add dispute functionality for contract duty and implement collection dates

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

@@ -7449,8 +7449,8 @@ export class TrainSchedulingService {
 
     // Target: a slot of this train set, or an empty consist-only wagon of the
     // built train (physical wagon with no slot row yet).
-    const targetSlot = slots.find((w) => w.id === dto.targetWagonId) ?? null;
-    const consistWagon = targetSlot
+    const slotById = slots.find((w) => w.id === dto.targetWagonId) ?? null;
+    const wagonForTarget = slotById
       ? null
       : schedule.trainSet?.trainId
         ? await this.dataSource.getRepository(Wagon).findOne({
@@ -7458,10 +7458,22 @@ export class TrainSchedulingService {
             relations: { wagonType: true },
           })
         : null;
-    if (!targetSlot && !consistWagon) {
+    if (!slotById && !wagonForTarget) {
       throw new NotFoundException('Target wagon is not part of this schedule');
     }
+    // A physical wagon holds at most one slot. When the caller addressed the
+    // wagon directly but a slot is already pinned to it, move into that slot
+    // rather than minting a second one on the same wagon.
+    const targetSlot =
+      slotById ??
+      (wagonForTarget
+        ? (slots.find((w) => w.physicalWagonId === wagonForTarget.id) ?? null)
+        : null);
+    const consistWagon = targetSlot ? null : wagonForTarget;
     const targetAllocs = targetSlot ? await loadAllocations(targetSlot.id) : [];
+    if (targetSlot && targetSlot.id === source.id) {
+      return this.getTrainScheduleById(scheduleId);
+    }
 
     const loadTypesOf = (allocs: WagonBookingAllocation[]) => [
       ...new Set(allocs.map((a) => (a.loadType ?? 'CONTAINER').toUpperCase())),
@@ -7525,19 +7537,6 @@ export class TrainSchedulingService {
       const slotRepo = manager.getRepository(TrainSetWagon);
       const allocs = manager.getRepository(WagonBookingAllocation);
 
-      // Empty consist wagon: repin the loaded slot onto that physical wagon.
-      // Allocations and load fields stay put; only the wagon identity changes.
-      if (consistWagon) {
-        await slotRepo.update(source.id, {
-          physicalWagonId: consistWagon.id,
-          wagonTypeId: consistWagon.wagonTypeId,
-          capacityTons: roundTons(Number(consistWagon.wagonType?.capacityTons ?? source.capacityTons)),
-          lengthMeters: roundTons(Number(consistWagon.wagonType?.lengthMeters ?? source.lengthMeters)),
-        });
-        return;
-      }
-
-      const target = targetSlot as TrainSetWagon;
       // Load-coupled slot fields travel with the load; wagon identity stays.
       const loadFieldsOf = (slot: TrainSetWagon) => ({
         assignedWeightTons: slot.assignedWeightTons,
@@ -7552,6 +7551,47 @@ export class TrainSchedulingService {
         alightYardId: null,
       };
       const sourceLoadFields = loadFieldsOf(source);
+
+      // Empty consist wagon with no slot row yet: give it one, then move the
+      // load into it. Repinning the SOURCE slot onto that wagon would have been
+      // fewer writes, but it renames the wagons instead of moving the load —
+      // the loaded slot becomes wagon B and B's identity pops out as an empty
+      // wagon where A used to be. Staff read that as the train re-ordering
+      // itself. A wagon must never change place because a container moved.
+      if (consistWagon) {
+        const { maxSequenceNo } = (await slotRepo
+          .createQueryBuilder('slot')
+          .select('COALESCE(MAX(slot.sequence_no), 0)', 'maxSequenceNo')
+          .where('slot.train_set_id = :trainSetId', { trainSetId: source.trainSetId })
+          .getRawOne<{ maxSequenceNo: string | number }>()) ?? { maxSequenceNo: 0 };
+
+        const created = await slotRepo.save(
+          slotRepo.create({
+            trainSetId: source.trainSetId,
+            wagonTypeId: consistWagon.wagonTypeId,
+            physicalWagonId: consistWagon.id,
+            // Plan-order key only — the consist is drawn in the train's coupling
+            // order (wagons.sequence_number), so appending here moves nothing.
+            // It just has to clear the (train_set_id, sequence_no) unique index.
+            sequenceNo: Number(maxSequenceNo) + 1,
+            capacityTons: roundTons(
+              Number(consistWagon.wagonType?.capacityTons ?? source.capacityTons),
+            ),
+            lengthMeters: roundTons(
+              Number(consistWagon.wagonType?.lengthMeters ?? source.lengthMeters),
+            ),
+            ...sourceLoadFields,
+          }),
+        );
+
+        for (const alloc of sourceAllocs) {
+          await allocs.update(alloc.id, { trainSetWagonId: created.id });
+        }
+        await slotRepo.update(source.id, emptyLoadFields);
+        return;
+      }
+
+      const target = targetSlot as TrainSetWagon;
       const targetLoadFields = targetAllocs.length ? loadFieldsOf(target) : emptyLoadFields;
 
       for (const alloc of sourceAllocs) {