<?php

/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Symfony\Component\DependencyInjection\Compiler;

/**

 * This is a directed graph of your services.

 *

 * This information can be used by your compiler passes instead of collecting

 * it themselves which improves performance quite a lot.

 *

 * @author Johannes M. Schmitt <schmittjoh@gmail.com>

 */

class ServiceReferenceGraph

{

    private $nodes;

    /**

     * Constructor.

     */

    public function __construct()

    {

        $this->nodes = array();

    }

    /**

     * Checks if the graph has a specific node.

     *

     * @param string $id Id to check

     */

    public function hasNode($id)

    {

        return isset($this->nodes[$id]);

    }

    /**

     * Gets a node by identifier.

     *

     * @param string $id The id to retrieve

     * @return ServiceReferenceGraphNode The node matching the supplied identifier

     * @throws \InvalidArgumentException

     */

    public function getNode($id)

    {

        if (!isset($this->nodes[$id])) {

            throw new \InvalidArgumentException(sprintf('There is no node with id "%s".', $id));

        }

        return $this->nodes[$id];

    }

    /**

     * Returns all nodes.

     *

     * @return array An array of all ServiceReferenceGraphNode objects

     */

    public function getNodes()

    {

        return $this->nodes;

    }

    /**

     * Clears all nodes.

     */

    public function clear()

    {

        $this->nodes = array();

    }

    /**

     * Connects 2 nodes together in the Graph.

     *

     * @param string $sourceId

     * @param string $sourceValue

     * @param string $destId

     * @param string $destValue

     * @param string $reference

     */

    public function connect($sourceId, $sourceValue, $destId, $destValue = null, $reference = null)

    {

        $sourceNode = $this->createNode($sourceId, $sourceValue);

        $destNode = $this->createNode($destId, $destValue);

        $edge = new ServiceReferenceGraphEdge($sourceNode, $destNode, $reference);

        $sourceNode->addOutEdge($edge);

        $destNode->addInEdge($edge);

    }

    /**

     * Creates a graph node.

     *

     * @param string $id

     * @param string $value

     * @return ServiceReferenceGraphNode

     */

    private function createNode($id, $value)

    {

        if (isset($this->nodes[$id]) && $this->nodes[$id]->getValue() === $value) {

            return $this->nodes[$id];

        }

        return $this->nodes[$id] = new ServiceReferenceGraphNode($id, $value);

    }

}