feat(clearance): preview charge documents before and after upload

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

@@ -1218,12 +1218,7 @@ export class BookingBatchService implements OnModuleInit {
         schedule.originStationId,
         budget.stops,
       );
-      const ledger = new WagonStockLedger(
-        stock.remainingByTypeId,
-        Math.max(1, budget.stops.length - 1),
-        stock.byYardId,
-        budget.stops,
-      );
+      const ledger = await this.stockLedgerFor(schedule, budget, [booking.id]);
       // On a multi-yard consist the pool that matters is the one standing at
       // the booking's own boarding yard — a type carried only in Mojo must not
       // be advertised to a customer boarding at Dire.
@@ -4782,18 +4777,36 @@ export class BookingBatchService implements OnModuleInit {
   private async stockLedgerFor(
     schedule: TrainSchedule,
     budget: CorridorBudget,
+    excludeBookingIds?: string[],
   ): Promise<WagonStockLedger> {
     const stock = await this.trainSchedulingService.wagonStockForSchedule(
       schedule.id,
       schedule.originStationId,
       budget.stops,
     );
-    return new WagonStockLedger(
+    const ledger = new WagonStockLedger(
       stock.remainingByTypeId,
       Math.max(1, budget.stops.length - 1),
       stock.byYardId,
       budget.stops,
     );
+    // Debit what is already committed, per boarding yard and wagon type — the
+    // same bookings the corridor budget subtracted. A booking with no resolvable
+    // wagon type still occupies steel, so it drains any type at its yard.
+    const [wagonDims, allowed] = await Promise.all([
+      this.loadWagonDims(),
+      this.loadAllowedWagonTypeIds(),
+    ]);
+    const anyType = [...stock.remainingByTypeId.keys()];
+    for (const b of await this.committedBookings(schedule, excludeBookingIds)) {
+      const typeIds = this.allowedWagonTypeIdsFor(b, allowed);
+      ledger.consume(
+        typeIds.length ? typeIds : anyType,
+        this.wagonsFor(b, wagonDims),
+        budget.legForYards(b.originYardId, b.destinationYardId),
+      );
+    }
+    return ledger;
   }
 
   /**
@@ -4956,6 +4969,29 @@ export class BookingBatchService implements OnModuleInit {
     // wagon serves disjoint legs — capacity freed past an alight yard is real.
     const stops = await this.stopsForSchedule(schedule);
     const budget = new CorridorBudget(stops, limits.base, limits.tolerance);
+    for (const b of await this.committedBookings(schedule, excludeBookingIds)) {
+      budget.subtract(
+        this.needFor(b, wagonDims),
+        budget.legForYards(b.originYardId, b.destinationYardId),
+      );
+    }
+    return budget;
+  }
+
+  /**
+   * Every booking already holding capacity on the schedule: allocated (linked),
+   * live-reserved (unexpired pay window or paid), and pending export requests
+   * that named this train. The ONE list both the abstract corridor budget and
+   * the per-yard wagon-type ledger must debit — when only the budget saw them,
+   * a train with 15 wagons planned at Mojo and 15 already booked from Mojo
+   * still advertised "15 free" there, because the whole-train budget had room
+   * left on that edge (from the other yard's wagons) and the ledger was born
+   * full.
+   */
+  private async committedBookings(
+    schedule: TrainSchedule,
+    excludeBookingIds?: string[],
+  ): Promise<Booking[]> {
     const allocated = (schedule.scheduleBookings ?? [])
       .map((sb) => sb.booking)
       .filter((b): b is Booking => Boolean(b));
@@ -4988,13 +5024,14 @@ export class BookingBatchService implements OnModuleInit {
         relations: ['bookingContainers'],
       })
     ).filter((b) => !excludeBookingIds?.includes(b.id));
-    for (const b of [...allocated, ...reserved, ...pendingHolds]) {
-      budget.subtract(
-        this.needFor(b, wagonDims),
-        budget.legForYards(b.originYardId, b.destinationYardId),
-      );
-    }
-    return budget;
+    // A booking can sit in more than one set (allocated AND still reserved);
+    // it holds its wagons once.
+    const seen = new Set<string>();
+    return [...allocated, ...reserved, ...pendingHolds].filter((b) => {
+      if (seen.has(b.id) || excludeBookingIds?.includes(b.id)) return false;
+      seen.add(b.id);
+      return true;
+    });
   }
 
