<?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;

use Symfony\Component\DependencyInjection\Alias;

use Symfony\Component\DependencyInjection\Reference;

use Symfony\Component\DependencyInjection\Definition;

use Symfony\Component\DependencyInjection\ContainerBuilder;

/**

 * Removes unused service definitions from the container.

 *

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

 */

class RemoveUnusedDefinitionsPass implements RepeatablePassInterface

{

    private $repeatedPass;

    /**

     * {@inheritDoc}

     */

    public function setRepeatedPass(RepeatedPass $repeatedPass)

    {

        $this->repeatedPass = $repeatedPass;

    }

    /**

     * Processes the ContainerBuilder to remove unused definitions.

     *

     * @param ContainerBuilder $container

     * @return void

     */

    public function process(ContainerBuilder $container)

    {

        $compiler = $container->getCompiler();

        $formatter = $compiler->getLoggingFormatter();

        $graph = $compiler->getServiceReferenceGraph();

        $hasChanged = false;

        foreach ($container->getDefinitions() as $id => $definition) {

            if ($definition->isPublic()) {

                continue;

            }

            if ($graph->hasNode($id)) {

                $edges = $graph->getNode($id)->getInEdges();

                $referencingAliases = array();

                $sourceIds = array();

                foreach ($edges as $edge) {

                    $node = $edge->getSourceNode();

                    $sourceIds[] = $node->getId();

                    if ($node->isAlias()) {

                        $referencingAlias[] = $node->getValue();

                    }

                }

                $isReferenced = (count(array_unique($sourceIds)) - count($referencingAliases)) > 0;

            } else {

                $referencingAliases = array();

                $isReferenced = false;

            }

            if (1 === count($referencingAliases) && false === $isReferenced) {

                $container->setDefinition((string) reset($referencingAliases), $definition);

                $definition->setPublic(true);

                $container->removeDefinition($id);

                $compiler->addLogMessage($formatter->formatRemoveService($this, $id, 'replaces alias '.reset($referencingAliases)));

            } else if (0 === count($referencingAliases) && false === $isReferenced) {

                $container->removeDefinition($id);

                $compiler->addLogMessage($formatter->formatRemoveService($this, $id, 'unused'));

                $hasChanged = true;

            }

        }

        if ($hasChanged) {

            $this->repeatedPass->setRepeat();

        }

    }

}