/*

  * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH

  *

  * 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 de.smartics.properties.api.core.util;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 import org.apache.commons.lang.StringUtils;

 /**

  * Utilities to normalize Javadoc comments.

  */

 public final class JavadocCommentHelper

 {

   // ********************************* Fields *********************************

   // --- constants ------------------------------------------------------------

   /**

    * The pattern matches inline Javadoc tags. In group 1 is the text that is to

    * be used and surrounded with {@link #prefix1} and {@link #suffix1}, if there

    * is no match for group 2. If group 2 is present, the text is to be used

    * without prefix/suffix 2.

    */

   private static final Pattern INLINE_PATTERN = Pattern.compile(

       "\\{@[\\w]+\\s*([#\\.\\w]+(\\([^)]*\\))?)\\s*([^}]+)?\\}", Pattern.MULTILINE);

   // --- members --------------------------------------------------------------

   /**

    * The prefix for group 1 match.

    */

   private final String prefix1;

   /**

    * The suffix for group 1 match.

    */

   private final String suffix1;

   /**

    * The prefix for group 2 match.

    */

   private final String prefix2;

   /**

    * The suffix for group 2 match.

    */

   private final String suffix2;

   // ****************************** Initializer *******************************

   // ****************************** Constructors ******************************

   /**

    * Default constructor.

    *

    * @param prefix1 the prefix for group 1 match.

    * @param suffix1 the suffix for group 1 match.

    * @param prefix2 the prefix for group 2 match.

    * @param suffix2 the suffix for group 2 match.

    */

   public JavadocCommentHelper(final String prefix1, final String suffix1,

       final String prefix2, final String suffix2)

   {

     this.prefix1 = prefix1;

     this.suffix1 = suffix1;

     this.prefix2 = prefix2;

     this.suffix2 = suffix2;

   }

   // ****************************** Inner Classes *****************************

   // ********************************* Methods ********************************

   // --- init -----------------------------------------------------------------

   // --- create ---------------------------------------------------------------

   /**

    * Creates a default helper for normalizing in an HTML context.

    *

    * @return the HTML version of the helper.

    */

   public static JavadocCommentHelper createHtml()

   {

     return new JavadocCommentHelper("<tt>", "</tt>", "<i>", "</i>");

   }

   /**

    * Creates a default helper for normalizing in text context.

    *

    * @return the text version of the helper.

    */

   public static JavadocCommentHelper createText()

   {

     return new JavadocCommentHelper("'", "'", "", "");

   }

   // --- get&set --------------------------------------------------------------

   // --- business -------------------------------------------------------------

   /**

    * Replaces Javadoc inline tags.

    *

    * @param fragment the fragment with inline tags.

    * @return the normalized fragment.

    */

   public String replaceJavadocInlines(final String fragment)

   {

     if (StringUtils.isBlank(fragment))

     {

       return fragment;

     }

     final StringBuffer buffer = new StringBuffer(fragment.length());

     final Matcher matcher = INLINE_PATTERN.matcher(fragment);

     while (matcher.find())

     {

       final String group2 = matcher.group(3);

       if (group2 != null)

       {

         final String replacement = prefix2 + group2 + suffix2;

         matcher.appendReplacement(buffer, replacement);

       }

       else

       {

         String group1 = matcher.group(1);

         if (group1.length() > 1 && group1.charAt(0) == '#')

         {

           group1 = group1.substring(1);

         }

         final String replacement = prefix1 + group1 + suffix1;

         matcher.appendReplacement(buffer, replacement);

       }

     }

     matcher.appendTail(buffer);

     return buffer.toString();

   }

   // --- object basics --------------------------------------------------------

 }