/*******************************************************************************
 * Copyright (c) 2016, 2017 Obeo.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.eef.sample.custom.widget.colorpicker;

import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.function.Consumer;

import org.eclipse.eef.EEFCustomWidgetDescription;
import org.eclipse.eef.core.api.EEFExpressionUtils;
import org.eclipse.eef.core.api.EditingContextAdapter;
import org.eclipse.eef.core.api.controllers.AbstractEEFCustomWidgetController;
import org.eclipse.eef.core.api.utils.EvalFactory;
import org.eclipse.sirius.common.interpreter.api.IInterpreter;
import org.eclipse.sirius.common.interpreter.api.IVariableManager;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;

/**
 * This class is used to provide utilities to single reference viewer controller.
 *
 * @author mbats
 */
public class ColorPickerController extends AbstractEEFCustomWidgetController implements IColorPickerController {

	/**
	 * Default color code.
	 */
	private static final int DEFAULT_COLOR_CODE = 255;

	/**
	 * Value expression id.
	 */
	private static final String VALUE_EXPRESSION_ID = "valueExpression"; //$NON-NLS-1$

	/**
	 * Add expression id.
	 */
	private static final String EDIT_EXPRESSION_ID = "editExpression"; //$NON-NLS-1$

	/**
	 * Separator.
	 */
	private static final String SEPARATOR = ","; //$NON-NLS-1$

	/**
	 * The consumer of a new value of the color.
	 */
	private Consumer<Color> newValueConsumer;

	/**
	 * The constructor.
	 *
	 * @param description
	 *            The description
	 * @param variableManager
	 *            The variable manager
	 * @param interpreter
	 *            The interpreter
	 * @param editingContextAdapter
	 *            The editing context adapter
	 */
	public ColorPickerController(EEFCustomWidgetDescription description, IVariableManager variableManager, IInterpreter interpreter,
			EditingContextAdapter editingContextAdapter) {
		super(description, variableManager, interpreter, editingContextAdapter);
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.eef.core.api.controllers.AbstractEEFWidgetController.refresh()
	 */
	@Override
	public void refresh() {
		super.refresh();

		Optional<String> optionalValueExpression = this.getCustomExpression(VALUE_EXPRESSION_ID);
		optionalValueExpression.ifPresent(valueExpression -> {
			this.newEval().logIfInvalidType(String.class).call(valueExpression, (value) -> {
				this.computeNewColorValue(value);
			});
		});
	}

	/**
	 * Computes the new value of the color.
	 *
	 * @param value
	 *            The string representation of the new color
	 */
	private void computeNewColorValue(String value) {
		int red = DEFAULT_COLOR_CODE;
		int green = DEFAULT_COLOR_CODE;
		int blue = DEFAULT_COLOR_CODE;
		if (value != null) {
			String[] rgb = value.split(SEPARATOR);
			if (rgb.length == 3) {
				try {
					red = Integer.parseInt(rgb[0]);
					green = Integer.parseInt(rgb[1]);
					blue = Integer.parseInt(rgb[2]);
					Color color = ColorHelper.getColor(red, green, blue);
					Optional.ofNullable(this.newValueConsumer).ifPresent(consumer -> {
						consumer.accept(color);
					});
				} catch (@SuppressWarnings("unused") NumberFormatException e) {
					// TODO Log warning about unexpected result format from the expression.
				}
			}
		}
	}

	@Override
	public void onNewValue(Consumer<Color> consumer) {
		this.newValueConsumer = consumer;
	}

	@Override
	public void removeNewValueConsumer() {
		this.newValueConsumer = null;
	}

	@Override
	protected EEFCustomWidgetDescription getDescription() {
		return this.description;
	}

	@Override
	public void updateValue(final RGB color) {
		this.editingContextAdapter.performModelChange(() -> {
			this.getCustomExpression(EDIT_EXPRESSION_ID).ifPresent(editExpression -> {
				Map<String, Object> variables = new HashMap<String, Object>();
				variables.putAll(this.variableManager.getVariables());
				variables.put(EEFExpressionUtils.EEFText.NEW_VALUE, color.red + SEPARATOR + color.green + SEPARATOR + color.blue);

				EvalFactory.of(this.interpreter, variables).call(editExpression);
			});
		});
	}

}