/**
 * 
 */
package org.gcube.portlets.user.dataminermanager.client;

import org.gcube.portlets.user.dataminermanager.client.DataMinerManager.MenuItem;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Image;

/**
 * 
 * @author Giancarlo Panichi email: <a
 *         href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a>
 *
 */
public abstract class Header extends HorizontalPanel {

	public abstract void select(MenuItem menuItem);

	private Image menuGoBack, menuExperiment, menuDataSpace, menuComputations;
	private MenuItem currentSelection = null;

	/**
	 * 
	 */
	public Header() {
		super();
		// this.setStyleAttribute("background-color", "#FFFFFF");
		Image logo = new Image(DataMinerManager.resources.logoLittle());
		logo.setAltText("Data Miner Manager");
		logo.setTitle("Data Miner Manager");
		logo.addStyleName("menuImgLogo");

		menuGoBack = new Image(DataMinerManager.resources.goBack());
		menuGoBack.addStyleName("menuItemImage");
		menuGoBack.addClickHandler(new ClickHandler() {
			@Override
			public void onClick(ClickEvent event) {
				if (setMenuSelected(null))
					select(null);
			}
		});

		menuDataSpace = new Image(
				DataMinerManager.resources.menuItemInputspace());
		menuDataSpace.addStyleName("menuItemImage");
		menuDataSpace.addClickHandler(new ClickHandler() {
			@Override
			public void onClick(ClickEvent event) {
				if (setMenuSelected(MenuItem.DATA_SPACE))
					select(MenuItem.DATA_SPACE);
			}
		});

		menuExperiment = new Image(
				DataMinerManager.resources.menuItemExperiment());
		menuExperiment.addStyleName("menuItemImage");
		menuExperiment.addClickHandler(new ClickHandler() {
			@Override
			public void onClick(ClickEvent event) {
				if (setMenuSelected(MenuItem.EXPERIMENT))
					select(MenuItem.EXPERIMENT);
			}
		});

		menuComputations = new Image(
				DataMinerManager.resources.menuItemComputations());
		menuComputations.addStyleName("menuItemImage");
		menuComputations.addClickHandler(new ClickHandler() {

			@Override
			public void onClick(ClickEvent event) {
				if (setMenuSelected(MenuItem.COMPUTATIONS))
					select(MenuItem.COMPUTATIONS);
			}
		});

		add(logo);
		add(menuGoBack);
		add(menuDataSpace);
		add(menuExperiment);
		add(menuComputations);

		this.setCellWidth(logo, "100px");
		this.setCellWidth(menuGoBack, "100px");
		this.setCellWidth(menuDataSpace, "80px");
		this.setCellWidth(menuExperiment, "80px"); //
		this.setCellWidth(menuComputations, "80px");

		menuGoBack.setVisible(false);
		menuDataSpace.setVisible(false);
		menuExperiment.setVisible(false);
		menuComputations.setVisible(false);
	}

	/**
	 * @param inputSpace
	 */
	public boolean setMenuSelected(MenuItem menuItem) {
		// return true if the menu was changed

		if (menuItem == currentSelection)
			return false; // nothing to change

		if (menuItem == null) {
			menuGoBack.setVisible(false);
			menuDataSpace.setVisible(false);
			menuExperiment.setVisible(false);
			menuComputations.setVisible(false);

			if (currentSelection == MenuItem.EXPERIMENT)
				menuExperiment.removeStyleName("menuItemImage-selected");
			else if (currentSelection == MenuItem.DATA_SPACE)
				menuDataSpace.removeStyleName("menuItemImage-selected");
			else if (currentSelection == MenuItem.COMPUTATIONS)
				menuComputations.removeStyleName("menuItemImage-selected");

		} else {
			if (currentSelection == null) {
				menuGoBack.setVisible(true);
				menuDataSpace.setVisible(true);
				menuExperiment.setVisible(true);
				menuComputations.setVisible(true);
			}

			if (currentSelection == MenuItem.EXPERIMENT)
				menuExperiment.removeStyleName("menuItemImage-selected");
			else if (currentSelection == MenuItem.DATA_SPACE)
				menuDataSpace.removeStyleName("menuItemImage-selected");
			else if (currentSelection == MenuItem.COMPUTATIONS)
				menuComputations.removeStyleName("menuItemImage-selected");

			/*
			 * Image imgNew=menuExperiment;
			 */

			/*
			 * Image imgNew = (menuItem == MenuItem.DATA_SPACE ? menuDataSpace :
			 * menuExperiment);
			 */

			Image imgNew = (menuItem == MenuItem.DATA_SPACE ? menuDataSpace
					: (menuItem == MenuItem.EXPERIMENT ? menuExperiment
							: menuComputations));

			imgNew.addStyleName("menuItemImage-selected");
		}

		currentSelection = menuItem;
		return true;
	}
}