Files
KS Jannette 2c86bba235
Some checks are pending
check / check (push) Waiting to run
general cleanup - removed old comments, enforced naming conventions etc
2026-03-04 23:29:58 -05:00

255 lines
7.9 KiB
Go

package handlers
import (
"encoding/json"
"io"
"log"
"net/http"
"github.com/stripe/stripe-go/v82"
checkoutsession "github.com/stripe/stripe-go/v82/checkout/session"
"github.com/stripe/stripe-go/v82/webhook"
"github.com/kjannette/koin-ping/backend/internal/config"
"github.com/kjannette/koin-ping/backend/internal/middleware"
"github.com/kjannette/koin-ping/backend/internal/models"
)
const webhookMaxBodyBytes = 65536
type StripeHandler struct {
users *models.UserModel
cfg *config.Config
}
func NewStripeHandler(users *models.UserModel, cfg *config.Config) *StripeHandler {
stripe.Key = cfg.StripeSecretKey
return &StripeHandler{users: users, cfg: cfg}
}
// CreateCheckoutSession creates a Stripe Checkout session for the monthly subscription.
func (h *StripeHandler) CreateCheckoutSession(w http.ResponseWriter, r *http.Request) {
userID := middleware.GetUserID(r.Context())
user, err := h.users.GetByID(r.Context(), userID)
if err != nil || user == nil {
log.Printf("Failed to get user %s: %v", userID, err)
writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to load user")
return
}
params := &stripe.CheckoutSessionParams{
Mode: stripe.String(string(stripe.CheckoutSessionModeSubscription)),
LineItems: []*stripe.CheckoutSessionLineItemParams{
{
Price: stripe.String(h.cfg.StripePriceID),
Quantity: stripe.Int64(1),
},
},
SuccessURL: stripe.String(h.cfg.FrontendURL + "/subscribe?payment=success&session_id={CHECKOUT_SESSION_ID}"),
CancelURL: stripe.String(h.cfg.FrontendURL + "/subscribe?payment=cancelled"),
ClientReferenceID: stripe.String(userID),
CustomerEmail: stripe.String(user.Email),
}
if user.StripeCustomerID != nil && *user.StripeCustomerID != "" {
params.Customer = user.StripeCustomerID
params.CustomerEmail = nil
}
s, err := checkoutsession.New(params)
if err != nil {
log.Printf("Failed to create Stripe checkout session: %v", err)
writeError(w, http.StatusInternalServerError, "STRIPE_ERROR", "Failed to create checkout session")
return
}
writeJSON(w, http.StatusOK, map[string]string{"url": s.URL})
}
// GetSubscriptionStatus returns the current user's subscription state.
func (h *StripeHandler) GetSubscriptionStatus(w http.ResponseWriter, r *http.Request) {
userID := middleware.GetUserID(r.Context())
user, err := h.users.GetByID(r.Context(), userID)
if err != nil || user == nil {
log.Printf("Failed to get user %s: %v", userID, err)
writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to load user")
return
}
writeJSON(w, http.StatusOK, map[string]any{
"subscription_status": user.SubscriptionStatus,
"subscription_created_at": user.SubscriptionCreatedAt,
})
}
// VerifyCheckoutSession retrieves a completed checkout session from Stripe,
// confirms payment, and activates the user's subscription in the database.
// This is the primary activation path; webhooks serve as a backup.
func (h *StripeHandler) VerifyCheckoutSession(w http.ResponseWriter, r *http.Request) {
userID := middleware.GetUserID(r.Context())
var body struct {
SessionID string `json:"session_id"`
}
if err := json.NewDecoder(r.Body).Decode(&body); err != nil || body.SessionID == "" {
writeError(w, http.StatusBadRequest, "BAD_REQUEST", "Missing session_id")
return
}
s, err := checkoutsession.Get(body.SessionID, nil)
if err != nil {
log.Printf("Failed to retrieve checkout session %s: %v", body.SessionID, err)
writeError(w, http.StatusBadRequest, "STRIPE_ERROR", "Invalid checkout session")
return
}
if s.ClientReferenceID != userID {
writeError(w, http.StatusForbidden, "FORBIDDEN", "Session does not belong to this user")
return
}
if s.PaymentStatus != stripe.CheckoutSessionPaymentStatusPaid {
writeError(w, http.StatusBadRequest, "PAYMENT_INCOMPLETE", "Payment has not been completed")
return
}
customerID := ""
if s.Customer != nil {
customerID = s.Customer.ID
}
subscriptionID := ""
if s.Subscription != nil {
subscriptionID = s.Subscription.ID
}
if customerID != "" {
if err := h.users.UpdateStripeCustomer(r.Context(), userID, customerID); err != nil {
log.Printf("VerifyCheckout: failed to save customer ID: %v", err)
}
}
if subscriptionID != "" && customerID != "" {
if err := h.users.ActivateSubscription(r.Context(), customerID, subscriptionID, "active"); err != nil {
log.Printf("VerifyCheckout: failed to activate subscription: %v", err)
}
}
log.Printf("Checkout verified for user %s, customer %s, subscription %s", userID, customerID, subscriptionID)
writeJSON(w, http.StatusOK, map[string]string{"subscription_status": "active"})
}
// HandleWebhook processes incoming Stripe webhook events.
