/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.maven.tools.plugin.generator;
  
  import javax.swing.text.MutableAttributeSet;
  import javax.swing.text.html.HTML;
  import javax.swing.text.html.HTMLEditorKit;
  import javax.swing.text.html.parser.ParserDelegator;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.StringReader;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Stack;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.artifact.DependencyResolutionRequiredException;
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.reporting.MavenReport;
  import org.codehaus.plexus.component.repository.ComponentDependency;
  import org.codehaus.plexus.util.StringUtils;
  import org.codehaus.plexus.util.xml.XMLWriter;
  import org.w3c.tidy.Tidy;
  
  /**
   * Convenience methods to play with Maven plugins.
   *
   * @author jdcasey
   */
  public final class GeneratorUtils {
      private GeneratorUtils() {
          // nop
      }
  
      /**
       * @param w not null writer
       * @param pluginDescriptor not null
       */
      public static void writeDependencies(XMLWriter w, PluginDescriptor pluginDescriptor) {
          w.startElement("dependencies");
  
          List<ComponentDependency> deps = pluginDescriptor.getDependencies();
          for (ComponentDependency dep : deps) {
              w.startElement("dependency");
  
              element(w, "groupId", dep.getGroupId());
  
              element(w, "artifactId", dep.getArtifactId());
  
              element(w, "type", dep.getType());
  
              element(w, "version", dep.getVersion());
  
              w.endElement();
          }
  
          w.endElement();
      }
  
      /**
       * @param w not null writer
       * @param name  not null
       * @param value could be null
       */
      public static void element(XMLWriter w, String name, String value) {
          w.startElement(name);
  
          if (value == null) {
             value = "";
         }
 
         w.writeText(value);
 
         w.endElement();
     }
 
     /**
      * @param artifacts not null collection of <code>Artifact</code>
      * @return list of component dependencies, without in provided scope
      */
     public static List<ComponentDependency> toComponentDependencies(Collection<Artifact> artifacts) {
         List<ComponentDependency> componentDeps = new LinkedList<>();
 
         for (Artifact artifact : artifacts) {
             if (Artifact.SCOPE_PROVIDED.equals(artifact.getScope())) {
                 continue;
             }
 
             ComponentDependency cd = new ComponentDependency();
 
             cd.setArtifactId(artifact.getArtifactId());
             cd.setGroupId(artifact.getGroupId());
             cd.setVersion(artifact.getVersion());
             cd.setType(artifact.getType());
 
             componentDeps.add(cd);
         }
 
         return componentDeps;
     }
 
     /**
      * Returns a literal replacement <code>String</code> for the specified <code>String</code>. This method
      * produces a <code>String</code> that will work as a literal replacement <code>s</code> in the
      * <code>appendReplacement</code> method of the {@link Matcher} class. The <code>String</code> produced will
      * match the sequence of characters in <code>s</code> treated as a literal sequence. Slashes ('\') and dollar
      * signs ('$') will be given no special meaning. TODO: copied from Matcher class of Java 1.5, remove once target
      * platform can be upgraded
      *
      * @see <a href="http://java.sun.com/j2se/1.5.0/docs/api/java/util/regex/Matcher.html">java.util.regex.Matcher</a>
      * @param s The string to be literalized
      * @return A literal string replacement
      */
     private static String quoteReplacement(String s) {
         if ((s.indexOf('\\') == -1) && (s.indexOf('$') == -1)) {
             return s;
         }
 
         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < s.length(); i++) {
             char c = s.charAt(i);
             if (c == '\\') {
                 sb.append('\\');
                 sb.append('\\');
             } else if (c == '$') {
                 sb.append('\\');
                 sb.append('$');
             } else {
                 sb.append(c);
             }
         }
 
         return sb.toString();
     }
 
     /**
      * Decodes javadoc inline tags into equivalent HTML tags. For instance, the inline tag "{@code <A&B>}" should be
      * rendered as "<code>&lt;A&amp;B&gt;</code>".
      *
      * @param description The javadoc description to decode, may be <code>null</code>.
      * @return The decoded description, never <code>null</code>.
      * @deprecated Only used for non java extractor
      */
     @Deprecated
     static String decodeJavadocTags(String description) {
         if (StringUtils.isEmpty(description)) {
             return "";
         }
 
         StringBuffer decoded = new StringBuffer(description.length() + 1024);
 
