/* 
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 org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoBoolean;
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.main.MyError;

/**
 * Take objects from the middle of a list adapted from AlgoKeepIf
 * 
 * @author Michael Borcherds
 */

public class AlgoCountIf3 extends AlgoElement {

	private GeoList inputList; // input
	private GeoNumeric result; // output
	private GeoBoolean bool; // input
	private GeoElement var;
	private int size;

	/**
	 * @param cons
	 *            construction
	 * @param label
	 *            label
	 * @param bool
	 *            boolean filter (dependent on var)
	 * @param var
	 *            variable to be substituted
	 * @param inputList
	 *            list
	 */
	public AlgoCountIf3(Construction cons, String label, GeoBoolean bool,
			GeoElement var, GeoList inputList) {
		super(cons);
		this.inputList = inputList;
		this.var = var;
		this.bool = bool;

		result = new GeoNumeric(cons);

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

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

	@Override
	protected void setInputOutput() {

		input = new GeoElement[3];
		input[0] = bool;
		input[1] = var;
		input[2] = inputList;

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

	/**
	 * @return resulting list
	 */
	public GeoNumeric getResult() {
		return result;
	}

	@Override
	public final void compute() {

		size = inputList.size();

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

		int count = 0;

		if (size > 0) {

			try {
				for (int i = 0; i < size; i++) {
					GeoElement geo = inputList.get(i);
					var.set(geo);
					this.setStopUpdateCascade(true);
					var.getAlgoUpdateSet()
							.updateAllUntil(bool.getParentAlgorithm());
					if (bool.getBoolean()) {
						count++;
					}
					this.setStopUpdateCascade(false);
				}
			} catch (MyError e) {
				// eg KeepIf[x(A)<2,A,{(1,1),(2,2),(3,3),1}]
				e.printStackTrace();
				result.setUndefined();
				return;
			}
		}

		result.setValue(count);

	}

}