/*******************************************************************************
 * Copyright (c) 2011, 2017 BestSolution.at and others.
 *
 * 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:
 *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 ******************************************************************************/
package org.eclipse.e4.tools.emf.ui.internal.common.uistructure;

import java.util.Collections;

import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.RegistryFactory;
import org.eclipse.e4.tools.emf.ui.common.IScriptingSupport;
import org.eclipse.e4.tools.emf.ui.internal.Messages;
import org.eclipse.e4.tools.emf.ui.internal.common.ControlHighlighter;
import org.eclipse.e4.tools.services.IResourcePool;
import org.eclipse.e4.ui.model.application.MApplicationElement;
import org.eclipse.e4.ui.model.internal.ModelUtils;
import org.eclipse.emf.databinding.EMFProperties;
import org.eclipse.emf.databinding.IEMFValueProperty;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

public class UIViewer {
	public TreeViewer createViewer(Composite parent, EStructuralFeature feature, final IObservableValue<?> master,
			IResourcePool resourcePool, final Messages messages) {
		final TreeViewer viewer = new TreeViewer(parent);
		viewer.setContentProvider(new WidgetContentProvider());
		viewer.setLabelProvider(new WidgetLabelProvider(resourcePool));
		IEMFValueProperty property = EMFProperties.value(feature);
		@SuppressWarnings("unchecked")
		IObservableValue<?> value = property.observeDetail(master);
		value.addValueChangeListener(event -> {
			if (event.diff.getNewValue() != null) {
				viewer.setInput(Collections.singleton(event.diff.getNewValue()));
				viewer.expandToLevel(2);
			} else {
				viewer.setInput(Collections.emptyList());
			}
		});

		final MenuManager mgr = new MenuManager();
		mgr.setRemoveAllWhenShown(true);
		mgr.addMenuListener(manager -> {
			final Object o = ((IStructuredSelection) viewer.getSelection()).getFirstElement();
			if (o instanceof Control) {
				manager.add(new Action(messages.ModelEditor_ShowControl) {
					@Override
					public void run() {
						ControlHighlighter.show((Control) o);
					}
				});
			}

			IExtensionRegistry registry = RegistryFactory.getRegistry();
			IExtensionPoint extPoint = registry.getExtensionPoint("org.eclipse.e4.tools.emf.ui.scripting"); //$NON-NLS-1$
			final IConfigurationElement[] elements = extPoint.getConfigurationElements();

			final IStructuredSelection s = (IStructuredSelection) viewer.getSelection();

			if (elements.length > 0 && !s.isEmpty()) {
				MenuManager scriptExecute = new MenuManager(messages.ModelEditor_Script);
				manager.add(scriptExecute);
				for (IConfigurationElement e : elements) {
					final IConfigurationElement le = e;
					scriptExecute.add(new Action(e.getAttribute("label")) { //$NON-NLS-1$
						@Override
						public void run() {
							try {
								MApplicationElement o = (MApplicationElement) master.getValue();
								IScriptingSupport support = (IScriptingSupport) le.createExecutableExtension("class"); //$NON-NLS-1$
								support.openEditor(viewer.getControl().getShell(), s.getFirstElement(),
										ModelUtils.getContainingContext(o));
							} catch (CoreException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
					});
				}
			}
		});

		viewer.getControl().setMenu(mgr.createContextMenu(viewer.getControl()));

		return viewer;
	}
}