/*
 *    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.util.Vector;

/**
 * Process is a class storing all connections of a case.
 */
public class Process {

	/**
	 * A Vector storing all Connection.
	 */
	private Vector<NodeConnection> m_ConnectionList;

	/**
	 * Constructs a Process.
	 */
	public Process() {
		m_ConnectionList = new Vector<NodeConnection>();
	}

	/**
	 * Returns a Vector containing all Connections.
	 * @return Vector of Connections.
	 */
	public Vector<NodeConnection> getConnectionList() {
		return m_ConnectionList;
	}

	/**
	 * Sets the Vector of Connections.
	 * @param a_List the Vector containing all Connections.
	 */
	public void setConnectionList(Vector<NodeConnection> a_List) {
		m_ConnectionList = a_List;
	}

	/**
	 * Gets tail nodes that are connected to the head node.
	 * @param a_NodeID ID of the head node.
	 * @return Vector storing ID of tail nodes.
	 */
	public Vector<String> getChildrenOfNode(String a_NodeID) {
		Vector<String> children = new Vector<String>();
		NodeConnection con = null;
		for (int i = 0; i < m_ConnectionList.size(); i++) {
			con = m_ConnectionList.elementAt(i);
			if (con.getHeadNodeID().equals(a_NodeID))
				children.addElement(con.getTailNodeID());
		}

		return children;
	}
	
	/**
	 * Returns number of tail nodes that are connected to the head node.
	 * @param a_NodeID ID of the head node.
	 * @return number of tail nodes.
	 */
	public int getNumberOfChildrenOfNode(String a_NodeID)
	{
		Vector<String> children = getChildrenOfNode(a_NodeID);
		if (children==null)
			return 0;
		else
			return children.size();
	}

	/**
	 * Gets head nodes that are connected to the tail node.
	 * @param a_NodeID ID of the tail node.
	 * @return Vector storing ID of head nodes.
	 */
	public Vector<String> getParentsOfNode(String a_NodeID) {
		Vector<String> parents = new Vector<String>();
		NodeConnection con = null;
		for (int i = 0; i < m_ConnectionList.size(); i++) {
			con = m_ConnectionList.elementAt(i);
			if (con.getTailNodeID().equals(a_NodeID))
				parents.addElement(con.getHeadNodeID());
		}

		return parents;
	}

	/**
	 * Returns number of head nodes that are connected to the tail node.
	 * @param a_NodeID ID of the tail node.
	 * @return number of head nodes.
	 */
	public int getNumberOfParentsOfNode(String a_NodeID)
	{
		Vector<String> parents = getParentsOfNode(a_NodeID);
		if (parents==null)
			return 0;
		else
			return parents.size();
	}

	/**
	 * Inserts a Connection between a head node and a tail node in this case.
	 * @param a_HeadNodeID ID of the head node.
	 * @param a_TailNodeID ID of the tail node.
	 * @return true if Connection is aded successfully; false otherwise.
	 */
	public boolean insertConnection(String a_HeadNodeID, int a_HeadChildrenNum, String a_TailNodeID, int a_TailParentsNum) {
		if (isConnectionExisted(a_HeadNodeID, a_TailNodeID))
			return false;
		if (isCyclic(a_HeadNodeID, a_TailNodeID))
			return false;
		if (getNumberOfChildrenOfNode(a_HeadNodeID)>=a_HeadChildrenNum)
			return false;
		if (getNumberOfParentsOfNode(a_TailNodeID)>=a_TailParentsNum)
			return false;
		m_ConnectionList.addElement(new NodeConnection(a_HeadNodeID, a_TailNodeID));
		printDebug();
		return true;
	}

	/**
	 * Remove connections connecting to two nodes.
	 * @param a_HeadNodeID ID of the parent node of the connection.
	 * @param a_TailNodeID ID of the tail node of the connection.
	 */
	public void removeConnectionBetweenNodes(
		String a_HeadNodeID,
		String a_TailNodeID) {
		NodeConnection existingCon = null;
		NodeConnection con = new NodeConnection(a_HeadNodeID, a_TailNodeID);
		for (int i = 0; i < m_ConnectionList.size(); i++) {
			existingCon = m_ConnectionList.elementAt(i);
			if (existingCon.equals(con)) {
				m_ConnectionList.remove(i);
				break;
			}
		}
		printDebug();
	}

	/**
	 * Remove connections connecting to a specific node.
	 * @param a_NodeID ID of the specified node.
	 */
	public void removeConnectionOfNode(String a_NodeID) {
		NodeConnection existingCon = null;
		for (int i = 0; i < m_ConnectionList.size(); i++) {
			existingCon = m_ConnectionList.elementAt(i);
			if (existingCon.containNode(a_NodeID)) {
				m_ConnectionList.remove(i);
				i--;
			}
		}
		printDebug();
	}

	/**
	 * Checks if a connection between two nodes exists.
	 * @param a_HeadNodeID ID of the head node.
	 * @param a_TailNodeID ID of the tail node.
	 * @return true if the connection or the reverse connection of the two nodes
	 * exists; false otherwise.
	 */
	private boolean isConnectionExisted(
		String a_HeadNodeID,
		String a_TailNodeID) {
		NodeConnection con = new NodeConnection(a_HeadNodeID, a_TailNodeID);
		NodeConnection existingCon = null;
		for (int i = 0; i < m_ConnectionList.size(); i++) {
			existingCon = m_ConnectionList.elementAt(i);
			if (existingCon.equals(con) || existingCon.equalsReverse(con))
				return true;
		}
		return false;
	}

	/**
	 * Check if the connection between the head and the tail nodes produces a cyclic path.
	 * @param a_HeadNodeID ID of the head node.
	 * @param a_TailNodeID ID of the tail node.
	 * @return true if the connection causes a cyclic path; false otherwise.
	 */
	private boolean isCyclic(String a_HeadNodeID, String a_TailNodeID) {
		Vector<String> nodes = getParentsOfNode(a_HeadNodeID);
		for (int i = 0; i < nodes.size(); i++) {
			if (nodes.elementAt(i).equals(a_TailNodeID))
				return true;
			else
				return isCyclic(nodes.elementAt(i), a_TailNodeID);
		}
		return false;
	}


	private void printDebug() {
		for (int i = 0; i < m_ConnectionList.size(); i++) {
		}
	}	
}