/* 
GeoGebra - Dynamic Mathematics for Everyone
http://www.geogebra.org

This file is part of GeoGebra.

This program is free software; you can redistribute it and/or modify it 
under the terms of the GNU General Public License as published by 
the Free Software Foundation.

 */

package org.geogebra.common.kernel.algos;

import java.util.Iterator;
import java.util.TreeSet;

import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.arithmetic.NumberValue;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.geos.GeoList;
import org.geogebra.common.kernel.geos.GeoNumeric;
import org.geogebra.common.kernel.geos.GeoPoint;
import org.geogebra.common.kernel.geos.GeoText;

/**
 * Sort a list. Adapted from AlgoMax and AlgoIterationList
 * 
 * @author Michael Borcherds
 * @version 04-01-2008
 */

public class AlgoSort extends AlgoElement {

	private GeoList inputList; // input
	private GeoList outputList; // output
	private int size;
	private GeoList valueList;

	/**
	 * Creates new list sorting algorithm
	 * 
	 * @param cons
	 *            construction
	 * @param label
	 *            label for output
	 * @param inputList
	 *            list to be sorted
	 */
	public AlgoSort(Construction cons, String label, GeoList inputList) {
		this(cons, inputList);
		outputList.setLabel(label);
	}

	/**
	 * Creates new list sorting algorithm
	 * 
	 * @param cons
	 *            construction
	 * @param label
	 *            label for output
	 * @param valueList
	 *            list of values that shall be sorted
	 * @param inputList
	 *            list of keys which determines order of values in sorted list
	 */
	public AlgoSort(Construction cons, String label, GeoList valueList,
			GeoList inputList) {
		this(cons, inputList, valueList);
		outputList.setLabel(label);
	}

	/**
	 * Creates new list sorting algorithm
	 * 
	 * @param cons
	 *            construction
	 * @param inputList
	 *            list of keys which determines order of values in sorted list
	 * @param valueList
	 *            list of values that shall be sorted
	 */
	public AlgoSort(Construction cons, GeoList inputList, GeoList valueList) {
		super(cons);
		this.inputList = inputList;
		this.valueList = valueList;

		outputList = new GeoList(cons);

		setInputOutput();
		compute();
	}

	/**
	 * Creates new list sorting algorithm
	 * 
	 * @param cons
	 *            construction
	 * @param inputList
	 *            to be sorted
	 */
	public AlgoSort(Construction cons, GeoList inputList) {
		this(cons, inputList, (GeoList) null);
	}

	@Override
	public Commands getClassName() {
		return Commands.Sort;
	}

	@Override
	protected void setInputOutput() {

		// make sure that x(Element[list,1]) will work even if the output list's
		// length is zero
		outputList.setTypeStringForXML(inputList.getTypeStringForXML());

		input = new GeoElement[valueList == null ? 1 : 2];
		if (valueList != null) {
			input[0] = valueList;
			input[1] = inputList;
		} else {
			input[0] = inputList;
		}
		super.setOutputLength(1);
		super.setOutput(0, outputList);
		setDependencies(); // done by AlgoElement
	}

	/**
	 * @return sorted list
	 */
	public GeoList getResult() {
		return outputList;
	}

	@Override
	public final void compute() {

		size = inputList.size();
		if (!inputList.isDefined() || size == 0) {
			outputList.setUndefined();
			return;
		}

		if (valueList != null
				&& (!valueList.isDefined() || valueList.size() != size)) {
			outputList.setUndefined();
			return;
		}

		GeoElement geo0 = inputList.get(0);

		Class<? extends GeoElement> geoClass = geo0.getClass();

		TreeSet<GeoElement> sortedSet;

		if (geo0.isGeoPoint()) {
			sortedSet = new TreeSet(GeoPoint.getComparatorX());

		} else if (geo0.isGeoText()) {
			sortedSet = new TreeSet(GeoText.getComparator());

		} else if (geo0 instanceof NumberValue) {
			sortedSet = new TreeSet(GeoNumeric.getComparator());

		} else {
			outputList.setUndefined();
			return;
		}

		// copy inputList into treeset
		for (int i = 0; i < size; i++) {
			GeoElement geo = inputList.get(i);
			if (geo.getClass().equals(geoClass)) {
				sortedSet.add(geo);
			} else {
				outputList.setUndefined();
				return;
			}
		}

		// copy the sorted treeset back into a list
		outputList.setDefined(true);
		outputList.clear();

		Iterator<GeoElement> iterator = sortedSet.iterator();
		if (valueList == null) {
			while (iterator.hasNext()) {
				// need to copy elements like eg {(1,1)} so the properties can
				// be set independently
				outputList.addCopy(iterator.next());
			}
		} else {
			while (iterator.hasNext()) {
				int pos = inputList.find(iterator.next());
				// need to copy elements like eg {(1,1)} so the properties can
				// be set independently

				outputList.addCopy(valueList.get(pos));
			}
		}
	}

}