package org.apache.maven.doxia.site.decoration.inheritance;
   
   /*
    * 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.
   */
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.maven.doxia.site.decoration.Banner;
  import org.apache.maven.doxia.site.decoration.Body;
  import org.apache.maven.doxia.site.decoration.DecorationModel;
  import org.apache.maven.doxia.site.decoration.LinkItem;
  import org.apache.maven.doxia.site.decoration.Logo;
  import org.apache.maven.doxia.site.decoration.Menu;
  import org.apache.maven.doxia.site.decoration.MenuItem;
  
  import org.codehaus.plexus.util.xml.Xpp3Dom;
  
  /**
   * Manage inheritance of the decoration model.
   *
   * @author <a href="mailto:brett@apache.org">Brett Porter</a>
   * @author <a href="mailto:henning@apache.org">Henning P. Schmiedehausen</a>
   * @version $Id: DefaultDecorationModelInheritanceAssembler.java 1092010 2011-04-14 05:43:45Z ltheussl $
   * @plexus.component role="org.apache.maven.doxia.site.decoration.inheritance.DecorationModelInheritanceAssembler"
   */
  public class DefaultDecorationModelInheritanceAssembler
      implements DecorationModelInheritanceAssembler
  {
      /** {@inheritDoc} */
      public void assembleModelInheritance( String name, DecorationModel child, DecorationModel parent,
                                            String childBaseUrl, String parentBaseUrl )
      {
          // cannot inherit from null parent.
          if ( parent == null )
          {
              return;
          }
  
          URLContainer urlContainer = new URLContainer( parentBaseUrl, childBaseUrl );
  
          if ( child.getBannerLeft() == null && parent.getBannerLeft() != null )
          {
              child.setBannerLeft( parent.getBannerLeft().clone());
              rebaseBannerPaths( child.getBannerLeft(), urlContainer );
          }
  
          if ( child.getBannerRight() == null && parent.getBannerRight() != null)
          {
              child.setBannerRight( parent.getBannerRight().clone());
              rebaseBannerPaths( child.getBannerRight(), urlContainer );
          }
  
          if ( child.getPublishDate() == null && parent.getPublishDate() != null )
          {
              child.setPublishDate( parent.getPublishDate().clone());
          }
  
          if ( child.getVersion() == null && parent.getVersion() != null )
          {
              child.setVersion( parent.getVersion().clone());
          }
  
          if ( child.getSkin() == null && parent.getSkin() != null )
          {
              child.setSkin( parent.getSkin().clone());
          }
  
          child.setPoweredBy( mergePoweredByLists( child.getPoweredBy(), parent.getPoweredBy(), urlContainer ) );
  
          if ( parent.getLastModified() > child.getLastModified() )
          {
              child.setLastModified( parent.getLastModified() );
          }
  
          assembleBodyInheritance( name, child, parent, urlContainer );
  
          assembleCustomInheritance( child, parent );
      }
  
      /** {@inheritDoc} */
      public void resolvePaths( final DecorationModel decoration, final String baseUrl )
      {
         if ( baseUrl == null )
         {
             return;
         }
 
         if ( decoration.getBannerLeft() != null )
         {
             relativizeBannerPaths( decoration.getBannerLeft(), baseUrl );
         }
 
         if ( decoration.getBannerRight() != null )
         {
             relativizeBannerPaths( decoration.getBannerRight(), baseUrl );
         }
 
         for ( Logo logo : decoration.getPoweredBy() )
         {
             relativizeLogoPaths( logo, baseUrl );
         }
 
         if ( decoration.getBody() != null )
         {
             for ( LinkItem linkItem : decoration.getBody().getLinks() )
             {
                 relativizeLinkItemPaths( linkItem, baseUrl );
             }
 
             for ( LinkItem linkItem : decoration.getBody().getBreadcrumbs() )
             {
                 relativizeLinkItemPaths( linkItem, baseUrl );
             }
 
             for ( Menu menu : decoration.getBody().getMenus() )
             {
                 relativizeMenuPaths( menu.getItems(), baseUrl );
             }
         }
     }
 
