//
//  ========================================================================
//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.deploy.graph;

import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

public class Path
{
    private final List<Edge> _edges = new CopyOnWriteArrayList<Edge>();
    private final List<Node> _nodes = new CopyOnWriteArrayList<Node>();

    public Path()
    {
    }

    public void add(Edge edge)
    {
        _edges.add(edge);
        if (_nodes.size() == 0)
        {
            _nodes.add(edge.getFrom());
        }
        else
        {
            assert _nodes.get(_nodes.size() - 1).equals(edge.getFrom());
        }
        _nodes.add(edge.getTo());
    }

    public Path forkPath()
    {
        Path ep = new Path();
        for (Edge edge : _edges)
        {
            ep.add(edge);
        }
        return ep;
    }

    public List<Node> getNodes()
    {
        return _nodes;
    }

    public List<Node> getEdges()
    {
        return _nodes;
    }

    public Node getNode(int index)
    {
        return _nodes.get(index);
    }

    public Node firstNode()
    {
        if (_nodes.size() == 0)
        {
            return null;
        }
        return _nodes.get(0);
    }

    public Node lastNode()
    {
        if (_nodes.size() == 0)
        {
            return null;
        }
        return _nodes.get(_nodes.size() - 1);
    }

    public int nodes()
    {
        return _nodes.size();
    }

    public int edges()
    {
        return _edges.size();
    }

    public boolean isEmpty()
    {
        return _edges.isEmpty();
    }

    public Edge firstEdge()
    {
        if (_edges.size() == 0)
        {
            return null;
        }
        return _edges.get(0);
    }

    public Edge lastEdge()
    {
        if (_edges.size() == 0)
        {
            return null;
        }
        return _edges.get(_edges.size() - 1);
    }

    public Edge getEdge(int index)
    {
        return _edges.get(index);
    }

    @Override
    public String toString()
    {
        return super.toString() + _nodes.toString();
    }
}