         Matcher matcher = Pattern.compile("\\{@(\\w+)\\s*([^\\}]*)\\}").matcher(description);
         while (matcher.find()) {
             String tag = matcher.group(1);
             String text = matcher.group(2);
             text = StringUtils.replace(text, "&", "&amp;");
             text = StringUtils.replace(text, "<", "&lt;");
             text = StringUtils.replace(text, ">", "&gt;");
             if ("code".equals(tag)) {
                 text = "<code>" + text + "</code>";
             } else if ("link".equals(tag) || "linkplain".equals(tag) || "value".equals(tag)) {
                 String pattern = "(([^#\\.\\s]+\\.)*([^#\\.\\s]+))?" + "(#([^\\(\\s]*)(\\([^\\)]*\\))?\\s*(\\S.*)?)?";
                 final int label = 7;
                 final int clazz = 3;
                 final int member = 5;
                 final int args = 6;
                 Matcher link = Pattern.compile(pattern).matcher(text);
                 if (link.matches()) {
                     text = link.group(label);
                     if (StringUtils.isEmpty(text)) {
                         text = link.group(clazz);
                         if (StringUtils.isEmpty(text)) {
                             text = "";
                         }
                         if (StringUtils.isNotEmpty(link.group(member))) {
                             if (StringUtils.isNotEmpty(text)) {
                                 text += '.';
                             }
                             text += link.group(member);
                             if (StringUtils.isNotEmpty(link.group(args))) {
                                 text += "()";
                             }
                         }
                     }
                 }
                 if (!"linkplain".equals(tag)) {
                     text = "<code>" + text + "</code>";
                 }
             }
             matcher.appendReplacement(decoded, (text != null) ? quoteReplacement(text) : "");
         }
         matcher.appendTail(decoded);
 
         return decoded.toString();
     }
 
     /**
      * Fixes some javadoc comment to become a valid XHTML snippet.
      *
      * @param description Javadoc description with HTML tags, may be <code>null</code>.
      * @return The description with valid XHTML tags, never <code>null</code>.
      * @deprecated Redundant for java extractor
      */
     @Deprecated
     public static String makeHtmlValid(String description) {
 
         if (StringUtils.isEmpty(description)) {
             return "";
         }
 
         String commentCleaned = decodeJavadocTags(description);
 
         // Using jTidy to clean comment
         Tidy tidy = new Tidy();
         tidy.setDocType("loose");
         tidy.setXHTML(true);
         tidy.setXmlOut(true);
         tidy.setInputEncoding("UTF-8");
         tidy.setOutputEncoding("UTF-8");
         tidy.setMakeClean(true);
         tidy.setNumEntities(true);
         tidy.setQuoteNbsp(false);
         tidy.setQuiet(true);
         tidy.setShowWarnings(true);
 
         ByteArrayOutputStream out = new ByteArrayOutputStream(commentCleaned.length() + 256);
         tidy.parse(new ByteArrayInputStream(commentCleaned.getBytes(StandardCharsets.UTF_8)), out);
         commentCleaned = new String(out.toByteArray(), StandardCharsets.UTF_8);
 
         if (StringUtils.isEmpty(commentCleaned)) {
             return "";
         }
 
         // strip the header/body stuff
         String ls = System.getProperty("line.separator");
         int startPos = commentCleaned.indexOf("<body>" + ls) + 6 + ls.length();
         int endPos = commentCleaned.indexOf(ls + "</body>");
         commentCleaned = commentCleaned.substring(startPos, endPos);
 
         return commentCleaned;
     }
 
     /**
      * Converts a HTML fragment as extracted from a javadoc comment to a plain text string. This method tries to retain
      * as much of the text formatting as possible by means of the following transformations:
      * <ul>
      * <li>List items are converted to leading tabs (U+0009), followed by the item number/bullet, another tab and
      * finally the item contents. Each tab denotes an increase of indentation.</li>
      * <li>Flow breaking elements as well as literal line terminators in preformatted text are converted to a newline
      * (U+000A) to denote a mandatory line break.</li>
      * <li>Consecutive spaces and line terminators from character data outside of preformatted text will be normalized
      * to a single space. The resulting space denotes a possible point for line wrapping.</li>
      * <li>Each space in preformatted text will be converted to a non-breaking space (U+00A0).</li>
      * </ul>
      *
      * @param html The HTML fragment to convert to plain text, may be <code>null</code>.
      * @return A string with HTML tags converted into pure text, never <code>null</code>.
      * @since 2.4.3
      * @deprecated Replaced by {@link HtmlToPlainTextConverter}
      */
     @Deprecated
     public static String toText(String html) {
         if (StringUtils.isEmpty(html)) {
             return "";
         }
 
         final StringBuilder sb = new StringBuilder();
 
