/* 
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.geos;

import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.StringTemplate;
import org.geogebra.common.kernel.arithmetic.ValidExpression;
import org.geogebra.common.kernel.kernelND.GeoElementND;

/**
 * Makes it possible to switch between the Extended form and the Input form
 * (Exactly the way the user entered it) subclasses must call super.toString()
 * and provide the "normal" or extended form with .valueString().
 *
 */
public abstract class GeoUserInputElement extends GeoElement {

	private boolean inputForm;
	private boolean validInputForm;

	/**
	 * Creates new element with user input
	 * 
	 * @param c
	 *            construction
	 */
	public GeoUserInputElement(Construction c) {
		super(c);

		// moved from GeoElement's constructor
		// must be called from the subclass, see
		// http://benpryor.com/blog/2008/01/02/dont-call-subclass-methods-from-a-superclass-constructor/
		setConstructionDefaults(); // init visual settings

		validInputForm = true;
	}

	/**
	 * Creates new element with user input
	 * 
	 * @param c
	 *            construction
	 * @param userInput
	 *            input defining this element
	 */
	public GeoUserInputElement(Construction c, ValidExpression userInput) {
		this(c);
		setDefinition(userInput.wrap());
	}

	/**
	 * If possible, switches input form on
	 */
	public void setInputForm() {
		inputForm = true && validInputForm;
	}

	/**
	 * Switches input form off
	 */
	public void setExtendedForm() {
		inputForm = false;
	}

	/**
	 * @return true iff input form is active
	 */
	public boolean isInputForm() {
		return inputForm;
	}

	@Override
	public String toString(StringTemplate tpl) {
		return label + ": " + toValueString(tpl);
	}

	@Override
	public String toValueString(StringTemplate tpl) {
		if (validInputForm && inputForm && getDefinition() != null) {
			return getDefinition().toValueString(tpl);
		}

		return toRawValueString(tpl);

	}

	@Override
	public void set(GeoElementND geo) {
		if (!(geo instanceof GeoUserInputElement)) {
			return;
		}
		reuseDefinition(geo);
	}

	/**
	 * @param tpl
	 *            string template
	 * @return raw string
	 */
	protected abstract String toRawValueString(StringTemplate tpl);

	/**
	 * @param b
	 *            true iff input should be considered valid
	 */
	public void setValidInputForm(boolean b) {
		validInputForm = b;
		if (!validInputForm) {
			inputForm = false;
		}
	}

	/**
	 * 
	 * @return true iff input is valid
	 */
	public boolean isValidInputForm() {
		return validInputForm;
	}

}