/*
    * 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.jetspeed.layout.impl;
  
  import java.util.List;
  import java.util.ArrayList;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.jetspeed.components.portletregistry.PortletRegistry;
  import org.apache.jetspeed.layout.PortletPlacementException;
  import org.apache.jetspeed.om.page.Fragment;
  import org.apache.jetspeed.om.page.Page;
  /***
   * NestedFragmentContext
   * 
   * This object captures the nested position of a fragment
   * within a page. Given a target fragment and a page,
   * the target fragment col/row within its parent is
   * recorded, followed by the target fragment's parent
   * col/row within its parent, etc.
   * 
   * The purpose of this object is to support the
   * create-new-page-on-edit feature. For example, when
   * a fragment is moved, causing the creation of a new
   * page, the information captured by this object 
   * allows the copy of the fragment in the new page to
   * be located.
   * 
   * @author <a>Steve Milek</a>
   * @author <a href="mailto:smilek@apache.org">Steve Milek</a>
   * @version $Id: $
   */
  public class NestedFragmentContext
  {
      protected static final Log log = LogFactory.getLog( NestedFragmentContext.class );
      protected static final String eol = System.getProperty( "line.separator" );
  	
  	private Fragment targetFragment;
  	private Fragment rootFragment;
  	private Page page;
  	private List fragmentLevels;
  	
  	public NestedFragmentContext( Fragment targetFragment, Page page, PortletRegistry registry )
  	    throws PortletPlacementException
  	{
  		this.targetFragment = targetFragment;
  		this.page = page;
  		this.rootFragment = page.getRootFragment();
  		init( registry );
  	}
  	
  	protected void init( PortletRegistry registry )
  	    throws PortletPlacementException
  	{
  		List nestedFragmentLevels = new ArrayList();
  		Fragment nextTarget = targetFragment;
  		Fragment nextParent = null;
  		do
  		{
  			nextParent = NestedFragmentContext.getParentFragmentById( nextTarget.getId(), rootFragment );
  			if ( nextParent != null )
  			{
  				NestedFragmentLevel level = new NestedFragmentLevel( nextTarget, nextParent, registry );
  				nestedFragmentLevels.add( level );
  				
  				nextTarget = nextParent;
  			}
  			else
  			{
  				if ( ! nextTarget.getId().equals( rootFragment.getId() ) )
  				{
  					throw new PortletPlacementException( "Cannot determine complete nested structure for fragment " + targetFragment.getId() );
  				}
  				nextTarget = null;
  			}
  		}
  		while ( nextTarget != null );
  		this.fragmentLevels = nestedFragmentLevels;
  	}
  	
  	public Fragment getFragmentOnNewPage( Page newPage, PortletRegistry registry )
  	    throws PortletPlacementException
  	{
  		Fragment newPageRootFragment = newPage.getRootFragment();
 		
 		int depth = fragmentLevels.size();
 		
 		Fragment nextFragment = newPageRootFragment;
 		for ( int i = depth -1; i >= 0 ; i-- )
 		{
 			NestedFragmentLevel level = (NestedFragmentLevel)fragmentLevels.get(i);
 			PortletPlacementContextImpl placement = new PortletPlacementContextImpl( newPage, registry, nextFragment );
 			try
 			{
 				nextFragment = placement.getFragmentAtOldCoordinate( new CoordinateImpl( level.getChildCol(), level.getChildRow() ) );
 			
 			}
 			catch ( PortletPlacementException ppex )
 			{
 				log.error( "getFragmentOnNewPage failure to locate fragment on new page (index=" + i + ") :" + eol + this.toString() + ( placement != null ? ( eol + placement.dumpFragments(null) ) : "" ) + eol, ppex );
 				throw ppex;
 			}
 		    catch ( RuntimeException ex )
 			{
 				log.error( "getFragmentOnNewPage failure to locate fragment on new page (index=" + i + ") :" + eol + this.toString() + ( placement != null ? ( eol + placement.dumpFragments(null) ) : "" ) + eol, ex );
 				throw ex;
 			}	
 		    if ( nextFragment == null )
 			{
 				throw new PortletPlacementException( "Cannot locate copy of fragment " + targetFragment.getId() + " in the new page structure :" + eol + this.toString() + ( placement != null ? ( eol + placement.dumpFragments(null) ) : "" ));
 			}
 		}
 		return nextFragment;
 	}
 	
 	public String toString()
 	{
 		StringBuffer out = new StringBuffer();
 		int depth = fragmentLevels.size();
 		int ldepth = 0;
 		for ( int i = depth -1; i >= 0 ; i-- )
 		{
 			NestedFragmentLevel level = (NestedFragmentLevel)fragmentLevels.get(i);
 			if ( ldepth > 0 )
 			{
 				out.append( eol );
 				for ( int j = 0 ; j < ldepth ; j++ )
 					out.append( "   " );
 			}
 			ldepth++;
 			out.append( level.toString() );
 		}
 		return out.toString();
 	}
 	
 	class NestedFragmentLevel
 	{
 		private int childRow;
 		private int childCol;
 		private Fragment child;
 		private Fragment parent;
 		
 		NestedFragmentLevel( Fragment child, Fragment parent, PortletRegistry registry )
 		    throws PortletPlacementException
 		{
 			this.child = child;
 			this.parent = parent;
 			PortletPlacementContextImpl placement = new PortletPlacementContextImpl( page, registry, parent );
             this.childRow = placement.getFragmentRow( child );
             this.childCol = placement.getFragmentCol( child );
 		}
 		
 		protected int getChildRow()
 		{
 			return this.childRow;
 		}
 		protected int getChildCol()
 		{
 			return this.childCol;
 		}
 		protected Fragment getChild()
 		{
 			return this.child;
 		}
 		protected Fragment getParent()
 		{
 			return this.parent;
 		}
 		public String toString()
 		{
 			return child.getType() + " col=" + childCol + " row=" + childRow  + " id=" + child.getId() + " parent-id=" + parent.getId() ;
 		}
 	}
 	
 	public static Fragment getParentFragmentById( String id, Fragment parent )
     {   
         // find fragment by id, tracking fragment parent
         if ( id == null )
         {
         	return null;
         }
 		
 		Fragment matchedParent = null;
         if( parent != null ) 
         {
             // process the children
             List children = parent.getFragments();
             for( int i = 0, cSize = children.size() ; i < cSize ; i++) 
             {
                 Fragment childFrag = (Fragment)children.get( i );
                 if ( childFrag != null ) 
                 {
                     if ( id.equals( childFrag.getId() ) )
                     {
                         matchedParent = parent;
                         break;
                     }
                     else
                     {
                         matchedParent = NestedFragmentContext.getParentFragmentById( id, childFrag );
                         if ( matchedParent != null )
                         {
                             break;
                         }
                     }
                 }
             }
         }
         return matchedParent;
     }
 }