         HTMLEditorKit.Parser parser = new ParserDelegator();
         HTMLEditorKit.ParserCallback htmlCallback = new MojoParserCallback(sb);
 
         try {
             parser.parse(new StringReader(makeHtmlValid(html)), htmlCallback, true);
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
 
         return sb.toString().replace('\"', '\''); // for CDATA
     }
 
     /**
      * ParserCallback implementation.
      */
     private static class MojoParserCallback extends HTMLEditorKit.ParserCallback {
         /**
          * Holds the index of the current item in a numbered list.
          */
         class Counter {
             int value;
         }
 
         /**
          * A flag whether the parser is currently in the body element.
          */
         private boolean body;
 
         /**
          * A flag whether the parser is currently processing preformatted text, actually a counter to track nesting.
          */
         private int preformatted;
 
         /**
          * The current indentation depth for the output.
          */
         private int depth;
 
         /**
          * A stack of {@link Counter} objects corresponding to the nesting of (un-)ordered lists. A
          * <code>null</code> element denotes an unordered list.
          */
         private Stack<Counter> numbering = new Stack<>();
 
         /**
          * A flag whether an implicit line break is pending in the output buffer. This flag is used to postpone the
          * output of implicit line breaks until we are sure that are not to be merged with other implicit line
          * breaks.
          */
         private boolean pendingNewline;
 
         /**
          * A flag whether we have just parsed a simple tag.
          */
         private boolean simpleTag;
 
         /**
          * The current buffer.
          */
         private final StringBuilder sb;
 
         /**
          * @param sb not null
          */
         MojoParserCallback(StringBuilder sb) {
             this.sb = sb;
         }
 
         /** {@inheritDoc} */
         @Override
         public void handleSimpleTag(HTML.Tag t, MutableAttributeSet a, int pos) {
             simpleTag = true;
             if (body && HTML.Tag.BR.equals(t)) {
                 newline(false);
             }
         }
 
         /** {@inheritDoc} */
         @Override
         public void handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos) {
             simpleTag = false;
             if (body && (t.breaksFlow() || t.isBlock())) {
                 newline(true);
             }
             if (HTML.Tag.OL.equals(t)) {
                 numbering.push(new Counter());
             } else if (HTML.Tag.UL.equals(t)) {
                 numbering.push(null);
             } else if (HTML.Tag.LI.equals(t)) {
                 Counter counter = numbering.peek();
                 if (counter == null) {
                     text("-\t");
                 } else {
                     text(++counter.value + ".\t");
                 }
                 depth++;
             } else if (HTML.Tag.DD.equals(t)) {
                 depth++;
             } else if (t.isPreformatted()) {
                 preformatted++;
             } else if (HTML.Tag.BODY.equals(t)) {
                 body = true;
             }
         }
 
         /** {@inheritDoc} */
         @Override
         public void handleEndTag(HTML.Tag t, int pos) {
             if (HTML.Tag.OL.equals(t) || HTML.Tag.UL.equals(t)) {
                 numbering.pop();
             } else if (HTML.Tag.LI.equals(t) || HTML.Tag.DD.equals(t)) {
                 depth--;
             } else if (t.isPreformatted()) {
                 preformatted--;
             } else if (HTML.Tag.BODY.equals(t)) {
                 body = false;
             }
             if (body && (t.breaksFlow() || t.isBlock()) && !HTML.Tag.LI.equals(t)) {
                 if ((HTML.Tag.P.equals(t)
                                 || HTML.Tag.PRE.equals(t)
                                 || HTML.Tag.OL.equals(t)
                                 || HTML.Tag.UL.equals(t)
                                 || HTML.Tag.DL.equals(t))
                         && numbering.isEmpty()) {
                     pendingNewline = false;
                     newline(pendingNewline);
                 } else {
                     newline(true);
                 }
             }
         }
 
         /** {@inheritDoc} */
         @Override
         public void handleText(char[] data, int pos) {
             /*
              * NOTE: Parsers before JRE 1.6 will parse XML-conform simple tags like <br/> as "<br>" followed by
              * the text event ">..." so we need to watch out for the closing angle bracket.
              */
             int offset = 0;
             if (simpleTag && data[0] == '>') {
                 simpleTag = false;
                 for (++offset; offset < data.length && data[offset] <= ' '; ) {
                     offset++;
                 }
             }
             if (offset < data.length) {
                 String text = new String(data, offset, data.length - offset);
                 text(text);
             }
         }
 