     /**
      * Resolves all relative paths between the elements in a banner. The banner element might contain relative paths
      * to the oldBaseUrl, these are changed to the newBannerUrl.
      *
      * @param banner
      * @param baseUrl
      */
     private void relativizeBannerPaths( final Banner banner, final String baseUrl )
     {
         // banner has been checked to be not null, both href and src may be empty or null
         banner.setHref( relativizeLink( banner.getHref(), baseUrl ) );
         banner.setSrc( relativizeLink( banner.getSrc(), baseUrl ) );
     }
 
     private void rebaseBannerPaths( final Banner banner, final URLContainer urlContainer )
     {
         if ( banner.getHref() != null ) // it may be empty
         {
             banner.setHref( rebaseLink( banner.getHref(), urlContainer ) );
         }
 
         if ( banner.getSrc() != null )
         {
             banner.setSrc( rebaseLink( banner.getSrc(), urlContainer ) );
         }
     }
 
     private void assembleCustomInheritance( final DecorationModel child, final DecorationModel parent )
     {
         if ( child.getCustom() == null )
         {
             child.setCustom( parent.getCustom() );
         }
         else
         {
             child.setCustom( Xpp3Dom.mergeXpp3Dom( (Xpp3Dom) child.getCustom(), (Xpp3Dom) parent.getCustom() ) );
         }
     }
 
     private void assembleBodyInheritance( final String name, final DecorationModel child, final DecorationModel parent,
                                           final URLContainer urlContainer )
     {
         Body cBody = child.getBody();
         Body pBody = parent.getBody();
 
         if ( cBody != null || pBody != null )
         {
             if ( cBody == null )
             {
                 cBody = new Body();
                 child.setBody( cBody );
             }
 
             if ( pBody == null )
             {
                 pBody = new Body();
             }
 
             if ( cBody.getHead() == null )
             {
                 cBody.setHead( pBody.getHead() );
             }
             else
             {
                 cBody.setHead( Xpp3Dom.mergeXpp3Dom( (Xpp3Dom) cBody.getHead(), (Xpp3Dom) pBody.getHead() ) );
             }
 
             cBody.setLinks( mergeLinkItemLists( cBody.getLinks(), pBody.getLinks(), urlContainer ) );
 
             if ( cBody.getBreadcrumbs().isEmpty() && !pBody.getBreadcrumbs().isEmpty() )
             {
                 LinkItem breadcrumb = new LinkItem();
                 breadcrumb.setName( name );
                 breadcrumb.setHref( "" );
                 cBody.getBreadcrumbs().add( breadcrumb );
             }
             cBody.setBreadcrumbs( mergeLinkItemLists( cBody.getBreadcrumbs(), pBody.getBreadcrumbs(), urlContainer ) );
 
             cBody.setMenus( mergeMenus( cBody.getMenus(), pBody.getMenus(), urlContainer ) );
         }
     }
 
     private List<Menu> mergeMenus( final List<Menu> childMenus, final List<Menu> parentMenus,
                                    final URLContainer urlContainer )
     {
         List<Menu> menus = new ArrayList<Menu>( childMenus.size() + parentMenus.size() );
 
         for ( Menu menu : childMenus )
         {
             menus.add( menu );
         }
 
         int topCounter = 0;
         for ( Menu menu : parentMenus )
         {
             if ( "top".equals( menu.getInherit() ) )
             {
                 final Menu clone = menu.clone();
 
                 rebaseMenuPaths( clone.getItems(), urlContainer );
 
                 menus.add( topCounter, clone );
                 topCounter++;
             }
             else if ( "bottom".equals( menu.getInherit() ) )
             {
                 final Menu clone = menu.clone();
 
                 rebaseMenuPaths( clone.getItems(), urlContainer );
 
                 menus.add( clone );
             }
         }
 
         return menus;
     }
 
     private void relativizeMenuPaths( final List<MenuItem> items, final String baseUrl )
     {
         for ( MenuItem item : items )
         {
             relativizeLinkItemPaths( item, baseUrl );
             relativizeMenuPaths( item.getItems(), baseUrl );
         }
     }
 
