/* ======================================================================
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.util;

import javax.swing.tree.*;
import java.io.*;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import org.bodington.database.PrimaryKey;

public class VisitationMutableTreeNode 
	extends DefaultMutableTreeNode 
	implements java.io.Serializable
	{
	
	private boolean contains_visitation_object=false;
	private int left_index=0;
	private int right_index=Integer.MAX_VALUE;
	boolean changed=false;

	//only used by root node
	private Hashtable keyed_nodes=null;

	public void indexSaved()
		{
		changed=false;
		}
	public boolean indexChanged()
		{
		return changed;
		}
	
	public void setLeftIndex( int l )
		{
		if ( l == left_index ) return;
		left_index = l;
		changed = true;
		}
	public int getLeftIndex()
		{
		return left_index;
		}
	public void setRightIndex( int r )
		{
		if ( r==right_index ) return;
		right_index = r;
		changed=true;
		}
	public int getRightIndex()
		{
		return right_index;
		}

	public void setUserObject( Object obj )
		{
		contains_visitation_object = false;
		setLeftIndex( -1 );
		setRightIndex( -1 );
		changed = false;
		super.setUserObject( obj );
		}
	
	public void setVisitationObject( VisitationObject v )
		{
		if ( getParent() != null || getChildCount()>0 )
			throw new IllegalStateException( "Illegal attempt to change the contents of a tree node." );
		
		contains_visitation_object = true;
		setLeftIndex( v.getLeftIndex() );
		setRightIndex( v.getRightIndex() );
		changed = false;
		super.setUserObject( v.getPrimaryKey() );
		}
		
	public PrimaryKey getPrimaryKey()
		{
		if ( !contains_visitation_object )	return null;
		Object obj = getUserObject();
		if ( obj==null )					return null;
		if ( !(obj instanceof PrimaryKey) ) return null;
		return (PrimaryKey)obj;
		}

	public void setParent( MutableTreeNode newParent )
		{
		boolean root_no_more = ( getParent()==null && newParent !=null );
		super.setParent( newParent );

		// if this was a root and now isn't
		// ditch the hashtable of nodes.
		if ( root_no_more )
			keyed_nodes = null;
		}


	public Enumeration findChangedNodes()
		{
		if ( getParent() != null )
			{
			VisitationMutableTreeNode root = (VisitationMutableTreeNode)getRoot();
			return root.findChangedNodes();
			}

		Vector changed = new Vector();
		Enumeration enumeration = this.preorderEnumeration();
		VisitationMutableTreeNode node;
		while ( enumeration.hasMoreElements() )
			{
			node=(VisitationMutableTreeNode)enumeration.nextElement();
			if ( node.contains_visitation_object )
				if ( node.indexChanged() )
					changed.addElement( node );
			}
			
		return changed.elements();
		}

	public VisitationMutableTreeNode findNode( PrimaryKey key )
		{
		if ( getParent() != null )
			{
			VisitationMutableTreeNode root = (VisitationMutableTreeNode)getRoot();
			return root.findNode( key );
			}

		if ( keyed_nodes == null )
			return null;
			
		return (VisitationMutableTreeNode)keyed_nodes.get( key );
		}

	private void addToLookup( VisitationMutableTreeNode node )
		{
		if ( getParent() != null )
			{
			VisitationMutableTreeNode root = (VisitationMutableTreeNode)getRoot();
			root.addToLookup( node );
			return;
			}
			
		if ( !node.contains_visitation_object )
			return;

