/**
 * Copyright (c) 2011, 2014 - Lunifera GmbH (Gross Enzersdorf, Austria), 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: 
 * 		Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.vaaclipse.common.ecview;

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

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

import org.eclipse.e4.core.services.events.IEventBroker;
import org.eclipse.e4.ui.model.application.MApplication;
import org.eclipse.e4.ui.model.application.ui.advanced.MPerspective;
import org.eclipse.e4.ui.model.application.ui.basic.MPart;
import org.eclipse.e4.ui.workbench.modeling.EModelService;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.osbp.ecview.core.common.context.IViewContext;
import org.eclipse.osbp.ecview.core.common.editpart.IViewEditpart;
import org.eclipse.osbp.ecview.core.common.model.core.YElement;
import org.eclipse.osbp.ecview.core.common.notification.ILifecycleEvent;
import org.eclipse.osbp.ecview.core.common.services.IWidgetAssocationsService;
import org.eclipse.osbp.vaaclipse.common.ecview.api.IECViewContainer;
import org.eclipse.osbp.vaaclipse.publicapi.events.IWidgetModelAssociations;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventHandler;

public class ECViewContainer implements IECViewContainer, EventHandler, IWidgetModelAssociations {

	private static final String ECVIEWS = "ecviews";

	@Inject
	private IEventBroker eventBroker;

	@Inject
	private EModelService modelService;

	@Inject
	private MApplication mApp;

	@Inject
	private IWidgetModelAssociations masterAssociations;

	private List<IViewEditpart> views = Collections.synchronizedList(new ArrayList<IViewEditpart>());

	@Override
	public List<IViewEditpart> getECViews() {
		return Collections.unmodifiableList(views);
	}

	@Override
	public void handleEvent(Event event) {
		ILifecycleEvent lifecycle = (ILifecycleEvent) event.getProperty(IEventBroker.DATA);
		if (lifecycle.getType().equals(ILifecycleEvent.CONTEXT_CREATED)) {
			IViewEditpart editpart = (IViewEditpart) lifecycle.getEditpart();
			if (views.contains(editpart)) {
				return;
			}
			views.add(editpart);
			if (editpart.getContext() == null) {
				return;
			}
			MPart part = editpart.getContext().getService(MPart.class.getName());
			if (part == null) {
				return;
			}
			MPerspective mPersp = modelService.getPerspectiveFor(part);
			if (mPersp == null) {
				return;
			}
			@SuppressWarnings("unchecked")
			List<IViewContext> contexts = (List<IViewContext>) mPersp.getTransientData().get(ECVIEWS);
			if (contexts == null) {
				contexts = new ArrayList<>();
				mPersp.getTransientData().put(ECVIEWS, contexts);
			}
			contexts.add(editpart.getContext());

		} else if (lifecycle.getType().equals(ILifecycleEvent.CONTEXT_DISPOSED)) {
			IViewEditpart editpart = (IViewEditpart) lifecycle.getEditpart();
			views.remove(editpart);
			if (editpart.getContext() == null) {
				return;
			}
			MPart part = editpart.getContext().getService(MPart.class.getName());
			if (part == null) {
				return;
			}
			MPerspective mPersp = modelService.getPerspectiveFor(part);
			if (mPersp == null) {
				return;
			}
			@SuppressWarnings("unchecked")
			List<IViewContext> contexts = (List<IViewContext>) mPersp.getTransientData().get(ECVIEWS);
			if (contexts != null) {
				contexts.remove(editpart.getContext());
			}
		}
	}

	@PostConstruct
	protected void setup() {
		// lets register this manager as a thirdparty delegate to find
		// assocations
		masterAssociations.addThirdParty(this);
		eventBroker.subscribe(IViewContext.TOPIC_LIFECYCLE, this);
	}

	@PreDestroy
	protected void destroy() {
		eventBroker.unsubscribe(this);
		masterAssociations.removeThirdParty(this);
	}

	@Override
	public EObject getElement(Object component) {
		synchronized (views) {
			for (IViewEditpart ep : views) {
				IWidgetAssocationsService<Object, YElement> service = ep.getContext()
						.getService(IWidgetAssocationsService.ID);
				EObject result = service.getModelElement(component);
				if (result != null) {
					return result;
				}
			}
		}

		return null;
	}

	@Override
	public Object getWidget(EObject element) {
		if (!(element instanceof YElement)) {
			return null;
		}
		synchronized (views) {
			for (IViewEditpart ep : views) {
				IWidgetAssocationsService<Object, YElement> service = ep.getContext()
						.getService(IWidgetAssocationsService.ID);
				Object result = service.getWidget((YElement) element);
				if (result != null) {
					return result;
				}
			}
		}

		return null;
	}

	@Override
	public boolean addThirdParty(IWidgetModelAssociations e) {
		throw new UnsupportedOperationException(
				"Not allowed for a thirdparty assocation! Use the main assocation instance to register thirdparties.");
	}

	@Override
	public boolean removeThirdParty(IWidgetModelAssociations o) {
		throw new UnsupportedOperationException(
				"Not allowed for a thirdparty assocation! Use the main assocation instance to register thirdparties.");
	}

	@Override
	public List<IViewContext> getECViews(MPerspective mPersp) {
		if (mPersp != null) {
			@SuppressWarnings("unchecked")
			List<IViewContext> contexts = (List<IViewContext>) mPersp.getTransientData().get(ECVIEWS);
			if (contexts != null) {
				return Collections.unmodifiableList(contexts);
			}
		}
		return Collections.emptyList();
	}

}