package org.sentrysoftware.maven.skin;
   
   /*-
    * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
    * Sentry Maven Skin Tools
    * ჻჻჻჻჻჻
    * Copyright 2017 - 2023 Sentry Software
    * ჻჻჻჻჻჻
    * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
   */
  
  import java.awt.Image;
  import java.awt.image.BufferedImage;
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.regex.Pattern;
  import java.util.stream.Collectors;
  
  import javax.imageio.IIOImage;
  import javax.imageio.ImageIO;
  import javax.imageio.ImageWriteParam;
  import javax.imageio.ImageWriter;
  import javax.imageio.spi.IIORegistry;
  import javax.imageio.stream.FileImageOutputStream;
  
  import org.apache.velocity.tools.config.DefaultKey;
  import org.jsoup.nodes.Element;
  
  import com.luciad.imageio.webp.WebPImageReaderSpi;
  import com.luciad.imageio.webp.WebPImageWriterSpi;
  import com.luciad.imageio.webp.WebPWriteParam;
  
  /**
   * Set of tools for handling images
   *
   */
  @DefaultKey("imageTool")
  public class ImageTool {
  
  	static {
  		// First, register the WEBP IOImage Writer and Reader
  		// (Note: this should be done automatically by IOImage, but it doesn't work
  		// with Plexus and Maven because of their specific ClassLoader)
  		IIORegistry iioRegistry = IIORegistry.getDefaultInstance();
  		iioRegistry.registerServiceProvider(new WebPImageWriterSpi());
  		iioRegistry.registerServiceProvider(new WebPImageReaderSpi());
  
  	}
  
  	/**
  	 * Patterns that matches with absolute URLs, like:
  	 * <ul>
  	 * <li>http://google.com
  	 * <li>ftp://cia.gov
  	 * <li>//sentrysoftware.com
  	 */
  	private static final Pattern ABSOLUTE_URL_PATTERN = Pattern.compile("^(?:[a-z]+:)?//", Pattern.CASE_INSENSITIVE);
  
  	/**
  	 * Create a new instance
  	 */
  	public ImageTool() {
  		/* Do nothing */
  	}
  
  	/**
  	 * Returns whether specified path is absolute or not.
  	 * <ul>
  	 * <li>http://google.com => absolute
  	 * <li>ftp://cia.gov => absolute
  	 * <li>//sentrysoftware.com => absolute
  	 * <li>path/file => relative
  	 *
  	 * @param path Path to test
  	 * @return whether specified path is absolute or not
  	 */
  	protected static boolean isAbsoluteUrl(final String path) {
  		return ABSOLUTE_URL_PATTERN.matcher(path).find();
  	}
  
  	/**
  	 * Check the image links in the document and make sure they refer to a file that
  	 * actually exists.
  	 *
 	 * @param body         the HTML content
 	 * @param basedir         Actual root directory of the site on the file system
 	 * @param currentDocument Logical path of the document being parsed (e.g.
 	 *                        "index.html", or "subdir/subpage.html")
 	 * @return the updated HTML content
 	 * @throws IOException when an image cannot be read or converted
 	 */
 	public Element checkImageLinks(
 			final Element body,
 			final String basedir,
 			final String currentDocument
 	) throws IOException {
 
 		// Initialization
 		List<String> errorList = new ArrayList<String>();
 
 		// basedir path
 		Path basedirPath = Paths.get(basedir).toAbsolutePath();
 
 		// First, calculate the real path of the current document
 		Path documentPath = Paths.get(basedir, currentDocument);
 
 		Path parentPath = documentPath.getParent();
 		if (parentPath == null) {
 			throw new IOException("Couldn't get the parent path of " + currentDocument);
 		}
 
 		// Select all images
 		List<Element> elements = body.select("img");
 
 		// For each image
 		for (Element element : elements) {
 
 			// Get the SRC attribute (the path)
 			String imageSrc = element.attr("src");
 			if (imageSrc.isEmpty()) {
 				continue;
 			}
 
 			// Skip absolute URLs
 			if (isAbsoluteUrl(imageSrc)) {
 				continue;
 			}
 
 			// Calculate the path to the actual picture file
 			Path sourcePath = documentPath.resolveSibling(imageSrc);
 			File sourceFile = sourcePath.toFile();
 
