/*
 * Jalview - A Sequence Alignment Editor and Viewer
 * Copyright (C) 2006 AM Waterhouse, J Procter, G Barton, M Clamp, S Searle
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
package jalview.datamodel;

/**
 * DOCUMENT ME!
 *
 * @author $author$
 * @version $Revision$
 */
public class BinaryNode
{
    Object element;
    String name;
    BinaryNode left;
    BinaryNode right;
    BinaryNode parent;

    /** DOCUMENT ME!! */
    public int bootstrap;

    /**
     * Creates a new BinaryNode object.
     */
    public BinaryNode()
    {
        left = right = parent = null;
        bootstrap = 0;
    }

    /**
     * Creates a new BinaryNode object.
     *
     * @param element DOCUMENT ME!
     * @param parent DOCUMENT ME!
     * @param name DOCUMENT ME!
     */
    public BinaryNode(Object element, BinaryNode parent, String name)
    {
        this.element = element;
        this.parent = parent;
        this.name = name;

        left = right = null;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public Object element()
    {
        return element;
    }

    /**
     * DOCUMENT ME!
     *
     * @param v DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public Object setElement(Object v)
    {
        return element = v;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode left()
    {
        return left;
    }

    /**
     * DOCUMENT ME!
     *
     * @param n DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode setLeft(BinaryNode n)
    {
        return left = n;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode right()
    {
        return right;
    }

    /**
     * DOCUMENT ME!
     *
     * @param n DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode setRight(BinaryNode n)
    {
        return right = n;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode parent()
    {
        return parent;
    }

    /**
     * DOCUMENT ME!
     *
     * @param n DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public BinaryNode setParent(BinaryNode n)
    {
        return parent = n;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isLeaf()
    {
        return (left == null) && (right == null);
    }

    /**
     * attaches FIRST and SECOND node arguments as the LEFT and RIGHT children of this node (removing any old references)
     * a null parameter DOES NOT mean that the pointer to the corresponding child node is set to  NULL - you  should use
     * setChild(null), or detach() for this.
     *
     */
    public void SetChildren(BinaryNode leftchild, BinaryNode rightchild)
    {
        if (leftchild != null)
        {
            this.setLeft(leftchild);
            leftchild.detach();
            leftchild.setParent(this);
        }

        if (rightchild != null)
        {
            this.setRight(rightchild);
            rightchild.detach();
            rightchild.setParent(this);
        }
    }

    /**
     * Detaches the node from the binary tree, along with all its child nodes.
     * @return BinaryNode The detached node.
     */
    public BinaryNode detach()
    {
        if (this.parent != null)
        {
            if (this.parent.left == this)
            {
                this.parent.left = null;
            }
            else
            {
                if (this.parent.right == this)
                {
                    this.parent.right = null;
                }
            }
        }

        this.parent = null;

        return this;
    }

    /**
     * Traverses up through the tree until a node with a free leftchild is discovered.
     * @return BinaryNode
     */
    public BinaryNode ascendLeft()
    {
        BinaryNode c = this;

        do
        {
            c = c.parent();
        }
        while ((c != null) && (c.left() != null) && !c.left().isLeaf());

        return c;
    }

    /**
     * Traverses up through the tree until a node with a free rightchild is discovered.
     * Jalview builds trees by descent on the left, so this may be unused.
     * @return BinaryNode
     */
    public BinaryNode ascendRight()
    {
        BinaryNode c = this;

        do
        {
            c = c.parent();
        }
        while ((c != null) && (c.right() != null) && !c.right().isLeaf());

        return c;
    }

    /**
     * DOCUMENT ME!
     *
     * @param name DOCUMENT ME!
     */
    public void setName(String name)
    {
        this.name = name;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getName()
    {
        return this.name;
    }

    /**
     * DOCUMENT ME!
     *
     * @param boot DOCUMENT ME!
     */
    public void setBootstrap(int boot)
    {
        this.bootstrap = boot;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public int getBootstrap()
    {
        return bootstrap;
    }
}