wikitext/core/org.eclipse.mylyn.wikitext.asciidoc/src/main/java/org/eclipse/mylyn/wikitext/asciidoc/internal/token/InlineImageReplacementToken.java

/*******************************************************************************
 * Copyright (c) 2015, 2016 Max Rydahl Andersen and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Max Rydahl Andersen - initial API and implementation, Bug 474084
 *     Patrik Suzzi <psuzzi@gmail.com> - Bug 474084
 *******************************************************************************/

package org.eclipse.mylyn.wikitext.asciidoc.internal.token;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

import org.eclipse.mylyn.wikitext.asciidoc.internal.AsciiDocContentState;
import org.eclipse.mylyn.wikitext.asciidoc.internal.util.LanguageSupport;
import org.eclipse.mylyn.wikitext.parser.Attributes;
import org.eclipse.mylyn.wikitext.parser.DocumentBuilder;
import org.eclipse.mylyn.wikitext.parser.DocumentBuilder.BlockType;
import org.eclipse.mylyn.wikitext.parser.DocumentBuilder.SpanType;
import org.eclipse.mylyn.wikitext.parser.ImageAttributes;
import org.eclipse.mylyn.wikitext.parser.markup.PatternBasedElement;
import org.eclipse.mylyn.wikitext.parser.markup.PatternBasedElementProcessor;

/**
 * Detects inline images and single line block images:
 *
 * <pre>
 * image::sunset.jpg[formatting options].
 * image:sunset.jpg[formatting options].
 * </pre>
 *
 * See http://asciidoctor.org/docs/user-manual/#images
 *
 * @author Max Rydahl Andersen
 */
public class InlineImageReplacementToken extends PatternBasedElement {
	public static final String ABSOLUTE_PATH_OR_URL_REGEX = "(?:\\/|[a-zA-Z]\\:[\\\\\\/]|(?:https?|ftp|file)\\:\\/\\/)[^\\s]+"; //$NON-NLS-1$

	@Override
	protected String getPattern(int groupOffset) {
		return "image::?(.*?)\\[(.*?)\\]"; //$NON-NLS-1$
	}

	@Override
	protected int getPatternGroupCount() {
		return 2;
	}

	@Override
	protected PatternBasedElementProcessor newProcessor() {
		return new InlineImageReplacementTokenProcessor();
	}

	public static class InlineImageReplacementTokenProcessor extends PatternBasedElementProcessor {

		private static final String LINK = "link"; //$NON-NLS-1$

		private static final String CAPTION = "caption"; //$NON-NLS-1$

		private static final String IMAGE = "image"; //$NON-NLS-1$

		private static final String TITLE = "title"; //$NON-NLS-1$

		private static final String HEIGHT = "height"; //$NON-NLS-1$

		private static final String WIDTH = "width"; //$NON-NLS-1$

		private static final String ALT = "alt"; //$NON-NLS-1$

		@Override
		public void emit() {
			String src = group(1);
			String formatting = group(2);

			List<String> positional = new ArrayList<>();
			positional.add(ALT);
			positional.add(WIDTH);
			positional.add(HEIGHT);

			Map<String, String> properties = LanguageSupport.parseFormattingProperties(formatting, positional);

			if (!properties.containsKey(ALT) || properties.get(ALT).isEmpty()) {
				// if no alt provided make one up using base filename
				// of source image name.
				int end = src.lastIndexOf("."); //$NON-NLS-1$

				if (end != -1) {
					String firstSrc = src.substring(0, end);
					int start = Math.max(firstSrc.lastIndexOf("/") + 1, 0); //$NON-NLS-1$
					properties.put(ALT, firstSrc.substring(start));
				} else {
					properties.put(ALT, src);
				}

			}

			if (!Pattern.matches(ABSOLUTE_PATH_OR_URL_REGEX, src)) {
				String imagesDir = getAsciiDocState().getAttribute(AsciiDocContentState.ATTRIBUTE_IMAGESDIR);
				if (imagesDir != null && !imagesDir.isEmpty()) {
					if (imagesDir.endsWith("/")) { //$NON-NLS-1$
						src = imagesDir + src;
					} else {
						src = imagesDir + "/" + src; //$NON-NLS-1$
					}
				}
			}

			if (group(0).startsWith("image::")) { // imageblock //$NON-NLS-1$
				Attributes imageSpanAttributes = new Attributes();
				imageSpanAttributes.setCssClass("imageblock"); //$NON-NLS-1$

				builder.beginBlock(BlockType.DIV, imageSpanAttributes);

				Attributes contentAttr = new Attributes();
				contentAttr.setCssClass("content"); //$NON-NLS-1$
				builder.beginBlock(BlockType.DIV, contentAttr);

				emitImage(builder, src, properties);

				builder.endBlock(); // content

				if (properties.containsKey(TITLE)) {
					Attributes attr = new Attributes();
					attr.setCssClass(TITLE);
					builder.beginBlock(BlockType.DIV, attr);
					if (properties.containsKey(CAPTION)) {
						builder.characters(properties.get(CAPTION));
					}
					builder.characters(properties.get(TITLE));
					builder.endBlock();
				}

				builder.endBlock(); // imageBlock

			} else { // inline image
				Attributes imageBlockAttr = new Attributes();
				imageBlockAttr.setCssClass(IMAGE);

				builder.beginSpan(SpanType.SPAN, imageBlockAttr);
				emitImage(builder, src, properties);
				builder.endSpan();

			}

		}

		static private void emitImage(DocumentBuilder builder, String src, Map<String, String> properties) {
			ImageAttributes attributes = new ImageAttributes();
			// TODO: find way to avoid unnecessary border=0 being added to
			// output
			attributes.setAlt(properties.get(ALT));

			if (properties.containsKey(HEIGHT)) {
				try {
					int height = Integer.parseInt(properties.get(HEIGHT));
					attributes.setHeight(height);
				} catch (NumberFormatException nfe) {
					// ignore
				}

			}

			if (properties.containsKey(WIDTH)) {
				try {
					int width = Integer.parseInt(properties.get(WIDTH));
					attributes.setWidth(width);
				} catch (NumberFormatException nfe) {
					// ignore
				}

			}

			if (properties.containsKey(LINK)) {
				Attributes linkAttributes = new Attributes();
				linkAttributes.setCssClass(IMAGE);
				builder.imageLink(linkAttributes, attributes, properties.get(LINK), src);
			} else {
				builder.image(attributes, src);
			}
		}

		protected AsciiDocContentState getAsciiDocState() {
			return (AsciiDocContentState) state;
		}
	}
}