 			// Skip external URLs
 			if (!sourcePath.toAbsolutePath().startsWith(basedirPath)) {
 				continue;
 			}
 
 			// Recalculate the relative link and see whether the original matches
 			// the recalculated one. If not, it means there is a problem in the case.
 			Path recalculatedPath = parentPath.toRealPath().relativize(sourcePath.toRealPath());
 			String sourcePathSlashString = sourcePath.toString().replace('\\', '/');
 			String recalculatedPathSlashString = recalculatedPath.toString().replace('\\', '/');
 			if (!recalculatedPathSlashString.endsWith(sourcePathSlashString) && !sourcePathSlashString.endsWith(recalculatedPathSlashString)) {
 				errorList.add("Referenced image " + imageSrc + " in " + currentDocument + " doesn't match case of actual file " + recalculatedPath);
 			}
 
 			// Sanity check
 			if (!sourceFile.isFile()) {
 				errorList.add("Referenced image " + imageSrc + " in " + currentDocument + " doesn't exist");
 			}
 
 		}
 
 		// Some errors, show them all
 		if (!errorList.isEmpty()) {
 			throw new IOException(errorList.stream().collect(Collectors.joining("\n")));
 		}
 
 		return body;
 
 	}
 
 
 	/**
 	 * Returns the extension of the file
 	 * <p>
 	 * @param file File
 	 * @return the extension of the file
 	 */
 	protected static String getExtension(final File file) {
 		String name = file.getName();
 		int dotIndex = name.lastIndexOf('.');
 		if (dotIndex > -1) {
 			return name.substring(dotIndex + 1);
 		}
 		return "";
 	}
 
 	/**
 	 * Returns the name of the file without its extension
 	 * <p>
 	 * @param file File
 	 * @return the name of the file without its extension
 	 */
 	protected static String getNameWithoutExtension(final File file) {
 		String name = file.getName();
 		int dotIndex = name.lastIndexOf('.');
 		if (dotIndex > -1) {
 			return name.substring(0, dotIndex);
 		}
 		return name;
 	}
 
 	/**
 	 * Create a thumbnail image file from the specified image file.
 	 * <p>
 	 * @param sourceFile File instance of the source image
 	 * @param thumbnailMark Suffix to be appended to the source file name to build the thumbnail file
 	 * @param maxWidth Maximum width of the thumbnail, 0 if no maximum width
 	 * @param maxHeight Maximum height of the thumbnail, 0 if no maximum height
 	 * @return File instance of the thumbail image
 	 * @throws IOException when cannot read the source image, or write the thumbnail file
 	 */
 	protected static File createThumbnail(
 			final File sourceFile,
 			final String thumbnailMark,
 			final int maxWidth,
 			final int maxHeight
 	) throws IOException {
 
 		// Sanity check
 		if (!sourceFile.isFile()) {
 			throw new IOException(sourceFile.getAbsolutePath() + " does not exist");
 		}
 
 		// Destination
 		File destination = new File(sourceFile.getParent(), getNameWithoutExtension(sourceFile) + thumbnailMark + ".jpg");
 
 		// Do we need to do anything? (if destination is newer than source, we skip)
 		if (Helper.getLastModifiedTime(sourceFile) < Helper.getLastModifiedTime(destination)) {
 			return destination;
 		}
 
 		// Read the specified image
 		BufferedImage sourceImage = ImageIO.read(sourceFile);
 		String imageType = getExtension(sourceFile).toLowerCase();
 
 		// Calculate the dimensions of the resulting thumbnail
 		int targetWidth = sourceImage.getWidth();
 		int targetHeight = sourceImage.getHeight();
 
 		if (maxWidth > 0 && targetWidth > maxWidth) {
 			targetHeight = targetHeight * maxWidth / targetWidth;
 			targetWidth = maxWidth;
 		}
 		if (maxHeight > 0 && targetHeight > maxHeight) {
 			targetWidth = targetWidth * maxHeight / targetHeight;
 			targetHeight = maxHeight;
 		}
 
 		// Rescale
 		Image resultingImage = sourceImage.getScaledInstance(targetWidth, targetHeight, Image.SCALE_SMOOTH);
 		BufferedImage outputImage = new BufferedImage(targetWidth, targetHeight, BufferedImage.TYPE_INT_RGB);
 		outputImage.getGraphics().drawImage(resultingImage, 0, 0, null);
 
