/*
 * Copyright (c) 2003-onwards Shaven Puppy Ltd
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Shaven Puppy' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.shavenpuppy.jglib.resources;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.net.URL;

import org.w3c.dom.Element;

import com.shavenpuppy.jglib.*;
/**
 * An ImageResource is a pointer to an Image held remotely, either at the other
 * end of a URL, or in the classpath.
 *
 * @author foo
 */
public class ImageResource extends Resource implements ImageWrapper {

	private static final long serialVersionUID = 1L;

	/*
	 * Resource data
	 */

	/** The image's location, which is a URL. For classpath resources, use classpath: as the URL */
	private String url;

	/*
	 * Transient data
	 */

	/** The loaded Image */
	private transient Image image;

	/**
	 * Resource constructor
	 * @param name
	 */
	public ImageResource(String name) {
		super(name);
	}

	@Override
	public void archive() {
		url = null;
	}

	/* (non-Javadoc)
	 * @see com.shavenpuppy.jglib.Resource#doCreate()
	 */
	@Override
	protected void doCreate() {
		try {
			BufferedInputStream bis;
			if (url.startsWith("classpath:")) {
				bis = new BufferedInputStream(getClass().getClassLoader().getResourceAsStream(url.substring(10)));
			} else {
				bis = new BufferedInputStream(new URL(url).openStream());
			}
			image = Image.read(bis);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	/* (non-Javadoc)
	 * @see com.shavenpuppy.jglib.Resource#doDestroy()
	 */
	@Override
	protected void doDestroy() {
		image = null;
	}

	/* (non-Javadoc)
	 * @see com.shavenpuppy.jglib.Resource#load(org.w3c.dom.Element, com.shavenpuppy.jglib.Resource.Loader)
	 */
	@Override
	public void load(Element element, Loader loader) throws Exception {
		super.load(element, loader);

		url = element.getAttribute("url");
	}

	/**
	 * @return the image
	 */
	@Override
	public final Image getImage() throws Exception {
		if (!isCreated()) {
			create();
		}
		if (image.getData() == null) {
			// Reload the image
			doCreate();
		}
		return image;
	}

	/* (non-Javadoc)
	 * @see com.shavenpuppy.jglib.Resource#doToXML(com.shavenpuppy.jglib.XMLResourceWriter)
	 */
	@Override
	protected void doToXML(XMLResourceWriter writer) throws IOException {
		writer.writeAttribute("url", url);
	}
}