fix issue

apps/edr-freight-api/src/modules/trains/trains.service.ts

@@ -1,15 +1,19 @@
-import { Injectable, NotFoundException } from '@nestjs/common';
+import { WagonStatus } from '@edr/types';
+import { ConflictException, Injectable, NotFoundException } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
-import { FindOptionsOrder, FindOptionsWhere, ILike, Repository } from 'typeorm';
+import { DataSource, FindOptionsOrder, FindOptionsWhere, ILike, Repository } from 'typeorm';
 import { CreateTrainDto } from './dto/create-train.dto';
 import { UpdateTrainDto } from './dto/update-train.dto';
+import { TrainLocomotive } from './entities/train-locomotive.entity';
 import { Train } from './entities/train.entity';
+import { Wagon } from '../wagons/entities/wagon.entity';
 
 @Injectable()
 export class TrainsService {
   constructor(
     @InjectRepository(Train)
     private readonly trainRepo: Repository<Train>,
+    private readonly dataSource: DataSource,
   ) {}
 
   create(dto: CreateTrainDto): Promise<Train> {
@@ -54,8 +58,40 @@ export class TrainsService {
     return this.trainRepo.save(train);
   }
 
+  /**
+   * Delete a built train. Blocked while it still has a live (DRAFT/SCHEDULED/
+   * DISPATCHED) schedule; otherwise its wagons are freed (back to AVAILABLE)
+   * and its locomotive links dropped so nothing is stranded, then the train is
+   * soft-deleted. Mirrors TrainBuilderService.disband but prefers softRemove.
+   */
   async remove(id: string): Promise<void> {
-    const train = await this.findById(id);
-    await this.trainRepo.remove(train);
+    await this.dataSource.transaction(async (manager) => {
+      const train = await manager.getRepository(Train).findOne({ where: { id } });
+      if (!train) throw new NotFoundException(`Train ${id} not found`);
+
+      const active: { count: string }[] = await manager.query(
+        `SELECT COUNT(*)::text AS count
+           FROM freight.train_schedules ts
+           JOIN freight.train_sets tset ON tset.id = ts.train_set_id
+          WHERE tset.train_id = $1
+            AND ts.deleted_at IS NULL
+            AND ts.status IN ('DRAFT', 'SCHEDULED', 'DISPATCHED')`,
+        [id],
+      );
+      if (Number(active[0]?.count ?? 0) > 0) {
+        throw new ConflictException(
+          'Train has active schedules; cancel them before deleting the train',
+        );
+      }
+
+      await manager
+        .getRepository(Wagon)
+        .update(
+          { trainId: train.id },
+          { trainId: null, sequenceNumber: null, status: WagonStatus.Available },
+        );
+      await manager.getRepository(TrainLocomotive).delete({ trainId: train.id });
+      await manager.getRepository(Train).softRemove(train);
+    });
   }
 }