         /** {@inheritDoc} */
         @Override
         public void flush() {
             flushPendingNewline();
         }
 
         /**
          * Writes a line break to the plain text output.
          *
          * @param implicit A flag whether this is an explicit or implicit line break. Explicit line breaks are
          *            always written to the output whereas consecutive implicit line breaks are merged into a single
          *            line break.
          */
         private void newline(boolean implicit) {
             if (implicit) {
                 pendingNewline = true;
             } else {
                 flushPendingNewline();
                 sb.append('\n');
             }
         }
 
         /**
          * Flushes a pending newline (if any).
          */
         private void flushPendingNewline() {
             if (pendingNewline) {
                 pendingNewline = false;
                 if (sb.length() > 0) {
                     sb.append('\n');
                 }
             }
         }
 
         /**
          * Writes the specified character data to the plain text output. If the last output was a line break, the
          * character data will automatically be prefixed with the current indent.
          *
          * @param data The character data, must not be <code>null</code>.
          */
         private void text(String data) {
             flushPendingNewline();
             if (sb.length() <= 0 || sb.charAt(sb.length() - 1) == '\n') {
                 for (int i = 0; i < depth; i++) {
                     sb.append('\t');
                 }
             }
             String text;
             if (preformatted > 0) {
                 text = data;
             } else {
                 text = data.replace('\n', ' ');
             }
             sb.append(text);
         }
     }
 
     /**
      * Find the best package name, based on the number of hits of actual Mojo classes.
      *
      * @param pluginDescriptor not null
      * @return the best name of the package for the generated mojo
      */
     public static String discoverPackageName(PluginDescriptor pluginDescriptor) {
         Map<String, Integer> packageNames = new HashMap<>();
 
         List<MojoDescriptor> mojoDescriptors = pluginDescriptor.getMojos();
         if (mojoDescriptors == null) {
             return "";
         }
         for (MojoDescriptor descriptor : mojoDescriptors) {
 
             String impl = descriptor.getImplementation();
             if (StringUtils.equals(descriptor.getGoal(), "help") && StringUtils.equals("HelpMojo", impl)) {
                 continue;
             }
             if (impl.lastIndexOf('.') != -1) {
                 String name = impl.substring(0, impl.lastIndexOf('.'));
                 if (packageNames.get(name) != null) {
                     int next = (packageNames.get(name)).intValue() + 1;
                     packageNames.put(name, Integer.valueOf(next));
                 } else {
                     packageNames.put(name, Integer.valueOf(1));
                 }
             } else {
                 packageNames.put("", Integer.valueOf(1));
             }
         }
 
         String packageName = "";
         int max = 0;
         for (Map.Entry<String, Integer> entry : packageNames.entrySet()) {
             int value = entry.getValue().intValue();
             if (value > max) {
                 max = value;
                 packageName = entry.getKey();
             }
         }
 
         return packageName;
     }
 
     /**
      * @param impl a Mojo implementation, not null
      * @param project a MavenProject instance, could be null
      * @return <code>true</code> is the Mojo implementation implements <code>MavenReport</code>,
      * <code>false</code> otherwise.
      * @throws IllegalArgumentException if any
      */
     @SuppressWarnings("unchecked")
     public static boolean isMavenReport(String impl, MavenProject project) throws IllegalArgumentException {
         if (impl == null) {
             throw new IllegalArgumentException("mojo implementation should be declared");
         }
 
         ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
         if (project != null) {
             List<String> classPathStrings;
             try {
                 classPathStrings = project.getCompileClasspathElements();
                 if (project.getExecutionProject() != null) {
                     classPathStrings.addAll(project.getExecutionProject().getCompileClasspathElements());
                 }
             } catch (DependencyResolutionRequiredException e) {
                 throw new IllegalArgumentException(e);
             }
 
             List<URL> urls = new ArrayList<>(classPathStrings.size());
             for (String classPathString : classPathStrings) {
                 try {
                     urls.add(new File(classPathString).toURL());
                 } catch (MalformedURLException e) {
                     throw new IllegalArgumentException(e);
                 }
             }
 
             classLoader = new URLClassLoader(urls.toArray(new URL[urls.size()]), classLoader);
         }
 
         try {
             Class<?> clazz = Class.forName(impl, false, classLoader);
 
             return MavenReport.class.isAssignableFrom(clazz);
         } catch (ClassNotFoundException e) {
             return false;
         }
     }
 }