/*

  * Copyright 2007-2013 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.exceptions.report.utils;

 import static de.smartics.exceptions.report.utils.StringFunction.indexOfFirstWhiteSpace;

 import java.util.ArrayList;

 import java.util.Iterator;

 import java.util.List;

 import org.apache.commons.lang.StringUtils;

 import com.thoughtworks.qdox.model.DocletTag;

 import com.thoughtworks.qdox.model.JavaAnnotatedElement;

 import com.thoughtworks.qdox.model.impl.DefaultDocletTag;

 import de.smartics.util.lang.Arg;

 /**

  * Parses the Javadoc body and returns the tags and text fragments as an

  * iterator.

  */

 public final class InlineJavadocTags implements Iterable<DocletTag>

 {

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

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

   /**

    * The identifier of doclets that only contain text.

    */

   public static final String TEXT_DOCLET_NAME = "{text}";

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

   /**

    * The annotated element whose Javadoc comment is to be parsed.

    */

   private final JavaAnnotatedElement element;

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

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

   /**

    * Default constructor.

    *

    * @param element the annotated element whose Javadoc comment is to be parsed.

    * @throws NullPointerException if {@code element} is <code>null</code>.

    */

   public InlineJavadocTags(final JavaAnnotatedElement element)

     throws NullPointerException

   {

     this.element = Arg.checkNotNull("element", element);

   }

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

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

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

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

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

   // CHECKSTYLE:OFF

   /**

    * Parses the Javadoc body and returns the tags and text fragments as an

    * iterator.

    *

    * @return the iterator over doclet tags and javadoc text.

    */

   @Override

   public Iterator<DocletTag> iterator()

   {

     final List<DocletTag> tags = new ArrayList<DocletTag>();

     final String comment = element.getComment();

     if (StringUtils.isBlank(comment))

     {

       return tags.iterator();

     }

     final int length = comment.length();

     final char[] commentArray = comment.toCharArray();

     final StringBuilder buffer = new StringBuilder(512);

     boolean inText = true;

     int lineNumber = 0;

     for (int i = 0; i < length; i++)

     {

       final char c = commentArray[i];

       if (inText)

       {

         if (c == '{')

         {

           if (commentArray[i + 1] == '@')

           {

             if (buffer.length() > 0)

             {

               final DocletTag textTag =

                   createTextTag(inText, buffer, lineNumber);

               tags.add(textTag);

               buffer.setLength(0);

             }

             i++;

             inText = false;

           }

           else

           {

             buffer.append(c);

           }

         }

         else

         {

           buffer.append(c);

         }

       }

       else

       {

         if (c == '}')

         {

           final DocletTag tag = createTag(buffer, lineNumber);

           tags.add(tag);

           buffer.setLength(0);

           inText = true;

         }

         else

         {

           buffer.append(c);

         }

       }

       if (c == '\n')

       {

         lineNumber++;

       }

     }

     if (buffer.length() > 0)

     {

       final DocletTag textTag = createTextTag(inText, buffer, lineNumber);

       tags.add(textTag);

     }

     return tags.iterator();

   }

   // CHECKSTYLE:ON

   private DocletTag createTextTag(final boolean inText,

       final StringBuilder buffer, final int lineNumber)

   {

     final String string = buffer.toString();

     final String value = inText ? string : "{@" + string;

     final DefaultDocletTag tag =

         new DefaultDocletTag(TEXT_DOCLET_NAME, value, element, lineNumber);

     return tag;

   }

   private DocletTag createTag(final StringBuilder buffer, final int lineNumber)

   {

     final int firstBlank = indexOfFirstWhiteSpace(buffer);

     final String name =

         firstBlank == -1 ? buffer.toString() : buffer

             .subSequence(0, firstBlank).toString();

     final String value =

         firstBlank != -1 && firstBlank + 1 < buffer.length() ? buffer

             .substring(firstBlank + 1).trim() : StringUtils.EMPTY;

     final DefaultDocletTag tag =

         new DefaultDocletTag(name, value, element, lineNumber);

     return tag;

   }

   /**

    * Checks if the given tag is a simple text element.

    *

    * @param tag the tag to test.

    * @return <code>true</code> if the tag is only a text, <code>false</code> if

    *         it is a doclet tag.

    * @throws NullPointerException if {@code tag} is <code>null</code>.

    */

   public static boolean isText(final DocletTag tag) throws NullPointerException

   {

     return TEXT_DOCLET_NAME.equals(tag.getName());

   }

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

 }