ui design for schedule

apps/edr-freight-api/src/modules/train-scheduling/train-scheduling.service.ts

@@ -1201,6 +1201,15 @@ export class TrainSchedulingService {
       const lineEntry = lineById.get(placement.bookingContainerId);
       if (!lineEntry) continue;
 
+      // Durably persist the container number on the booking container line first, so it
+      // survives a refresh regardless of whether a wagon allocation slot can be matched
+      // below. booking_container is the source of truth re-read into the preview units.
+      if (placement.containerNumber && placement.containerNumber.trim()) {
+        await manager.getRepository(BookingContainer).update(placement.bookingContainerId, {
+          containerNumber: placement.containerNumber.trim(),
+        });
+      }
+
       const allocationId = allocationBySlotBooking.get(
         `${placement.sequenceNo}:${lineEntry.bookingId}`,
       );
@@ -1226,13 +1235,6 @@ export class TrainSchedulingService {
           bookingContainerId: placement.bookingContainerId,
         });
       }
-
-      // Save container number to booking_container when staff enters a new container number
-      if (placement.containerNumber && placement.containerNumber.trim()) {
-        await manager.getRepository(BookingContainer).update(placement.bookingContainerId, {
-          containerNumber: placement.containerNumber.trim(),
-        });
-      }
     }
 
     if (containerItems.length) {

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

@@ -53,6 +53,7 @@ export type ContainerUnitRow = {
   wagonsPerUnit?: number;
   containersPerWagon?: number;
   teuSlots?: number;
+  containerNumber?: string | null;
 };
 
 export type ContainerPlacementInput = {
@@ -121,7 +122,7 @@ export function buildContainerWagonPlan(
     allocations: [],
   }));
 
-  return allocateBookingsToSlots(bookings, basePlan, AllocationLoadType.Container).map((slot) => ({
+  return allocateContainersToSlots(bookings, basePlan).map((slot) => ({
     ...slot,
     slotLoadType: 'CONTAINER' as SlotLoadType,
   }));
@@ -223,6 +224,7 @@ export function expandBookingContainerUnits(bookings: Booking[]): ContainerUnitR
           wagonsPerUnit,
           containersPerWagon: perWagon,
           teuSlots,
+          containerNumber: line.containerNumber ?? null,
         });
       }
     }
@@ -290,6 +292,65 @@ function allocateBookingsToSlots(
   });
 }
 
+/**
+ * Allocate container bookings across wagon slots by TEU capacity. A wagon holds at most
+ * 2 TEU, so it carries either one 40ft container (2 TEU) or two 20ft containers (1 TEU
+ * each) — a 40ft is NEVER mixed onto the same wagon as a 20ft. Every physical container
+ * maps to a real wagon allocation, and this mirrors the frontend auto-fill packing
+ * exactly so a placement's sequenceNo always lands on a slot that holds an allocation
+ * for its booking.
+ *
+ * Weight-based packing (allocateBookingsToSlots) is wrong for containers: it collapses
+ * several light containers into the first wagons by tonnage and leaves later container
+ * units without an allocation slot, which silently drops their container items on assign.
+ */
+function allocateContainersToSlots(
+  bookings: Booking[],
+  basePlan: WagonPlanSlot[],
+): WagonPlanSlot[] {
+  const slots = basePlan.map((slot) => ({
+    ...slot,
+    assignedWeightTons: 0,
+    allocations: [] as WagonAllocationRecord[],
+  }));
+  if (!slots.length) return slots;
+
+  const units = expandBookingContainerUnits(bookings);
+  let currentSlotIndex = 0;
+  let teuInCurrentSlot = 0;
+
+  for (const unit of units) {
+    const teu = unit.teuSlots ?? teuSlotsForSizeFt(unit.sizeFt ?? 20);
+
+    // Move to the next wagon once this one can't fit the container's TEU. This keeps a
+    // 40ft (2 TEU) alone on its wagon and never pairs it with a 20ft.
+    if (teuInCurrentSlot > 0 && teuInCurrentSlot + teu > MAX_TEU_SLOTS_PER_WAGON) {
+      currentSlotIndex += 1;
+      teuInCurrentSlot = 0;
+    }
+
+    const slot = slots[Math.min(currentSlotIndex, slots.length - 1)]!;
+
+    let allocation = slot.allocations.find((a) => a.bookingId === unit.bookingId);
+    if (!allocation) {
+      allocation = {
+        bookingId: unit.bookingId,
+        bookingReference: unit.bookingReference,
+        allocatedWeightTons: 0,
+        loadType: AllocationLoadType.Container,
+      };
+      slot.allocations.push(allocation);
+    }
+    allocation.allocatedWeightTons = roundTons(
+      allocation.allocatedWeightTons + unit.grossWeightTons,
+    );
+    slot.assignedWeightTons = roundTons(slot.assignedWeightTons + unit.grossWeightTons);
+    teuInCurrentSlot += teu;
+  }
+
+  return slots;
+}
+
 export function expandContainerItems(
   booking: Booking,
   allocationId: string,