<?php

/*

 * This file is part of the Assetic package, an OpenSky project.

 *

 * (c) 2010-2011 OpenSky Project Inc

 *

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

 * file that was distributed with this source code.

 */

namespace Assetic\Factory\Loader;

use Assetic\Factory\AssetFactory;

use Assetic\Factory\Resource\ResourceInterface;

/**

 * Loads asset formulae from PHP files.

 *

 * @author Kris Wallsmith <kris.wallsmith@gmail.com>

 */

abstract class BasePhpFormulaLoader implements FormulaLoaderInterface

{

    protected $factory;

    protected $prototypes;

    public function __construct(AssetFactory $factory)

    {

        $this->factory = $factory;

        $this->prototypes = array();

        foreach ($this->registerPrototypes() as $prototype => $options) {

            $this->addPrototype($prototype, $options);

        }

    }

    public function addPrototype($prototype, array $options = array())

    {

        $tokens = token_get_all('<?php '.$prototype);

        array_shift($tokens);

        $this->prototypes[$prototype] = array($tokens, $options);

    }

    public function load(ResourceInterface $resource)

    {

        if (!$nbProtos = count($this->prototypes)) {

            throw new \LogicException('There are no prototypes registered.');

        }

        $buffers = array_fill(0, $nbProtos, '');

        $bufferLevels = array_fill(0, $nbProtos, 0);

        $buffersInWildcard = array();

        $tokens = token_get_all($resource->getContent());

        $calls = array();

        while ($token = array_shift($tokens)) {

            $current = self::tokenToString($token);

            // loop through each prototype (by reference)

            foreach (array_keys($this->prototypes) as $i) {

                $prototype =& $this->prototypes[$i][0];

                $options = $this->prototypes[$i][1];

                $buffer =& $buffers[$i];

                $level =& $bufferLevels[$i];

                if (isset($buffersInWildcard[$i])) {

                    switch ($current) {

                        case '(': ++$level; break;

                        case ')': --$level; break;

                    }

                    $buffer .= $current;

                    if (!$level) {

                        $calls[] = array($buffer.';', $options);

                        $buffer = '';

                        unset($buffersInWildcard[$i]);

                    }

                } elseif ($current == self::tokenToString(current($prototype))) {

                    $buffer .= $current;

                    if ('*' == self::tokenToString(next($prototype))) {

                        $buffersInWildcard[$i] = true;

                        ++$level;

                    }

                } else {

                    reset($prototype);

                    unset($buffersInWildcard[$i]);

                    $buffer = '';

                }

            }

        }

        $formulae = array();

        foreach ($calls as $call) {

            $formulae += call_user_func_array(array($this, 'processCall'), $call);

        }

        return $formulae;

    }

    private function processCall($call, array $protoOptions = array())

    {

        $tmp = tempnam(sys_get_temp_dir(), 'assetic');

        file_put_contents($tmp, implode("\n", array(

            '<?php',

            $this->registerSetupCode(),

            $call,

            'echo serialize($_call);',

        )));

        $args = unserialize(shell_exec('php '.escapeshellarg($tmp)));

        unlink($tmp);

        $inputs  = isset($args[0]) ? self::argumentToArray($args[0]) : array();

        $filters = isset($args[1]) ? self::argumentToArray($args[1]) : array();

        $options = isset($args[2]) ? $args[2] : array();

        if (!isset($options['debug'])) {

            $options['debug'] = $this->factory->isDebug();

        }

        if (!is_array($options)) {

            throw new \RuntimeException('The third argument must be omitted, null or an array.');

        }

        // apply the prototype options

        $options += $protoOptions;

        if (!isset($options['name'])) {

            $options['name'] = $this->factory->generateAssetName($inputs, $filters, $options);

        }

        return array($options['name'] => array($inputs, $filters, $options));

    }

    /**

     * Returns an array of prototypical calls and options.

     *

     * @return array Prototypes and options

     */

    abstract protected function registerPrototypes();

    /**

     * Returns setup code for the reflection scriptlet.

     *

     * @return string Some PHP setup code

     */

    abstract protected function registerSetupCode();

    static protected function tokenToString($token)

    {

        return is_array($token) ? $token[1] : $token;

    }

    static protected function argumentToArray($argument)

    {

        return is_array($argument) ? $argument : array_filter(array_map('trim', explode(',', $argument)));

    }

}