<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Crypt

 * @subpackage Math

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: BigInteger.php 23439 2010-11-23 21:10:14Z alexander $

 */

/**

 * Support for arbitrary precision mathematics in PHP.

 *

 * Zend_Crypt_Math_BigInteger is a wrapper across three PHP extensions: bcmath, gmp

 * and big_int. Since each offer similar functionality, but availability of

 * each differs across installations of PHP, this wrapper attempts to select

 * the fastest option available and encapsulate a subset of its functionality

 * which all extensions share in common.

 *

 * This class requires one of the three extensions to be available. BCMATH

 * while the slowest, is available by default under Windows, and under Unix

 * if PHP is compiled with the flag "--enable-bcmath". GMP requires the gmp

 * library from http://www.swox.com/gmp/ and PHP compiled with the "--with-gmp"

 * flag. BIG_INT support is available from a big_int PHP library available from

 * only from PECL (a Windows port is not available).

 *

 * @category   Zend

 * @package    Zend_Crypt

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Crypt_Math_BigInteger

{

    /**

     * Holds an instance of one of the three arbitrary precision wrappers.

     *

     * @var Zend_Crypt_Math_BigInteger_Interface

     */

    protected $_math = null;

    /**

     * Constructor; a Factory which detects a suitable PHP extension for

     * arbitrary precision math and instantiates the suitable wrapper

     * object.

     *

     * @param string $extension

     * @throws  Zend_Crypt_Math_BigInteger_Exception

     */

    public function __construct($extension = null)

    {

        if ($extension !== null && !in_array($extension, array('bcmath', 'gmp', 'bigint'))) {

            require_once('Zend/Crypt/Math/BigInteger/Exception.php');

            throw new Zend_Crypt_Math_BigInteger_Exception('Invalid extension type; please use one of bcmath, gmp or bigint');

        }

        $this->_loadAdapter($extension);

    }

    /**

     * Redirect all public method calls to the wrapped extension object.

     *

     * @param   string $methodName

     * @param   array $args

     * @throws  Zend_Crypt_Math_BigInteger_Exception

     */

    public function __call($methodName, $args)

    {

        if(!method_exists($this->_math, $methodName)) {

            require_once 'Zend/Crypt/Math/BigInteger/Exception.php';

            throw new Zend_Crypt_Math_BigInteger_Exception('invalid method call: ' . get_class($this->_math) . '::' . $methodName . '() does not exist');

        }

        return call_user_func_array(array($this->_math, $methodName), $args);

    }

    /**

     * @param string $extension

     * @throws  Zend_Crypt_Math_BigInteger_Exception

     */

    protected function _loadAdapter($extension = null)

    {

        if ($extension === null) {

            if (extension_loaded('gmp')) {

                $extension = 'gmp';

            //} elseif (extension_loaded('big_int')) {

            //    $extension = 'big_int';

            } else {

                $extension = 'bcmath';

            }

        }

        if($extension == 'gmp' && extension_loaded('gmp')) {

            require_once 'Zend/Crypt/Math/BigInteger/Gmp.php';

            $this->_math = new Zend_Crypt_Math_BigInteger_Gmp();

        //} elseif($extension == 'bigint' && extension_loaded('big_int')) {

        //    require_once 'Zend/Crypt_Math/BigInteger/Bigint.php';

        //    $this->_math = new Zend_Crypt_Math_BigInteger_Bigint();

        } elseif ($extension == 'bcmath' && extension_loaded('bcmath')) {

            require_once 'Zend/Crypt/Math/BigInteger/Bcmath.php';

            $this->_math = new Zend_Crypt_Math_BigInteger_Bcmath();

        } else {

            require_once 'Zend/Crypt/Math/BigInteger/Exception.php';

            throw new Zend_Crypt_Math_BigInteger_Exception($extension . ' big integer precision math support not detected');

        }

    }

}