/* ======================================================================
   Parts Copyright 2006 University of Leeds, Oxford University, University of the Highlands and Islands.

   Licensed 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.bodington.messaging;

import org.apache.log4j.Logger;

import java.util.Enumeration;
import java.util.Vector;
import java.util.Hashtable;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.DefaultMutableTreeNode;

import org.bodington.database.PrimaryKey;
import org.bodington.server.BuildingContext;
import org.bodington.server.BuildingServerException;
import org.bodington.server.resources.*;
import org.bodington.text.BigString;
import org.bodington.util.VisitationMutableTreeNode;
import org.bodington.server.realm.User;


public class MessagingRoom extends org.bodington.server.resources.Resource
	{
    private static Logger log = Logger.getLogger(MessagingRoom.class);
    
    public static final int TYPE_UNKNOWN        =-1;
	public static final int TYPE_PLAIN			=0;
	public static final int TYPE_MULTIPLEXED	=1;
	public static final int TYPE_PERSONAL		=2;
	
	PrimaryKey messaging_room_id;
	int type_of_room = TYPE_UNKNOWN;
	

	private transient MessageTreeNode root;
	private transient Vector top;
	
	private transient Hashtable summaries=null;
	
	
    public Class sessionClass()
    	{
        // This method is derived from class org.bodington.server.resources.Resource
        // to do: code goes here
        return org.bodington.messaging.MessagingRoomSessionImpl.class;
    	}
    	
    	
   	public static MessagingRoom findMessagingRoom( PrimaryKey key )
		throws BuildingServerException
		{
		return (MessagingRoom)findPersistentObject( key, "org.bodington.messaging.MessagingRoom" );
		}
	public static Enumeration findMessagingRooms( String where )
	    throws BuildingServerException
	    {
	    return findPersistentObjects( where, "org.bodington.messaging.MessagingRoom" );
	    }
	public static Enumeration findMessagingRooms( String where, String order )
	    throws BuildingServerException
	    {
	    return findPersistentObjects( where, order, "org.bodington.messaging.MessagingRoom" );
	    }

    public PrimaryKey getPrimaryKey()
		{
        return getMessagingRoomId();
        }

    public void setPrimaryKey(PrimaryKey key)
    	{
    	setMessagingRoomId( key );
    	}
    	

    public PrimaryKey getMessagingRoomId()
		{
        return messaging_room_id;
        }

    public void setMessagingRoomId(PrimaryKey key)
    	{
    	messaging_room_id = key;
    	setResourceId( key );
    	setUnsaved();
    	}
    	
    	
	public int getTypeOfRoom()
		{
		return type_of_room;
		}
	public void setTypeOfRoom( int r )
		{
		if ( r==type_of_room ) return;
		type_of_room=r;
    	setUnsaved();
		}


	public Message createMessage()
		throws BuildingServerException
		{
		return createMessage( null, true );
		}
		
	public Message createMessage( PrimaryKey replyto_mid, boolean branch )
		throws BuildingServerException
		{
		MessageSummary summary;
		PrimaryKey parent_mid=replyto_mid;
		
		if ( replyto_mid!=null && !containsMessage( replyto_mid ) )
			throw new BuildingServerException( "Can't reply to message from another room here." );
		
		
		// follow on recorded as a reply to the same message that selected
		// message is a reply to
		if ( !branch && replyto_mid!=null )
			{
			summary = getMessageSummary( replyto_mid );
			parent_mid = summary.getParentMessageId();
			if ( parent_mid == null )
				throw new BuildingServerException( "Can't find message to place this message under." );
			}
		
		
		Message message = new Message();
		message.setMessagingRoomId( messaging_room_id );
		message.setCreatedTime( new java.sql.Timestamp(System.currentTimeMillis()) );
		message.setUpdatedTime( message.getCreatedTime() );
		message.setSeen( false );
		message.setLeftIndex( -1 );
		message.setRightIndex( -1 );
		message.setParentMessageId( parent_mid );
		message.setReplyToMessageId( replyto_mid );
			
		return message;
		}


	public void postMessage( Message message )
		throws BuildingServerException
		{
		MessageTreeNode[] path;
		MessageTreeNode root, parent, node;
		Message parent_message;
		MessageSummary summary;
		
		
		root = getMessageRoot();
		parent = root;
		
		message.save();
		if ( message.getParentMessageId() != null )
			{
			parent = (MessageTreeNode)root.findNode( message.getParentMessageId() );
			if ( parent == null )
				throw new BuildingServerException( "Can't find original message in this room to reply to." );
			}

		parent.add( message );

		saveMessages();
		
		getMessageSummaries();
		summary = message.getSummary();
		summaries.put( summary.getMessageId(), summary );
		}


	public void saveMessages()
		throws BuildingServerException
		{
		Enumeration enumeration;
		MessageTreeNode root, parent, node;
		PrimaryKey key;
		Message message;
		
		root = getMessageRoot();
		enumeration = root.findChangedNodes();
		while ( enumeration.hasMoreElements() )
			{
			node = (MessageTreeNode)enumeration.nextElement();
			key = node.getPrimaryKey();
			if ( key == null )
				continue;
			message = Message.findMessage( key );
			if ( message!=null )
				{
				message.setLeftIndex( node.getLeftIndex() );
				message.setRightIndex( node.getRightIndex() );
				message.save();
				node.indexSaved();
				}
			//Make sure node knows that message has been saved
			}
		}

