feat(F-189): completed feature

project/src/modules/pos/application/build-pos-receipt.ts

@@ -4,6 +4,18 @@ import { AppError } from '../../../shared/errors.js';
 
 type Queryable = Pick<pg.Pool, 'query'> | Pick<pg.PoolClient, 'query'>;
 
+interface ReturnedItemRow {
+  id: string;
+  quantity: number;
+  returned_quantity: number;
+  unit_price_cents: number;
+  discount_cents: number;
+  tax_cents: number;
+  name: string;
+  sku: string;
+  is_free_item: boolean;
+}
+
 interface ReceiptOrderRow {
   id: string;
   receipt_number: string | null;
@@ -165,3 +177,75 @@ function integerOrNull(value: unknown): number | null {
 function integerOrZero(value: unknown): number {
   return typeof value === 'number' && Number.isInteger(value) ? value : 0;
 }
+
+/**
+ * Build a return/reversal receipt based on the original POS order.
+ *
+ * The returned payload uses negative line totals and prices `R-<original>` as
+ * its receipt number without persisting a separate sequence. The `paidCents`
+ * block is replaced with a `refundedCents` flag and the receipt is flagged
+ * `isReturn=true` so renderers can style it accordingly.
+ */
+export async function buildPosReturnReceipt(
+  queryable: Queryable,
+  orderId: string,
+  refundedCents: number,
+): Promise<PosReceipt> {
+  const original = await buildPosReceipt(queryable, orderId);
+  const itemResult = await queryable.query<ReturnedItemRow>(
+    `SELECT id, quantity, returned_quantity, unit_price_cents, discount_cents, tax_cents,
+            name, sku, is_free_item
+       FROM orders_items WHERE order_id = $1 ORDER BY created_at, id`,
+    [orderId],
+  );
+  const items = itemResult.rows
+    .filter((row) => row.returned_quantity > 0)
+    .map((row) => {
+      const returnedQuantity = Number(row.returned_quantity);
+      const unitPrice = Number(row.unit_price_cents);
+      const discount = Number(row.discount_cents);
+      const tax = Number(row.tax_cents);
+      const subtotal = unitPrice * returnedQuantity;
+      const discountCents = discount * returnedQuantity;
+      const taxCents = tax * returnedQuantity;
+      const total = subtotal - discountCents + taxCents;
+      return {
+        name: row.name,
+        sku: row.sku,
+        quantity: returnedQuantity,
+        unitPriceCents: unitPrice,
+        subtotalCents: subtotal,
+        discountCents,
+        taxCents,
+        totalCents: -total,
+        freeItem: row.is_free_item,
+      };
+    });
+  const subtotal = items.reduce((sum, item) => sum + item.subtotalCents, 0);
+  const discount = items.reduce((sum, item) => sum + item.discountCents, 0);
+  const tax = items.reduce((sum, item) => sum + item.taxCents, 0);
+  return {
+    receiptNumber: original.receiptNumber.startsWith('R-')
+      ? original.receiptNumber
+      : `R-${original.receiptNumber}`,
+    orderId: original.orderId,
+    issuedAt: original.issuedAt,
+    company: original.company,
+    terminal: original.terminal,
+    cashier: original.cashier,
+    sessionId: original.sessionId,
+    customerEmail: original.customerEmail,
+    items,
+    subtotalCents: -subtotal,
+    discountCents: -discount,
+    taxCents: -tax,
+    totalCents: -refundedCents,
+    payments: [],
+    changeCents: 0,
+    header: original.header,
+    returnPolicy: original.returnPolicy,
+    footer: original.footer,
+    originalReceiptNumber: original.receiptNumber,
+    isReturn: true,
+  };
+}