/*
    * 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.jxr;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.Map;
  import java.util.TreeMap;
  
  import org.apache.maven.jxr.pacman.ClassType;
  import org.apache.maven.jxr.pacman.PackageManager;
  import org.apache.maven.jxr.pacman.PackageType;
  import org.apache.velocity.Template;
  import org.apache.velocity.VelocityContext;
  import org.apache.velocity.app.VelocityEngine;
  
  /**
   * This class creates the navigational pages for jxr's cross-referenced source
   * files. The navigation is inspired by javadoc, so it should have a familiar feel.
   *
   * Creates the following files:
   * <ul>
   * <li>{@code index.html}            main index containing the frameset</li>
   * <li>{@code overview-frame.html}   list of the project's packages              (top left)</li>
   * <li>{@code allclasses-frame.html} list of all classes in the project          (bottom left)</li>
   * <li>{@code overview-summary.html} top-level listing of the project's packages (main frame)</li>
   *
   * <li>
   * Package specific:
   * <ul>
   * <li>{@code package-summary.html} listing of all classes in this package    (main frame)</li>
   * <li>{@code package-frame.html}   listing of all classes in this package    (bottom left)</li>
   * </ul>
   * </li>
   * </ul>
   *
   * @author <a href="mailto:bellingard@gmail.com">Fabrice Bellingard </a>
   * @author <a href="mailto:brian@brainslug.org">Brian Leonard</a>
   */
  public class DirectoryIndexer {
      /*
       * JavaCodeTransform uses this to cross-reference package references
       * with that package's main summary page.
       */
      static final String INDEX = "package-summary.html";
  
      /*
       * Path to the root output directory.
       */
      private String root;
  
      /*
       * Package Manager for this project.
       */
      private PackageManager packageManager;
  
      /*
       * see the getter/setter docs for these properties
       */
      private String outputEncoding;
  
      private String templateDir;
  
      private String windowTitle;
  
      private String docTitle;
  
      private String bottom;
  
      /**
       * Constructor for the DirectoryIndexer object
       *
       * @param packageManager PackageManager for this project
       * @param root Path of the root output directory
       */
      public DirectoryIndexer(PackageManager packageManager, String root) {
          this.packageManager = packageManager;
          this.root = root;
      }
 
     /**
      * OutputEncoding is the encoding of output files.
      *
      * @param outputEncoding output encoding
      */
     public void setOutputEncoding(String outputEncoding) {
         this.outputEncoding = outputEncoding;
     }
 
     /**
      * Gets the output encoding.
      * @return output encoding
      */
     public String getOutputEncoding() {
         return outputEncoding;
     }
 
     /**
      * {@code templateDir} is the location of the jelly template files used
      * to generate the navigation pages.
      *
      * @param templateDir location of the template directory
      */
     public void setTemplateDir(String templateDir) {
         this.templateDir = templateDir;
     }
 
     /**
      * Gets the template directory.
      *
      * @return location of the template directory
      */
     public String getTemplateDir() {
         return templateDir;
     }
 
     /**
      * {@code windowTitle} is used in the output's &lt;title&gt; tags
      * see the javadoc documentation for the property of the same name
      *
      * @param windowTitle the &lt;title&gt; attribute
      */
     public void setWindowTitle(String windowTitle) {
         this.windowTitle = windowTitle;
     }
 
     /**
      * Gets the window title.
      *
      * @return window title
      */
     public String getWindowTitle() {
         return windowTitle;
     }
 
     /**
      * {@code docTitle} is used as a page heading for the summary files.<br>
      * See the javadoc documentation for the property of the same name
      *
      * @param docTitle major page heading
      */
     public void setDocTitle(String docTitle) {
         this.docTitle = docTitle;
     }
 
     /**
      * Gets the major page heading.
      *
      * @return major page heading
      */
     public String getDocTitle() {
         return docTitle;
     }
 
     /**
      * Bottom is a footer for the navigation pages, usually a copyright.<br>
      * See the javadoc documentation for the property of the same name.
      *
      * @param bottom page footer
      */
     public void setBottom(String bottom) {
         this.bottom = bottom;
     }
 
     /**
      * Gets the footer for the navigation pages.
      *
      * @return bottom page footer
      */
     public String getBottom() {
         return bottom;
     }
 
     /**
      * Does the actual indexing.
      *
      * @throws JxrException If something went wrong
      */
     public void process() throws JxrException {
         ProjectInfo info = getProjectInfo();
 
         VelocityEngine engine = new VelocityEngine();
         setProperties(engine);
         try {
             engine.init();
         } catch (Exception e) {
             throw new JxrException("Error initializing Velocity", e);
         }
 
         VelocityContext context = new VelocityContext();
         context.put("outputEncoding", getOutputEncoding());
         context.put("windowTitle", getWindowTitle());
         context.put("docTitle", getDocTitle());
         context.put("bottom", getBottom());
         context.put("info", info);
 
         doVelocity("index", root, context, engine);
         doVelocity("overview-frame", root, context, engine);
         doVelocity("allclasses-frame", root, context, engine);
         doVelocity("overview-summary", root, context, engine);
 
         for (PackageInfo pkgInfo : info.getAllPackages().values()) {
             VelocityContext subContext = new VelocityContext(context);
             subContext.put("pkgInfo", pkgInfo);
 
             String outDir = root + '/' + pkgInfo.getDir();
             doVelocity("package-summary", outDir, subContext, engine);
             doVelocity("package-frame", outDir, subContext, engine);
         }
     }
 
