From 5b5881183385b33819ad65e98e686bb883a1f2cc Mon Sep 17 00:00:00 2001
From: Laurent Cozic <laurent@cozic.net>
Date: Thu, 7 Oct 2021 14:19:40 +0100
Subject: [PATCH] Server: Add support for promotion codes

---
 Assets/WebsiteAssets/templates/plans.mustache | 10 +++---
 packages/server/src/routes/index/stripe.ts    | 34 +++++++++++++++----
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/Assets/WebsiteAssets/templates/plans.mustache b/Assets/WebsiteAssets/templates/plans.mustache
index f70c0ccf2..1a8579b02 100644
--- a/Assets/WebsiteAssets/templates/plans.mustache
+++ b/Assets/WebsiteAssets/templates/plans.mustache
@@ -59,7 +59,7 @@
 	<script>
 		const urlQuery = new URLSearchParams(location.search);
 		let subscriptionPeriod = 'monthly';
-		var stripe = Stripe('{{{stripeConfig.publishableKey}}}');
+		const stripe = Stripe('{{{stripeConfig.publishableKey}}}');
 
 		let checkoutSessionUser = null;
 
@@ -82,9 +82,9 @@
 		}
 
 		var createCheckoutSession = function(priceId) {
-			const coupon = urlQuery.get('coupon') || '';
+			const promotionCode = urlQuery.get('promo') || '';
 
-			console.info('Creating Stripe session for price:', priceId, 'Coupon:', coupon);
+			console.info('Creating Stripe session for price:', priceId, 'Promotion code:', promotionCode);
 
 			return fetch("{{{stripeConfig.webhookBaseUrl}}}/stripe/createCheckoutSession", {
 				method: "POST",
@@ -92,8 +92,8 @@
 					"Content-Type": "application/json"
 				},
 				body: JSON.stringify({
-					priceId: priceId,
-					coupon: coupon,
+					priceId,
+					promotionCode,
 					email: checkoutSessionUser ? checkoutSessionUser.email : '',
 				})
 			}).then(async function(result) {
diff --git a/packages/server/src/routes/index/stripe.ts b/packages/server/src/routes/index/stripe.ts
index 4d4bda879..5834ff556 100644
--- a/packages/server/src/routes/index/stripe.ts
+++ b/packages/server/src/routes/index/stripe.ts
@@ -4,7 +4,7 @@ import { RouteType } from '../../utils/types';
 import { AppContext } from '../../utils/types';
 import { bodyFields } from '../../utils/requestUtils';
 import globalConfig from '../../config';
-import { ErrorForbidden, ErrorNotFound } from '../../utils/errors';
+import { ErrorBadRequest, ErrorForbidden, ErrorNotFound } from '../../utils/errors';
 import { Stripe } from 'stripe';
 import Logger from '@joplin/lib/Logger';
 import getRawBody = require('raw-body');
@@ -35,6 +35,7 @@ async function stripeEvent(stripe: Stripe, req: any): Promise<Stripe.Event> {
 interface CreateCheckoutSessionFields {
 	priceId: string;
 	coupon: string;
+	promotionCode: string;
 	email: string;
 }
 
@@ -145,15 +146,30 @@ export const postHandlers: PostHandlers = {
 		};
 
 		if (fields.coupon) {
-			delete checkoutSession.allow_promotion_codes;
-
 			checkoutSession.discounts = [
 				{
 					coupon: fields.coupon.trim(),
 				},
 			];
+		} else if (fields.promotionCode) {
+			const p = await stripe.promotionCodes.list({ code: fields.promotionCode });
+			const codes = p.data;
+			if (!codes.length) throw new ErrorBadRequest(`Could not find promotion code: ${fields.promotionCode}`);
+
+			// Should not be possible in our setup since a unique code is
+			// created for each customer.
+			if (codes.length > 1) console.warn(`Found more than one promotion code: ${fields.promotionCode}`);
+
+			checkoutSession.discounts = [
+				{
+					promotion_code: codes[0].id,
+				},
+			];
 		}
 
+		// "You may only specify one of these parameters: allow_promotion_codes, discounts"
+		if (checkoutSession.discounts) delete checkoutSession.allow_promotion_codes;
+
 		if (fields.email) {
 			checkoutSession.customer_email = fields.email.trim();
 
@@ -184,7 +200,7 @@ export const postHandlers: PostHandlers = {
 
 	// # How to test the complete workflow locally
 	//
-	// - In website/build.ts, set the env to "dev", then build the website - `npm run watch-website`
+	// - In website/build.ts, set the env to "dev", then build the website - `npm run watchWebsite`
 	// - Start the Stripe CLI tool: `stripe listen --forward-to http://joplincloud.local:22300/stripe/webhook`
 	// - Copy the webhook secret, and paste it in joplin-credentials/server.env (under STRIPE_WEBHOOK_SECRET)
 	// - Start the local Joplin Server, `npm run start-dev`, running under http://joplincloud.local:22300
@@ -422,14 +438,15 @@ const getHandlers: Record<string, StripeRouteHandler> = {
 				<script>
 					var stripe = Stripe(${JSON.stringify(stripeConfig().publishableKey)});
 
-					var createCheckoutSession = function(priceId) {
+					var createCheckoutSession = function(priceId, promotionCode) {
 						return fetch("/stripe/createCheckoutSession", {
 							method: "POST",
 							headers: {
 								"Content-Type": "application/json"
 							},
 							body: JSON.stringify({
-								priceId: priceId
+								priceId,
+								promotionCode,
 							})
 						}).then(function(result) {
 							return result.json();
@@ -438,6 +455,7 @@ const getHandlers: Record<string, StripeRouteHandler> = {
 				</script>
 			</head>
 			<body>
+				Promotion code: <input id="promotion_code" type="text"/> <br/>
 				<button id="checkout_basic">Subscribe Basic</button>
 				<button id="checkout_pro">Subscribe Pro</button>
 				<button id="checkout_custom">Subscribe Custom</button>
@@ -455,7 +473,9 @@ const getHandlers: Record<string, StripeRouteHandler> = {
 					}
 
 					function createSessionAndRedirect(priceId) {
-						createCheckoutSession(priceId).then(function(data) {
+						var promotionCode = document.getElementById('promotion_code').value;
+
+						createCheckoutSession(priceId, promotionCode).then(function(data) {
 							// Call Stripe.js method to redirect to the new Checkout page
 							stripe
 								.redirectToCheckout({