changes

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

@@ -7090,9 +7090,19 @@ export class TrainSchedulingService {
 
     await this.dataSource.transaction(async (manager) => {
       await manager.getRepository(TrainSetWagon).delete(trainSetWagonId);
+      // Recount from the slot rows rather than decrementing the cached counter.
+      // A blind `wagonCount - 1` desyncs the moment two removals race or the
+      // in-memory schedule graph is stale, and the counter is what the schedule
+      // capacity math reads.
+      const remaining = await manager.getRepository(TrainSetWagon).find({
+        where: { trainSetId: schedule.trainSetId },
+        select: { id: true, lengthMeters: true },
+      });
       await manager.getRepository(TrainSet).update(schedule.trainSetId, {
-        wagonCount: Math.max(0, (schedule.trainSet?.wagonCount ?? 0) - 1),
-        totalLengthMeters: Math.max(0, (schedule.trainSet?.totalLengthMeters ?? 0) - (wagon.lengthMeters ?? 0)),
+        wagonCount: remaining.length,
+        totalLengthMeters: roundTons(
+          remaining.reduce((sum, w) => sum + (Number(w.lengthMeters) || 0), 0),
+        ),
       });
     });