 		// Write the thumbnail file
 		ImageIO.write(outputImage, imageType, destination);
 
 		return destination;
 
 	}
 
 	/**
 	 * Saves the specified image file as a WEBP image.
 	 * <p>
 	 * @param sourceFile image file to convert to WEBP
 	 * @return a File instance of the converted image, or null if the file was already a WEBP
 	 * @throws IOException when cannot read the image file
 	 */
 	protected static File saveImageFileAsWebp(final File sourceFile) throws IOException {
 
 		// Sanity check
 		if (!sourceFile.isFile()) {
 			throw new IOException(sourceFile.getAbsolutePath() + " does not exist");
 		}
 
 		// Output file
 		String webpImagePath = getNameWithoutExtension(sourceFile) + ".webp";
 		File webpFile = new File(sourceFile.getParent(), webpImagePath);
 
 		// Do we need to do anything? (if destination is newer than source, we skip)
 		if (Helper.getLastModifiedTime(sourceFile) < Helper.getLastModifiedTime(webpFile)) {
 			return webpFile;
 		}
 
 		// Read the specified image
 		BufferedImage sourceImage = ImageIO.read(sourceFile);
 		if (sourceImage == null) {
 			return null;
 		}
 
 		// Image type (skip if webp)
 		String imageType = getExtension(sourceFile).toLowerCase();
 		if ("webp".equals(imageType)) {
 			return null;
 		}
 
 		// Obtain a WebP ImageWriter instance
 		ImageWriter writer = ImageIO.getImageWritersBySuffix("webp").next();
 
 		// Configure encoding parameters: LOSSY for jpeg and jpg, LOSSLESS otherwise
 		WebPWriteParam writeParam = new WebPWriteParam(writer.getLocale());
 		writeParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
 		if ("jpeg".equals(imageType) || "jpg".equals(imageType)) {
 			writeParam.setCompressionType(writeParam.getCompressionTypes()[WebPWriteParam.LOSSY_COMPRESSION]);
 		} else {
 			writeParam.setCompressionType(writeParam.getCompressionTypes()[WebPWriteParam.LOSSLESS_COMPRESSION]);
 		}
 
 		// Configure the output on the ImageWriter
 		writer.setOutput(new FileImageOutputStream(webpFile));
 
 		// Write the WEBP image
 		writer.write(null, new IIOImage(sourceImage, null, null), writeParam);
 
 		// Return the file
 		return webpFile;
 
 	}
 
 	/**
 	 * Upgrades all images in the specified HTML document to WEBP.
 	 *
 	 * @param body         the HTML content
 	 * @param selector        CSS selector to select all images to upgrade
 	 *                        ("img.screenshot" will process all &lt;IMG
 	 *                        class="screenshot"&gt; elements)
 	 * @param basedir         Actual root directory of the site on the file system
 	 * @param currentDocument Logical path of the document being parsed (e.g.
 	 *                        "index.html", or "subdir/subpage.html")
 	 * @return the updated HTML content
 	 * @throws IOException when an image cannot be read or converted
 	 */
 	public Element convertImagesToWebp(
 			final Element body,
 			final String selector,
 			final String basedir,
 			final String currentDocument
 	) throws IOException {
 
 		// basedir path
 		Path basedirPath = Paths.get(basedir).toAbsolutePath();
 
 		// First, calculate the real path of the current document
 		Path documentPath = Paths.get(basedir, currentDocument);
 
 		Path parentPath = documentPath.getParent();
 		if (parentPath == null) {
 			throw new IOException("Couldn't get parent path of " + currentDocument);
 		}
 
 		// Select all images
 		List<Element> elements = body.select(selector);
 
 		// For each image
 		for (Element element : elements) {
 
 			// Get the SRC attribute (the path)
 			String imageSrc = element.attr("src");
 			if (imageSrc.isEmpty()) {
 				continue;
 			}
 
 			// Skip absolute URLs
 			if (isAbsoluteUrl(imageSrc)) {
 				continue;
 			}
 
 			// Calculate the path to the actual picture file
 			Path sourcePath = documentPath.resolveSibling(imageSrc);
 			File sourceFile = sourcePath.toFile();
 