   /**

apps/edr-freight-api/src/modules/train-scheduling/booking-batch.yard-stock-debit.spec.ts

@@ -0,0 +1,115 @@
+import { BookingBatchService } from './booking-batch.service';
+import { CorridorBudget } from './corridor-capacity.util';
+import { RouteMilestone } from '../routes/entities/route-milestone.entity';
+import { Booking } from '../bookings/entities/booking.entity';
+
+/**
+ * Regression: a train with 15 wagons planned at Mojo and a 15-wagon booking
+ * already committed from Mojo advertised "15 free at Mojo" — the whole-train
+ * corridor budget still had room on that edge (GMP's wagons), and the per-yard
+ * stock ledger was born full. The ledger must be debited by the SAME committed
+ * bookings the budget subtracts.
+ */
+describe('BookingBatchService — per-yard stock ledger debits committed bookings', () => {
+  const GMP = 'gmp', MOJO = 'mojo', DCT = 'dct';
+  const booking = (id: string, originYardId: string, wagonsRequired: number) =>
+    ({
+      id,
+      freightType: 'BULK',
+      cargoTypeId: 'ct-coffee',
+      wagonsRequired,
+      originYardId,
+      destinationYardId: DCT,
+      cargoTotalWeightVgm: 1,
+      bookingContainers: [],
+    }) as unknown as Booking;
+
+  const schedule = {
+    id: 'S-35',
+    routeId: 'route-1',
+    originStationId: GMP,
+    destinationStationId: DCT,
+    scheduleBookings: [{ booking: booking('BK-118', MOJO, 15) }, { booking: booking('BK-120', GMP, 1) }],
+  } as never;
+
+  const makeService = (pendingHolds: Booking[] = []) => {
+    const milestoneRepo = {
+      find: jest.fn().mockResolvedValue([
+        { yardId: GMP, sequenceNo: 1 },
+        { yardId: MOJO, sequenceNo: 2 },
+        { yardId: DCT, sequenceNo: 3 },
+      ]),
+    };
+    const emptyRepo = { find: jest.fn().mockResolvedValue([]) };
+    // Booking.find is only used for OPERATION_REQUEST_PENDING export holds.
+    const bookingRepo = { find: jest.fn().mockResolvedValue(pendingHolds) };
+    const dataSource = {
+      getRepository: jest.fn((entity: unknown) =>
+        entity === RouteMilestone ? milestoneRepo : entity === Booking ? bookingRepo : emptyRepo,
+      ),
+      query: jest.fn(async (sql: string) =>
+        sql.includes('cargo_type_wagon_types') ? [{ typeId: 'ct-coffee', wagonTypeId: 'nw5' }] : [],
+      ),
+    };
+    const trainSchedulingService = {
+      wagonStockForSchedule: jest.fn().mockResolvedValue({
+        mode: 'TRAIN',
+        remainingByTypeId: new Map([['nw5', 46]]),
+        codesByTypeId: new Map([['nw5', 'NW5']]),
+        byYardId: new Map([
+          [GMP, new Map([['nw5', 31]])],
+          [MOJO, new Map([['nw5', 15]])],
+        ]),
+      }),
+    };
+    return new BookingBatchService(
+      dataSource as never,
+      { findReservedForSchedule: jest.fn().mockResolvedValue([]) } as never,
+      {} as never,
+      {} as never,
+      {} as never,
+      {} as never,
+      trainSchedulingService as never,
+      {} as never,
+      {} as never,
+      {} as never,
+    );
+  };
+
+  const budget = () =>
+    new CorridorBudget([GMP, MOJO, DCT], {
+      wagons: 46,
+      weightTons: Number.POSITIVE_INFINITY,
+      lengthMeters: Number.POSITIVE_INFINITY,
+    });
+
+  it('shows 0 free at Mojo once its 15 planned wagons are booked, while GMP keeps its own', async () => {
+    const service = makeService() as unknown as {
+      stockLedgerFor: BookingBatchService['stockLedgerFor'];
+    };
+    const b = budget();
+    const ledger = await service.stockLedgerFor(schedule, b);
+    expect(ledger.availableFor(['nw5'], b.legOf(MOJO, DCT)!)).toBe(0);
+    expect(ledger.availableFor(['nw5'], b.legOf(GMP, DCT)!)).toBe(30);
+  });
+
+  it('a pending export request already holds its wagons at its yard (before staff accept)', async () => {
+    const service = makeService([booking('BK-REQ', MOJO, 10)]) as unknown as {
+      stockLedgerFor: BookingBatchService['stockLedgerFor'];
+    };
+    const emptySchedule = { ...(schedule as object), scheduleBookings: [] } as never;
+    const b = budget();
+    const ledger = await service.stockLedgerFor(emptySchedule, b);
+    expect(ledger.availableFor(['nw5'], b.legOf(MOJO, DCT)!)).toBe(5);
+    expect(ledger.availableFor(['nw5'], b.legOf(GMP, DCT)!)).toBe(31);
+  });
+
+  it('excludes the booking being evaluated so a request never blocks its own accept', async () => {
+    const service = makeService() as unknown as {
+      stockLedgerFor: BookingBatchService['stockLedgerFor'];
+    };
+    const b = budget();
+    const ledger = await service.stockLedgerFor(schedule, b, ['BK-118']);
+    expect(ledger.availableFor(['nw5'], b.legOf(MOJO, DCT)!)).toBe(15);
+  });
+});

