// Copyright (C) 2012 The Android Open Source Project
//
// 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.
package com.google.gerrit.server.documentation;
import static org.pegdown.Extensions.ALL;
import static org.pegdown.Extensions.HARDWRAPS;
import com.google.common.base.Strings;
import org.eclipse.jgit.util.RawParseUtils;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.pegdown.LinkRenderer;
import org.pegdown.PegDownProcessor;
import org.pegdown.ToHtmlSerializer;
import org.pegdown.ast.HeaderNode;
import org.pegdown.ast.Node;
import org.pegdown.ast.RootNode;
import org.pegdown.ast.TextNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.concurrent.atomic.AtomicBoolean;
public class MarkdownFormatter {
private static final Logger log =
LoggerFactory.getLogger(MarkdownFormatter.class);
private static final String css;
static {
AtomicBoolean file = new AtomicBoolean();
String src;
try {
src = readPegdownCss(file);
} catch (IOException err) {
log.warn("Cannot load pegdown.css", err);
src = "";
}
css = file.get() ? null : src;
}
private static String readCSS() {
if (css != null) {
return css;
}
try {
return readPegdownCss(new AtomicBoolean());
} catch (IOException err) {
log.warn("Cannot load pegdown.css", err);
return "";
}
}
public byte[] markdownToDocHtml(String md, String charEnc)
throws UnsupportedEncodingException {
RootNode root = parseMarkdown(md);
String title = findTitle(root);
StringBuilder html = new StringBuilder();
html.append("<html>");
html.append("<head>");
if (!Strings.isNullOrEmpty(title)) {
html.append("<title>").append(title).append("</title>");
}
html.append("<style type=\"text/css\">\n")
.append(readCSS())
.append("\n</style>");
html.append("</head>");
html.append("<body>\n");
html.append(new ToHtmlSerializer(new LinkRenderer()).toHtml(root));
html.append("\n</body></html>");
return html.toString().getBytes(charEnc);
}
public String extractTitleFromMarkdown(byte[] data, String charEnc) {
String md = RawParseUtils.decode(Charset.forName(charEnc), data);
return findTitle(parseMarkdown(md));
}
private String findTitle(Node root) {
if (root instanceof HeaderNode) {
HeaderNode h = (HeaderNode) root;
if (h.getLevel() == 1
&& h.getChildren() != null
&& !h.getChildren().isEmpty()) {
StringBuilder b = new StringBuilder();
for (Node n : root.getChildren()) {
if (n instanceof TextNode) {
b.append(((TextNode) n).getText());
}
}
return b.toString();
}
}
for (Node n : root.getChildren()) {
String title = findTitle(n);
if (title != null) {
return title;
}
}
return null;
}
private RootNode parseMarkdown(String md) {
return new PegDownProcessor(ALL & ~(HARDWRAPS))
.parseMarkdown(md.toCharArray());
}
private static String readPegdownCss(AtomicBoolean file)
throws IOException {
String name = "pegdown.css";
URL url = MarkdownFormatter.class.getResource(name);
if (url == null) {
throw new FileNotFoundException("Resource " + name);
}
file.set("file".equals(url.getProtocol()));
InputStream in = url.openStream();
try {
TemporaryBuffer.Heap tmp = new TemporaryBuffer.Heap(128 * 1024);
tmp.copy(in);
return new String(tmp.toByteArray(), "UTF-8");
} finally {
in.close();
}
}
}