/*******************************************************************************
 * Copyright (c) 2011 Manumitting Technologies, Inc.
 *
 * 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:
 *     Brian de Alwis (MT) - initial API and implementation
 *******************************************************************************/
package org.eclipse.pde.spy.css;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.eclipse.e4.ui.css.core.dom.CSSStylableElement;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.swt.custom.CTabItem;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolItem;
import org.w3c.dom.NodeList;

@SuppressWarnings("restriction")
public class WidgetTreeProvider implements ITreeContentProvider {
	private static final Object[] EMPTY_ARRAY = new Object[0];

	@Override
	public Object[] getElements(Object inputElement) {
		if (inputElement instanceof Object[]) {
			return (Object[]) inputElement;
		} else if (inputElement instanceof Collection) {
			return ((Collection<?>) inputElement).toArray();
		}
		return getChildren(inputElement);
	}

	@Override
	public Object[] getChildren(Object parentElement) {
		if (parentElement instanceof Display) {
			List<Shell> shells = new ArrayList<>();
			for (Shell s : ((Display) parentElement).getShells()) {
				if (!s.isDisposed()) {
					shells.add(s);
				}
			}
			return shells.toArray();
		}
		CSSStylableElement element = CssSpyPart.getCSSElement(parentElement);
		if (element == null) {
			return EMPTY_ARRAY;
		}
		NodeList kids = element.getChildNodes();
		ArrayList<Object> children = new ArrayList<>(kids.getLength());
		for (int i = 0; i < kids.getLength(); i++) {
			if (kids.item(i) instanceof CSSStylableElement kid) {
				children.add(kid.getNativeWidget());
			}
		}
		return children.toArray();
	}

	@Override
	public Object getParent(Object element) {
		if (element instanceof Control) {
			Control control = (Control) element;
			return control.isDisposed() ? null : control.getParent();
		} else if (element instanceof CTabItem) {
			return ((CTabItem) element).getParent();
		} else if (element instanceof ToolItem) {
			return ((ToolItem) element).getParent();
		}
		return null;
	}

	@Override
	public boolean hasChildren(Object element) {
		return getChildren(element).length > 0;
	}

}
