<?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_Bcmath 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_Bcmath implements Zend_Crypt_Math_BigInteger_Interface

{

    /**

     * Initialise a big integer into an extension specific type. This is not

     * applicable to BCMath.

     * @param string $operand

     * @param int $base

     * @return string

     */

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

    {

        return $operand;

    }

    /**

     * Adds two arbitrary precision numbers

     *

     * @param string $left_operand

     * @param string $right_operand

     * @return string

     */

    public function add($left_operand, $right_operand)

    {

        return bcadd($left_operand, $right_operand);

    }

    /**

     * @param string $left_operand

     * @param string $right_operand

     * @return string

     */

    public function subtract($left_operand, $right_operand)

    {

        return bcsub($left_operand, $right_operand);

    }

    /**

     * 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.

     * @param string $left_operand

     * @param string $right_operand

     * @return int

     */

    public function compare($left_operand, $right_operand)

    {

        return bccomp($left_operand, $right_operand);

    }

    /**

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

     * is zero.

     * @param string $left_operand

     * @param string $right_operand

     * @return string|null

     */

    public function divide($left_operand, $right_operand)

    {

        return bcdiv($left_operand, $right_operand);

    }

    /**

     * @param string $left_operand

     * @return string

     */

    public function modulus($left_operand, $modulus)

    {

        return bcmod($left_operand, $modulus);

    }

    /**

     * @param string $left_operand

     * @param string $right_operand

     * @return string

     */

    public function multiply($left_operand, $right_operand)

    {

        return bcmul($left_operand, $right_operand);

    }

    /**

     * @param string $left_operand

     * @param string $right_operand

     * @return string

     */

    public function pow($left_operand, $right_operand)

    {

        return bcpow($left_operand, $right_operand);

    }

    /**

     * @param string $left_operand

     * @param string $right_operand

     * @return string

     */

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

    {

        return bcpowmod($left_operand, $right_operand, $modulus);

    }

    /**

     * @return string

     */

    public function sqrt($operand)

    {

        return bcsqrt($operand);

    }

    public function binaryToInteger($operand)

    {

        $result = '0';

        while (strlen($operand)) {

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

            $result = bcadd(bcmul($result, 256), $ord);

            $operand = substr($operand, 1);

        }

        return $result;

    }

    public function integerToBinary($operand)

    {

        $cmp = bccomp($operand, 0);

        $return = '';

        if ($cmp == 0) {

            return "\0";

        }

        while (bccomp($operand, 0) > 0) {

            $return = chr(bcmod($operand, 256)) . $return;

            $operand = bcdiv($operand, 256);

        }

        if (ord($return[0]) > 127) {

            $return = "\0" . $return;

        }

        return $return;

    }

    /**public function integerToBinary($operand)

    {

        $return = '';

        while(bccomp($operand, '0')) {

            $return .= chr(bcmod($operand, '256'));

            $operand = bcdiv($operand, '256');

        }

        return $return;

    }**/ // Prior version for referenced offset

    public function hexToDecimal($operand)

    {

        $return = '0';

        while(strlen($hex)) {

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

            $dec = bcadd(bcmul($return, 65536), $hex);

            $operand = substr($operand, 4);

        }

        return $return;

    }