Stripe: Add Support for Affirm Pay Later (#3737)

Co-authored-by: Raphael Michel <michel@rami.io>

src/pretix/plugins/stripe/payment.py

@@ -123,7 +123,7 @@ logger = logging.getLogger('pretix.plugins.stripe')
 # - Mexico Bank Transfer: ✗
 #
 # Buy now, pay later
-# - Affirm: ✗
+# - Affirm: ✓
 # - Afterpay/Clearpay: ✗
 # - Klarna: ✗
 #
@@ -431,6 +431,16 @@ class StripeSettingsHolder(BasePaymentProvider):
                                  'before work properly.'),
                      required=False,
                  )),
+                ('method_affirm',
+                 forms.BooleanField(
+                     label=_('Affirm'),
+                     disabled=self.event.currency not in ['USD', 'CAD'],
+                     help_text=' '.join([
+                         str(_('Needs to be enabled in your Stripe account first.')),
+                         str(_('Only available for payments between $50 and $30,000.'))
+                     ]),
+                     required=False,
+                 )),
             ] + extra_fields + list(super().settings_form_fields.items()) + moto_settings
         )
         if not self.settings.connect_client_id or self.settings.secret_key:
@@ -866,6 +876,7 @@ class StripeMethod(BasePaymentProvider):
 class StripePaymentIntentMethod(StripeMethod):
     identifier = ''
     method = ''
+    redirect_action_handling = 'iframe'  # or redirect
 
     def payment_is_valid_session(self, request):
         return request.session.get('payment_stripe_{}_payment_method_id'.format(self.method), '') != ''
@@ -896,6 +907,9 @@ class StripePaymentIntentMethod(StripeMethod):
 
         try:
             if self.payment_is_valid_session(request):
+                payment_method_id = request.session.get('payment_stripe_{}_payment_method_id'.format(self.method), None)
+                idempotency_key_seed = payment_method_id if payment_method_id is not None else payment.full_id
+
                 params = {}
                 params.update(self._connect_kwargs(payment))
                 params.update(self.api_kwargs)
@@ -913,7 +927,7 @@ class StripePaymentIntentMethod(StripeMethod):
                 intent = stripe.PaymentIntent.create(
                     amount=self._get_amount(payment),
                     currency=self.event.currency.lower(),
-                    payment_method=request.session['payment_stripe_{}_payment_method_id'.format(self.method)],
+                    payment_method=payment_method_id,
                     payment_method_types=[self.method],
                     confirmation_method='manual',
                     confirm=True,
@@ -928,7 +942,7 @@ class StripePaymentIntentMethod(StripeMethod):
                         'code': payment.order.code
                     },
                     # TODO: Is this sufficient?
-                    idempotency_key=str(self.event.id) + payment.order.code + request.session['payment_stripe_{}_payment_method_id'.format(self.method)],
+                    idempotency_key=str(self.event.id) + payment.order.code + idempotency_key_seed,
                     return_url=build_absolute_uri(self.event, 'plugins:stripe:sca.return', kwargs={
                         'order': payment.order.code,
                         'payment': payment.pk,
@@ -1288,6 +1302,49 @@ class StripeSEPADirectDebit(StripePaymentIntentMethod):
                     del request.session['payment_stripe_sepa_debit_{}'.format(field)]
 
 
+class StripeAffirm(StripePaymentIntentMethod):
+    identifier = 'stripe_affirm'
+    verbose_name = _('Affirm via Stripe')
+    public_name = _('Affirm')
+    method = 'affirm'
+    redirect_action_handling = 'redirect'
+
+    def payment_is_valid_session(self, request):
+        # Affirm does not have a payment_method_id, so we set it manually to None during checkout.
+        # But we still need to check for its presence here.
+        if 'payment_stripe_{}_payment_method_id'.format(self.method) in request.session:
+            return True
+        return False
+
+    def checkout_prepare(self, request, cart):
+        # Affirm does not have a payment_method_id, so we set it manually to None during checkout, so that we can
+        # verify later on if we are in or outside the checkout process.
+        request.session['payment_stripe_{}_payment_method_id'.format(self.method)] = None
+        return True
+
+    def is_allowed(self, request: HttpRequest, total: Decimal=None) -> bool:
+        return Decimal(50.00) <= total <= Decimal(30000.00) and super().is_allowed(request, total)
+
+    def order_change_allowed(self, order: Order, request: HttpRequest=None) -> bool:
+        return Decimal(50.00) <= order.pending_sum <= Decimal(30000.00) and super().order_change_allowed(order, request)
+
+    def _payment_intent_kwargs(self, request, payment):
+        return {
+            'payment_method_data': {
+                'type': 'affirm',
+            }
+        }
+
+    def payment_form_render(self, request, total, order=None) -> str:
+        template = get_template('pretixplugins/stripe/checkout_payment_form_affirm.html')
+        ctx = {
+            'request': request,
+            'event': self.event,
+            'total': self._decimal_to_int(total),
+        }
+        return template.render(ctx)
+
+
 class StripeGiropay(StripeMethod):
     identifier = 'stripe_giropay'
     verbose_name = _('giropay via Stripe')