/*
	public Vector getTopLevelMessageIds()
		throws BuildingServerException
		{
		Message message;
		if ( top == null )
			{
			top = new Vector();
			Enumeration enumeration = 
				Message.findMessages( 
					"parent_message_id IS NULL AND message_room_id = " + messaging_room_id.toString(),
					"created_time" );
			while ( enumeration.hasMoreElements() )
				{
				message = (Message)enumeration.nextElement();
				top.addElement( message );
				}
			}
		return top;
		}
*/

	public boolean containsMessage( PrimaryKey mid )
		throws BuildingServerException
		{
		MessageTreeNode root, node;
		
		root = getMessageRoot();
		node = (MessageTreeNode)root.findNode( mid );
		return node!=null;
		}

	public MessageSummary getMessageSummary( PrimaryKey key )
		throws BuildingServerException
		{
                    
                // in the case of a null key return a message summary that
                // represents the "root" which means this MessagingRoom
                if ( key == null )
                {
                    MessageSummary summary = new MessageSummary();
                    summary.setMessagingRoomId( this.getMessagingRoomId() );
                    summary.setSubject( this.getTitle() );
                    summary.setBigStringId( this.getIntroductionBigStringId() );
                    return summary;
                }
                
		Message m = Message.findMessage( key );
		
		if ( m==null )
		    return null;
		
		if ( m.getMessagingRoomId().equals( this.getMessagingRoomId() ) )
		    return m.getSummary();
		
		throw new BuildingServerException( "Technical problem: attempt to access message in another room." );
		}
		
	public Hashtable getMessageSummaries()
		throws BuildingServerException
		{
		Enumeration enumeration;
		Message message;
		MessageSummary summary;
		
		if ( summaries ==null )
			{
			summaries = new Hashtable();
			
			enumeration = Message.findMessages( "messaging_room_id = " + getMessagingRoomId() );
			while ( enumeration.hasMoreElements() )
				{
				message = (Message)enumeration.nextElement();
				summary = message.getSummary();
				summaries.put( summary.getMessageId(), summary );
				}
			}

		return summaries;
		}

	public Hashtable getDifferentMessageSummaries( Hashtable keys )
		throws BuildingServerException
		{
		Enumeration enumeration;
		PrimaryKey key;
		Message message;
		MessageSummary summary;
		Hashtable s = getMessageSummaries();
		Hashtable r = new Hashtable();
		
		if ( s == null )
			return r;
			
		enumeration = s.keys();
		while ( enumeration.hasMoreElements() )
			{
			key = (PrimaryKey)enumeration.nextElement();
			if ( !keys.containsKey( key ) )
				{
				summary = (MessageSummary)s.get( key );
				r.put( key, summary );
				}
			}

		return r;
		}

/*
	public Vector findAllMessageIds()
		{
		if ( top == null )
			{
			top = new Vector();
			Enumeration enumeration = Message.findMessage( 
					"message_room_id = " + message_room_id.toString(),
					"created_time" );
			while ( enumeration.hasMoreElements() )
				{
				}
			}
		}
*/


	public synchronized MessageTreeNode getMessageRoot()
		throws BuildingServerException
        {
            return getMessageNode( null );
        }
        
	public synchronized MessageTreeNode getMessageNode( PrimaryKey mid )
		throws BuildingServerException
		{
		int i;
		Vector nodes_in_order;
		Message message;
		PrimaryKey key, parentkey;
		MessageTreeNode current_node, parent_node;
		
		if ( root == null )
			{
			//the root is not a message - just an empty defaultmutabletreenode
			summaries = new Hashtable();
			root = new MessageTreeNode();

			
			//sorted this way we can be certain that parents are always loaded before children
			Enumeration enumeration = 
				Message.findMessages( 
					"messaging_room_id = " + messaging_room_id.toString(), "left_index, created_time" );

			nodes_in_order = new Vector();
			
			while ( enumeration.hasMoreElements() )
				{
				message = (Message)enumeration.nextElement();
				summaries.put( message.getPrimaryKey(), message.getSummary() );
				parentkey = message.getParentMessageId();
				
				current_node = new MessageTreeNode();
				current_node.setVisitationObject( message );

