    Metadatum metadatum = Metadatum.findMetadatumByIdAndName( user.getUserId(), name );
	    
	    if ( value == null )
	    {
		if ( metadatum != null )
		    metadatum.delete();
		return;
	    }
	    
	    if ( metadatum == null )
	    {
		metadatum = new Metadatum();
		metadatum.setObjectId( user.getUserId() );
		metadatum.setName( name );
	    }
	    metadatum.setValue( value );
	    metadatum.save();
	}
		    

        private class InternalX509Authenticator implements Authenticator
        {
            PrimaryKey authenticated_user_id = null;
            X509Certificate authenticated_cert = null;
            
            public void changeCredentials(Properties credentials) throws AuthenticationException
            {
                // ignore
            }
            
            public PrimaryKey getAuthenticatedUserId() throws AuthenticationException
            {
                return authenticated_user_id;
            }
            
            public String getAuthenticationError() throws AuthenticationException
            {
                return null;
            }
            
            public boolean isAnonymous() throws AuthenticationException
            {
                return false;
            }
            
            public boolean isAuthenticated() throws AuthenticationException
            {
                return authenticated_user_id != null;
            }
            
            public void setAuthenticationCredentials(Properties credentials) throws AuthenticationException
            {
                // ignore
            }
            
            public void setClientX509( X509Certificate cert )
            throws BuildingServerException, AuthenticationException
            {
                java.security.cert.X509Certificate stored_cert;
                int serial = cert.getSerialNumber().intValue();
                String dn = cert.getSubjectDN().getName();
                UserX509 user_x509;
                
                // look for certificates with same serial number
                // and DN
                Enumeration enumeration = UserX509.findUserX509s( serial, dn );
                while ( enumeration.hasMoreElements() )
                {
                    // for each certificate with same serial and dn see if it
                    // exactly matches the one the user presented.
                    user_x509 = (UserX509)enumeration.nextElement();
                    stored_cert = user_x509.getX509Certificate();
                    if ( cert.equals( stored_cert ) )
                    {
                        authenticated_user_id = user_x509.getUserId();
                        authenticated_cert = cert;
                        return;
                    }
                }

            }
        }


        public HomeContainerSession getHomeContainerSession() throws BuildingServerException
        {
            //TODO Need a better way of discovering the container.
            Resource resource = ResourceTreeManager.getInstance().findResource(new String[]{"users"});
            return (HomeContainerSession) BuildingSessionManagerImpl.getSession(resource);
        }
        
        
	}