feat: empty container Import

apps/edr-freight-api/src/modules/rule-engine/services/rates.service.ts

@@ -24,7 +24,12 @@ import { IRatesRepository, RATES_REPOSITORY } from '../interfaces/rates.reposito
 import { IYardsRepository, YARDS_REPOSITORY } from '../interfaces/yards.repository.interface';
 
 /** Categories priced per rail leg — they carry an origin → destination yard pair. */
-const BASE_FREIGHT_CATEGORIES: readonly Rate['appliesTo'][] = ['BULK', 'CONTAINER', 'INTERCITY'];
+const BASE_FREIGHT_CATEGORIES: readonly Rate['appliesTo'][] = [
+  'BULK',
+  'CONTAINER',
+  'EMPTY_CONTAINER',
+  'INTERCITY',
+];
 /**
  * Surcharges sold per cargo kind: the admin says container or bulk, a
  * container fee then names its container type and a bulk fee its commodity.
@@ -381,6 +386,30 @@ export class RatesService {
       return;
     }
 
+    if (appliesTo === 'EMPTY_CONTAINER') {
+      // Northbound repositioning only. Southbound empties are already sold by
+      // the WITH_RETURN surcharge and empty_return_requests; a second path to
+      // the same movement would let the business double-sell it.
+      if (tradeDirection !== 'IMPORT') {
+        throw new BadRequestException(
+          'An empty container rate is import-only for now.',
+        );
+      }
+      // Size is the entire scope of an empty rate — there is no cargo to narrow
+      // by, so the box type must be named and a commodity must not be.
+      if (!containerTypeId) {
+        throw new BadRequestException(
+          'An empty container rate must name the container type it covers.',
+        );
+      }
+      if (cargoTypeId) {
+        throw new BadRequestException(
+          'An empty container rate cannot be scoped to a bulk cargo type.',
+        );
+      }
+      return;
+    }
+
     if (tradeDirection !== 'IMPORT' && tradeDirection !== 'EXPORT') {
       throw new BadRequestException(
         `${appliesTo === 'BULK' ? 'Bulk' : 'Container'} freight must be either IMPORT or EXPORT.`,