/*******************************************************************************
 * Copyright (c) 2004, 2016 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui.internal.intro.impl.model;

import org.eclipse.ui.internal.intro.impl.model.url.IntroURL;
import org.eclipse.ui.internal.intro.impl.model.url.IntroURLParser;
import org.eclipse.ui.internal.intro.impl.model.util.ModelUtil;
import org.osgi.framework.Bundle;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/**
 * An intro Link. This model class is responsible for parsing and creating an
 * IntroURL class instance if the URL happens to be a valid intro url.
 */
public class IntroLink extends AbstractTextElement {

	protected static final String TAG_LINK = "link"; //$NON-NLS-1$

	private static final String ATT_LABEL = "label"; //$NON-NLS-1$
	private static final String ATT_URL = "url"; //$NON-NLS-1$
	private static final String TAG_IMG = "img"; //$NON-NLS-1$

	private final String label;
	private String url;
	private IntroImage img;
	private IntroURL introURL;

	/**
	 * @param element
	 */
	IntroLink(Element element, Bundle bundle, String base) {
		super(element, bundle);
		url = getAttribute(element, ATT_URL);
		label = getAttribute(element, ATT_LABEL);

		url = ModelUtil.resolveURL(base, url, bundle);
		if (url != null) {
			// check the URL.
			IntroURLParser parser = new IntroURLParser(url);
			if (parser.hasIntroUrl())
				introURL = parser.getIntroURL();
		}

		// There should be at most one img element.
		NodeList imgElements = element.getElementsByTagName(TAG_IMG);
		if (imgElements.getLength() > 0) {
			img = new IntroImage((Element) imgElements.item(0), getBundle(),
				base);
			img.setParent(this);
		}
	}

	/**
	 * @return Returns the label.
	 */
	public String getLabel() {
		IntroModelRoot root = getModelRoot();
		 if (root!=null) {
			 return root.resolveVariables(label);
		 }
		 return label;
	}

	/**
	 * @return Returns the url.
	 */
	public String getUrl() {
		return url;
	}

	/**
	 * Retruns an IntroURL instance if link has a valid intro url. Returns null
	 * otherwise.
	 *
	 * @return Returns the introURL.
	 */
	public IntroURL getIntroURL() {
		return introURL;
	}

	@Override
	public int getType() {
		return AbstractIntroElement.LINK;
	}

	/**
	 * @return Returns the img.
	 */
	public IntroImage getImg() {
		return img;
	}

	/**
	 * Deep copy since class has mutable objects.
	 */
	@Override
	public Object clone() throws CloneNotSupportedException {
		IntroLink clone = (IntroLink) super.clone();
		if (img != null) {
			IntroImage cloneIntroImage = (IntroImage) img.clone();
			cloneIntroImage.setParent(clone);
			clone.img = cloneIntroImage;
		}
		// no need to clobe IntroURL.
		return clone;
	}
}