		PrimaryKey key = node.getPrimaryKey();
		if ( key==null )
			return;

		if ( keyed_nodes == null )
			keyed_nodes = new Hashtable();

		keyed_nodes.put( key, node );
		}
		
	public void add( MutableTreeNode newChild )
		throws IllegalArgumentException, IllegalStateException
		{
		insert( newChild, this.getChildCount() );
		}
		
		
	public void insert( MutableTreeNode newChild, int pos )
		throws IllegalArgumentException, IllegalStateException
		{
		VisitationMutableTreeNode v_root, v_child, node;
		Enumeration v_set;
		int insert_at, childcount;
		PrimaryKey key;
		
		if ( !(newChild instanceof VisitationMutableTreeNode) )
			throw new IllegalStateException( "Can't move elements of that class in this tree." );
		if ( newChild.getParent() != null )
			throw new IllegalStateException( "Can't move elements in this tree." );
		if ( newChild.getChildCount() >0 )
			throw new IllegalStateException( "Can't add branches to this tree." );
		
		v_child = (VisitationMutableTreeNode) newChild;
		v_root = getVisitationRoot();
		
		if ( v_root == null )
			{
			v_child.setLeftIndex( 0 );
			v_child.setRightIndex( 1 );
			addToLookup( v_child );
			super.insert( newChild, pos );
			return;
			}
		
		childcount = this.getChildCount();
		if ( pos<0 || pos > childcount )
			pos = childcount;
		
		if ( pos<childcount )
			{
			node = (VisitationMutableTreeNode)this.getChildAt( pos );
			insert_at = node.getLeftIndex();
			}
		else
			insert_at = this.getRightIndex();
		
		v_child.setLeftIndex( insert_at );
		v_child.setRightIndex( insert_at+1 );
		
		v_set = v_root.preorderEnumeration();
		
		while ( v_set.hasMoreElements() )
			{
			node = (VisitationMutableTreeNode) v_set.nextElement();
			
			if ( node.getLeftIndex() >= insert_at )
				node.setLeftIndex( node.getLeftIndex()+2 );
			if ( node.getRightIndex() >= insert_at )
				node.setRightIndex( node.getRightIndex()+2 );
			}
			
		addToLookup( v_child );
		super.insert( newChild, pos );
		}
	
	private synchronized int reindexChildren( int visitation )
		{
		VisitationMutableTreeNode v_node;
		
		this.setLeftIndex( visitation++ );
		
		if ( this.getChildCount()>0 )
			{
			for (	v_node = (VisitationMutableTreeNode)this.getFirstChild(); 
					v_node !=null; 
					v_node = (VisitationMutableTreeNode)v_node.getNextSibling() )
				{
				visitation = v_node.reindexChildren( visitation );
				}
			}
		
		this.setRightIndex( visitation++ );
		
		return visitation;
		}
	
	public synchronized VisitationMutableTreeNode getVisitationRoot()
		{
		int i;
		TreeNode[] path;
		TreeNode node;
		VisitationMutableTreeNode v_root=null, v_node;
		Enumeration v_set;
		
		// find the node at that is the container for the
		// same visitation set as this node and reindex the
		// left an right indexes for all ancestors.

		if ( !this.contains_visitation_object )
			return null;
		
		//get path to root
		path = this.getPath();
		if ( path.length == 0 )
			return null;

		if ( path.length == 1 )
			{
			v_root = (VisitationMutableTreeNode)path[0];
			if ( v_root.contains_visitation_object )
				return v_root;
			return null;
			}
		
		//work back down root to find first node of visitation set
		for ( i=(path.length-2); i>=0; i-- )
			{
			v_node = (VisitationMutableTreeNode)path[i];
			// if this isn't the right type of node previous node
			// must have been the v_root
			if ( !v_node.contains_visitation_object )
				{
				v_root = (VisitationMutableTreeNode)path[i+1];
				break;
				}
			}
		// if all the nodes in the path are the right type then
		// the root is at the start of the path.
		if ( i<0 )
			v_root = (VisitationMutableTreeNode)path[0];
			
		return v_root;
		}
		
	public synchronized void reindex()
		{
		VisitationMutableTreeNode v_root=null;

		v_root = getVisitationRoot();
		
		// reindex children (recursive method)
		if ( v_root!=null )
			v_root.reindexChildren( 0 );
		}
	}