/*
 *    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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

package eti.bi.alphaminer.vo;

import java.io.Serializable;

/**
 * Connection is a class representing connection of two nodes in a case.
 */
public class NodeConnection implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * ID of the head node.
	 */
	private String m_HeadNodeID;

	/**
	 * ID of the tail node.
	 */
	private String m_TailNodeID;

	/**
	 * Contructs a Connection
	 */
	public NodeConnection() {
	}

	/**
	 * Constructs a Connection instance that represents a linkage between a head
	 * node and a tail node.
	 * @param a_HeadNodeID ID of the head node.
	 * @param a_TailNodeID ID of the tail node.
	 */
	public NodeConnection(String a_HeadNodeID, String a_TailNodeID) {
		m_HeadNodeID = a_HeadNodeID;
		m_TailNodeID = a_TailNodeID;
	}

	/**
	 * Returns ID of the head node of this connection.
	 * @return ID of the head node.
	 */
	public String getHeadNodeID() {
		return m_HeadNodeID;
	}

	/**
	 * Sets ID of the head node of this connection.
	 * @param a_ID of the head node.
	 */
	public void setHeadNodeID(String a_ID) {
		m_HeadNodeID = a_ID;
	}

	/**
	 * Returns ID of the tail node of this connection.
	 * @return ID of the tail node.
	 */
	public String getTailNodeID() {
		return m_TailNodeID;
	}

	/**
	 * Sets ID of the tail node of this connection.
	 * @param a_ID of the tail node.
	 */
	public void setTailNodeID(String a_ID) {
		m_TailNodeID = a_ID;
	}

	/**
	 * Checks if a specific node involves in the connection.
	 * @param a_NodeID ID of the node to be checked.
	 * @return true if the node involvoes in the connection; false otherwise.
	 */
	public boolean containNode(String a_NodeID) {
		if (m_HeadNodeID.equals(a_NodeID) || m_TailNodeID.equals(a_NodeID))
			return true;
		else
			return false;
	}

	/**
	 * Compares a specific Connection object with the current instance for
	 * equality.
	 * @param a_Connection the Connection to be compared for equality with this
	 * instance.
	 * @return true if the specified Conenction is equals to this Connection;
	 * false otherwise.
	 */
	public boolean equals(NodeConnection a_Connection) {
		if (m_HeadNodeID.equals(a_Connection.getHeadNodeID())
			&& m_TailNodeID.equals(a_Connection.getTailNodeID()))
			return true;
		else
			return false;
	}

	/**
	 * Compares a specific Connection object with the current instance for reverse
	 * equality.
	 * @param a_Connection the Connection to be compared for equality with this
	 * instance.
	 * @return true if the head node of the specified Connection equals to
	 * the tail node of this Connection and the tail node of the specified
	 * Connection equals to the head node of this Connection; false otherwise.
	 */
	public boolean equalsReverse(NodeConnection a_Connection) {
		if (m_HeadNodeID.equals(a_Connection.getTailNodeID())
			&& m_TailNodeID.equals(a_Connection.getHeadNodeID()))
			return true;
		else
			return false;
	}
}