				if ( parentkey==null )
					{
					root.add( current_node );
					}
				else
					{
					//look backwards in previous nodes for parent
					for ( i=nodes_in_order.size()-1; i>=0; i-- )
						{
						parent_node = (MessageTreeNode)nodes_in_order.elementAt( i );
						key = parent_node.getPrimaryKey();
						if ( key.equals( parentkey ) )
							{
							parent_node.add( current_node );
							break;  //leave loop with i set to index of parent
							}
						}
					if ( i<0 ) //loop above is exited with i<0 if no parent was found.
						{
						// A message was found that can't be placed - abandon this method of
						// loading and use more laborious method.
						root = new MessageTreeNode();
						loadMessages( root );
						root.reindex();
						saveMessages();
						return root;
						}
					}

				nodes_in_order.addElement( current_node );
				}
			
			
			root.reindex();
			}

                if ( mid == null )
                    return root;
                
		return (MessageTreeNode)root.findNode( mid );
		}
		

	private static StringBuffer load_where;
	private static Message load_mess;
	private synchronized void loadMessages( MessageTreeNode node )
		throws BuildingServerException
		{
		Enumeration enumeration;
		MessageTreeNode child_node;
		
		if ( load_where==null )
			load_where = new StringBuffer( 100 );
		load_where.setLength( 0 );
		
		load_where.append( "messaging_room_id = " );
		load_where.append( messaging_room_id.toString() );
		
		if ( node.getPrimaryKey() == null )
			load_where.append( " AND parent_message_id IS NULL" );
		else
			{
			load_where.append( " AND parent_message_id = " );
			load_where.append( node.getPrimaryKey().toString() );
			}
		
		enumeration = Message.findMessages( load_where.toString(), "created_time" );
		while ( enumeration.hasMoreElements() )
			{
			load_mess = (Message)enumeration.nextElement();
			if ( summaries!=null )
				summaries.put( load_mess.getPrimaryKey(), load_mess.getSummary() );
			child_node = new MessageTreeNode();
			child_node.setVisitationObject( load_mess );
			node.add( child_node );
			
			loadMessages( child_node );
			}
		
		}
		
		
	public static void main( String[] params )
		{
		MessagingRoom room = new MessagingRoom();
		Message message1, message2, message3;
		BigString text;
		String t = "The quick brown fox jumped over the lazy dog.";
		
		try
			{
			room.setPrimaryKey( new PrimaryKey(0x1000) );
			
			text = new BigString();
			text.setString( t );
			
			message1 = room.createMessage();
			message1.setSubject( "Message Number 1" );
			message1.setBigStringId( text.getBigStringId() );
			room.postMessage( message1 );
			
			text = new BigString();
			text.setString( t );
			
			message2 = room.createMessage();
			message2.setSubject( "Message Number 2" );
			message2.setBigStringId( text.getBigStringId() );
			room.postMessage( message2 );
			
			text = new BigString();
			text.setString( t );
			
			message3 = room.createMessage( message1.getMessageId(), true );
			message3.setSubject( "Message Number 3" );
			message3.setBigStringId( text.getBigStringId() );
			room.postMessage( message3 );

			}
		catch ( Exception ex )
			{
			log.error( ex.getMessage(), ex );
			}
		
		log.info( "Done." );
		}

	
	public void checkUpload( String pathname, String mime_type )
		throws BuildingServerException
		{
		log.debug( "MessagingRoom.checkUpload( \"" + pathname + "\", \"" + mime_type + "\" );" );
		
		String p;
		
		p = pathname;
		if ( p.startsWith( "/" ) )
			 p = p.substring( 1 );
		
		// messaging room only allows files stored in folders that
		// correspond to message IDs.
		if ( p.indexOf( "/" )<1 )
			throw new BuildingServerException( "In messaging rooms you cannot upload to the root folder." );

		if ( p.indexOf( "/" ) != p.lastIndexOf( "/" ) )
			throw new BuildingServerException( "In messaging rooms you can only upload to a folder corresponding to one of your own messages. (a)" );
			
		String folder = p.substring( 0, p.indexOf( "/" ) );

		log.debug( folder );
		
		PrimaryKey mid;
		try
			{
			mid = new PrimaryKey( Integer.parseInt( folder ) );
			}
		catch ( NumberFormatException nfex )
			{
			throw new BuildingServerException( "In messaging rooms you can only upload to a folder corresponding to one of your own messages. (b)" );
			}
		if ( mid==null )
			throw new BuildingServerException( "In messaging rooms you can only upload to a folder corresponding to one of your own messages. (c)" );
			
		if ( !containsMessage( mid ) )
			throw new BuildingServerException( "In messaging rooms you can only upload to a folder corresponding to one of your own messages. (d)" );
		
		MessageSummary summary = getMessageSummary( mid );
		User user = (User)BuildingContext.getContext().getUser();
		if ( !user.getUserId().equals( summary.getUserId() ) )
			throw new BuildingServerException( "You can't attach a file to someone else's message." );
		}


    public int getResourceType()
    	{
    	return RESOURCE_MESSAGINGROOM;
    	}
	}