 			// Skip external URLs
 			if (!sourcePath.toAbsolutePath().startsWith(basedirPath)) {
 				continue;
 			}
 
 			// Sanity check
 			if (!sourceFile.isFile()) {
 				throw new IOException(sourceFile.getAbsolutePath() + " (referenced as " + imageSrc + ") does not exist");
 			}
 
 			// Save as webp
 			File webpFile = saveImageFileAsWebp(sourceFile);
 			if (webpFile == null) {
 				continue;
 			}
 
 			// Calculate the src path of the webp image
 			String webpSrc = parentPath.relativize(webpFile.toPath()).toString().replace('\\', '/');
 
 			// Now wrap the IMG element with <picture> and <source srcset="...webp">
 			element
 				.wrap("<picture>")
 				.parent()
 				.prependElement("source")
 				.attr("srcset", webpSrc)
 				.attr("type", "image/webp");
 
 		}
 
 		return body;
 
 	}
 
 
 	/**
 	 * Explicitly states the width and height of each image in the specified document.
 	 *
 	 * @param body         the HTML content
 	 * @param selector        CSS selector to select all images to upgrade
 	 *                        ("img.screenshot" will process all &lt;IMG
 	 *                        class="screenshot"&gt; elements)
 	 * @param basedir         Actual root directory of the site on the file system
 	 * @param currentDocument Logical path of the document being parsed (e.g.
 	 *                        "index.html", or "subdir/subpage.html")
 	 * @return the updated HTML content
 	 * @throws IOException when an image cannot be read or converted
 	 */
 	public Element explicitImageSize(
 			final Element body,
 			final String selector,
 			final String basedir,
 			final String currentDocument
 	) throws IOException {
 
 		// basedir path
 		Path basedirPath = Paths.get(basedir).toAbsolutePath();
 
 		// First, calculate the real path of the current document
 		Path documentPath = Paths.get(basedir, currentDocument);
 
 		// Select all images
 		List<Element> elements = body.select(selector);
 
 		// For each image
 		for (Element element : elements) {
 
 			// Get the SRC attribute (the path)
 			String imageSrc = element.attr("src");
 			if (imageSrc.isEmpty()) {
 				continue;
 			}
 
 			// Skip absolute URLs
 			if (isAbsoluteUrl(imageSrc)) {
 				continue;
 			}
 
 			// If size and height are already specified, skip
 			if (element.attr("style").matches("(^|\\b)(width:|height:)")
 					|| !element.attr("height").isEmpty()
 					|| !element.attr("width").isEmpty()) {
 				continue;
 			}
 
 			// Calculate the path to the actual picture file
 			Path sourcePath = documentPath.resolveSibling(imageSrc);
 			File sourceFile = sourcePath.toFile();
 
 			// Skip external URLs
 			if (!sourcePath.toAbsolutePath().startsWith(basedirPath)) {
 				continue;
 			}
 
 			// Sanity check
 			if (!sourceFile.isFile()) {
 				throw new IOException(sourceFile.getAbsolutePath() + " (referenced as " + imageSrc + ") does not exist");
 			}
 
 			// Read the image
 			BufferedImage sourceImage = ImageIO.read(sourceFile);
 			if (sourceImage == null) {
 				continue;
 			}
 
 			// Now set the width and height attributes (and CSS)
 			element
 				.attr("width", String.valueOf(sourceImage.getWidth()))
 				.attr("height", String.valueOf(sourceImage.getHeight()))
 				.attr("style", String.format(
 						"width: %dpx; height: %dpx;%s",
 						sourceImage.getWidth(),
 						sourceImage.getHeight(),
 						element.attr("style")
 				));
 
 		}
 
 		return body;
 