apps/edr-freight-api/src/modules/train-scheduling/container-placement.util.ts

@@ -28,20 +28,30 @@ export function resolveContainerNumber(unit: ContainerUnitForPlacement): string
 export function autoFillPlacements(
   units: ContainerUnitForPlacement[],
   containerSlots: number[],
+  /**
+   * TEU already taken per slot sequenceNo by placements the caller supplied.
+   * Without it a partial auto-fill restarted at wagon #1 and stacked a second
+   * 40ft onto a wagon another booking's placement had already filled.
+   */
+  occupiedTeuBySlot: ReadonlyMap<number, number> = new Map(),
 ): ContainerPlacementInput[] {
   if (!units.length || !containerSlots.length) return [];
 
   const placements: ContainerPlacementInput[] = [];
   const MAX_TEU_PER_WAGON = 2;
   let currentSlotIndex = 0;
-  let teuInCurrentSlot = 0;
+  let teuInCurrentSlot = occupiedTeuBySlot.get(containerSlots[0]!) ?? 0;
 
   for (const unit of units) {
     const teu = unit.teuSlots ?? (unit.sizeFt && unit.sizeFt >= 40 ? 2 : 1);
 
-    if (teuInCurrentSlot > 0 && teuInCurrentSlot + teu > MAX_TEU_PER_WAGON) {
+    while (
+      teuInCurrentSlot > 0 &&
+      teuInCurrentSlot + teu > MAX_TEU_PER_WAGON &&
+      currentSlotIndex < containerSlots.length - 1
+    ) {
       currentSlotIndex += 1;
-      teuInCurrentSlot = 0;
+      teuInCurrentSlot = occupiedTeuBySlot.get(containerSlots[currentSlotIndex]!) ?? 0;
     }
 
     const sequenceNo =
@@ -62,6 +72,25 @@ export function autoFillPlacements(
   return placements;
 }
 
+/** TEU per slot sequenceNo consumed by the given placements. */
+export function occupiedTeuBySlot(
+  placements: ReadonlyArray<{ bookingContainerId: string; unitIndex: number; sequenceNo: number }>,
+  units: ContainerUnitForPlacement[],
+): Map<number, number> {
+  const teuOfUnit = new Map(
+    units.map((u) => [
+      `${u.bookingContainerId}:${u.unitIndex}`,
+      u.teuSlots ?? (u.sizeFt && u.sizeFt >= 40 ? 2 : 1),
+    ]),
+  );
+  const out = new Map<number, number>();
+  for (const p of placements) {
+    const teu = teuOfUnit.get(`${p.bookingContainerId}:${p.unitIndex}`) ?? 1;
+    out.set(p.sequenceNo, (out.get(p.sequenceNo) ?? 0) + teu);
+  }
+  return out;
+}
+
 export function findMissingContainerNumberIssues(
   units: ContainerUnitForPlacement[],
   placements: ContainerPlacementInput[],

apps/edr-freight-api/src/modules/train-scheduling/dto/assign-bookings.dto.ts

@@ -56,6 +56,14 @@ export class AssignBookingsDto {
   @IsBoolean()
   forceAssign?: boolean;
 
