feat: move to V2

apps/api/src/ledger/product-fields.ts

@@ -0,0 +1,66 @@
+import { Prisma } from '../prisma/prisma.service';
+
+/** The fields of a product that the dashboard and the terminals change; stock changes through its own rules. */
+export const PRODUCT_FIELDS = [
+  'name', 'category', 'priceInCents', 'buyPriceInCents', 'lowStockThreshold', 'desiredStock', 'archived', 'imageId',
+] as const;
+export type ProductField = (typeof PRODUCT_FIELDS)[number];
+
+export type ProductChanges = {
+  name?: string;
+  category?: string | null;
+  priceInCents?: number;
+  buyPriceInCents?: number | null;
+  lowStockThreshold?: number | null;
+  desiredStock?: number | null;
+  archived?: boolean;
+  imageId?: string | null;
+};
+
+type FieldTimes = Partial<Record<ProductField, string>>;
+
+/**
+ * Merges [changes] made at [at] into a product whose fields were last changed at [times]: per field, the latest
+ * change wins. A price changed on the dashboard and a name changed on an offline terminal both survive; a change
+ * that arrives late (a terminal coming back online) loses to a newer change of the same field.
+ *
+ * Returns the Prisma data to write (empty when nothing wins) and the product's new field times.
+ */
+export function mergeProductChanges(times: unknown, changes: ProductChanges, at: Date, current?: { archivedAt: Date | null }) {
+  const previous = (times && typeof times === 'object' ? times : {}) as FieldTimes;
+  const next: FieldTimes = { ...previous };
+  const data: Prisma.ProductUncheckedUpdateInput = {};
+
+  for (const field of PRODUCT_FIELDS) {
+    const value = changes[field];
+    if (value === undefined) continue;
+    const last = previous[field];
+    if (last && new Date(last) > at) continue;
+
+    next[field] = at.toISOString();
+    if (field === 'archived') {
+      // Archiving again keeps the original archive time
+      data.archivedAt = value ? (current?.archivedAt ?? at) : null;
+    } else {
+      (data as Record<string, unknown>)[field] = value;
+    }
+  }
+
+  return { data, fieldUpdatedAt: next as Prisma.InputJsonObject, changed: Object.keys(data).length > 0 };
+}
+
+/** Field times for a product created at [at]: every field it was created with. */
+export function createdFieldTimes(changes: ProductChanges, at: Date): Prisma.InputJsonObject {
+  return Object.fromEntries(PRODUCT_FIELDS.filter((f) => changes[f] !== undefined).map((f) => [f, at.toISOString()]));
+}
+
+/**
+ * When a change made now on the dashboard happened: now, or just after the latest field time when a terminal whose
+ * clock runs a little ahead stamped one later. A change on the dashboard is made last, so it wins.
+ */
+export function dashboardChangeTime(now: Date, times: unknown): Date {
+  const stamps = Object.values((times && typeof times === 'object' ? times : {}) as Record<string, string>)
+    .map((t) => new Date(t).getTime())
+    .filter((t) => !Number.isNaN(t));
+  return new Date(Math.max(now.getTime(), ...stamps));
+}