def parse_url(url: str) -> tuple:
    """
    parse url and the result is tuple of
    (hostname, port, resource path and the flag of secure mode)

    Parameters
    ----------
    url: str
        url string.
    """
    if ":" not in url:
        raise ValueError("url is invalid")

    scheme, url = url.split(":", 1)

    parsed = urlparse(url, scheme="http")
    if parsed.hostname:
        hostname = parsed.hostname
    else:
        raise ValueError("hostname is invalid")
    port = 0
    if parsed.port:
        port = parsed.port

    is_secure = False
    if scheme == "ws":
        if not port:
            port = 80
    elif scheme == "wss":
        is_secure = True
        if not port:
            port = 443
    else:
        raise ValueError("scheme %s is invalid" % scheme)

    if parsed.path:
        resource = parsed.path
    else:
        resource = "/"

    if parsed.query:
        resource += f"?{parsed.query}"

    return hostname, port, resource, is_secure

    parse url and the result is tuple of
    (hostname, port, resource path and the flag of secure mode)

    Parameters
    ----------
    url: str
        url string.
    
websocket/_url.py