/*******************************************************************************
 * Copyright (c) 2012 Rushan R. Gilmullin and others.
 * 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:
 *     Rushan R. Gilmullin - initial API and implementation
 *******************************************************************************/
 package org.eclipse.osbp.vaaclipse.emf;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;

import org.eclipse.e4.core.contexts.Active;
import org.eclipse.e4.core.contexts.IEclipseContext;
import org.eclipse.e4.core.di.annotations.Optional;
import org.eclipse.e4.core.services.events.IEventBroker;
import org.eclipse.e4.ui.model.application.ui.MUIElement;
import org.eclipse.e4.ui.model.application.ui.advanced.MPerspectiveStack;
import org.eclipse.e4.ui.model.application.ui.basic.MPart;
import org.eclipse.e4.ui.model.application.ui.basic.MPartSashContainer;
import org.eclipse.e4.ui.model.application.ui.basic.MTrimmedWindow;
import org.eclipse.e4.ui.workbench.UIEvents;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.osbp.vaaclipse.emf.api.view.IConstants;
import org.eclipse.osbp.vaadin.emf.api.EmfModelElementClickEvent;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventHandler;
import org.eclipse.osbp.vaaclipse.publicapi.events.IWidgetModelAssociations;
import org.eclipse.osbp.vaaclipse.publicapi.events.VaaclipseUiEvents;

import com.vaadin.event.LayoutEvents;
import com.vaadin.ui.AbstractOrderedLayout;
import com.vaadin.ui.Component;

@SuppressWarnings("serial")
public class ModeledUiClickController implements
		LayoutEvents.LayoutClickListener, EventHandler {

	@Inject
	private IEclipseContext context;

	@Inject
	private IEventBroker eventBroker;

	private boolean enabled;

	private AbstractOrderedLayout content;

	@PostConstruct
	protected void setup() {
	}

	@Inject
	protected void activate(@Active @Optional MTrimmedWindow window) {
		if (content != null) {
			return;
		}

		if (window != null) {
			content = (AbstractOrderedLayout) window.getContext().get(
					"rootLayoutClickNotifier");
		}

		if (content != null) {
			setEnabled(true);
		}
	}

	public void setEnabled(boolean value) {
		if (content == null) {
			return;
		}
		this.enabled = value;
		if (enabled) {
			content.addLayoutClickListener(this);

			// e4 ui model
			eventBroker.subscribe(
					UIEvents.ElementContainer.TOPIC_SELECTEDELEMENT, this);
			eventBroker.subscribe(UIEvents.Item.TOPIC_SELECTED, this);
			eventBroker.subscribe(VaaclipseUiEvents.Item.TOPIC_EXECUTED, this);

		} else {
			if (content != null) {
				content.removeLayoutClickListener(this);
				content = null;
			}

			eventBroker.unsubscribe(this);
		}
	}

	public boolean isEnabled() {
		return enabled;
	}

	@Override
	public void layoutClick(LayoutEvents.LayoutClickEvent event) {
		Component clickedUI = event.getClickedComponent();
		EObject clickedModel = context.get(IWidgetModelAssociations.class)
				.getElement(clickedUI);

		if (clickedModel == null) {
			return;
		}

		// if designer parts where clicked, then do not send event
		if (!isDesignerPart(clickedModel)) {
			eventBroker.send(IConstants.TOPIC__ELEMENT_CLICKED,
					new EmfModelElementClickEvent(clickedUI,
							(EObject) clickedModel));
		}
	}

	@PreDestroy
	protected void destroy() {
		if (isEnabled()) {
			setEnabled(false);
		}
		context = null;
		eventBroker = null;
		content = null;
	}

	@Override
	public void handleEvent(Event event) {

		// if a perspective was selected, we need to send a layoutclick event
		//
		if (event.getProperty(UIEvents.EventTags.ELEMENT) instanceof MPerspectiveStack) {
			// events from e4 application model
			//
			String type = (String) event.getProperty(UIEvents.EventTags.TYPE);
			if (UIEvents.EventTypes.SET.equals(type)
					&& event.getProperty(UIEvents.EventTags.ATTNAME).equals(
							"selectedElement")) {
				MUIElement newValue = (MUIElement) event
						.getProperty(UIEvents.EventTags.NEW_VALUE);
				// if designer parts where clicked, then do not send event
				if (!isDesignerPart((EObject) newValue)) {
					Object widget = context.get(IWidgetModelAssociations.class)
							.getWidget((EObject) newValue);
					eventBroker.send(IConstants.TOPIC__ELEMENT_CLICKED,
							new EmfModelElementClickEvent(widget,
									(EObject) newValue));
				}
			}
		} else if (event.getTopic().endsWith(
				VaaclipseUiEvents.Item.TOPIC_EXECUTED)) {
			// events from e4 application model -> executed items
			//
			MUIElement item = (MUIElement) event.getProperty(IEventBroker.DATA);
			// if designer parts where clicked, then do not send event
			if (!isDesignerPart((EObject) item)) {
				Object widget = context.get(IWidgetModelAssociations.class)
						.getWidget((EObject) item);
				eventBroker.send(IConstants.TOPIC__ELEMENT_CLICKED,
						new EmfModelElementClickEvent(widget, (EObject) item));
			}
		}
	}

	/**
	 * Check if the model or its parent up to part or sashContainer have the tag
	 * "designerPart".
	 * 
	 * @param element
	 * @return
	 */
	private boolean isDesignerPart(EObject element) {
		if (element == null) {
			return false;
		}

		if (!(element instanceof MUIElement)) {
			return false;
		}

		MUIElement uiElement = (MUIElement) element;
		if (element instanceof MPart || element instanceof MPartSashContainer) {
			// do not check parents
			return uiElement.getTags().contains(IConstants.TAG__DESIGNER_PARTS);
		}
		if (uiElement.getTags().contains(IConstants.TAG__DESIGNER_PARTS)) {
			// it is designer part
			return false;
		} else {
			// check up the parent until part or sashcontainer reached
			EObject parent = ((EObject) element).eContainer();
			return isDesignerPart(parent);
		}
	}
}