<?php

/*
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 */

namespace Friendica\Directory\Utils;

/**
 * Description of Network
 *
 * @author Hypolite Petovan <hypolite@mrpetovan.com>
 */
class Network
{
	/**
	 * Check if a hostname is public and non-reserved
	 *
	 * @param  string $host
	 * @return bool
	 */
	public static function isPublicHost(string $host): bool
	{
		if (!$host) {
			return false;
		}

		if ($host === 'localhost') {
			return false;
		}

		// RFC 2606
		if ($host === 'example.com' || $host === 'example.net' || $host === 'example.org') {
			return false;
		}

		// RFC 2606 -continued
		$tld = substr($host, strrpos($host, '.'));
		if ($tld === '.test' || $tld === '.example' || $tld === '.invalid' || $tld === '.localhost') {
			return false;
		}

		// Private/Reserved IP ranges
		if (filter_var($host, FILTER_VALIDATE_IP) && !filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
			return false;
		}

		return true;
	}
}