<?php
declare(strict_types=1);
/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2018 Spomky-Labs
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*/
namespace Jose\Component\Core\Util;
/**
* @internal
*/
class BigInteger
{
/**
* Holds the BigInteger's value.
*
* @var \GMP
*/
private $value;
private function __construct(\GMP $value)
{
$this->value = $value;
}
/**
* @return BigInteger
*/
public static function createFromGMPResource(\GMP $value): self
{
return new self($value);
}
/**
* @return BigInteger
*/
public static function createFromBinaryString(string $value): self
{
$value = '0x'.\unpack('H*', $value)[1];
$value = \gmp_init($value, 16);
return new self($value);
}
/**
* @return BigInteger
*/
public static function createFromDecimal(int $value): self
{
$value = \gmp_init($value, 10);
return new self($value);
}
/**
* Converts a BigInteger to a binary string.
*/
public function toBytes(): string
{
if (0 === \gmp_cmp($this->value, \gmp_init(0))) {
return '';
}
$temp = \gmp_strval(\gmp_abs($this->value), 16);
$temp = \mb_strlen($temp, '8bit') & 1 ? '0'.$temp : $temp;
$temp = \hex2bin($temp);
return \ltrim($temp, \chr(0));
}
/**
* Adds two BigIntegers.
*
* @param BigInteger $y
*
* @return BigInteger
*/
public function add(self $y): self
{
$value = \gmp_add($this->value, $y->value);
return self::createFromGMPResource($value);
}
/**
* Subtracts two BigIntegers.
*
* @param BigInteger $y
*
* @return BigInteger
*/
public function subtract(self $y): self
{
$value = \gmp_sub($this->value, $y->value);
return self::createFromGMPResource($value);
}
/**
* Multiplies two BigIntegers.
*
* @param BigInteger $x
*
* @return BigInteger
*/
public function multiply(self $x): self
{
$value = \gmp_mul($this->value, $x->value);
return self::createFromGMPResource($value);
}
/**
* Divides two BigIntegers.
*
* @param BigInteger $x
*
* @return BigInteger
*/
public function divide(self $x): self
{
$value = \gmp_div($this->value, $x->value);
return self::createFromGMPResource($value);
}
/**
* Performs modular exponentiation.
*
* @param BigInteger $e
* @param BigInteger $n
*
* @return BigInteger
*/
public function modPow(self $e, self $n): self
{
$value = \gmp_powm($this->value, $e->value, $n->value);
return self::createFromGMPResource($value);
}
/**
* Performs modular exponentiation.
*
* @param BigInteger $d
*
* @return BigInteger
*/
public function mod(self $d): self
{
$value = \gmp_mod($this->value, $d->value);
return self::createFromGMPResource($value);
}
/**
* Calculates modular inverses.
*
* @param BigInteger $n
*
* @return BigInteger
*/
public function modInverse(self $n): self
{
$value = \gmp_invert($this->value, $n->value);
return self::createFromGMPResource($value);
}
/**
* Compares two numbers.
*
* @param BigInteger $y
*/
public function compare(self $y): int
{
return \gmp_cmp($this->value, $y->value);
}
/**
* @param BigInteger $y
*/
public function equals(self $y): bool
{
return 0 === $this->compare($y);
}
/**
* @param BigInteger $y
*
* @return BigInteger
*/
public static function random(self $y): self
{
$zero = self::createFromDecimal(0);
return self::createFromGMPResource(\gmp_random_range($zero->value, $y->value));
}
/**
* @param BigInteger $y
*
* @return BigInteger
*/
public function gcd(self $y): self
{
return self::createFromGMPResource(\gmp_gcd($this->value, $y->value));
}
/**
* @param BigInteger $y
*/
public function lowerThan(self $y): bool
{
return 0 > $this->compare($y);
}
public function isEven(): bool
{
$zero = self::createFromDecimal(0);
$two = self::createFromDecimal(2);
return $this->mod($two)->equals($zero);
}
}