 	}
 
 	/**
 	 * For all images in the document, create the corresponding thumbnail, and wrap
 	 * the picture elements with the specified template.
 	 * <p>
 	 * The specified template may reference the below "macros":
 	 * <ul>
 	 * <li><code>%imgWidth%</code>: the original image width
 	 * <li><code>%imgHeight%</code>: the original image height
 	 * <li><code>%imgAlt%</code>: the image alternate text (it's description)
 	 * <li><code>%thumbWidth%</code>: the thumbnail image width
 	 * <li><code>%thumbHeight%</code>: the thumbnail image height
 	 * <li><code>%thumbSrc%</code>: the thumbnail image source path
 	 * </ul>
 	 *
 	 * @param body         the HTML content
 	 * @param selector        CSS selector to select all images to upgrade
 	 *                        ("img.screenshot" will process all &lt;IMG
 	 *                        class="screenshot"&gt; elements)
 	 * @param basedir         Actual root directory of the site on the file system
 	 * @param currentDocument Logical path of the document being parsed (e.g.
 	 *                        "index.html", or "subdir/subpage.html")
 	 * @param maxWidth        Maximum width for the thumbnail (or 0 for no maximum)
 	 * @param maxHeight       Maximum height for the thumbnail (or 0 for no maximum)
 	 * @param wrapTemplate    HTML code wrap the image element with. This will be
 	 *                        typically used to create the thumbnail element. The HTML
 	 *                        can reference macros.
 	 * @return the updated HTML content
 	 * @throws IOException when an image cannot be read or converted
 	 */
 	public Element convertImagesToThumbnails(
 			final Element body,
 			final String selector,
 			final String basedir,
 			final String currentDocument,
 			final int maxWidth,
 			final int maxHeight,
 			final String wrapTemplate
 	) throws IOException {
 
 		// basedir path
 		Path basedirPath = Paths.get(basedir).toAbsolutePath();
 
 		// First, calculate the real path of the current document
 		Path documentPath = Paths.get(basedir, currentDocument);
 
 		Path parentPath = documentPath.getParent();
 		if (parentPath == null) {
 			throw new IOException("Couldn't get parent path of " + currentDocument);
 		}
 
 		// Select all images
 		List<Element> elements = body.select(selector);
 
 		// For each image
 		for (Element element : elements) {
 
 			// Get the SRC attribute (the path)
 			String imageSrc = element.attr("src");
 			if (imageSrc.isEmpty()) {
 				continue;
 			}
 
 			// Skip absolute URLs
 			if (isAbsoluteUrl(imageSrc)) {
 				continue;
 			}
 
 			// Get the ALT attribute (the description)
 			String imageAlt = element.attr("alt");
 
 			// Calculate the path to the actual picture file
 			Path sourcePath = documentPath.resolveSibling(imageSrc);
 			File sourceFile = sourcePath.toFile();
 
 			// Skip external URLs
 			if (!sourcePath.toAbsolutePath().startsWith(basedirPath)) {
 				continue;
 			}
 
 			// Sanity check
 			if (!sourceFile.isFile()) {
 				throw new IOException(sourceFile.getAbsolutePath() + " (referenced as " + imageSrc + ") does not exist");
 			}
 
 			// Image size
 			BufferedImage sourceImage = ImageIO.read(sourceFile);
 			int sourceWidth = sourceImage.getWidth();
 			int sourceHeight = sourceImage.getHeight();
 
 			// Create the thumbnail
 			File thumbnailFile = createThumbnail(sourceFile, "-thumbnail", maxWidth, maxHeight);
 
 			// Read the thumbnail and get its size
 			BufferedImage thumbnailImage = ImageIO.read(thumbnailFile);
 			int thumbnailWidth = thumbnailImage.getWidth();
 			int thumbnailHeight = thumbnailImage.getHeight();
 
 			// Calculate the src path of the webp image
 			String thumbnailSrc = parentPath.relativize(thumbnailFile.toPath()).toString().replace('\\', '/');
 
 			// Replace macros in the wrap template
 			String wrapHtml = wrapTemplate
 				.replaceAll("%imgWidth%", String.valueOf(sourceWidth))
 				.replaceAll("%imgHeight%", String.valueOf(sourceHeight))
 				.replaceAll("%thumbWidth%", String.valueOf(thumbnailWidth))
 				.replaceAll("%thumbHeight%", String.valueOf(thumbnailHeight))
 				.replaceAll("%thumbSrc%", thumbnailSrc)
 				.replaceAll("%imgAlt%", imageAlt);
 
 			// Now wrap the IMG element with template
 			// If the IMG element is inside a PICTURE element, wrap the PICTURE element
 			Element pictureElement = element;
 			if ("PICTURE".equalsIgnoreCase(element.parent().tagName())) {
 				pictureElement = element.parent();
 			}
 			pictureElement.wrap(wrapHtml);
 
 		}
 
 		return body;
 
 	}
 
 
 }