def select_login_form(forms):
    """
    Select form having highest probability for login class.

    :param dict forms: Nested dict containing label probabilities for each
        form.
    :returns: (login form, login meta)
    :rtype: tuple
    """
    login_form = None
    login_meta = None
    login_prob = 0

    for form, meta in forms:
        for type_, prob in meta["form"].items():
            if type_ == "login" and prob > login_prob:
                login_form = form
                login_meta = meta
                login_prob = prob

    return login_form, login_meta