<?php

/*

 * This file is part of Twig.

 *

 * (c) 2010 Fabien Potencier

 * (c) 2010 Arnaud Le Blanc

 *

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

 * file that was distributed with this source code.

 */

/**

 * Default implementation of a token parser broker.

 *

 * @package twig

 * @author  Arnaud Le Blanc <arnaud.lb@gmail.com>

 */

class Twig_TokenParserBroker implements Twig_TokenParserBrokerInterface

{

    protected $parser;

    protected $parsers = array();

    protected $brokers = array();

    /**

     * Constructor.

     *

     * @param array|Traversable $parsers A Traversable of Twig_TokenParserInterface instances

     * @param array|Traversable $brokers A Traversable of Twig_TokenParserBrokerInterface instances

     */

    public function __construct($parsers = array(), $brokers = array())

    {

        foreach ($parsers as $parser) {

            if (!$parser instanceof Twig_TokenParserInterface) {

                throw new Twig_Error('$parsers must a an array of Twig_TokenParserInterface');

            }

            $this->parsers[$parser->getTag()] = $parser;

        }

        foreach ($brokers as $broker) {

            if (!$broker instanceof Twig_TokenParserBrokerInterface) {

                throw new Twig_Error('$brokers must a an array of Twig_TokenParserBrokerInterface');

            }

            $this->brokers[] = $broker;

        }

    }

    /**

     * Adds a TokenParser.

     *

     * @param Twig_TokenParserInterface $parser A Twig_TokenParserInterface instance

     */

    public function addTokenParser(Twig_TokenParserInterface $parser)

    {

        $this->parsers[$parser->getTag()] = $parser;

    }

    /**

     * Adds a TokenParserBroker.

     *

     * @param Twig_TokenParserBroker $broker A Twig_TokenParserBroker instance

     */

    public function addTokenParserBroker(Twig_TokenParserBroker $broker)

    {

        $this->brokers[] = $broker;

    }

    /**

     * Gets a suitable TokenParser for a tag.

     *

     * First looks in parsers, then in brokers.

     *

     * @param string $tag A tag name

     *

     * @return null|Twig_TokenParserInterface A Twig_TokenParserInterface or null if no suitable TokenParser was found

     */

    public function getTokenParser($tag)

    {

        if (isset($this->parsers[$tag])) {

            return $this->parsers[$tag];

        }

        $broker = end($this->brokers);

        while (false !== $broker) {

            $parser = $broker->getTokenParser($tag);

            if (null !== $parser) {

                return $parser;

            }

            $broker = prev($this->brokers);

        }

        return null;

    }

    public function getParser()

    {

        return $this->parser;

    }

    public function setParser(Twig_ParserInterface $parser)

    {

        $this->parser = $parser;

        foreach ($this->parsers as $tokenParser) {

            $tokenParser->setParser($parser);

        }

        foreach ($this->brokers as $broker) {

            $broker->setParser($parser);

        }

    }

}