/**
 * Copyright (C) 2001-2017 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.visualization;

import java.util.LinkedList;
import java.util.List;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.Statistics;
import com.rapidminer.operator.ResultObjectAdapter;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.Tools;


/**
 * This class encapsulates some very simple statistics about the given attributes. These are the
 * ranges of the attributes and the average or mode values for numerical or nominal attributes
 * respectively. This information is automatically calculated and displayed by the graphical user
 * interface of RapidMiner. Since they cannot be displayed with the command line version of
 * RapidMiner the operator {@link DataStatisticsOperator} can be used as a workaround in cases where
 * the graphical user interface cannot be used.
 * 
 * @author Ingo Mierswa
 */
public class DataStatistics extends ResultObjectAdapter {

	private static final long serialVersionUID = -9182815345498602690L;

	private List<String> statistics = new LinkedList<String>();

	@Override
	public String getName() {
		return "Data Statistics";
	}

	public void addInfo(ExampleSet exampleSet, Attribute attribute) {
		StringBuffer result = new StringBuffer(attribute.toString() + ": ");
		if (Ontology.ATTRIBUTE_VALUE_TYPE.isA(attribute.getValueType(), Ontology.DATE_TIME)) {
			long minMilliseconds = (long) exampleSet.getStatistics(attribute, Statistics.MINIMUM);
			long maxMilliseconds = (long) exampleSet.getStatistics(attribute, Statistics.MAXIMUM);
			long difference = maxMilliseconds - minMilliseconds;
			String duration = "length = ";
			if (attribute.getValueType() == Ontology.DATE) {
				// days
				duration += com.rapidminer.tools.Tools.formatIntegerIfPossible(Math.round(difference
						/ (24.0d * 60.0d * 60.0d * 1000.0d)))
						+ " days";
			} else if (attribute.getValueType() == Ontology.TIME) {
				// hours
				duration += com.rapidminer.tools.Tools.formatIntegerIfPossible(Math.round(difference
						/ (60.0d * 60.0d * 1000.0d)))
						+ " hours";
			} else if (attribute.getValueType() == Ontology.DATE_TIME) {
				// days
				duration += com.rapidminer.tools.Tools.formatIntegerIfPossible(Math.round(difference
						/ (24.0d * 60.0d * 60.0d * 1000.0d)))
						+ " days";
			}
			result.append(duration);
		} else if (attribute.isNominal()) {
			result.append("mode = "
					+ attribute.getMapping().mapIndex((int) exampleSet.getStatistics(attribute, Statistics.MODE)));
		} else {
			result.append("avg = " + exampleSet.getStatistics(attribute, Statistics.AVERAGE) + " +/- "
					+ Math.sqrt(exampleSet.getStatistics(attribute, Statistics.VARIANCE)));
		}
		result.append("; unknown = " + exampleSet.getStatistics(attribute, Statistics.UNKNOWN));
		statistics.add(result.toString());
	}

	@Override
	public String toString() {
		StringBuffer result = new StringBuffer();
		statistics.forEach(s -> result.append(s + Tools.getLineSeparator()));
		return result.toString();
	}

	public String getExtension() {
		return "sta";
	}

	public String getFileDescription() {
		return "data statistics";
	}
}