src/pretix/plugins/stripe/signals.py

@@ -45,15 +45,16 @@ from pretix.presale.signals import html_head, process_response
 @receiver(register_payment_providers, dispatch_uid="payment_stripe")
 def register_payment_provider(sender, **kwargs):
     from .payment import (
-        StripeAlipay, StripeBancontact, StripeCC, StripeEPS, StripeGiropay,
+        StripeAffirm, StripeAlipay, StripeBancontact, StripeCC, StripeEPS,
-        StripeIdeal, StripeMultibanco, StripePrzelewy24, StripeSEPADirectDebit,
+        StripeGiropay, StripeIdeal, StripeMultibanco, StripePrzelewy24,
-        StripeSettingsHolder, StripeSofort, StripeWeChatPay,
+        StripeSEPADirectDebit, StripeSettingsHolder, StripeSofort,
+        StripeWeChatPay,
     )
 
     return [
         StripeSettingsHolder, StripeCC, StripeGiropay, StripeIdeal, StripeAlipay, StripeBancontact,
         StripeSofort, StripeEPS, StripeMultibanco, StripePrzelewy24, StripeWeChatPay,
-        StripeSEPADirectDebit,
+        StripeSEPADirectDebit, StripeAffirm,
     ]
 
 

src/pretix/plugins/stripe/static/pretixplugins/stripe/pretix-stripe.js

@@ -6,6 +6,7 @@ var pretixstripe = {
     elements: null,
     card: null,
     sepa: null,
+    affirm: null,
     paymentRequest: null,
     paymentRequestButton: null,
 
@@ -163,6 +164,14 @@ var pretixstripe = {
                             $('.stripe-container').closest("form").find(".checkout-button-row .btn-primary").prop("disabled", false);
                         });
                     }
+                    if ($("#stripe-affirm").length) {
+                        pretixstripe.affirm = pretixstripe.elements.create('affirmMessage', {
+                            'amount': parseInt($("#stripe_affirm_total").val()),
+                            'currency': $("#stripe_affirm_currency").val(),
+                        });
+
+                        pretixstripe.affirm.mount('#stripe-affirm');
+                    }
                     if ($("#stripe-payment-request-button").length && pretixstripe.paymentRequest != null) {
                         pretixstripe.paymentRequestButton = pretixstripe.elements.create('paymentRequestButton', {
                             paymentRequest: pretixstripe.paymentRequest,
@@ -207,24 +216,44 @@ var pretixstripe = {
             }
         });
     },
-    'handleCardActioniFrame': function (payment_intent_next_action_redirect_url) {
+    'handlePaymentRedirectAction': function (payment_intent_next_action_redirect_url) {
         waitingDialog.show(gettext("Contacting your bank …"));
-        let iframe = document.createElement('iframe');
+
-        iframe.src = payment_intent_next_action_redirect_url;
+        let payment_intent_redirect_action_handling = $.trim($("#stripe_payment_intent_redirect_action_handling").html());
-        iframe.className = 'embed-responsive-item';
+        if (payment_intent_redirect_action_handling === 'iframe') {
-        $('#scacontainer').append(iframe);
+            let iframe = document.createElement('iframe');
-        $('#scacontainer iframe').on("load", function () {
+            iframe.src = payment_intent_next_action_redirect_url;
-            waitingDialog.hide();
+            iframe.className = 'embed-responsive-item';
-        });
+            $('#scacontainer').append(iframe);
+            $('#scacontainer iframe').on("load", function () {
+                waitingDialog.hide();
+            });
+        } else if (payment_intent_redirect_action_handling === 'redirect') {
+            window.location.href = payment_intent_next_action_redirect_url;
+        }
     }
 };
 $(function () {
     if ($("#stripe_payment_intent_SCA_status").length) {
-        window.parent.postMessage('3DS-authentication-complete.' + $.trim($("#order_status").html()), '*');
+        let payment_intent_redirect_action_handling = $.trim($("#stripe_payment_intent_redirect_action_handling").html());
-        return;
+        let order_status = $.trim($("#order_status").html());
+        let order_url = $.trim($("#order_url").html())
+
+        if (payment_intent_redirect_action_handling === 'iframe') {
+            window.parent.postMessage('3DS-authentication-complete.' + order_status, '*');
+            return;
+        } else if (payment_intent_redirect_action_handling === 'redirect') {
+            waitingDialog.show(gettext("Confirming your payment …"));
+
+            if (order_status === 'p') {
+                window.location.href = order_url + '?paid=yes';
+            } else {
+                window.location.href = order_url;
+            }
+        }
     } else if ($("#stripe_payment_intent_next_action_redirect_url").length) {
         let payment_intent_next_action_redirect_url = $.trim($("#stripe_payment_intent_next_action_redirect_url").html());
-        pretixstripe.handleCardActioniFrame(payment_intent_next_action_redirect_url);
+        pretixstripe.handlePaymentRedirectAction(payment_intent_next_action_redirect_url);
     } else if ($("#stripe_payment_intent_client_secret").length) {
         let payment_intent_client_secret = $.trim($("#stripe_payment_intent_client_secret").html());
         pretixstripe.handleCardAction(payment_intent_client_secret);
@@ -247,11 +276,15 @@ $(function () {
     if (!$(".stripe-container").length)
         return;
 