+  @ApiPropertyOptional({
+    description:
+      'Linked bookings the plan cannot seat stay linked as WAITING_FOR_WAGON instead of failing the whole allocation (auto-allocation mode). Requested bookingIds still fail loudly.',
+  })
+  @IsOptional()
+  @IsBoolean()
+  keepDeferredLinked?: boolean;
+
   @ApiPropertyOptional({ type: [ContainerPlacementDto] })
   @IsOptional()
   @IsArray()

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

@@ -199,6 +199,7 @@ import {
   isPlaceholderContainerNumber,
   placementsForBookings,
   type ContainerUnitForPlacement,
+  occupiedTeuBySlot,
 } from '../container-placement.util';
 
 const SCHEDULABLE_BOOKING_STATUSES = ['PAID'] as const;
@@ -1996,7 +1997,11 @@ export class TrainSchedulingService {
         );
         if (unplacedUnits.length) {
           const slots = getContainerSlotSequenceNos(preview.wagonPlan);
-          const generated = autoFillPlacements(unplacedUnits, slots);
+          const generated = autoFillPlacements(
+            unplacedUnits,
+            slots,
+            occupiedTeuBySlot(containerPlacements ?? [], units),
+          );
           const missing = findMissingContainerNumberIssues(unplacedUnits, generated);
           if (missing.length) {
             throw new BadRequestException({
@@ -2053,16 +2058,23 @@ export class TrainSchedulingService {
     // Linked ride-alongs count as requested too: silently dropping one here is
     // exactly the delete-and-recreate orphan this method must never produce.
     const plannedIds = new Set(validation.bookings.map((b) => b.id));
-    const droppedRequested = allBookingIds.filter((id) => !plannedIds.has(id));
+    const dropped = allBookingIds.filter((id) => !plannedIds.has(id));
+    const reasonById = new Map(
+      validation.deferredBookings.map((d) => [d.id, `${d.reference}: ${d.reason}`]),
+    );
+    const detailOf = (id: string) =>
+      reasonById.get(id) ?? `${id}: does not fit the train's wagon stock or capacity`;
+    // Auto-allocation (keepDeferredLinked): an ALREADY-LINKED booking the plan
+    // cannot seat — e.g. it boards at a yard whose planned wagons are all taken
+    // — stays linked and is parked WAITING_FOR_WAGON for staff, instead of
+    // aborting the whole rebuild and leaving every OTHER paid booking without a
+    // wagon too. Explicitly requested ids still fail loudly.
+    const keptDeferredIds = dto.keepDeferredLinked
+      ? dropped.filter((id) => !dto.bookingIds.includes(id))
+      : [];
+    const droppedRequested = dropped.filter((id) => !keptDeferredIds.includes(id));
     if (droppedRequested.length) {
-      const reasonById = new Map(
-        validation.deferredBookings.map((d) => [d.id, `${d.reference}: ${d.reason}`]),
-      );
-      const details = droppedRequested.map(
-        (id) =>
-          reasonById.get(id) ??
-          `${id}: does not fit the train's wagon stock or capacity`,
-      );
+      const details = droppedRequested.map(detailOf);
       throw new BadRequestException({
         message: `Cannot allocate — ${details.join('; ')}`,
         violations: details,
@@ -2072,6 +2084,9 @@ export class TrainSchedulingService {
     }
 
     const { bookings, wagonPlan, warnings, deferredBookings } = validation;
+    for (const id of keptDeferredIds) {
+      warnings.push(`${detailOf(id)} — kept on the schedule, waiting for a wagon`);
+    }
     const totalWeightTons = validation.summary.totalWeightTons;
     const totalLengthMeters = validation.summary.totalLengthMeters;
 
@@ -2179,10 +2194,10 @@ export class TrainSchedulingService {
         wagonPlan,
       );
 
-      const scheduleBookingRecords = bookings.map((booking) => ({
-        trainScheduleId: scheduleId,
-        bookingId: booking.id,
-      }));
+      const scheduleBookingRecords = [
+        ...bookings.map((booking) => booking.id),
+        ...keptDeferredIds,
+      ].map((bookingId) => ({ trainScheduleId: scheduleId, bookingId }));
       await this.trainScheduleBookingsRepository.createMany(scheduleBookingRecords, manager);
 
       await this.persistAllocationsAndLoads(
@@ -2208,6 +2223,13 @@ export class TrainSchedulingService {
           manager,
         );
       }
+      for (const bookingId of keptDeferredIds) {
+        await this.bookingsRepository.updateSchedulingFields(
+          bookingId,
+          { schedulingStatus: SchedulingStatus.WaitingForWagon },
+          manager,
+        );
+      }
 
