A handy helper function that recreates the full URL for the current
    request or parts of it.  Here an example:

    >>> from werkzeug import create_environ
    >>> env = create_environ("/?param=foo", "http://localhost/script")
    >>> get_current_url(env)
    'http://localhost/script/?param=foo'
    >>> get_current_url(env, root_only=True)
    'http://localhost/script/'
    >>> get_current_url(env, host_only=True)
    'http://localhost/'
    >>> get_current_url(env, strip_querystring=True)
    'http://localhost/script/'

    :param environ: the WSGI environment to get the current URL from.
    :param root_only: set `True` if you only want the root URL.
    :param strip_querystring: set to `True` if you don't want the querystring.
    :param host_only: set to `True` if the host URL should be returned.

def get_current_url(environ, root_only=False, strip_querystring=False, host_only=False):
    """A handy helper function that recreates the full URL for the current
    request or parts of it.  Here an example:

    >>> from werkzeug import create_environ
    >>> env = create_environ("/?param=foo", "http://localhost/script")
    >>> get_current_url(env)
    'http://localhost/script/?param=foo'
    >>> get_current_url(env, root_only=True)
    'http://localhost/script/'
    >>> get_current_url(env, host_only=True)
    'http://localhost/'
    >>> get_current_url(env, strip_querystring=True)
    'http://localhost/script/'

    :param environ: the WSGI environment to get the current URL from.
    :param root_only: set `True` if you only want the root URL.
    :param strip_querystring: set to `True` if you don't want the querystring.
    :param host_only: set to `True` if the host URL should be returned.
    """
    tmp = [environ["wsgi.url_scheme"], "://", get_host(environ)]
    cat = tmp.append
    if host_only:
        return "".join(tmp) + "/"
    cat(quote(environ.get("SCRIPT_NAME", "").rstrip("/")))
    if root_only:
        cat("/")
    else:
        cat(quote("/" + environ.get("PATH_INFO", "").lstrip("/")))
        if not strip_querystring:
            qs = environ.get("QUERY_STRING")
            if qs:
                cat("?" + qs)
    return "".join(tmp)