fix repeatable migrations

db/routines/R__016_fn_ev_session_transition.sql

@@ -0,0 +1,87 @@
+create or replace function ems.fn_ev_session_transition(
+  p_site_id int,
+  p_charger_id int,
+  p_prev_status text,
+  p_new_status text,
+  p_measured_at timestamptz
+)
+returns jsonb
+language plpgsql
+as $fn$
+declare
+  v_vehicle_id int;
+begin
+  if p_prev_status is not distinct from p_new_status then
+    return jsonb_build_object('action', 'none');
+  end if;
+
+  if p_prev_status = 'available' and p_new_status is distinct from 'available' then
+    select av.id
+    into v_vehicle_id
+    from ems.asset_vehicle av
+    where av.site_id = p_site_id
+      and av.default_charger_id = p_charger_id
+      and av.active = true
+    order by av.id
+    limit 1;
+
+    perform ems.fn_update_ev_arrival_stats(
+      p_site_id,
+      p_charger_id,
+      v_vehicle_id,
+      p_measured_at
+    );
+
+    insert into ems.ev_session (
+      site_id,
+      charger_id,
+      vehicle_id,
+      session_start,
+      target_soc_pct,
+      target_deadline
+    )
+    select
+      ac.site_id,
+      ac.id,
+      av.id,
+      now(),
+      av.default_target_soc_pct,
+      case
+        when av.default_deadline_hour is not null then
+          (
+            (timezone('Europe/Prague', now()))::date + interval '1 day'
+            + make_interval(hours => av.default_deadline_hour)
+          )::timestamp at time zone 'Europe/Prague'
+      end
+    from ems.asset_ev_charger ac
+    left join lateral (
+      select v.id, v.default_target_soc_pct, v.default_deadline_hour
+      from ems.asset_vehicle v
+      where v.default_charger_id = ac.id
+        and v.site_id = ac.site_id
+        and v.active = true
+      order by v.id
+      limit 1
+    ) av on true
+    where ac.id = p_charger_id
+      and ac.site_id = p_site_id
+    on conflict (charger_id) where session_end is null do nothing;
+
+    return jsonb_build_object('action', 'arrival');
+  end if;
+
+  if p_prev_status is distinct from 'available' and p_new_status = 'available' then
+    update ems.ev_session es
+    set session_end = now()
+    where es.charger_id = p_charger_id
+      and es.session_end is null;
+
+    return jsonb_build_object('action', 'departure');
+  end if;
+
+  return jsonb_build_object('action', 'none');
+end;
+$fn$;
+
+comment on function ems.fn_ev_session_transition(int, int, text, text, timestamptz) is
+  'Detekce příjezdu/odjezdu EV po změně statusu nabíječky (telemetry_collector).';