/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.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.preprocessing.transformation.aggregation;

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

/**
 * @author Marius Helf 
 *
 */
public class ConcatAggregator implements Aggregator {

	private ConcatAggregationFunction function;
	boolean first = true;
	private StringBuilder concatenation = new StringBuilder();

	public ConcatAggregator(ConcatAggregationFunction concatAggregationFunction) {
		this.function = concatAggregationFunction;
	}

	@Override
	public void count(Example example) {
		
		Attribute sourceAttribute = function.getSourceAttribute();
		double value = example.getValue(sourceAttribute);
		if (!Double.isNaN(value)) {
			if (first) {
				first = false;
			} else {
				concatenation.append(function.getSeparator());
			}
			String nominalValue = sourceAttribute.getMapping().mapIndex((int) value);
			concatenation.append(nominalValue);
		}
	}

	@Override
	public void count(Example example, double weight) {
		count(example);
	}

	@Override
	public void set(Attribute attribute, DataRow row) {
		int idx = attribute.getMapping().mapString(concatenation.toString());
		attribute.setValue(row, idx);
	}

}