/**
 * Licensed to Neo Technology under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Neo Technology 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.neo4j.examples.server.plugins;

import org.neo4j.graphalgo.GraphAlgoFactory;
import org.neo4j.graphalgo.PathFinder;
import org.neo4j.graphdb.DynamicRelationshipType;
import org.neo4j.graphdb.Expander;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Path;
import org.neo4j.kernel.Traversal;
import org.neo4j.server.plugins.Description;
import org.neo4j.server.plugins.Parameter;
import org.neo4j.server.plugins.PluginTarget;
import org.neo4j.server.plugins.ServerPlugin;
import org.neo4j.server.plugins.Source;

public class ShortestPath extends ServerPlugin
{
    @Description( "Find the shortest path between two nodes." )
    @PluginTarget( Node.class )
    public Iterable<Path> shortestPath(
            @Source Node source,
            @Description( "The node to find the shortest path to." ) @Parameter( name = "target" ) Node target,
            @Description( "The relationship types to follow when searching for the shortest path(s). Order is insignificant, if omitted all types are followed." ) @Parameter( name = "types", optional = true ) String[] types,
            @Description( "The maximum path length to search for, default value (if omitted) is 4." ) @Parameter( name = "depth", optional = true ) Integer depth )
    {
        Expander expander;
        if ( types == null )
        {
            expander = Traversal.expanderForAllTypes();
        }
        else
        {
            expander = Traversal.emptyExpander();
            for ( int i = 0; i < types.length; i++ )
            {
                expander = expander.add( DynamicRelationshipType.withName( types[i] ) );
            }
        }
        PathFinder<Path> shortestPath = GraphAlgoFactory.shortestPath( expander, depth == null ? 4
                : depth.intValue() );
        return shortestPath.findAllPaths( source, target );
    }
}
