<?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

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

 */

/**

 * @see Zend_Crypt_Math_BigInteger_Interface

 */

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

/**

 * Support for arbitrary precision mathematics in PHP.

 *

 * Zend_Crypt_Math_BigInteger_Gmp is a wrapper across the PHP BCMath

 * extension.

 *

 * @category   Zend

 * @package    Zend_Crypt

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

 */

class Zend_Crypt_Math_BigInteger_Gmp implements Zend_Crypt_Math_BigInteger_Interface

{

    /**

     * Initialise a big integer into an extension specific type.

     * @param string $operand

     * @param int $base

     * @return string

     */

    public function init($operand, $base = 10)

    {

        return $operand;

    }

    /**

     * Adds two arbitrary precision numbers

     *

     * @return string

     */

    public function add($left_operand, $right_operand)

    {

        $result = gmp_add($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function subtract($left_operand, $right_operand)

    {

        $result = gmp_sub($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * Compare two big integers and returns result as an integer where 0 means

     * both are identical, 1 that left_operand is larger, or -1 that

     * right_operand is larger.

     * @return int

     */

    public function compare($left_operand, $right_operand)

    {

        $result = gmp_cmp($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * Divide two big integers and return result or NULL if the denominator

     * is zero.

     * @return string|null

     */

    public function divide($left_operand, $right_operand)

    {

        $result = gmp_div($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function modulus($left_operand, $modulus)

    {

        $result = gmp_mod($left_operand, $modulus);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function multiply($left_operand, $right_operand)

    {

        $result = gmp_mul($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function pow($left_operand, $right_operand)

    {

        $result = gmp_pow($left_operand, $right_operand);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function powmod($left_operand, $right_operand, $modulus)

    {

        $result = gmp_powm($left_operand, $right_operand, $modulus);

        return gmp_strval($result);

    }

    /**

     * @return string

     */

    public function sqrt($operand)

    {

        $result = gmp_sqrt($operand);

        return gmp_strval($result);

    }

    public function binaryToInteger($operand)

    {

        $result = '0';

        while (strlen($operand)) {

            $ord = ord(substr($operand, 0, 1));

            $result = gmp_add(gmp_mul($result, 256), $ord);

            $operand = substr($operand, 1);

        }

        return gmp_strval($result);

    }

    public function integerToBinary($operand)

    {

        $bigInt = gmp_strval($operand, 16);

        if (strlen($bigInt) % 2 != 0) {

            $bigInt = '0' . $bigInt;

        } else if ($bigInt[0] > '7') {

            $bigInt = '00' . $bigInt;

        }

        $return = pack("H*", $bigInt);

        return $return;

    }

    public function hexToDecimal($operand)

    {

        $return = '0';

        while(strlen($hex)) {

            $hex = hexdec(substr($operand, 0, 4));

            $dec = gmp_add(gmp_mul($return, 65536), $hex);

            $operand = substr($operand, 4);

        }

        return $return;

    }