CREATE TABLE IF NOT EXISTS public.visitor_stats (
  id text PRIMARY KEY,
  count bigint NOT NULL DEFAULT 0
);

INSERT INTO public.visitor_stats (id, count)
VALUES ('global', 0)
ON CONFLICT (id) DO NOTHING;

CREATE OR REPLACE FUNCTION public.increment_visitor()
RETURNS bigint
LANGUAGE sql
AS $$
  UPDATE public.visitor_stats
  SET count = count + 1
  WHERE id = 'global'
  RETURNING count;
$$;

ALTER TABLE public.visitor_stats ENABLE ROW LEVEL SECURITY;

CREATE POLICY visitor_stats_select ON public.visitor_stats
  FOR SELECT TO anon
  USING (true);

GRANT SELECT ON public.visitor_stats TO anon;
GRANT EXECUTE ON FUNCTION public.increment_visitor() TO anon, authenticated;