/*
 *  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.datatable;

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

import com.rapidminer.gui.new_plotter.utility.DataStructureUtils;
import com.rapidminer.tools.container.Pair;

/**
 * A sort provider which sorts the rows based on the values of one column.
 * Nominal values are sorted by the string values, all other column types
 * use the double values for sorting.
 * 
 * @author Marius Helf
 *
 */
public class DataTableNaturalSortProvider implements DataTableSortProvider {
	boolean ascending;
	int columnIdx;
	
	
	public DataTableNaturalSortProvider(int columnIdx, boolean ascending) {
		super();
		this.ascending = ascending;
		this.columnIdx = columnIdx;
	}



	@Override
	public int[] getIndexMapping(DataTable dataTable) {
		if (columnIdx >= 0 && columnIdx < dataTable.getColumnNumber()) {

			// get list of all values, either nominal or numeric
			List<Pair<Double,? extends Comparable>> allValues = new LinkedList<Pair<Double,? extends Comparable>>();
			if (dataTable.isNominal(columnIdx)) {
				double rowIdx = 0;
				for (DataTableRow row : dataTable) {
					allValues.add(new Pair<Double,Comparable>(rowIdx, row.getValue(columnIdx)));
					rowIdx += 1;
				}
			} else {
				double rowIdx = 0;
				for (DataTableRow row : dataTable) {
					allValues.add(new Pair<Double,Comparable>(rowIdx, row.getValue(columnIdx)));
					rowIdx += 1;
				}
			}

			// sort list
			Collections.sort(allValues, new DataStructureUtils.PairComparator(ascending));

			// create mapping from idx and values
			int[] indexMapping = new int[allValues.size()];
			int idx = 0;
			for (Pair<Double, ? extends Comparable> entry : allValues) {
				indexMapping[idx] = entry.getFirst().intValue();
				++idx;
			}
			return indexMapping;
		} else {
			int rowCount = dataTable.getRowNumber();
			int[] indexMapping = new int[rowCount];
			for (int i = 0; i < rowCount; ++i) {
				indexMapping[i] = i;
			}
			return indexMapping;
		}
	}
	
	@Override
	public DataTableNaturalSortProvider clone() {
		DataTableNaturalSortProvider clone = new DataTableNaturalSortProvider(columnIdx, ascending);
		return clone;
	}
}