-- Approval-time configuration identity. DDL and its marker commit atomically.
BEGIN;
-- Existing rows retain all fields; the new epoch invalidates old complete proofs.
-- This schema addition does not activate the delayed-approval execution protocol.
LOCK TABLE public.traffic_settings, public.uptime_settings,
  public.internet_path_settings IN ACCESS EXCLUSIVE MODE;
ALTER TABLE public.traffic_settings ADD COLUMN poll_configuration_epoch uuid NOT NULL DEFAULT pg_catalog.gen_random_uuid();
ALTER TABLE public.uptime_settings ADD COLUMN poll_configuration_epoch uuid NOT NULL DEFAULT pg_catalog.gen_random_uuid();
ALTER TABLE public.internet_path_settings ADD COLUMN poll_configuration_epoch uuid NOT NULL DEFAULT pg_catalog.gen_random_uuid();
CREATE FUNCTION public.server_poll_settings_epoch_guard() RETURNS trigger
LANGUAGE plpgsql SET search_path = pg_catalog AS $epoch$
BEGIN
  IF TG_TABLE_SCHEMA <> 'public' OR TG_TABLE_NAME NOT IN
    ('traffic_settings', 'uptime_settings', 'internet_path_settings')
    OR TG_LEVEL <> 'ROW' OR TG_WHEN <> 'BEFORE' THEN
    RAISE EXCEPTION 'unexpected poll settings epoch trigger target';
  END IF;
  IF TG_OP = 'INSERT' THEN
    -- Never accept an epoch supplied by an importer or application caller.
    NEW.poll_configuration_epoch := pg_catalog.gen_random_uuid();
  ELSIF TG_OP = 'UPDATE' THEN
    -- Every unknown/future field is configuration by default. Only these four
    -- current collector fields are excluded; created_at stays significant.
    IF (pg_catalog.to_jsonb(NEW) - ARRAY['poll_configuration_epoch',
        'last_collected_at', 'last_duration_ms', 'last_error', 'updated_at'])
      IS DISTINCT FROM
       (pg_catalog.to_jsonb(OLD) - ARRAY['poll_configuration_epoch',
        'last_collected_at', 'last_duration_ms', 'last_error', 'updated_at']) THEN
      NEW.poll_configuration_epoch := pg_catalog.gen_random_uuid();
    ELSE
      NEW.poll_configuration_epoch := OLD.poll_configuration_epoch;
    END IF;
  ELSE
    RAISE EXCEPTION 'unexpected poll settings epoch trigger operation';
  END IF;
  RETURN NEW;
END;
$epoch$;
CREATE TRIGGER server_poll_settings_epoch BEFORE INSERT OR UPDATE ON public.traffic_settings
FOR EACH ROW EXECUTE FUNCTION public.server_poll_settings_epoch_guard();
CREATE TRIGGER server_poll_settings_epoch BEFORE INSERT OR UPDATE ON public.uptime_settings
FOR EACH ROW EXECUTE FUNCTION public.server_poll_settings_epoch_guard();
CREATE TRIGGER server_poll_settings_epoch BEFORE INSERT OR UPDATE ON public.internet_path_settings
FOR EACH ROW EXECUTE FUNCTION public.server_poll_settings_epoch_guard();
ALTER TABLE public.traffic_settings ENABLE ALWAYS TRIGGER server_poll_settings_epoch;
ALTER TABLE public.uptime_settings ENABLE ALWAYS TRIGGER server_poll_settings_epoch;
ALTER TABLE public.internet_path_settings ENABLE ALWAYS TRIGGER server_poll_settings_epoch;
INSERT INTO schema_migrations(id) VALUES('0042_server_poll_settings_epoch') ON CONFLICT(id) DO NOTHING;
COMMIT;