package jcgp.gui.settings.parameters;

import java.text.DecimalFormat;

import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.geometry.Pos;
import javafx.scene.control.Control;
import javafx.scene.control.TextField;
import jcgp.backend.parameters.DoubleParameter;
import jcgp.backend.parameters.ParameterStatus;
import jcgp.gui.settings.SettingsPane;

/**
 * This extension of @code{GUIParameter} uses a @code{TextField} to display
 * the value of a @code{DoubleParameter}. It cannot be constructed
 * directly - instead, use @code{GUIParameter.create()}.
 * <br><br>
 * See {@link GUIParameter} for more information.
 * 
 * @author Eduardo Pedroni
 */
public class GUIDoubleParameter extends GUIParameter<Number> {

	private TextField textField;
	private DecimalFormat decimalFormat;
	
	/**
	 * This protected constructor is intended for use
	 * by the factory method only.
	 * 
	 */
	protected GUIDoubleParameter(DoubleParameter parameter, SettingsPane sp) {
		super(parameter, sp);
	}
	
	@Override
	protected Control makeControl() {
		// we use a text field, and a formatting class to enforce decimals
		decimalFormat = new DecimalFormat();
		decimalFormat.setMaximumFractionDigits(10);
		textField = new TextField(decimalFormat.format(parameter.get().doubleValue()));
		textField.setStyle(VALID_PARAMETER_STYLE);
		textField.setAlignment(Pos.CENTER_RIGHT);
		textField.prefWidthProperty().bind(widthProperty().divide(2));
		return textField;
	}

	@Override
	protected void setControlListeners() {
		/* pass the TextField value back to the parameter whenever it gets
		 * modified, provided it is not empty, the experiment isn't running
		 * and it matches the double-precision regex filter */
		textField.textProperty().addListener(new ChangeListener<String>() {
			@Override
			public void changed(
					ObservableValue<? extends String> observable,
					String oldValue, String newValue) {
				if (!settingsPane.isExperimentRunning()) {
					if (newValue.matches("^[-+]?[0-9]*\\.?[0-9]+$")) {
						if (!newValue.isEmpty()) {
							double value = Double.parseDouble(newValue);
							parameter.set(value);
							settingsPane.revalidateParameters();
						}
					} else {
						refreshValue();
					}
				}
			}
		});
		/* if the TextField loses focus and is empty, set it to the current
		 * value of the parameter */
		textField.focusedProperty().addListener(new ChangeListener<Boolean>() {
			@Override
			public void changed(
					ObservableValue<? extends Boolean> observable,
					Boolean oldValue, Boolean newValue) {
				if (!newValue) {
					refreshValue();
				}
			}
		});
	}

	@Override
	protected void setValidityStyle() {
		// update the Control's style and tooltip based on the status of the parameter
		if (parameter.getStatus() == ParameterStatus.INVALID) {
			textField.setStyle(BASE_TEXT_STYLE + INVALID_PARAMETER_STYLE);
			textField.setTooltip(tooltip);
			tooltip.setText(parameter.getStatus().getDetails());
		} else if (parameter.getStatus() == ParameterStatus.WARNING || parameter.getStatus() ==  ParameterStatus.WARNING_RESET) {
			textField.setStyle(BASE_TEXT_STYLE + WARNING_PARAMETER_STYLE);
			textField.setTooltip(tooltip);
			tooltip.setText(parameter.getStatus().getDetails());
		} else {
			textField.setStyle(BASE_TEXT_STYLE + VALID_PARAMETER_STYLE);
			textField.setTooltip(null);
		}
	}
	
	@Override
	public void refreshValue() {
		if (!textField.isFocused()) {
			textField.setText(decimalFormat.format(parameter.get().doubleValue()));
		}
	}
}