feat: add completed documents per month graph

packages/lib/server-only/user/get-monthly-completed-document.ts

@@ -0,0 +1,35 @@
+import { DateTime } from 'luxon';
+
+import { prisma } from '@documenso/prisma';
+
+export type GetCompletedDocumentsMonthlyResult = Array<{
+  month: string;
+  count: number;
+  cume_count: number;
+}>;
+
+type GetCompletedDocumentsMonthlyQueryResult = Array<{
+  month: Date;
+  count: bigint;
+  cume_count: bigint;
+}>;
+
+export const getCompletedDocumentsMonthly = async () => {
+  const result = await prisma.$queryRaw<GetCompletedDocumentsMonthlyQueryResult>`
+    SELECT
+      DATE_TRUNC('month', "completedAt") AS "month",
+      COUNT("id") as "count",
+      SUM(COUNT("id")) OVER (ORDER BY DATE_TRUNC('month', "completedAt")) as "cume_count"
+    FROM "Document"
+    WHERE "status" = 'COMPLETED'
+    GROUP BY "month"
+    ORDER BY "month" DESC
+    LIMIT 12
+  `;
+
+  return result.map((row) => ({
+    month: DateTime.fromJSDate(row.month).toFormat('yyyy-MM'),
+    count: Number(row.count),
+    cume_count: Number(row.cume_count),
+  }));
+};