package bjc.utils.gui.panels;

import java.text.ParseException;
import java.util.function.Consumer;

import javax.swing.JFormattedTextField;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;

import bjc.utils.gui.layout.HLayout;

/**
 * A simple input panel for a slider-controlled value and a manual-input field
 * for setting the slider
 *
 * @author ben
 *
 */
public class SliderInputPanel extends JPanel {
	private final class NumberFormatter extends JFormattedTextField.AbstractFormatter {
		private static final long serialVersionUID = -4448291795913908270L;

		private final int minValue;
		private final int maxValue;

		private final int initValue;

		public NumberFormatter(final SliderSettings settings) {
			minValue = settings.minValue;
			maxValue = settings.maxValue;

			initValue = settings.initValue;
		}

		@Override
		public Object stringToValue(final String text) throws ParseException {
			try {
				final int val = Integer.parseInt(text);

				if(val < minValue)
					throw new ParseException("Value must be greater than " + minValue, 0);
				else if(val > maxValue)
					throw new ParseException("Value must be smaller than " + maxValue, 0);
				else
					return val;
			} catch(final NumberFormatException nfex) {
				final ParseException pex = new ParseException("Value must be a valid integer", 0);

				pex.initCause(nfex);

				throw pex;
			}
		}

		@Override
		public String valueToString(final Object value) throws ParseException {
			if(value == null) return Integer.toString(initValue);

			return Integer.toString((Integer) value);
		}
	}

	/**
	 * Represents the settings for a slider
	 *
	 * @author ben
	 *
	 */
	public static class SliderSettings {
		/**
		 * The minimum value of the slider
		 */
		public final int minValue;
		/**
		 * The maximum value of the slider
		 */
		public final int maxValue;

		/**
		 * The initial value of the slider
		 */
		public final int initValue;

		/**
		 * Create a new slider settings, with the initial value in the
		 * middle
		 *
		 * @param min
		 *        The minimum value of the slider
		 * @param max
		 *        The maximum value of the slider
		 */
		public SliderSettings(final int min, final int max) {
			this(min, max, (min + max) / 2);
		}

		/**
		 * Create a new set of slider sttings
		 *
		 * @param min
		 *        The minimum slider value
		 * @param max
		 *        The maximum slider value
		 * @param init
		 *        Th initial slider value
		 */
		public SliderSettings(final int min, final int max, final int init) {
			minValue = min;
			maxValue = max;

			initValue = init;
		}
	}

	private static final long serialVersionUID = 2956394160569961404L;
	private final JSlider slider;
	private final JFormattedTextField field;

	/**
	 * Create a new slider input panel
	 *
	 * @param lab
	 *        The label for the field
	 * @param settings
	 *        The settings for slider values
	 * @param majorTick
	 *        The setting for where to place big ticks
	 * @param minorTick
	 *        The setting for where to place small ticks
	 * @param action
	 *        The action to execute for a given value
	 */
	public SliderInputPanel(final String lab, final SliderSettings settings, final int majorTick,
			final int minorTick, final Consumer<Integer> action) {
		setLayout(new HLayout(3));

		final JLabel label = new JLabel(lab);

		slider = new JSlider(settings.minValue, settings.maxValue, settings.initValue);
		field = new JFormattedTextField(new NumberFormatter(settings));

		slider.setMajorTickSpacing(majorTick);
		slider.setMinorTickSpacing(minorTick);
		slider.setPaintTicks(true);
		slider.setPaintLabels(true);

		slider.addChangeListener((event) -> {
			if(slider.getValueIsAdjusting()) {
				// Do nothing
			} else {
				final int val = slider.getValue();

				field.setValue(val);

				action.accept(val);
			}
		});

		field.setFocusLostBehavior(JFormattedTextField.COMMIT_OR_REVERT);
		field.setColumns(15);
		field.addPropertyChangeListener("value", (event) -> {
			final Object value = field.getValue();

			if(value == null) {
				// Do nothing
			} else {
				slider.setValue((Integer) value);
			}
		});

		add(label);
		add(slider);
		add(field);
	}

	/**
	 * Reset the values in this panel to a specified value
	 *
	 * @param value
	 *        The value to reset the fields to
	 */
	public void resetValues(final int value) {
		slider.setValue(value);

		field.setValue(value);
	}
}