/*
 *  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.learner.subgroups.hypothesis;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;

import java.io.Serializable;


/**
 * A literator for a rule.
 * 
 * @author Tobias Malbrecht
 */
public class Literal implements Serializable {

	private static final long serialVersionUID = 8699112785374243323L;
	
	private Attribute attribute = null;
	
	private double value = 0.0d;
	
	public Literal(Attribute attribute, double value) {
		this.attribute = attribute;
		this.value = value;
	}
	
	public boolean applicable(Example example) {
		return (example.getValue(attribute) == value);
	}
	
	public Attribute getAttribute() {
		return attribute;
	}
	
	public double getValue() {
		return value;
	}

	public String getValueAsString() {
		return attribute.getMapping().mapIndex((int) value);
	}
	
	@Override
	public int hashCode() {
		return this.attribute.hashCode() ^ Integer.valueOf((int) value);
	}
	
	public boolean contradicts(Literal otherLiteral) {
		if (this.attribute.equals(otherLiteral.attribute) && (this.value != otherLiteral.value)) {
			return true;
		}
		return false;
	}
	
	@Override
	public boolean equals(Object object) {
		if (object == null) {
			return false;
		}
		if (getClass() != object.getClass()) {
			return false;
		}
		Literal otherLiteral = (Literal) object;
		if (attribute.equals(otherLiteral.attribute) && (this.value == otherLiteral.value)) {
			return true;
		}
		return false;
	}
	
	@Override
	public String toString() {
		return attribute.getName() + "=" + attribute.getMapping().mapIndex((int) value);
	}
}