class UriComparator

final class UriComparator {
    
    /**
     * Determines if a modified URL should be considered cross-origin with
     * respect to an original URL.
     */
    public static function isCrossOrigin(UriInterface $original, UriInterface $modified) : bool {
        if (\strcasecmp($original->getHost(), $modified->getHost()) !== 0) {
            return true;
        }
        if ($original->getScheme() !== $modified->getScheme()) {
            return true;
        }
        if (self::computePort($original) !== self::computePort($modified)) {
            return true;
        }
        return false;
    }
    private static function computePort(UriInterface $uri) : int {
        $port = $uri->getPort();
        if (null !== $port) {
            return $port;
        }
        return 'https' === $uri->getScheme() ? 443 : 80;
    }
    private function __construct() {
        // cannot be instantiated
    }

}