From 08ce8f8d90606a75efd3b68f27b3ff4c98649983 Mon Sep 17 00:00:00 2001
From: mijinummi <tech.md.auwal@gmail.com>
Date: Sat, 28 Mar 2026 16:59:19 +0100
Subject: [PATCH] Enhanced Dashboard Analytics & Reporting (#211)

---
 .../src/analytics/analytics.controller.ts     | 22 +++++++++++++
 .../src/analytics/analytics.repository.ts     | 32 +++++++++++++++++++
 .../src/analytics/analytics.service.ts        | 21 ++++++++++++
 .../analytics/tests/analytics.service.spec.ts | 26 +++++++++++++++
 app/backend/src/utils/csv-export.ts           |  6 ++++
 app/backend/src/utils/pdf-export.ts           | 14 ++++++++
 6 files changed, 121 insertions(+)
 create mode 100644 app/backend/src/analytics/analytics.controller.ts
 create mode 100644 app/backend/src/analytics/analytics.repository.ts
 create mode 100644 app/backend/src/analytics/analytics.service.ts
 create mode 100644 app/backend/src/analytics/tests/analytics.service.spec.ts
 create mode 100644 app/backend/src/utils/csv-export.ts
 create mode 100644 app/backend/src/utils/pdf-export.ts

diff --git a/app/backend/src/analytics/analytics.controller.ts b/app/backend/src/analytics/analytics.controller.ts
new file mode 100644
index 0000000..e2987cf
--- /dev/null
+++ b/app/backend/src/analytics/analytics.controller.ts
@@ -0,0 +1,22 @@
+import { Controller, Get, Query } from "@nestjs/common";
+import { AnalyticsService } from "./analytics.service";
+
+@Controller("analytics")
+export class AnalyticsController {
+  constructor(private readonly service: AnalyticsService) {}
+
+  @Get("dashboard")
+  async dashboard(@Query("userId") userId: string) {
+    return this.service.getDashboardData(userId);
+  }
+
+  @Get("time-series")
+  async timeSeries(@Query("userId") userId: string, @Query("interval") interval: "day" | "week" | "month") {
+    return this.service.getTimeSeriesData(userId, interval);
+  }
+
+  @Get("export")
+  async export(@Query("userId") userId: string, @Query("format") format: "csv" | "pdf") {
+    return this.service.exportReport(userId, format);
+  }
+}
diff --git a/app/backend/src/analytics/analytics.repository.ts b/app/backend/src/analytics/analytics.repository.ts
new file mode 100644
index 0000000..13e3c88
--- /dev/null
+++ b/app/backend/src/analytics/analytics.repository.ts
@@ -0,0 +1,32 @@
+import { AppDataSource } from "../data-source";
+import { Transaction } from "../entities/transaction.entity";
+
+export const transactionRepo = AppDataSource.getRepository(Transaction);
+
+export async function getTotalVolumeUSD(userId: string) {
+  return transactionRepo
+    .createQueryBuilder("t")
+    .select("SUM(t.amount_usd)", "total")
+    .where("t.userId = :userId", { userId })
+    .getRawOne();
+}
+
+export async function getAssetDistribution(userId: string) {
+  return transactionRepo
+    .createQueryBuilder("t")
+    .select("t.asset, SUM(t.amount_usd)", "total")
+    .where("t.userId = :userId", { userId })
+    .groupBy("t.asset")
+    .getRawMany();
+}
+
+export async function getTimeSeries(userId: string, interval: "day" | "week" | "month") {
+  return transactionRepo
+    .createQueryBuilder("t")
+    .select(`DATE_TRUNC('${interval}', t.createdAt)`, "period")
+    .addSelect("SUM(t.amount_usd)", "total")
+    .where("t.userId = :userId", { userId })
+    .groupBy("period")
+    .orderBy("period", "ASC")
+    .getRawMany();
+}
diff --git a/app/backend/src/analytics/analytics.service.ts b/app/backend/src/analytics/analytics.service.ts
new file mode 100644
index 0000000..afbdbc5
--- /dev/null
+++ b/app/backend/src/analytics/analytics.service.ts
@@ -0,0 +1,21 @@
+import { getTotalVolumeUSD, getAssetDistribution, getTimeSeries } from "./analytics.repository";
+import { exportToCSV } from "../utils/csv-export";
+import { exportToPDF } from "../utils/pdf-export";
+
+export class AnalyticsService {
+  async getDashboardData(userId: string) {
+    const totalVolume = await getTotalVolumeUSD(userId);
+    const distribution = await getAssetDistribution(userId);
+    return { totalVolume, distribution };
+  }
+
+  async getTimeSeriesData(userId: string, interval: "day" | "week" | "month") {
+    return getTimeSeries(userId, interval);
+  }
+
+  async exportReport(userId: string, format: "csv" | "pdf") {
+    const data = await this.getDashboardData(userId);
+    if (format === "csv") return exportToCSV(data);
+    if (format === "pdf") return exportToPDF(data);
+  }
+}
diff --git a/app/backend/src/analytics/tests/analytics.service.spec.ts b/app/backend/src/analytics/tests/analytics.service.spec.ts
new file mode 100644
index 0000000..7640db1
--- /dev/null
+++ b/app/backend/src/analytics/tests/analytics.service.spec.ts
@@ -0,0 +1,26 @@
+import { AnalyticsService } from "../analytics.service";
+
+describe("AnalyticsService", () => {
+  const service = new AnalyticsService();
+
+  it("should return dashboard data", async () => {
+    const data = await service.getDashboardData("user1");
+    expect(data).toHaveProperty("totalVolume");
+    expect(data).toHaveProperty("distribution");
+  });
+
+  it("should return time series data", async () => {
+    const series = await service.getTimeSeriesData("user1", "day");
+    expect(Array.isArray(series)).toBe(true);
+  });
+
+  it("should export CSV", async () => {
+    const csv = await service.exportReport("user1", "csv");
+    expect(typeof csv).toBe("string");
+  });
+
+  it("should export PDF", async () => {
+    const pdf = await service.exportReport("user1", "pdf");
+    expect(typeof pdf).toBe("string");
+  });
+});
diff --git a/app/backend/src/utils/csv-export.ts b/app/backend/src/utils/csv-export.ts
new file mode 100644
index 0000000..87c18b7
--- /dev/null
+++ b/app/backend/src/utils/csv-export.ts
@@ -0,0 +1,6 @@
+import { Parser } from "json2csv";
+
+export function exportToCSV(data: any) {
+  const parser = new Parser();
+  return parser.parse(data);
+}
diff --git a/app/backend/src/utils/pdf-export.ts b/app/backend/src/utils/pdf-export.ts
new file mode 100644
index 0000000..e3ca053
--- /dev/null
+++ b/app/backend/src/utils/pdf-export.ts
@@ -0,0 +1,14 @@
+import PDFDocument from "pdfkit";
+
+export function exportToPDF(data: any) {
+  const doc = new PDFDocument();
+  let buffers: Buffer[] = [];
+  doc.on("data", buffers.push.bind(buffers));
+  doc.on("end", () => Buffer.concat(buffers));
+
+  doc.text("Financial Report");
+  doc.text(JSON.stringify(data, null, 2));
+  doc.end();
+
+  return Buffer.concat(buffers).toString("base64");
+}