// This endpoint must NOT require authentication (Stripe calls it directly).
func (h *StripeHandler) HandleWebhook(w http.ResponseWriter, r *http.Request) {
payload, err := io.ReadAll(io.LimitReader(r.Body, webhookMaxBodyBytes))
if err != nil {
log.Printf("Error reading webhook body: %v", err)
w.WriteHeader(http.StatusServiceUnavailable)
return
}
sig := r.Header.Get("Stripe-Signature")
event, err := webhook.ConstructEvent(payload, sig, h.cfg.StripeWebhookSecret)
if err != nil {
log.Printf("Webhook signature verification failed: %v", err)
w.WriteHeader(http.StatusBadRequest)
return
}
switch event.Type {
case "checkout.session.completed":
h.handleCheckoutCompleted(r, event)
case "customer.subscription.updated":
h.handleSubscriptionUpdated(r, event)
case "customer.subscription.deleted":
h.handleSubscriptionDeleted(r, event)
default:
log.Printf("Unhandled Stripe event type: %s", event.Type)
}
w.WriteHeader(http.StatusOK)
}
func (h *StripeHandler) handleCheckoutCompleted(r *http.Request, event stripe.Event) {
var session stripe.CheckoutSession
if err := json.Unmarshal(event.Data.Raw, &session); err != nil {
log.Printf("Error parsing checkout session: %v", err)
return
}
userID := session.ClientReferenceID
if userID == "" {
log.Println("Checkout session missing client_reference_id")
return
}
customerID := ""
if session.Customer != nil {
customerID = session.Customer.ID
}
subscriptionID := ""
if session.Subscription != nil {
subscriptionID = session.Subscription.ID
}
if customerID != "" {
if err := h.users.UpdateStripeCustomer(r.Context(), userID, customerID); err != nil {
log.Printf("Failed to save Stripe customer ID: %v", err)
}
}
if subscriptionID != "" && customerID != "" {
if err := h.users.ActivateSubscription(r.Context(), customerID, subscriptionID, "active"); err != nil {
log.Printf("Failed to activate subscription: %v", err)
}
}
log.Printf("Checkout completed for user %s, customer %s, subscription %s", userID, customerID, subscriptionID)
}
func (h *StripeHandler) handleSubscriptionUpdated(r *http.Request, event stripe.Event) {
var sub stripe.Subscription
if err := json.Unmarshal(event.Data.Raw, &sub); err != nil {
log.Printf("Error parsing subscription update: %v", err)
return
}
customerID := ""
if sub.Customer != nil {
customerID = sub.Customer.ID
}
if customerID == "" {
return
}
status := string(sub.Status)
if err := h.users.ActivateSubscription(r.Context(), customerID, sub.ID, status); err != nil {
log.Printf("Failed to update subscription status: %v", err)
}
log.Printf("Subscription %s updated to %s for customer %s", sub.ID, status, customerID)
}
func (h *StripeHandler) handleSubscriptionDeleted(r *http.Request, event stripe.Event) {
var sub stripe.Subscription
if err := json.Unmarshal(event.Data.Raw, &sub); err != nil {
log.Printf("Error parsing subscription deletion: %v", err)
return
}
customerID := ""
if sub.Customer != nil {
customerID = sub.Customer.ID
}
if customerID == "" {
return
}
if err := h.users.UpdateSubscriptionStatus(r.Context(), customerID, "canceled"); err != nil {
log.Printf("Failed to mark subscription canceled: %v", err)
}
log.Printf("Subscription canceled for customer %s", customerID)
}