def METHOD_NAME(
    ctx: click.Context, site_name: Optional[str] = None, all_sites: bool = False
) -> None:
    """
    Remove all files from a Data Docs site.
    This is a useful first step if you wish to completely re-build a site from scratch.
    """
    context = ctx.obj.data_context
    usage_event_end: str = ctx.obj.usage_event_end
    if (site_name is None and all_sites is False) or (site_name and all_sites):
        toolkit.exit_with_failure_message_and_stats(
            data_context=context,
            usage_event=usage_event_end,
            message="<red>Please specify either --all to clean all sites or a specific site using --site-name</red>",
        )
    try:
        # if site_name is None, context.clean_data_docs(site_name=site_name)
        # will clean all sites.
        context.clean_data_docs(site_name=site_name)
        send_usage_message(
            data_context=context,
            event=usage_event_end,
            success=True,
        )
        cli_message("<green>Cleaned data docs</green>")
    except DataContextError as de:
        toolkit.exit_with_failure_message_and_stats(
            data_context=context,
            usage_event=usage_event_end,
            message=f"<red>{de}</red>",
        )