/*
 * Copyright (c) 2006 Wisconsin Court System and  Patrick Wright
 * Copyright (c) 2007 Cay S. Horstmann
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
package com.horstmann.slidy2png;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xhtmlrenderer.context.AWTFontResolver;
import org.xhtmlrenderer.css.style.CalculatedStyle;
import org.xhtmlrenderer.extend.UserAgentCallback;
import org.xhtmlrenderer.extend.UserInterface;
import org.xhtmlrenderer.layout.BoxBuilder;
import org.xhtmlrenderer.layout.Layer;
import org.xhtmlrenderer.layout.LayoutContext;
import org.xhtmlrenderer.layout.SharedContext;
import org.xhtmlrenderer.render.BlockBox;
import org.xhtmlrenderer.render.Box;
import org.xhtmlrenderer.render.PageBox;
import org.xhtmlrenderer.render.RenderingContext;
import org.xhtmlrenderer.render.ViewportBox;
import org.xhtmlrenderer.simple.extend.XhtmlNamespaceHandler;
import org.xhtmlrenderer.swing.Java2DFontContext;
import org.xhtmlrenderer.swing.Java2DOutputDevice;
import org.xhtmlrenderer.swing.Java2DTextRenderer;
import org.xhtmlrenderer.swing.NaiveUserAgent;
import org.xhtmlrenderer.swing.SwingReplacedElementFactory;
import org.xhtmlrenderer.util.FSImageWriter;
import org.xhtmlrenderer.util.ImageUtil;

public class MultiPageRenderer {
	private SharedContext sharedContext;
	private Java2DOutputDevice outputDevice;
	private Document doc;
	private Box root;

	public MultiPageRenderer(File file) throws IOException {
		String url = file.toURI().toURL().toExternalForm();
		BufferedImage outputImage = ImageUtil.createCompatibleBufferedImage(1,
				1);
		outputDevice = new Java2DOutputDevice(outputImage);
		UserAgentCallback userAgent = new NaiveUserAgent();
		sharedContext = new SharedContext(userAgent);
		AWTFontResolver fontResolver = new AWTFontResolver();
		sharedContext.setFontResolver(fontResolver);
		SwingReplacedElementFactory replacedElementFactory = new SwingReplacedElementFactory();
		sharedContext.setReplacedElementFactory(replacedElementFactory);
		sharedContext.setTextRenderer(new Java2DTextRenderer());
		sharedContext.setDPI(72);
		sharedContext.setDotsPerPixel(1);
		sharedContext.setPrint(true);
		sharedContext.setInteractive(false);
		doc = sharedContext.getUac().getXMLResource(url).getDocument();
		sharedContext.setBaseURL(url);
		sharedContext.setNamespaceHandler(new XhtmlNamespaceHandler());
		sharedContext.getCss().setDocumentContext(sharedContext,
				sharedContext.getNamespaceHandler(), doc,
				new NullUserInterface());
	}

	public void renderImages(String outputPath, String extension)
			throws IOException {
		layout();
		RenderingContext rc = sharedContext.newRenderingContextInstance();
		root.getLayer().assignPagePaintingPositions(rc, Layer.PAGED_MODE_PRINT);
		List pages = root.getLayer().getPages();
		PageBox first = Layer.createPageBox(rc, null);
		int width = first.getWidth(rc);
		int height = first.getHeight(rc);
		BufferedImage outputImage = ImageUtil.createCompatibleBufferedImage(
				width, height, BufferedImage.TYPE_INT_RGB);
		FSImageWriter fsw = new FSImageWriter();
		for (int i = 0; i < pages.size(); i++) {
			outputDevice = new Java2DOutputDevice(outputImage);
			Graphics2D newG = (Graphics2D) outputImage.getGraphics();
			newG.getRenderingHints().put(RenderingHints.KEY_RENDERING,
					RenderingHints.VALUE_RENDER_QUALITY);
			rc.setFontContext(new Java2DFontContext(newG));
			rc.setOutputDevice(outputDevice);
			sharedContext.getTextRenderer().setup(rc.getFontContext());
			sharedContext.getTextRenderer().setSmoothingThreshold(8);
			PageBox page = (PageBox) pages.get(i);
			rc.setPage(i, page);
			ImageUtil.clearImage(outputImage);
			paintPage(rc, page);
			newG.dispose();

			String num = "000" + (i + 1);
			num = num.substring(num.length() - 3);
			String name = outputPath + num + extension;
			System.out.println(name);
			OutputStream os = new BufferedOutputStream(new FileOutputStream(
					name));
			;
			try {
				fsw.write(outputImage, os);
			} finally {
				os.close();
			}
			outputImage.flush();
		}
	}

	private void layout() {
		LayoutContext result = sharedContext.newLayoutContextInstance();
		Graphics2D g = outputDevice.getGraphics();
		result.setFontContext(new Java2DFontContext(g));
		sharedContext.getTextRenderer().setup(result.getFontContext());
		LayoutContext c = result;
		BlockBox root = BoxBuilder.createRootBox(c, doc);
		PageBox first = Layer.createPageBox(c, null);
		Rectangle rect = new Rectangle(0, 0, first.getContentWidth(c), first
				.getContentHeight(c));
		root.setContainingBlock(new ViewportBox(rect));
		root.layout(c);
		Dimension dim = root.getLayer().getPaintingDimension(c);
		root.getLayer().trimEmptyPages(c, dim.height);
		this.root = root;
	}

	private void paintPage(RenderingContext c, PageBox page) {
		Shape working = outputDevice.getClip();
		Rectangle content = page.getPrintingClippingBounds(c);
		outputDevice.clip(content);
		int top = -page.getPaintingTop()
				+ page.getMarginBorderPadding(c, CalculatedStyle.TOP);
		int left = page.getMarginBorderPadding(c, CalculatedStyle.LEFT);
		outputDevice.translate(left, top);
		root.getLayer().paint(c, 0, 0);
		outputDevice.translate(-left, -top);
		outputDevice.setClip(working);
		page.paintAlternateFlows(c, root.getLayer(), Layer.PAGED_MODE_PRINT, 0);
		page.paintBorder(c, 0, Layer.PAGED_MODE_PRINT);
		outputDevice.setClip(working);
	}

	private static final class NullUserInterface implements UserInterface {
		public boolean isHover(Element e) {
			return false;
		}

		public boolean isActive(Element e) {
			return false;
		}

		public boolean isFocus(Element e) {
			return false;
		}
	}

	public static void main(String[] args) throws IOException {
		if (args.length != 1) {
			System.err.println("Usage: ... slidyfile");
		}
		File f = new File(args[0]);
		if (f.exists()) {
			String outputPath = f.getAbsolutePath();
			outputPath = outputPath.substring(0, outputPath.lastIndexOf("."));
			new MultiPageRenderer(f).renderImages(outputPath, ".png");
		} else
			System.err.println("File not found: " + args[0]);
	}
}