/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.operator.clustering;

import java.util.Collection;
import java.util.LinkedList;

/**
 * This class is an extension of the HierarchicalClusterNode, representing the leaf nodes of a
 * hierarchical cluster tree. These Nodes are the only nodes containing the links to examples by 
 * storing example ids.
 * @author Sebastian Land
 */
public class HierarchicalClusterLeafNode extends HierarchicalClusterNode {
	private static final long serialVersionUID = -8181571984420396236L;

	private Collection<Object> exampleIds;
	
	public HierarchicalClusterLeafNode(String clusterId) {
		super(clusterId);
	}
	public HierarchicalClusterLeafNode(String clusterId, Collection<Object> exampleIds) {
		super(clusterId);
		this.exampleIds = exampleIds;
	}
	
	public HierarchicalClusterLeafNode(int clusterId, Collection<Object> exampleIds) {
		this(clusterId + "", exampleIds);
	}

	public HierarchicalClusterLeafNode(int clusterId, Object exampleId) {
		super(clusterId + "");
		this.exampleIds = new LinkedList<Object>();
		this.exampleIds.add(exampleId);
	}

	/**
	 * Returns an empty collection since it is leaf
	 */
	@Override
	public Collection<HierarchicalClusterNode> getSubNodes() {
		return new LinkedList<HierarchicalClusterNode>();
	}

	/**
	 * Get the number of subnodes: Is always 0 since this node is leaf
	 */
	@Override
	public int getNumberOfSubNodes() {
		return 0;
	}

	@Override
	public double getDistance() {
		return 0d;
	}

	/**
	 * Get all objects (as representend by their IDs) in this leaf.
	 */
	@Override
	public Collection<Object> getExampleIdsInSubtree() {
		return exampleIds;
	}

	@Override
	public int getNumberOfExamplesInSubtree() {
		return exampleIds.size();
	}

	public void addSubNode(HierarchicalClusterLeafNode node) {}
	
	@Override
	public String toString() {
		return getClusterId() + ":" + getNumberOfExamplesInSubtree();
	}

}