auto allocation and batch managemnt, tracking the train

apps/edr-freight-api/src/modules/train-scheduling/train-capacity.util.spec.ts

@@ -0,0 +1,41 @@
+import {
+  bookingTrainLengthMeters,
+  deriveTrainCapacityFromLocomotive,
+} from './train-capacity.util';
+
+describe('train-capacity.util', () => {
+  const nw5 = { lengthMeters: 14, capacityTons: 70 };
+
+  it('derives wagon slots from locomotive length and weight, not a fixed 53', () => {
+    const shortLoco = deriveTrainCapacityFromLocomotive(
+      { maxPullWeightTons: 2000, maxTrainLengthMeters: 280 },
+      [nw5],
+    );
+    expect(shortLoco.maxWagonSlots).toBe(20); // 280 / 14
+    expect(shortLoco.maxWagonSlots).not.toBe(53);
+
+    const heavyLoco = deriveTrainCapacityFromLocomotive(
+      { maxPullWeightTons: 2100, maxTrainLengthMeters: 760 },
+      [nw5],
+    );
+    expect(heavyLoco.maxWagonSlots).toBe(30); // min(54, 30) from weight 2100/70
+  });
+
+  it('uses shortest wagon type when mixed types are present', () => {
+    const longBulk = { lengthMeters: 18, capacityTons: 80 };
+    const mixed = deriveTrainCapacityFromLocomotive(
+      { maxPullWeightTons: 3500, maxTrainLengthMeters: 760 },
+      [nw5, longBulk],
+    );
+    expect(mixed.maxWagonSlots).toBe(
+      Math.min(Math.floor(760 / 14), Math.floor(3500 / 70)),
+    );
+  });
+
+  it('computes booking length by freight type', () => {
+    expect(
+      bookingTrainLengthMeters('CONTAINER', 2, { container: 14, bulk: 14 }),
+    ).toBe(28);
+    expect(bookingTrainLengthMeters('BULK', 3, { container: 14, bulk: 18 })).toBe(54);
+  });
+});