/* 
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.advanced;

import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.algos.AlgoElement;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.geos.GeoList;

/**
 * adapted from AlgoJoin
 * 
 * @author Simon
 * @version 2011-11-15
 * 
 */
public class AlgoFlatten extends AlgoElement {

	private GeoList inputList; // input
	private GeoList outputList; // output

	public AlgoFlatten(Construction cons, String label, GeoList inputList) {
		super(cons);

		this.inputList = inputList;

		outputList = new GeoList(cons);

		setInputOutput();
		compute();
		outputList.setLabel(label);
	}

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

	@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[1];

		input[0] = inputList;

		super.setOutputLength(1);
		super.setOutput(0, outputList);
		setDependencies(); // done by AlgoElement
	}

	public GeoList getResult() {
		return outputList;
	}

	@Override
	public final void compute() {

		if (!inputList.isDefined()) {
			outputList.setUndefined();
			return;
		}

		outputList.setDefined(true);
		outputList.clear();

		flatten(outputList, inputList);
	}

	private void flatten(GeoList outputList, GeoList list) {
		int size = list.size();
		for (int i = 0; i < size; i++) {
			GeoElement element = list.get(i);
			if (element.isGeoList()) {
				flatten(outputList, (GeoList) element);
			} else {
				outputList.add(element.copyInternal(cons));
			}
		}
	}

}