From 6e29980f705f310557d81aae789862a6431f31c1 Mon Sep 17 00:00:00 2001
From: Satoshi Ebisawa <satoshi.ebisawa@route06.co.jp>
Date: Mon, 16 Dec 2024 15:15:08 +0900
Subject: [PATCH] Setup stripe billing-meter webhook endpoint

---
 app/webhooks/stripe/billing-meter/route.ts | 93 ++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 app/webhooks/stripe/billing-meter/route.ts

diff --git a/app/webhooks/stripe/billing-meter/route.ts b/app/webhooks/stripe/billing-meter/route.ts
new file mode 100644
index 00000000..e221ac97
--- /dev/null
+++ b/app/webhooks/stripe/billing-meter/route.ts
@@ -0,0 +1,93 @@
+/**
+ * Handle Stripe Billing Meter webhooks
+ *
+ * Error codes: https://docs.stripe.com/billing/subscriptions/usage-based/recording-usage-api#error-codes
+ */
+import { stripe } from "@/services/external/stripe";
+import { captureEvent, captureException } from "@sentry/nextjs";
+import type Stripe from "stripe";
+
+const relevantEvents = new Set([
+	"v1.billing.meter.error_report_triggered",
+	"v1.billing.meter.no_meter_found",
+]);
+
+export async function POST(req: Request) {
+	const body = await req.text();
+	const sig = req.headers.get("stripe-signature") as string;
+	const webhookSecret = process.env.STRIPE_BILLING_METER_WEBHOOK_SECRET;
+	let thinEvent: Stripe.ThinEvent;
+
+	try {
+		if (!sig || !webhookSecret)
+			return new Response("Webhook secret not found.", { status: 400 });
+		thinEvent = stripe.parseThinEvent(body, sig, webhookSecret);
+		console.log(`🔔  Webhook received: ${thinEvent.type}`);
+	} catch (err: unknown) {
+		console.log(`❌ Error: ${err}`);
+		captureException(err);
+		return new Response(`Webhook Error: ${err}`, { status: 400 });
+	}
+
+	if (!relevantEvents.has(thinEvent.type)) {
+		return new Response(`Unsupported event type: ${thinEvent.type}`, {
+			status: 400,
+		});
+	}
+
+	const event = await stripe.v2.core.events.retrieve(thinEvent.id);
+	try {
+		console.error(
+			`
+				Stripe Billing Meter Error Report:
+				Period: ${event.data.validation_start} - ${event.data.validation_end}
+				Summary: ${event.data.developer_message_summary}
+				Error Count: ${event.data.reason.error_count}`
+				.trim()
+				.replace(/^\s+/gm, "    "),
+		);
+
+		for (const errorType of event.data.reason.error_types) {
+			console.error(
+				`Error Type: ${errorType.code} (${errorType.error_count} occurrences)`,
+			);
+			for (const error of errorType.sample_errors) {
+				console.error(`  - ${error.error_message}`);
+			}
+		}
+		if ("related_object" in event && event.related_object != null) {
+			console.error(
+				`
+				Related Object:
+        ID: ${event.related_object.id}
+        Type: ${event.related_object.type}
+        URL: ${event.related_object.url}`
+					.trim()
+					.replace(/^\s+/gm, "    "),
+			);
+		}
+
+		captureEvent({
+			message: "Stripe Billing Meter Error",
+			level: "error",
+			extra: {
+				validationPeriod: {
+					start: event.data.validation_start,
+					end: event.data.validation_end,
+				},
+				summary: event.data.developer_message_summary,
+				errors: event.data.reason.error_types,
+				relatedObject: "related_object" in event ? event.related_object : null,
+			},
+		});
+	} catch (error) {
+		console.log(error);
+		return new Response(
+			"Webhook handler failed. View your Next.js function logs.",
+			{
+				status: 400,
+			},
+		);
+	}
+	return new Response(JSON.stringify({ received: true }));
+}