refactor(sync): move the delta feed's domain pages out of its route

src/lib/sync/changes/read-rows.ts

@@ -0,0 +1,147 @@
+/**
+ * The per-domain keyset walks of the delta feed.
+ *
+ * Live and soft-deleted rows come out of the same scan: a soft-delete bumps
+ * `updatedAt`, so a tombstone is just a row whose `deletedAt` is non-null.
+ * Each walk fetches `limit + 1` rows to detect `hasMore` without a count
+ * query.
+ */
+import { prisma } from "@/lib/db";
+import type { Prisma } from "@/generated/prisma/client";
+import type { DomainWatermark, SyncCursor } from "@/lib/sync/cursor";
+import { dayLogSymptomInclude } from "@/lib/cycle/dto";
+
+const MEASUREMENT_SELECT = {
+  id: true,
+  externalId: true,
+  type: true,
+  value: true,
+  unit: true,
+  measuredAt: true,
+  source: true,
+  notes: true,
+  notesEncrypted: true,
+  syncVersion: true,
+  deletedAt: true,
+  updatedAt: true,
+} satisfies Prisma.MeasurementSelect;
+
+const MOOD_SELECT = {
+  id: true,
+  date: true,
+  mood: true,
+  score: true,
+  moodA1: true,
+  stressA2: true,
+  energyA3: true,
+  connectionA4: true,
+  stabilityA5: true,
+  context: true,
+  tags: true,
+  note: true,
+  noteEncrypted: true,
+  moodLoggedAt: true,
+  source: true,
+  syncVersion: true,
+  deletedAt: true,
+  updatedAt: true,
+} satisfies Prisma.MoodEntrySelect;
+
+const INTAKE_SELECT = {
+  id: true,
+  medicationId: true,
+  scheduledFor: true,
+  takenAt: true,
+  skipped: true,
+  source: true,
+  autoRecorded: true,
+  syncVersion: true,
+  deletedAt: true,
+  updatedAt: true,
+} satisfies Prisma.MedicationIntakeEventSelect;
+
+export type MeasurementRow = Prisma.MeasurementGetPayload<{
+  select: typeof MEASUREMENT_SELECT;
+}>;
+export type MoodRow = Prisma.MoodEntryGetPayload<{
+  select: typeof MOOD_SELECT;
+}>;
+export type IntakeRow = Prisma.MedicationIntakeEventGetPayload<{
+  select: typeof INTAKE_SELECT;
+}>;
+export type CycleDayRow = Prisma.CycleDayLogGetPayload<{
+  include: typeof dayLogSymptomInclude;
+}>;
+export type CycleRow = Prisma.MenstrualCycleGetPayload<object>;
+
+/**
+ * Build the `(updatedAt, id)` keyset predicate for a domain's watermark.
+ * Empty object (full scan) when the client has no watermark for it yet.
+ */
+function keysetFilter(wm: DomainWatermark | undefined) {
+  if (!wm) return {};
+  const at = new Date(wm.updatedAtMs);
+  return {
+    OR: [
+      { updatedAt: { gt: at } },
+      { AND: [{ updatedAt: at }, { id: { gt: wm.id } }] },
+    ],
+  };
+}
+
+export interface DomainRows {
+  measurements: MeasurementRow[];
+  mood: MoodRow[];
+  intakes: IntakeRow[];
+  cycleDays: CycleDayRow[];
+  cycles: CycleRow[];
+}
+
+/**
+ * Read one page plus one row of every domain past its watermark. The cycle
+ * walks are skipped outright when the module is off, not filtered after the
+ * fact, so the disabled rows are never read out of Postgres at all.
+ */
+export async function readDomainRows(
+  userId: string,
+  cursor: SyncCursor,
+  limit: number,
+  cycleEnabled: boolean,
+): Promise<DomainRows> {
+  const [measurements, mood, intakes, cycleDays, cycles] = await Promise.all([
+    prisma.measurement.findMany({
+      where: { userId, ...keysetFilter(cursor.measurements) },
+      orderBy: [{ updatedAt: "asc" }, { id: "asc" }],
+      take: limit + 1,
+      select: MEASUREMENT_SELECT,
+    }),
+    prisma.moodEntry.findMany({
+      where: { userId, ...keysetFilter(cursor.mood) },
+      orderBy: [{ updatedAt: "asc" }, { id: "asc" }],
+      take: limit + 1,
+      select: MOOD_SELECT,
+    }),
+    prisma.medicationIntakeEvent.findMany({
+      where: { userId, ...keysetFilter(cursor.intakes) },
+      orderBy: [{ updatedAt: "asc" }, { id: "asc" }],
+      take: limit + 1,
+      select: INTAKE_SELECT,
+    }),
+    cycleEnabled
+      ? prisma.cycleDayLog.findMany({
+          where: { userId, ...keysetFilter(cursor.cycleDays) },
+          orderBy: [{ updatedAt: "asc" }, { id: "asc" }],
+          take: limit + 1,
+          include: dayLogSymptomInclude,
+        })
+      : [],
+    cycleEnabled
+      ? prisma.menstrualCycle.findMany({
+          where: { userId, ...keysetFilter(cursor.cycles) },
+          orderBy: [{ updatedAt: "asc" }, { id: "asc" }],
+          take: limit + 1,
+        })
+      : [],
+  ]);
+  return { measurements, mood, intakes, cycleDays, cycles };
+}