       if (schedule.status === TrainScheduleStatusEnum.Draft && bookings.length > 0) {
         await this.trainSchedulesRepository.updateStatus(
@@ -4928,6 +4950,7 @@ export class TrainSchedulingService {
       stock,
       legs: legByBookingId,
       edgeCount: Math.max(1, stops.length - 1),
+      stops,
     });
     violations.push(...planned.configIssues);
     const fittingBookings = planned.fitting;
@@ -9362,8 +9385,7 @@ export class TrainSchedulingService {
 
     if (!performAssign || !assignableIds.length) return result;
 
-    const needsPlacements = containerBookings.some((b) => assignableSet.has(b.id));
-    if (needsPlacements && !assignPlacements.length) {
+    if (containerBookings.some((b) => assignableSet.has(b.id)) && !assignPlacements.length) {
       return {
         ...result,
         violations: [...result.violations, 'Container placements could not be generated'],
@@ -9371,12 +9393,14 @@ export class TrainSchedulingService {
     }
 
     try {
+      // No placements handed over on purpose: the assign re-plans the WHOLE
+      // linked set (incl. non-eligible linked bookings such as one already in
+      // transit), so slot numbers from THIS preview would not line up with the
+      // plan it builds — it auto-fills every unit against its own plan instead.
+      // The preview placements above only serve the missing-number check.
       await this.assignBookingsToSchedule(
         schedule.id,
-        {
-          bookingIds: assignableIds,
-          containerPlacements: needsPlacements ? assignPlacements : undefined,
-        },
+        { bookingIds: assignableIds, keepDeferredLinked: true },
         undefined,
       );
       result.assignedBookingIds = assignableIds;
@@ -10044,8 +10068,11 @@ export class TrainSchedulingService {
     if (!booking) return null;
 
     const wagonAssignedIds = await this.getWagonAssignedBookingIds(scheduleId);
+    // Count the fleet at the yard the BOOKING boards from, not the train's
+    // origin: on a split consist a Mojo booking can only ride Mojo wagons, and
+    // Gelan's 31 spare wagons told a paying customer there was no shortage.
     const fleetCounts = await this.countFleetAvailability(
-      schedule.originStationId,
+      booking.originYardId ?? schedule.originStationId,
       scheduleId,
     );
     const fleetByTypeId = new Map(

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

@@ -443,3 +443,50 @@ describe('planWagonsWithStock — break-bulk (PER_ITEM) item-aware packing', ()
     expect(result.plan.map((s) => s.assignedWeightTons)).toEqual([70, 30]);
   });
 });
+
+describe('planWagonsWithStock — consist split across yards', () => {
+  const GMP = 'gmp', MOJO = 'mojo', DCT = 'dct';
+  const boards = (id: string, quantity: number, originYardId: string): Booking =>
+    ({ ...containerBooking(id, quantity, quantity), originYardId, destinationYardId: DCT }) as Booking;
+  const allowed = { byContainerTypeId: new Map([['ct-1', [nw6]]]), byCargoTypeId: new Map() };
+  const legsFor = (bookings: Booking[]) =>
+    new Map(bookings.map((b) => [b.id, { from: b.originYardId === GMP ? 0 : 1, to: 2 }]));
+  const splitStock = {
+    mode: 'TRAIN' as const,
+    remainingByTypeId: new Map([[nw6.id, 46]]),
+    codesByTypeId: new Map([[nw6.id, nw6.code]]),
+    byYardId: new Map([
+      [GMP, new Map([[nw6.id, 31]])],
+      [MOJO, new Map([[nw6.id, 15]])],
+    ]),
+  };
+
+  it('seats a boarding yard only from the wagons planned there', () => {
+    // 20fts pack two per wagon: BKG-A's 30 boxes take all 15 Mojo wagons;
+    // BKG-B needs 2 more at Mojo → deferred, while BKG-C at Gelan still fits
+    // (the whole-train 46 is irrelevant).
+    const bookings = [boards('BKG-A', 30, MOJO), boards('BKG-B', 4, MOJO), boards('BKG-C', 2, GMP)];
+    const result = planWagonsWithStock({
+      bookings, allowed, stock: splitStock, legs: legsFor(bookings), edgeCount: 2, stops: [GMP, MOJO, DCT],
+    });
+    expect(result.fitting.map((b) => b.id)).toEqual(['BKG-A', 'BKG-C']);
+    expect(result.deferred.map((d) => d.reference)).toEqual(['BKG-B']);
+    expect(result.deferred[0]!.reason).toContain('planned at the boarding yard');
+    expect(result.plan).toHaveLength(16);
+  });
+
+  it('never lets a Gelan 20ft share a wagon that only exists at Mojo', () => {
+    const stock = {
+      ...splitStock,
+      remainingByTypeId: new Map([[nw6.id, 1]]),
+      byYardId: new Map([[MOJO, new Map([[nw6.id, 1]])]]),
+    };
+    const bookings = [boards('BKG-M', 1, MOJO), boards('BKG-G', 1, GMP)];
+    const result = planWagonsWithStock({
+      bookings, allowed, stock, legs: legsFor(bookings), edgeCount: 2, stops: [GMP, MOJO, DCT],
+    });
+    // The Mojo wagon has TEU room, but it is not standing in Gelan.
+    expect(result.fitting.map((b) => b.id)).toEqual(['BKG-M']);
+    expect(result.deferred.map((d) => d.reference)).toEqual(['BKG-G']);
+  });
+});

