create or replace function ems.fn_ev_arrival_prediction_bundle(p_site_id int)
returns jsonb
language plpgsql
stable
as $fn$
declare
  v_tz text;
  v_tomorrow date;
  v_n_sessions int;
  v_insufficient boolean;
  v_chargers jsonb := '{}'::jsonb;
  r record;
  v_rows jsonb;
begin
  select coalesce(nullif(trim(s.timezone), ''), 'Europe/Prague')
  into v_tz
  from ems.site s
  where s.id = p_site_id;

  if not found then
    return jsonb_build_object('error', 'site_not_found');
  end if;

  v_tomorrow := (
    (current_timestamp at time zone v_tz)::date + 1
  );

  select count(*)::int
  into v_n_sessions
  from ems.ev_session
  where site_id = p_site_id;

  v_insufficient := coalesce(v_n_sessions, 0) < 5;

  for r in
    select id, code
    from ems.asset_ev_charger
    where site_id = p_site_id
    order by id
  loop
    select coalesce(
      jsonb_agg(
        jsonb_build_object(
          'hour', x.expected_hour,
          'confidence_pct', x.confidence_pct,
          'samples', x.sample_count
        )
        order by x.expected_hour
      ),
      '[]'::jsonb
    )
    into v_rows
    from ems.fn_ev_expected_arrival(p_site_id, r.id, v_tomorrow) x;

    v_chargers := v_chargers || jsonb_build_object(
      r.code::text,
      jsonb_build_object('tomorrow', coalesce(v_rows, '[]'::jsonb))
    );
  end loop;

  return jsonb_build_object(
    'insufficient_data', v_insufficient,
    'tomorrow_date', v_tomorrow,
    'chargers', v_chargers
  );
end;
$fn$;

comment on function ems.fn_ev_arrival_prediction_bundle(int) is
  'Predikce příjezdů pro všechny nabíječky (nahrazuje N+1 volání fn_ev_expected_arrival).';