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(root)/Frameworks and Technologies/Neo4J Samples/Neo4JTutorial/src/main/java/com/linkscreens/graphsin/repository/MediaItemNode.java @ 27

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package com.linkscreens.graphsin.repository;

import java.util.Collections;
import java.util.Date;

import org.neo4j.graphdb.Direction;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Path;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.traversal.TraversalDescription;
import org.neo4j.helpers.collection.IterableWrapper;

public class MediaItemNode {
        public static final String DESCRIPTION = "description";
        public static final String ID = "id";

        private final Node underlyingNode;
   
    public MediaItemNode( Node album) {
         this.underlyingNode = album;
        }
   
    private GraphDatabaseService graphDb()
    {
        return underlyingNode.getGraphDatabase();
    }
   
    protected Node getUnderlyingNode()
    {
        return underlyingNode;
    }
   
    public String getId(){
        return (String)underlyingNode.getProperty( ID );
    }
   
    public String getDescription()
    {
        return (String)underlyingNode.getProperty( DESCRIPTION );
    }
   
    @Override
    public int hashCode()
    {
        return underlyingNode.hashCode();
    }

    @Override
    public boolean equals( Object o )
    {
        return o instanceof MediaItemNode &&
                underlyingNode.equals( ( (MediaItemNode)o ).getUnderlyingNode() );
    }

    @Override
    public String toString()
    {
        return "MediaItem[" + getDescription() + "]";
    }
   
    //managing statuses
   
    private Node createNewCommentNode( String text )
    {
        Node com = graphDb().createNode();
        com.setProperty( StatusUpdateNode.TEXT, text );
        com.setProperty( StatusUpdateNode.DATE, new Date().getTime() );
        return com;
    }
   
    public Iterable<CommentNode> getComments()
    {
        Relationship firstStatus = underlyingNode.getSingleRelationship(
                        RelTypes.COMMENT, Direction.OUTGOING );
       
        if ( firstStatus == null )
        {
            return Collections.emptyList(); //don't have any comment
        }

        // START SNIPPET: getStatusTraversal
        TraversalDescription traversal = graphDb().traversalDescription()
                .depthFirst()
                .relationships( RelTypes.NEXT_COMMENT );
        // END SNIPPET: getStatusTraversal


        return new IterableWrapper<CommentNode, Path>(
                traversal.traverse( firstStatus.getEndNode() ) )
        {
            @Override
            protected CommentNode underlyingObjectToObject( Path path )
            {
                return new CommentNode( path.endNode() );
            }
        };
    }
   
    public void addStatus( String text )
    {
        CommentNode oldStatus;
        if ( getComments().iterator().hasNext() )
        {
            oldStatus = getComments().iterator().next();
        } else
        {
            oldStatus = null;
        }

        Node newStatus = createNewCommentNode( text );

        if ( oldStatus != null )
        {
            underlyingNode.getSingleRelationship( RelTypes.COMMENT, Direction.OUTGOING ).delete();
            newStatus.createRelationshipTo( oldStatus.getUnderlyingNode(), RelTypes.NEXT_COMMENT );
        }

        underlyingNode.createRelationshipTo( newStatus, RelTypes.COMMENT );
    }

   



}