Replace legacy Stripe Charge API by Payment{setup, intent}

uncloud/uncloud_pay/stripe.py

@@ -10,6 +10,10 @@ import uncloud.secrets
 # Static stripe configuration used below.
 CURRENCY = 'chf'
 
+# README: We use the Payment Intent API as described on
+#   https://stripe.com/docs/payments/save-and-reuse
+
+# For internal use only.
 stripe.api_key = uncloud.secrets.STRIPE_KEY
 
 # Helper (decorator) used to catch errors raised by stripe logic.
@@ -82,6 +86,9 @@ class CreditCard():
 
 # Actual Stripe logic.
 
+def public_api_key():
+    return uncloud.settings.STRIPE_PUBLIC_KEY
+
 def get_customer_id_for(user):
     try:
         # .get() raise if there is no matching entry.
@@ -99,15 +106,17 @@ def get_customer_id_for(user):
             return None
 
 @handle_stripe_error
-def create_card(customer_id, credit_card):
-    return stripe.Customer.create_source(
-            customer_id,
-            card={
-                'number': credit_card.number,
-                'exp_month': credit_card.exp_month,
-                'exp_year': credit_card.exp_year,
-                'cvc': credit_card.cvc
-                })
+def create_setup_intent(customer_id):
+    return stripe.SetupIntent.create(customer=customer_id)
+
+@handle_stripe_error
+def get_setup_intent(setup_intent_id):
+    return stripe.SetupIntent.retrieve(setup_intent_id)
+
+def get_payment_method(payment_method_id):
+    return stripe.PaymentMethod.retrieve(payment_method_id)
+
+## Legacy
 
 @handle_stripe_error
 def get_card(customer_id, card_id):
@@ -116,13 +125,16 @@ def get_card(customer_id, card_id):
 @handle_stripe_error
 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
+    # https://stripe.com/docs/api/payment_intents/create#create_payment_intent-amount
     adjusted_amount = int(amount * 100)
-    return stripe.Charge.create(
-            amount=adjusted_amount,
-            currency=CURRENCY,
-            customer=customer_id,
-            source=card_id)
+    return stripe.PaymentIntent.create(
+        amount=adjusted_amount,
+        currency=CURRENCY,
+        customer=customer_id,
+        payment_method=card_id,
+        off_session=True,
+        confirm=True,
+    )
 
 @handle_stripe_error
 def create_customer(name, email):