Stripe: creates GET endpoint for customer portal session

api/api.go

@@ -159,6 +159,9 @@ func (a *API) initRouter() http.Handler {
 		// get stripe checkout session info
 		log.Infow("new route", "method", "GET", "path", subscriptionsCheckoutSession)
 		r.Get(subscriptionsCheckoutSession, a.checkoutSessionHandler)
+		// get stripe subscription portal session info
+		log.Infow("new route", "method", "GET", "path", subscriptionsPortal)
+		r.Get(subscriptionsPortal, a.createSubscriptionPortalSessionHandler)
 	})
 
 	// Public routes

api/docs.md

@@ -38,6 +38,7 @@
 - [🔰 Subscriptions](#-subscriptions)
   - [🛒 Create Checkout session](#-create-checkout-session)
   - [🛍️ Get Checkout session info](#-get-checkout-session-info)
+  - [🔗 Create Subscription Portal Session](#-create-subscription-portal-session)
 
 </details>
 
@@ -971,4 +972,26 @@ This request can be made only by organization admins.
 |:---:|:---:|:---|
 | `400` | `40010` | `malformed URL parameter` |
 | `400` | `40023` | `session not found` |
+| `500` | `50002` | `internal server error` |
+
+### 🔗 Create Subscription Portal Session
+
+* **Path** `/subscriptions/{orgAddress}/portal`
+* **Method** `GET`
+* **Headers**
+  * `Authentication: Bearer <user_token>`
+
+* **Response**
+```json
+{
+  "portalURL": "https://portal.stripe.com/session/..."
+}
+```
+
+* **Errors**
+
+| HTTP Status | Error code | Message |
+|:---:|:---:|:---|
+| `401` | `40001` | `user not authorized` |
+| `400` | `40011` | `no organization provided` |
 | `500` | `50002` | `internal server error` |

api/routes.go

@@ -70,4 +70,6 @@ const (
 	subscriptionsCheckout = "/subscriptions/checkout"
 	// GET /subscriptions/checkout/{sessionID} to get the checkout session information
 	subscriptionsCheckoutSession = "/subscriptions/checkout/{sessionID}"
+	// GET /subscriptions/portal to get the stripe subscription portal URL
+	subscriptionsPortal = "/subscriptions/{address}/portal/"
 )

api/stripe.go

@@ -234,3 +234,36 @@ func (a *API) getSubscriptionOrgInfo(event *stripe.Event) (*stripeService.Stripe
 
 	return stripeSubscriptionInfo, org, nil
 }
+
+// createSubscriptionPortalSessionHandler handles the creation of a Stripe customer portal session
+// based on the organization creator email..
+// It requires the user to be authenticated and to have admin role for the organization.
+func (a *API) createSubscriptionPortalSessionHandler(w http.ResponseWriter, r *http.Request) {
+	user, ok := userFromContext(r.Context())
+	if !ok {
+		ErrUnauthorized.Write(w)
+		return
+	}
+	// get the organization info from the request context
+	org, _, ok := a.organizationFromRequest(r)
+	if !ok {
+		ErrNoOrganizationProvided.Write(w)
+		return
+	}
+	if !user.HasRoleFor(org.Address, db.AdminRole) {
+		ErrUnauthorized.Withf("user is not admin of organization").Write(w)
+		return
+	}
+	session, err := a.stripe.CreatePortalSession(org.Creator)
+	if err != nil {
+		ErrStripeError.Withf("Cannot create customer portal session: %v", err).Write(w)
+		return
+	}
+
+	data := &struct {
+		PortalURL string `json:"portalURL"`
+	}{
+		PortalURL: session.URL,
+	}
+	httpWriteJSON(w, data)
+}

stripe/stripe.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/stripe/stripe-go/v81"
+	portalSession "github.com/stripe/stripe-go/v81/billingportal/session"
 	"github.com/stripe/stripe-go/v81/checkout/session"
 	"github.com/stripe/stripe-go/v81/customer"
 	"github.com/stripe/stripe-go/v81/price"
@@ -291,3 +292,22 @@ func (s *StripeClient) RetrieveCheckoutSession(sessionID string) (*ReturnStatus,
 	}
 	return data, nil
 }
+
+// CreatePortalSession creates a new billing portal session for a customer based on an email address.
+func (s *StripeClient) CreatePortalSession(customerEmail string) (*stripe.BillingPortalSession, error) {
+	// get stripe customer based on provided email
+	customerParams := &stripe.CustomerListParams{
+		Email: stripe.String(customerEmail),
+	}
+	var customerID string
+	if customers := customer.List(customerParams); customers.Next() {
+		customerID = customers.Customer().ID
+	} else {
+		return nil, fmt.Errorf("could not find customer with email %s", customerEmail)
+	}
+
+	params := &stripe.BillingPortalSessionParams{
+		Customer: &customerID,
+	}
+	return portalSession.New(params)
+}