<?php

namespace JNews\Paywall\Gateways\Stripe\Lib\Util;

/**
 * A basic random generator. This is in a separate class so we the generator
 * can be injected as a dependency and replaced with a mock in tests.
 */
class Random_Generator {

	/**
	 * Returns a random value between 0 and $max.
	 *
	 * @param float $max (optional)
	 * @return float
	 */
	public function randFloat( $max = 1.0 ) {
		return mt_rand() / mt_getrandmax() * $max;
	}

	/**
	 * Returns a v4 UUID.
	 *
	 * @return string
	 */
	public function uuid() {
		$arr    = array_values( unpack( 'N1a/n4b/N1c', openssl_random_pseudo_bytes( 16 ) ) );
		$arr[2] = ( $arr[2] & 0x0fff ) | 0x4000;
		$arr[3] = ( $arr[3] & 0x3fff ) | 0x8000;
		return vsprintf( '%08x-%04x-%04x-%04x-%04x%08x', $arr );
	}
}