     private void rebaseMenuPaths( final List<MenuItem> items, final URLContainer urlContainer )
     {
         for ( MenuItem item : items )
         {
             rebaseLinkItemPaths( item, urlContainer );
             rebaseMenuPaths( item.getItems(), urlContainer );
         }
     }
 
     private void relativizeLinkItemPaths( final LinkItem item, final String baseUrl )
     {
         item.setHref( relativizeLink( item.getHref(), baseUrl ) );
     }
 
     private void rebaseLinkItemPaths( final LinkItem item, final URLContainer urlContainer )
     {
         item.setHref( rebaseLink( item.getHref(), urlContainer ) );
     }
 
     private void relativizeLogoPaths( final Logo logo, final String baseUrl )
     {
         logo.setImg( relativizeLink( logo.getImg(), baseUrl ) );
         relativizeLinkItemPaths( logo, baseUrl );
     }
 
     private void rebaseLogoPaths( final Logo logo, final URLContainer urlContainer )
     {
         logo.setImg( rebaseLink( logo.getImg(), urlContainer ) );
         rebaseLinkItemPaths( logo, urlContainer );
     }
 
     private List<LinkItem> mergeLinkItemLists( final List<LinkItem> childList, final List<LinkItem> parentList,
                                                final URLContainer urlContainer )
     {
         List<LinkItem> items = new ArrayList<LinkItem>( childList.size() + parentList.size() );
 
         for ( LinkItem item : parentList )
         {
             if ( !items.contains( item ) )
             {
                 final LinkItem clone = item.clone();
 
                 rebaseLinkItemPaths( clone, urlContainer );
 
                 items.add( clone );
             }
         }
 
         for ( LinkItem item : childList )
         {
             if ( !items.contains( item ) )
             {
                 items.add( item );
             }
         }
 
         return items;
     }
 
     private List<Logo> mergePoweredByLists( final List<Logo> childList, final List<Logo> parentList,
                                             final URLContainer urlContainer )
     {
         List<Logo> logos = new ArrayList<Logo>( childList.size() + parentList.size() );
 
         for ( Logo logo : parentList )
         {
             if ( !logos.contains( logo ) )
             {
                 final Logo clone = logo.clone();
 
                 rebaseLogoPaths( clone, urlContainer );
 
                 logos.add( clone );
             }
         }
 
         for ( Logo logo : childList )
         {
             if ( !logos.contains( logo ) )
             {
                 logos.add( logo );
             }
         }
 
         return logos;
     }
 
     // rebase only affects relative links, a relative link wrt an old base gets translated,
     // so it points to the same location as viewed from a new base
     private String rebaseLink( final String link, final URLContainer urlContainer )
     {
         if ( link == null || urlContainer.getOldPath() == null )
         {
             return link;
         }
 
         final URIPathDescriptor oldPath = new URIPathDescriptor( urlContainer.getOldPath(), link );
 
         return oldPath.rebaseLink( urlContainer.getNewPath() ).toString();
     }
 
     // relativize only affects absolute links, if the link has the same scheme, host and port
     // as the base, it is made into a relative link as viewed from the base
     private String relativizeLink( final String link, final String baseUri )
     {
         if ( link == null || baseUri == null )
         {
             return link;
         }
 
         // this shouldn't be necessary, just to swallow mal-formed hrefs
         try
         {
             final URIPathDescriptor path = new URIPathDescriptor( baseUri, link );
 
             return path.relativizeLink().toString();
         }
         catch ( IllegalArgumentException e )
         {
             return link;
         }
     }
 
     /**
      * Contains an old and a new path.
      */
     public final class URLContainer
     {
 
         private final String oldPath;
 
         private final String newPath;
 
         /**
          * Construct a URLContainer.
          *
          * @param oldPath the old path.
          * @param newPath the new path.
          */
         public URLContainer( final String oldPath, final String newPath )
         {
             this.oldPath = oldPath;
             this.newPath = newPath;
         }
 
         /**
          * Get the new path.
          *
          * @return the new path.
          */
         public String getNewPath()
         {
             return this.newPath;
         }
 
         /**
          * Get the old path.
          *
          * @return the old path.
          */
         public String getOldPath()
         {
             return this.oldPath;
         }
     }
 }