From e0cb6ac670d674a45023041d0ba615a70997774d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timoth=C3=A9e=20Floure?= <timothee.floure@posteo.net>
Date: Tue, 3 Mar 2020 18:16:25 +0100
Subject: [PATCH] Allow for charging customers

---
 uncloud/uncloud_pay/models.py      | 17 ++++++++++-------
 uncloud/uncloud_pay/serializers.py |  5 ++++-
 uncloud/uncloud_pay/stripe.py      | 14 +++++++++-----
 uncloud/uncloud_pay/views.py       | 16 +++++++++-------
 4 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/uncloud/uncloud_pay/models.py b/uncloud/uncloud_pay/models.py
index fa775fc..772ab38 100644
--- a/uncloud/uncloud_pay/models.py
+++ b/uncloud/uncloud_pay/models.py
@@ -86,16 +86,19 @@ class PaymentMethod(models.Model):
     def charge(self, amount):
         if amount > 0: # Make sure we don't charge negative amount by errors...
             if self.source == 'stripe':
-                # TODO: wire to stripe, see meooow-payv1/strip_utils.py
-                payment = Payment(owner=self.owner, source=self.source, amount=amount)
-                payment.save() # TODO: Check return status
+                stripe_customer = StripeCustomer.objects.get(owner=self.owner).stripe_id
+                charge_request = uncloud_pay.stripe.charge_customer(amount, stripe_customer, self.stripe_card_id)
+                if charge_request['error'] == None:
+                    payment = Payment(owner=self.owner, source=self.source, amount=amount)
+                    payment.save() # TODO: Check return status
 
-                return True
+                    return payment
+                else:
+                    raise Exception('Stripe error: {}'.format(charge_request['error']))
             else:
-                # We do not handle that source yet.
-                return False
+                raise Exception('This payment method is unsupported/cannot be charged.')
         else:
-            return False
+            raise Exception('Cannot charge negative amount.')
 
     class Meta:
         unique_together = [['owner', 'primary']]
diff --git a/uncloud/uncloud_pay/serializers.py b/uncloud/uncloud_pay/serializers.py
index f5136f6..94c9b61 100644
--- a/uncloud/uncloud_pay/serializers.py
+++ b/uncloud/uncloud_pay/serializers.py
@@ -38,7 +38,10 @@ class PaymentMethodSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = PaymentMethod
-        fields = ['source', 'description', 'primary', 'stripe_card_last4']
+        fields = ['uuid', 'source', 'description', 'primary', 'stripe_card_last4']
+
+class ChargePaymentMethodSerializer(serializers.Serializer):
+    amount = serializers.DecimalField(max_digits=10, decimal_places=2)
 
 class CreditCardSerializer(serializers.Serializer):
     number = serializers.IntegerField()
diff --git a/uncloud/uncloud_pay/stripe.py b/uncloud/uncloud_pay/stripe.py
index ab2d865..4f28d94 100644
--- a/uncloud/uncloud_pay/stripe.py
+++ b/uncloud/uncloud_pay/stripe.py
@@ -21,7 +21,7 @@ def handle_stripe_error(f):
             'error': None
         }
 
-        common_message = "Currently it's not possible to make payments."
+        common_message = "Currently it is not possible to make payments."
         try:
             response_object = f(*args, **kwargs)
             response = {
@@ -114,11 +114,15 @@ def get_card(customer_id, card_id):
     return stripe.Customer.retrieve_source(customer_id, card_id)
 
 @handle_stripe_error
-def charge_customer(amount, source):
+def charge_customer(amount, customer_id, card_id):
+    # Amount is in CHF but stripes requires smallest possible unit.
+    # See https://stripe.com/docs/api/charges/create
+    adjusted_amount = int(amount * 100)
     return stripe.Charge.create(
-            amount=amount,
-            currenty=CURRENCY,
-            source=source)
+            amount=adjusted_amount,
+            currency=CURRENCY,
+            customer=customer_id,
+            source=card_id)
 
 @handle_stripe_error
 def create_customer(name, email):
diff --git a/uncloud/uncloud_pay/views.py b/uncloud/uncloud_pay/views.py
index 294b518..a6066b4 100644
--- a/uncloud/uncloud_pay/views.py
+++ b/uncloud/uncloud_pay/views.py
@@ -63,6 +63,8 @@ class PaymentMethodViewSet(viewsets.ModelViewSet):
     def get_serializer_class(self):
         if self.action == 'create':
             return CreatePaymentMethodSerializer
+        elif self.action == 'charge':
+            return ChargePaymentMethodSerializer
         else:
             return PaymentMethodSerializer
 
@@ -99,18 +101,18 @@ class PaymentMethodViewSet(viewsets.ModelViewSet):
         output_serializer = PaymentMethodSerializer(payment_method)
         return Response(output_serializer.data)
 
-    # TODO: find a way to customize serializer for actions.
-    # drf-action-serializer module seems to do that.
     @action(detail=True, methods=['post'])
     def charge(self, request, pk=None):
         payment_method = self.get_object()
         serializer = self.get_serializer(data=request.data)
         serializer.is_valid(raise_exception=True)
-        amount = serializer.data['amount']
-        if payment_method.charge(amount):
-            return Response({'charged', amount})
-        else:
-            return Response(status=status.HTTP_500_INTERNAL_ERROR)
+        amount = serializer.validated_data['amount']
+        try:
+            payment = payment_method.charge(amount)
+            output_serializer = PaymentSerializer(payment)
+            return Response(output_serializer.data)
+        except Exception as e:
+            return Response({'error': str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
 
 ###
 # Admin views.