feat: open page api (#1419)

apps/openpage-api/lib/growth/get-user-monthly-growth.ts

@@ -0,0 +1,38 @@
+import { DateTime } from 'luxon';
+
+import { kyselyPrisma, sql } from '@documenso/prisma';
+
+export const getUserMonthlyGrowth = async (type: 'count' | 'cumulative' = 'count') => {
+  const qb = kyselyPrisma.$kysely
+    .selectFrom('User')
+    .select(({ fn }) => [
+      fn<Date>('DATE_TRUNC', [sql.lit('MONTH'), 'User.createdAt']).as('month'),
+      fn.count('id').as('count'),
+      fn
+        .sum(fn.count('id'))
+        // eslint-disable-next-line @typescript-eslint/consistent-type-assertions, @typescript-eslint/no-explicit-any
+        .over((ob) => ob.orderBy(fn('DATE_TRUNC', [sql.lit('MONTH'), 'User.createdAt']) as any))
+        .as('cume_count'),
+    ])
+    .groupBy('month')
+    .orderBy('month', 'desc')
+    .limit(12);
+
+  const result = await qb.execute();
+
+  const transformedData = {
+    labels: result.map((row) => DateTime.fromJSDate(row.month).toFormat('MMM yyyy')).reverse(),
+    datasets: [
+      {
+        label: type === 'count' ? 'New Users' : 'Total Users',
+        data: result
+          .map((row) => (type === 'count' ? Number(row.count) : Number(row.cume_count)))
+          .reverse(),
+      },
+    ],
+  };
+
+  return transformedData;
+};
+
+export type GetUserMonthlyGrowthResult = Awaited<ReturnType<typeof getUserMonthlyGrowth>>;