fix issue

apps/edr-freight-api/src/modules/train-scheduling/wagon-plan-flex.util.ts

@@ -154,10 +154,46 @@ const shortageFor = (
             ),
         )
       : Math.max(1, containerWagonsForLines(booking.bookingContainers ?? []));
-  const wagonsAvailable = candidates.reduce(
-    (sum, wt) => sum + availableOf(wt.id),
-    0,
-  );
+
+  const freeByType = candidates.map((wt) => ({ wt, free: availableOf(wt.id) }));
+  const wagonsAvailable = freeByType.reduce((sum, c) => sum + c.free, 0);
+
+  // PER_TON bulk: a bare wagon COUNT lies when the types carry different
+  // tonnage for this cargo. 14 NW5 (30T) + 10 PW2 (20T) is "24 wagons free"
+  // against a 24-wagon need, yet only 620T of the 695T booking fits — which
+  // is how a deferral could read "needs 24, 24 available (short 1)". Size the
+  // shortfall in the wagons the cargo's OWN caps require: how many more
+  // wagons of the best remaining type would carry the leftover tonnage.
+  const tons = bookingCargoTons(booking);
+  const perItem =
+    Number(booking.bulkTotalWeightTons ?? 0) > 0 &&
+    Number(booking.cargoTotalWeightVgm ?? 0) > 0;
+  if (booking.freightType === 'BULK' && !perItem && tons > 0) {
+    let seatable = 0;
+    let usedWagons = 0;
+    for (const { wt, free } of freeByType) {
+      const perWagon = bulkTonsPerWagon(booking.cargoType, wt.id, Number(wt.capacityTons));
+      if (!(perWagon > 0) || free <= 0) continue;
+      seatable += free * perWagon;
+      usedWagons += free;
+    }
+    if (seatable < tons) {
+      const bestPerWagon = Math.max(
+        1,
+        ...candidates.map((wt) =>
+          bulkTonsPerWagon(booking.cargoType, wt.id, Number(wt.capacityTons)),
+        ),
+      );
+      return {
+        wagonTypeCodes: [...new Set(candidates.map((wt) => wt.code))].join('/'),
+        wagonsNeeded,
+        wagonsAvailable: usedWagons,
+        // Wagons of the best type still missing to carry the leftover tonnage.
+        wagonsShort: Math.max(1, Math.ceil((tons - seatable) / bestPerWagon)),
+      };
+    }
+  }
+
   return {
     wagonTypeCodes: [...new Set(candidates.map((wt) => wt.code))].join('/'),
     wagonsNeeded,