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

@@ -93,6 +93,12 @@ type OpenSlot = {
   legKey: string;
   /** Contiguous stop-index span this wagon physically rides (union of its cargo legs). */
   covered: { from: number; to: number };
+  /**
+   * Boarding-yard pool this wagon was opened from — the yard the consist plans
+   * it at (`''` when the consist is not split across yards). A Mojo wagon
+   * cannot later be stretched back to board at Gelan.
+   */
+  pool: string;
 };
 
 /** Stop-index range a booking occupies: edges `from..to-1` of the corridor. */
@@ -197,9 +203,19 @@ export function planWagonsWithStock(params: {
    */
   legs?: Map<string, BookingLeg>;
   edgeCount?: number;
+  /**
+   * Ordered corridor stop ids, parallel to the edges. Required for a consist
+   * split across yards (`stock.byYardId`): a booking then draws ONLY from the
+   * wagons planned at the yard it boards from (`stops[leg.from]`) — the
+   * whole-train count would happily plan 17 Mojo wagons on a train that has
+   * 15 there and 31 in Gelan, and the physical pin then fails after the
+   * customer has paid.
+   */
+  stops?: readonly string[];
 }): FlexPlanResult {
   const { bookings, allowed, stock, legs } = params;
   const edgeCount = Math.max(1, params.edgeCount ?? 1);
+  const stops = params.stops ?? [];
   const openSlots: OpenSlot[] = [];
   const fitting: Booking[] = [];
   const deferred: DeferredBookingRow[] = [];
@@ -214,32 +230,45 @@ export function planWagonsWithStock(params: {
   };
   const legKeyOf = (leg: BookingLeg) => `${leg.from}-${leg.to}`;
 
-  // Wagons of a type in use per corridor edge. A type is available for a leg
-  // when its busiest edge WITHIN that leg still has stock spare — the max over
-  // edges is the number of physical wagons the type needs simultaneously.
+  // Split consist: each boarding yard is its own pool of steel (mirrors
+  // WagonStockLedger). Single-yard consist / loose yard pool: one pool ''.
+  const poolOf = (leg: BookingLeg): string =>
+    stock.byYardId ? (stops[leg.from] ?? '') : '';
+  const rowKeyFor = (wagonTypeId: string, pool: string): string =>
+    pool ? `${pool}\u0000${wagonTypeId}` : wagonTypeId;
+  const totalFor = (wagonTypeId: string, pool: string): number =>
+    pool
+      ? (stock.byYardId?.get(pool)?.get(wagonTypeId) ?? 0)
+      : (stock.remainingByTypeId.get(wagonTypeId) ?? 0);
+
+  // Wagons of a type in use per corridor edge, per pool. A type is available
+  // for a leg when its busiest edge WITHIN that leg still has stock spare — the
+  // max over edges is the number of physical wagons the type needs simultaneously.
   const usedPerEdge = new Map<string, number[]>();
-  const usedRow = (wagonTypeId: string): number[] => {
-    let row = usedPerEdge.get(wagonTypeId);
+  const usedRow = (key: string): number[] => {
+    let row = usedPerEdge.get(key);
     if (!row) {
       row = new Array<number>(edgeCount).fill(0);
-      usedPerEdge.set(wagonTypeId, row);
+      usedPerEdge.set(key, row);
     }
     return row;
   };
   const availableFor = (wagonTypeId: string, leg: BookingLeg): number => {
-    const total = stock.remainingByTypeId.get(wagonTypeId) ?? 0;
-    const row = usedPerEdge.get(wagonTypeId);
+    const pool = poolOf(leg);
+    const total = totalFor(wagonTypeId, pool);
+    const row = usedPerEdge.get(rowKeyFor(wagonTypeId, pool));
     if (!row) return total;
     let busiest = 0;
     for (let e = leg.from; e < leg.to; e += 1) busiest = Math.max(busiest, row[e] ?? 0);
     return total - busiest;
   };
 
