Merge pull request #248 from codewithzubair07/feature/financial-insights-api-190

feat: implement financial insights aggregation API (Issue #190)

Author: Baskarayelu

app/api/insights/route.ts

@@ -0,0 +1,128 @@
+import { NextRequest, NextResponse } from "next/server";
+
+/**
+ * Financial Insights Aggregation API
+ *
+ * Supported query params:
+ * ?period=current_month
+ * ?period=last_3_months
+ * ?period=last_year
+ *
+ * NOTE:
+ * Currently uses mock transaction data.
+ * Historical persistence not implemented yet.
+ */
+
+type Transaction = {
+  id: string;
+  amount: number;
+  type: "spending" | "savings" | "bill" | "insurance";
+  category: string;
+  date: Date;
+};
+
+// Mock Data (Replace with DB later)
+const transactions: Transaction[] = [
+  {
+    id: "1",
+    amount: 500,
+    type: "spending",
+    category: "Food",
+    date: new Date("2026-02-01"),
+  },
+  {
+    id: "2",
+    amount: 200,
+    type: "savings",
+    category: "Emergency Fund",
+    date: new Date("2026-02-05"),
+  },
+  {
+    id: "3",
+    amount: 300,
+    type: "bill",
+    category: "Electricity",
+    date: new Date("2026-01-15"),
+  },
+  {
+    id: "4",
+    amount: 150,
+    type: "insurance",
+    category: "Health Insurance",
+    date: new Date("2025-12-10"),
+  },
+];
+
+function filterByPeriod(period: string, txs: Transaction[]) {
+  const now = new Date();
+
+  if (period === "current_month") {
+    return txs.filter(
+      (t) =>
+        t.date.getMonth() === now.getMonth() &&
+        t.date.getFullYear() === now.getFullYear()
+    );
+  }
+
+  if (period === "last_3_months") {
+    const past = new Date();
+    past.setMonth(now.getMonth() - 3);
+    return txs.filter((t) => t.date >= past);
+  }
+
+  if (period === "last_year") {
+    const past = new Date();
+    past.setFullYear(now.getFullYear() - 1);
+    return txs.filter((t) => t.date >= past);
+  }
+
+  return txs;
+}
+
+export async function GET(req: NextRequest) {
+  const { searchParams } = new URL(req.url);
+  const period = searchParams.get("period") || "current_month";
+
+  const filtered = filterByPeriod(period, transactions);
+
+  const spendingTotal = filtered
+    .filter((t) => t.type === "spending")
+    .reduce((sum, t) => sum + t.amount, 0);
+
+  const savingsTotal = filtered
+    .filter((t) => t.type === "savings")
+    .reduce((sum, t) => sum + t.amount, 0);
+
+  const billsTotal = filtered
+    .filter((t) => t.type === "bill")
+    .reduce((sum, t) => sum + t.amount, 0);
+
+  const insuranceTotal = filtered
+    .filter((t) => t.type === "insurance")
+    .reduce((sum, t) => sum + t.amount, 0);
+
+  // Category Breakdown
+  const breakdown = filtered.reduce((acc: any, t) => {
+    acc[t.category] = (acc[t.category] || 0) + t.amount;
+    return acc;
+  }, {});
+
+  // Trend Data (Monthly grouping)
+  const trend = filtered.reduce((acc: any, t) => {
+    const month = `${t.date.getFullYear()}-${t.date.getMonth() + 1}`;
+    acc[month] = (acc[month] || 0) + t.amount;
+    return acc;
+  }, {});
+
+  return NextResponse.json({
+    period,
+    spendingTotal,
+    savingsTotal,
+    billsTotal,
+    insuranceTotal,
+    breakdown,
+    trend,
+    note:
+      "Data currently generated from mock transactions. Historical DB integration pending.",
+  });
+}