     /*
      * Sets Velocity properties to find templates.
      */
     private void setProperties(VelocityEngine engine) {
         Path templateDirFile = Paths.get(getTemplateDir());
         if (templateDirFile.isAbsolute()) {
             // the property has been overridden: need to use a FileResourceLoader
             engine.setProperty("resource.loaders", "file");
             engine.setProperty(
                     "resource.loader.file.class", "org.apache.velocity.runtime.resource.loader.FileResourceLoader");
             engine.setProperty("resource.loader.file.path", templateDirFile.toString());
         } else {
             // use of the default templates
             engine.setProperty("resource.loaders", "classpath");
             engine.setProperty(
                     "resource.loader.classpath.class",
                     "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
         }
     }
 
     /*
      * Generate the HTML file according to the Velocity template
      */
     private void doVelocity(String templateName, String outDir, VelocityContext context, VelocityEngine engine)
             throws JxrException {
         // output file
         File file = new File(outDir, templateName + ".html");
         file.getParentFile().mkdirs();
 
         try (Writer writer = new OutputStreamWriter(new FileOutputStream(file), getOutputEncoding())) {
             // template file
             StringBuilder templateFile = new StringBuilder();
             File templateDirFile = new File(getTemplateDir());
             if (!templateDirFile.isAbsolute()) {
                 // default templates
                 templateFile.append(getTemplateDir());
                 templateFile.append('/');
             }
             templateFile.append(templateName);
             templateFile.append(".vm");
             Template template = engine.getTemplate(templateFile.toString());
 
             // do the merge
             template.merge(context, writer);
             writer.flush();
         } catch (Exception e) {
             throw new JxrException("Error merging velocity template", e);
         }
     }
 
     /*
      * Creates a Map of other Maps containing information about
      * this project's packages and classes, obtained from the PackageManager.
      *
      * allPackages collection of Maps with package info, with the following format
      *   {name}    package name (e.g., "org.apache.maven.jxr")
      *   {dir}     package dir relative to the root output dir (e.g., "org/apache/maven/jxr")
      *   {rootRef} relative link to root output dir (e.g., "../../../../") note trailing slash
      *   {classes} collection of Maps with class info
      *      {name}  class name (e.g., "DirectoryIndexer")
      *      {dir}   duplicate of package {dir}
      *
      * allClasses collection of Maps with class info, format as above
      *
      */
     ProjectInfo getProjectInfo() {
         Map<String, PackageInfo> allPackages = new TreeMap<>();
         Map<String, ClassInfo> allClasses = new TreeMap<>();
 
         for (PackageType pkg : packageManager.getPackageTypes()) {
             String pkgName = pkg.getName();
             String pkgDir = pkgName.replace('.', '/');
             String rootRef = pkgName.replaceAll("[^\\.]+(\\.|$)", "../");
 
             // special case for the default package
             // javadoc doesn't deal with it, but it's easy for us
             if (pkgName.length() == 0) {
                 pkgName = "(default package)";
                 pkgDir = ".";
                 rootRef = "./";
             }
 
             Map<String, ClassInfo> pkgClasses = new TreeMap<>();
             for (ClassType clazz : pkg.getClassTypes()) {
                 String className = clazz.getName();
 
                 ClassInfo classInfo = new ClassInfo(className, pkgDir);
 
                 classInfo.setFilename(clazz.getFilename());
 
                 pkgClasses.put(className, classInfo);
 
                 // Adding package name to key in order to ensure classes with identical names in different packages are
                 // all included.
                 allClasses.put(className + "#" + pkgName, classInfo);
             }
 
             PackageInfo pkgInfo = new PackageInfo(pkgName, pkgDir);
             pkgInfo.setClasses(pkgClasses);
             pkgInfo.setRootRef(rootRef);
 
             allPackages.put(pkgName, pkgInfo);
         }
 
         return new ProjectInfo(allPackages, allClasses);
     }
 
     /**
      *
      * @author Robert Scholte
      * @since 3.2.0
      */
     public static class ProjectInfo {
         private final Map<String, PackageInfo> allPackages;
 
         private final Map<String, ClassInfo> allClasses;
 
         public ProjectInfo(Map<String, PackageInfo> allPackages, Map<String, ClassInfo> allClasses) {
             this.allPackages = allPackages;
             this.allClasses = allClasses;
         }
 
         public Map<String, PackageInfo> getAllPackages() {
             return allPackages;
         }
 
         public Map<String, ClassInfo> getAllClasses() {
             return allClasses;
         }
     }
 
     /**
      *
      * @author Robert Scholte
      * @since 3.2.0
      */
     public static class PackageInfo {
         private final String name;
 
         private final String dir;
 
         Map<String, ClassInfo> classes;
 
         private String rootRef;
 
         public PackageInfo(String name, String dir) {
             this.name = name;
             this.dir = dir;
         }
 
         public String getName() {
             return name;
         }
 
         public String getDir() {
             return dir;
         }
 
         public void setClasses(Map<String, ClassInfo> classes) {
             this.classes = classes;
         }
 
         public Map<String, ClassInfo> getClasses() {
             return classes;
         }
 
         public void setRootRef(String rootRef) {
             this.rootRef = rootRef;
         }
 
         public String getRootRef() {
             return rootRef;
         }
     }
 
     /**
      * Holds class information
      *
      * @author Robert Scholte
      * @since 3.2.0
      */
     public static class ClassInfo {
         private final String name;
 
         private final String dir;
 
         private String filename;
 
         public ClassInfo(String name, String dir) {
             super();
             this.name = name;
             this.dir = dir;
         }
 
         public String getName() {
             return name;
         }
 
         public String getDir() {
             return dir;
         }
 
         public void setFilename(String filename) {
             this.filename = filename;
         }
 
         public String getFilename() {
             return filename;
         }
     }
 }