fix BA cutoff

backend/services/planning_engine.py

@@ -59,7 +59,7 @@ NEG_SELL_CURTAIL_PENALTY_CZK_KWH = 1.0
 NEG_SELL_PV_CHARGE_REWARD_CZK_KWH = 0.8
 # Měkký tlak: v okně sell<0 dobít na soc_max (ne zastavit na ~94 % kvůli curtail).
 NEG_SELL_SOC_UNDERFILL_PENALTY_CZK_PER_WH = 0.35
-PLANNER_BUILD_TAG = "2026-05-25-neg-sell-no-export-fixed-v8"
+PLANNER_BUILD_TAG = "2026-05-25-purchase-fixed-neg-sell-v9"
 CORRECTION_WINDOW_H  = 1        # hodina zpět pro výpočet korekčního faktoru
 CORRECTION_MIN_CLAMP = 0.5      # spodní limit korekčního faktoru
 CORRECTION_MAX_CLAMP = 1.5      # horní limit korekčního faktoru
@@ -665,11 +665,20 @@ def _slot_profitable_battery_export(
     return sell_t > acq + min_spread
 
 
+def _purchase_pricing_fixed(grid: Any) -> bool:
+    """Režim nákupu z DB (`site_market_config.purchase_pricing_mode`), ne odhad z rozptylu buy."""
+    return (
+        str(getattr(grid, "purchase_pricing_mode", "spot") or "spot").strip().lower()
+        == "fixed"
+    )
+
+
 def _horizon_fixed_tariff_like(slots: list[PlanningSlot]) -> bool:
     """
-    Fixní nákup (KV1): buy v horizontu je prakticky konstantní.
+    Heuristika pro drahý import / charge_acquisition: buy v horizontu je prakticky konstantní.
     U spotu (home-01) nesmí expensive_import používat charge_acquisition — jinak
     buy > ~1 Kč označí téměř všechny sloty jako drahé (gi=0 pro dům) → Infeasible.
+    BA81 má fixní nákup v DB, ale NT/VT → buy skáče; proto neg-sell export řídí _purchase_pricing_fixed.
     """
     buys = [float(s.buy_price) for s in slots if float(s.buy_price) >= 0.0]
     if not buys:
@@ -1184,7 +1193,8 @@ def solve_dispatch(
         else min(float(s.buy_price) for s in slots)
     )
     min_spread_pre = float(degradation_cost_effective)
-    fixed_tariff_like_pre = _horizon_fixed_tariff_like(slots)
+    purchase_fixed_pre = _purchase_pricing_fixed(grid)
+    fixed_tariff_like_pre = purchase_fixed_pre or _horizon_fixed_tariff_like(slots)
     profitable_export_ts_pre: set[int] = set()
     if om == "AUTO":
         for _t in range(T):
@@ -1641,8 +1651,9 @@ def solve_dispatch(
                 prob += ge[t] == 0
                 prob += ge_pv[t] == 0
                 prob += ge_bat[t] == 0
-            elif fixed_tariff_like_pre:
-                # BA81: při sell<0 neexportovat (záporná cena výkupu = platíš za export).
+            elif purchase_fixed_pre:
+                # Fixní nákup + spot výkup (BA81, KV1 bez block_export): sell<0 = platíš za vývoz.
+                # Nesouvisí s NT/VT skokem buy — řídí se výkupní cenou, ne rozptylem buy v horizontu.
                 # Přebytek FVE → baterie / curtail A; B přes z_gen_cutoff nebo bc_pv.
                 prob += ge[t] == 0
                 prob += ge_pv[t] == 0
@@ -1833,7 +1844,7 @@ def solve_dispatch(
                 float(s.pv_b_forecast_w) > 0
                 and not getattr(grid, "block_export_on_negative_sell", False)
                 and sell_t < 0
-                and not fixed_tariff_like_pre
+                and not purchase_fixed_pre
             ) or (
                 # KV1: plná baterie + kladný sell — neblokovat ge_pv==0 (jinak masivní curtail).
                 getattr(grid, "block_export_on_negative_sell", False)
@@ -1842,7 +1853,7 @@ def solve_dispatch(
             )
             # BA81: export pole B jen při kladném sell (po sell<0 jinak ge==0 výše).
             fixed_pv_b_export_cap = (
-                fixed_tariff_like_pre
+                purchase_fixed_pre
                 and float(s.pv_b_forecast_w) > 0
                 and not getattr(grid, "block_export_on_negative_sell", False)
                 and sell_t >= 0
@@ -1870,7 +1881,7 @@ def solve_dispatch(
             # Spot (home-01): buy > min ne-záporného buy v horizontu.
             # Fixní tarif (KV1): navíc buy > charge_acquisition (konstantní buy ≈ ref).
             expensive_import_slot = buy_t > ref_buy_horizon + min_spread
-            if _horizon_fixed_tariff_like(slots):
+            if fixed_tariff_like_pre:
                 expensive_import_slot = expensive_import_slot or (
                     buy_t > charge_acquisition_czk_kwh + min_spread
                 )
@@ -2600,11 +2611,14 @@ async def _load_site_context(site_id: int, db):
     )
 
     g = ctx["grid"]
+    m = ctx.get("market") or {}
     grid = SimpleNamespace(
         max_import_power_w=int(g["max_import_power_w"]),
         max_export_power_w=int(g["max_export_power_w"]),
         block_export_on_negative_sell=bool(g.get("block_export_on_negative_sell") or False),
         deye_gen_microinverter_cutoff_enabled=bool(g.get("deye_gen_microinverter_cutoff_enabled") or False),
+        purchase_pricing_mode=str(m.get("purchase_pricing_mode") or "spot").strip().lower(),
+        sale_pricing_mode=str(m.get("sale_pricing_mode") or "spot").strip().lower(),
     )
 
     vehicles: list[SimpleNamespace] = []