-    if ($("input[name=payment][value=stripe]").is(':checked') || $("input[name=payment][value=stripe_sepa_debit]").is(':checked') || $(".payment-redo-form").length) {
+    if (
+        $("input[name=payment][value=stripe]").is(':checked')
+        || $("input[name=payment][value=stripe_sepa_debit]").is(':checked')
+        || $("input[name=payment][value=stripe_affirm]").is(':checked')
+        || $(".payment-redo-form").length) {
         pretixstripe.load();
     } else {
         $("input[name=payment]").change(function () {
-            if (['stripe', 'stripe_sepa_debit'].indexOf($(this).val()) > -1) {
+            if (['stripe', 'stripe_sepa_debit', 'stripe_affirm'].indexOf($(this).val()) > -1) {
                 pretixstripe.load();
             }
         })

src/pretix/plugins/stripe/templates/pretixplugins/stripe/checkout_payment_form_affirm.html

@@ -0,0 +1,20 @@
+{% load i18n %}
+{% load bootstrap3 %}
+
+<div class="form-horizontal stripe-container">
+    <div id="stripe-affirm">
+        <span class="fa fa-spinner fa-spin"></span>
+        <!-- a Stripe Element will be inserted here. -->
+    </div>
+
+    <p class="help-block">
+        {% blocktrans trimmed %}
+            After you submitted your order, we will redirect you to the payment service provider to complete your
+            payment.
+            You will then be redirected back here to get your tickets.
+        {% endblocktrans %}
+    </p>
+
+    <input type="hidden" name="stripe_affirm_total" value="{{ total }}" id="stripe_affirm_total"/>
+    <input type="hidden" id="stripe_affirm_currency" value="{{ event.currency }}"/>
+</div>

src/pretix/plugins/stripe/templates/pretixplugins/stripe/sca.html

@@ -8,6 +8,7 @@
     {% include "pretixplugins/stripe/presale_head.html" with settings=stripe_settings %}
     <script type="text/plain" id="stripe_payment_intent_client_secret">{{ payment_intent_client_secret }}</script>
     <script type="text/plain" id="stripe_payment_intent_next_action_redirect_url">{{ payment_intent_next_action_redirect_url }}</script>
+    <script type="text/plain" id="stripe_payment_intent_redirect_action_handling">{{ payment_intent_redirect_action_handling }}</script>
 {% endblock %}
 {% block content %}
     <div class="panel panel-primary">

src/pretix/plugins/stripe/templates/pretixplugins/stripe/sca_return.html

@@ -8,7 +8,9 @@
     {{ block.super }}
     {% include "pretixplugins/stripe/presale_head.html" with settings=stripe_settings %}
     <script type="text/plain" id="stripe_payment_intent_SCA_status">3DS-authentication-complete</script>
+    <script type="text/plain" id="stripe_payment_intent_redirect_action_handling">{{ payment_intent_redirect_action_handling }}</script>
     <script type="text/plain" id="order_status">{{ order.status }}</script>
+    <script type="text/plain" id="order_url">{{ order_url }}</script>
 {% endblock %}
 {% block page %}
     <div class="text-center">

src/pretix/plugins/stripe/views.py

@@ -599,6 +599,7 @@ class ScaView(StripeOrderView, View):
                 ctx['payment_intent_client_secret'] = intent.client_secret
             elif intent.next_action.type == 'redirect_to_url':
                 ctx['payment_intent_next_action_redirect_url'] = intent.next_action.redirect_to_url['url']
+                ctx['payment_intent_redirect_action_handling'] = prov.redirect_action_handling
 
             r = render(request, 'pretixplugins/stripe/sca.html', ctx)
             r._csp_ignore = True
@@ -623,8 +624,16 @@ class ScaReturnView(StripeOrderView, View):
             messages.error(request, str(e))
 
         self.order.refresh_from_db()
+        ctx = {
+            'order': self.order,
+            'payment_intent_redirect_action_handling': prov.redirect_action_handling,
+            'order_url': eventreverse(self.request.event, 'presale:event.order', kwargs={
+                'order': self.order.code,
+                'secret': self.order.secret
+            }),
+        }
 
-        return render(request, 'pretixplugins/stripe/sca_return.html', {'order': self.order})
+        return render(request, 'pretixplugins/stripe/sca_return.html', ctx)
 
 
 class OrganizerSettingsFormView(DecoupleMixin, OrganizerDetailViewMixin, AdministratorPermissionRequiredMixin, FormView):