-  const noStockMessage = (candidates: WagonType[]): string => {
+  const noStockMessage = (candidates: WagonType[], leg: BookingLeg): string => {
     const codes = candidates.map((wt) => wt.code).join('/');
-    return stock.mode === 'TRAIN'
-      ? `Train has no free ${codes} wagon left`
-      : `No available ${codes} wagon at the yard`;
+    if (stock.mode !== 'TRAIN') return `No available ${codes} wagon at the yard`;
+    return poolOf(leg)
+      ? `Train has no free ${codes} wagon planned at the boarding yard`
+      : `Train has no free ${codes} wagon left`;
   };
 
   /** Open a new wagon of one of the candidate types, consuming stock on the leg's edges. */
@@ -251,7 +280,7 @@ export function planWagonsWithStock(params: {
   ): OpenSlot | PlacementProblem => {
     const inStock = candidates.filter((wt) => availableFor(wt.id, leg) > 0);
     if (!inStock.length) {
-      return { kind: 'stock', message: noStockMessage(candidates), candidates };
+      return { kind: 'stock', message: noStockMessage(candidates, leg), candidates };
     }
     // Bulk favors the largest wagon (fewest wagons for the tonnage); containers
     // favor the deepest stock so the consist drains evenly. Ties keep config order.
@@ -261,7 +290,8 @@ export function planWagonsWithStock(params: {
           availableFor(b.id, leg) - availableFor(a.id, leg)
         : availableFor(b.id, leg) - availableFor(a.id, leg),
     )[0];
-    const row = usedRow(chosen.id);
+    const pool = poolOf(leg);
+    const row = usedRow(rowKeyFor(chosen.id, pool));
     for (let e = leg.from; e < leg.to; e += 1) row[e] = (row[e] ?? 0) + 1;
     const open: OpenSlot = {
       slot: slotFromWagonType(chosen, kind),
@@ -271,6 +301,7 @@ export function planWagonsWithStock(params: {
       freeCapacityTons: Number(chosen.capacityTons),
       legKey: legKeyOf(leg),
       covered: { ...leg },
+      pool,
     };
     openSlots.push(open);
     return open;
@@ -290,8 +321,11 @@ export function planWagonsWithStock(params: {
    * slot's type spare — extending the span puts this wagon on those edges.
    */
   const canExtendSpan = (open: OpenSlot, leg: BookingLeg): boolean => {
-    const total = stock.remainingByTypeId.get(open.slot.wagonTypeId) ?? 0;
-    const row = usedPerEdge.get(open.slot.wagonTypeId);
+    // A pooled wagon boards where its yard is; it cannot be stretched back to
+    // an EARLIER stop (the steel is not there), only ridden further.
+    if (open.pool && leg.from < open.covered.from) return false;
+    const total = totalFor(open.slot.wagonTypeId, open.pool);
+    const row = usedPerEdge.get(rowKeyFor(open.slot.wagonTypeId, open.pool));
     const from = Math.min(open.covered.from, leg.from);
     const to = Math.max(open.covered.to, leg.to);
     for (let e = from; e < to; e += 1) {
@@ -303,7 +337,7 @@ export function planWagonsWithStock(params: {
 
   /** Grow the slot's span onto the leg's new edges, consuming stock there. */
   const extendSpan = (open: OpenSlot, leg: BookingLeg): void => {
-    const row = usedRow(open.slot.wagonTypeId);
+    const row = usedRow(rowKeyFor(open.slot.wagonTypeId, open.pool));
     const from = Math.min(open.covered.from, leg.from);
     const to = Math.max(open.covered.to, leg.to);
     for (let e = from; e < to; e += 1) {