/*******************************************************************************
 * Copyright (c) 2001, 2010 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *     
 *******************************************************************************/
package org.eclipse.wst.xml.ui.internal.editor;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.wst.sse.core.internal.util.JarUtilities;
import org.eclipse.wst.xml.core.internal.contentmodel.CMNode;
import org.eclipse.wst.xml.core.internal.contentmodel.modelquery.ModelQuery;
import org.eclipse.wst.xml.core.internal.modelquery.ModelQueryUtil;
import org.eclipse.wst.xml.ui.internal.XMLUIPlugin;
import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

/**
 * @author nsd
 */
public class CMImageUtil {

	public static String SMALL_ICON_URL = "small-icon"; //$NON-NLS-1$

	public static CMNode getDeclaration(Node node) {
		CMNode decl = null;
		ModelQuery mq = null;
		switch (node.getNodeType()) {
			case Node.ATTRIBUTE_NODE : {
				mq = ModelQueryUtil.getModelQuery(((Attr) node).getOwnerDocument());
				decl = mq.getCMAttributeDeclaration((Attr) node);
			}
				break;
			case Node.ELEMENT_NODE : {
				mq = ModelQueryUtil.getModelQuery(node.getOwnerDocument());
				decl = mq.getCMElementDeclaration((Element) node);
			}
				break;
		}
		return decl;
	}

	public static Image getImage(CMNode cmnode) {
		if (cmnode == null) {
			return null;
		}
		Image image = null;
		// cache CM-specified images with the XML UI plugin
		String imageURLString = (String) cmnode.getProperty(SMALL_ICON_URL);
		if ((imageURLString != null) && (imageURLString.length() > 0)) {
			/* First ensure that the descriptor itself is cached */
			ImageDescriptor imageDescriptor = getImageDescriptor(imageURLString);
			if (imageDescriptor != null) {
				/*
				 * Then obtain the image from the registry so that it is both
				 * cached and properly disposed of later
				 */
				image = getImageRegistry().get(imageURLString);
			}
		}
		return image;
	}

	public static ImageDescriptor getImageDescriptor(CMNode cmnode) {
		if (cmnode == null) {
			return null;
		}
		// cache CM-specified images with the XML UI plugin
		String imageURLString = (String) cmnode.getProperty(SMALL_ICON_URL);
		ImageDescriptor descriptor = null;
		if ((imageURLString != null) && (imageURLString.length() > 0)) {
			descriptor = getImageDescriptor(imageURLString);
		}
		return descriptor;
	}

	private static ImageDescriptor getImageDescriptor(String imageURLString) {
		ImageDescriptor descriptor = getImageRegistry().getDescriptor(imageURLString);
		if (descriptor == null) {
			try {
				URL imageURL = new URL(imageURLString);
				InputStream inputStream = JarUtilities.getInputStream(imageURL);
				try {
					if (inputStream != null) {
						ImageData data = new ImageData(inputStream);
						descriptor = ImageDescriptor.createFromImageData(data);
						getImageRegistry().put(imageURLString, descriptor);
					}
				}
				catch (SWTException e) {
					/*
					 * There was a problem loading image from stream
					 * (corrupt, missing, etc.)
					 */
					if (inputStream != null)
						inputStream.close();
				}
			}
			catch (MalformedURLException e) {
				descriptor = null;
			}
			catch (IOException e) {
				descriptor = null;
			}
		}
		return descriptor;
	}

	private static final ImageRegistry getImageRegistry() {
		return XMLUIPlugin.getInstance().getImageRegistry();
	}

	/**
	 * 
	 */
	private CMImageUtil() {
		super();
	}
}