/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 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.example.set;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.AttributeTransformation;


/** This transformation simply returns the same value. 
 *  
 *  @author Ingo Mierswa
 *  @version $Id: AttributeTransformationReplaceMissing.java,v 1.2 2008/05/09 19:22:49 ingomierswa Exp $
 */
public class AttributeTransformationReplaceMissing implements AttributeTransformation {

	private Map<String, Double> replacementMap;
	
	public AttributeTransformationReplaceMissing(Map<String, Double> replacementMap) {
		this.replacementMap = replacementMap;
	}

	public AttributeTransformationReplaceMissing(AttributeTransformationReplaceMissing other) {
		this.replacementMap = new HashMap<String, Double>();
		Iterator<Map.Entry<String, Double>> i = other.replacementMap.entrySet().iterator();
		while (i.hasNext()) {
			Map.Entry<String, Double> entry = i.next();
			this.replacementMap.put(entry.getKey(), Double.valueOf(entry.getValue()));
		}
	}
	
	public Object clone() {
		return new AttributeTransformationReplaceMissing(this);
	}
	
	public void setReplacementMap(Map<String,Double> replacementMap) {
		this.replacementMap = replacementMap;
	}
	
	public double inverseTransform(Attribute attribute, double value) {
		return value;
	}

	public boolean isReversable() {
		return false;
	}

	public double transform(Attribute attribute, double value) {
		if (Double.isNaN(value)) {
			Double replacement = replacementMap.get(attribute.getName());
			if (replacement != null)
				return replacement;
			else
				return value;
		} else {
			return value;
		}
	}
}