/**
 *                                                                            
 * Copyright (c) 2011, 2016 - Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 *                                                                            
 * All rights reserved. This program and the accompanying materials           
 * are made available under the terms of the Eclipse Public License 2.0        
 * which accompanies this distribution, and is available at                  
 * https://www.eclipse.org/legal/epl-2.0/                                 
 *                                 
 * SPDX-License-Identifier: EPL-2.0                                 
 *                                                                            
 * Contributors:   
 * Christophe Loetz (Loetz GmbH&Co.KG) - initial implementation 
 */
 package org.eclipse.osbp.infogrid.vaadin;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.osbp.infogrid.api.IGridSourceDescriptor;

import com.vaadin.data.Item;
import com.vaadin.ui.AbstractSelect.ItemCaptionMode;
import com.vaadin.ui.ComboBox;
import com.vaadin.ui.Component;
import com.vaadin.ui.CssLayout;
import com.vaadin.ui.CustomComponent;
import com.vaadin.ui.VerticalLayout;

/**
 * This component needs configuration by IGridSourceDescriptor. They need to be
 * added from outside logic.
 */
@SuppressWarnings("serial")
public class GridComponent extends CustomComponent {

	private ComboBox sourceSelector;
	private CssLayout gridArea;

	private List<IGridSourceDescriptor> sources;
	private IGridSourceDescriptor currentSource;

	private VerticalLayout layout;
	private Object currentInput;

	public GridComponent() {
		initUI();
	}

	/**
	 * Initializes the UI.
	 */
	protected void initUI() {

		sourceSelector = new ComboBox();
		sourceSelector.addContainerProperty("caption", String.class,
				"undefined ID");
		sourceSelector.addContainerProperty("gridSource",
				IGridSourceDescriptor.class, null);

		sourceSelector.setItemCaptionMode(ItemCaptionMode.PROPERTY);
		sourceSelector.setItemCaptionPropertyId("caption");

		sourceSelector.addValueChangeListener(e -> sourceChanged());

		gridArea = new CssLayout();
		gridArea.setSizeFull();

		layout = new VerticalLayout(sourceSelector, gridArea);
		layout.setExpandRatio(gridArea, 1.0f);
		setCompositionRoot(layout);
	}

	/**
	 * Is called if the source became changed.
	 */
	protected void sourceChanged() {
		Item item = sourceSelector.getItem(sourceSelector.getValue());
		if (item == null) {
			setSelectedSource(null);
		} else {
			setSelectedSource((IGridSourceDescriptor) item.getItemProperty(
					"gridSource").getValue());
		}
	}

	/**
	 * Sets the selected source descriptor.
	 * 
	 * @param source
	 */
	public void setSelectedSource(IGridSourceDescriptor source) {
		// TODO
		// if (currentSource == source) {
		// return;
		// }

		if (source != null && !sources.contains(source)) {
			return;
		}

		currentSource = source;
		gridArea.removeAllComponents();
		if (currentSource != null) {
			Component component = (Component) currentSource.getComponent();
			component.setSizeFull();
			gridArea.addComponent(component);
			currentSource.setInput(currentInput);
		}
	}

	/**
	 * Returns all descriptors.
	 * 
	 * @return
	 */
	public List<IGridSourceDescriptor> getSourceDescriptors() {
		return Collections.unmodifiableList(sources);
	}

	/**
	 * Sets all available descriptors to this component. The descriptors are
	 * responsible to create the UI content.
	 * 
	 * @param sources
	 */
	@SuppressWarnings("unchecked")
	public void setSourceDescriptors(List<IGridSourceDescriptor> sources) {
		sourceSelector.removeAllItems();
		for (IGridSourceDescriptor source : sources) {
			Item item = sourceSelector.getItem(sourceSelector.addItem());
			item.getItemProperty("caption").setValue(source.getId());
			item.getItemProperty("gridSource").setValue(source);
		}

		this.sources = new ArrayList<>(sources);
	}

	/**
	 * Sets the value of the component.
	 * 
	 * @param input
	 */
	public void setValue(Object input) {
		if (currentInput == input) {
			return;
		}
		currentInput = input;

		if (currentSource != null) {
			currentSource.setInput(currentInput);
		}
	}

	public void dispose() {

	}

}