<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: Sebastian Krupinski <krupinski01@gmail.com>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

namespace KTXF\Utile;

/**
 * UUID Generator Utility Class
 * 
 * Generates RFC 4122 compliant UUIDs (version 4 - random)
 */
class UUID {

	/**
	 * Generate a random UUID v4
	 * 
	 * @return string UUID in format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
	 */
	public static function v4(): string {
		// Generate 16 random bytes
		$bytes = random_bytes(16);
		
		// Set version to 4 (random)
		$bytes[6] = chr((ord($bytes[6]) & 0x0f) | 0x40);
		
		// Set variant to RFC 4122
		$bytes[8] = chr((ord($bytes[8]) & 0x3f) | 0x80);
		
		// Format as UUID string
		return vsprintf(
			'%s%s-%s-%s-%s-%s%s%s',
			str_split(bin2hex($bytes), 4)
		);
	}

	/**
	 * Validate a UUID string
	 * 
	 * @param string $uuid UUID to validate
	 * @return bool True if valid UUID format
	 */
	public static function isValid(string $uuid): bool {
		return (bool)preg_match(
			'/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i',
			$uuid
		);
	}

}