/*
    * 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.renderer.html;
  
  import static de.smartics.exceptions.report.utils.StringFunction.indexOfFirstWhiteSpace;
  import static de.smartics.exceptions.report.utils.StringFunction.indexOfSecondWhiteSpace;
  
  import org.apache.commons.lang.StringUtils;
  
  import com.thoughtworks.qdox.model.DocletTag;
  import com.thoughtworks.qdox.model.JavaAnnotatedElement;
  import com.thoughtworks.qdox.model.JavaClass;
  import com.thoughtworks.qdox.model.JavaField;
  
  /**
   * Base implementation that renders the see, link and linkplain tags as HTML.
   */
  public abstract class AbstractHtmlLinkTagRenderer
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The value of the flag is <code>true</code> if the text is written as is,
     * <code>false</code> if it should be rendered in code font.
     */
    private final boolean plain;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param plain the value of the flag is <code>true</code> if the text is
     *          written as is, <code>false</code> if it should be rendered in code
     *          font.
     */
    protected AbstractHtmlLinkTagRenderer(final boolean plain)
    {
      this.plain = plain;
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Renders the tag to the buffer.
     *
     * @param buffer the buffer to write to.
     * @param tag the tag to render.
     * @return a reference to the {@code buffer}.
     */
    public StringBuilder render(final StringBuilder buffer, final DocletTag tag)
    {
      final String label = getLabel(tag);
  
      final String linkTarget = calcLinkTarget(tag);
      if (StringUtils.isBlank(label))
      {
        renderIntro(buffer, linkTarget);
  
        final JavaClass classDoc = Utils.referencedClass(tag);
        if (classDoc != null)
        {
          buffer.append(classDoc.getName());
        }
        final String memberString = Utils.referencedMemberName(tag);
        if (StringUtils.isNotBlank(memberString))
        {
          if (classDoc != null && !tag.getValue().startsWith("#"))
          {
            buffer.append('.');
          }
          buffer.append(memberString);
       }
 
       renderExtro(buffer, linkTarget);
     }
     else
     {
       renderIntro(buffer, linkTarget);
       buffer.append(label);
       renderExtro(buffer, linkTarget);
     }
 
     return buffer;
   }
 
   private void renderIntro(final StringBuilder buffer, final String linkTarget)
   {
     if (!plain)
     {
       buffer.append("<code>");
     }
     if (linkTarget != null)
     {
       buffer.append("<a href=\"" + linkTarget + "\">");
     }
   }
 
   private void renderExtro(final StringBuilder buffer, final String linkTarget)
   {
     if (linkTarget != null)
     {
       buffer.append("</a>");
     }
     if (!plain)
     {
       buffer.append("</code>");
     }
   }
 
   private String calcLinkTarget(final DocletTag tag)
   {
     final String text = tag.getValue();
     final String linkTarget;
     final int length = text.length();
     if (length > 1 && text.startsWith("#")) // NOPMD
     {
       final JavaAnnotatedElement context = tag.getContext();
       if (context instanceof JavaField)
       {
         final JavaClass type = ((JavaField) context).getDeclaringClass();
         final String fqn = type.getFullyQualifiedName();
         final String id = getTarget(tag);
         linkTarget = "#" + fqn + '_' + id;
       }
       else
       {
         linkTarget = null;
       }
     }
     else if (length > 1 && text.contains("#"))
     {
       final JavaClass classDoc = Utils.referencedClass(tag);
       if (classDoc != null && classDoc.isA("de.smartics.exceptions.core.Code"))
       {
         final String id = Utils.referencedMemberName(tag);
         final String fqn = classDoc.getFullyQualifiedName();
         linkTarget = "#" + fqn + '_' + id;
       }
       else
       {
         linkTarget = null;
       }
     }
     else
     {
       linkTarget = null;
     }
     return linkTarget;
   }
 
   private String getTarget(final DocletTag tag)
   {
     final String value = tag.getValue();
 
     final int index = indexOfFirstWhiteSpace(value);
     final String target;
     if (index != -1 && index + 1 < value.length())
     {
       target = value.substring(0, index);
     }
     else
     {
       target = value;
     }
     final String normalized = StringUtils.remove(target, '#');
     return normalized;
   }
 
   private String getLabel(final DocletTag tag)
   {
     final String value = tag.getValue();
 
     final int index = indexOfSecondWhiteSpace(value);
     if (index != -1 && index + 1 < value.length())
     {
       final String label = value.substring(index + 1);
       return label;
     }
     return null;
   }
 
   // --- object basics --------------------------------------------------------
 
 }