Add rudimentary (MAC-Failing) refund support

pretix · Apr 12, 2022 · f44fadc · f44fadc
1 parent 6a46119
commit f44fadc
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Showing 2 changed files with 77 additions and 31 deletions.
diff --git a/pretix_computop/payment.py b/pretix_computop/payment.py
@@ -1,11 +1,13 @@
 import hashlib
 import importlib
 import json
+import urllib
 from base64 import b16encode, b16decode
 from collections import OrderedDict
 from decimal import Decimal
 from urllib.parse import urlencode
 
+import requests
 from Crypto.Hash import SHA256, HMAC
 from Crypto.Util import Padding
 from django import forms
@@ -19,7 +21,7 @@
 
 from pretix.base.decimal import round_decimal
 from pretix.base.forms import SecretKeySettingsField
-from pretix.base.models import Event, OrderPayment, Order
+from pretix.base.models import Event, OrderPayment, Order, OrderRefund
 from pretix.base.payment import BasePaymentProvider
 from pretix.base.settings import SettingsSandbox
 from pretix.multidomain.urlreverse import build_absolute_uri
@@ -197,6 +199,54 @@ def execute_payment(self, request: HttpRequest, payment: OrderPayment) -> str:
         payment.save(update_fields=['info'])
         return self.apiurl + '?' + urlencode(payload)
 
+    def payment_refund_supported(self, payment: OrderPayment) -> bool:
+        if 'PayID' in payment.info:
+            return True
+        return False
+
+    def payment_partial_refund_supported(self, payment: OrderPayment) -> bool:
+        if 'PayID' in payment.info:
+            return True
+        return False
+
+    def execute_refund(self, refund: OrderRefund):
+        data = {
+            'MerchantID': self.settings.get('merchant_id'),
+            'Amount': self._decimal_to_int(refund.amount),
+            'Currency': self.event.currency,
+            'MAC': self._calculate_hmac(
+                transaction_id=refund.full_id,
+                amount_or_status=str(self._decimal_to_int(refund.amount)),
+                currency_or_code=self.event.currency),
+            'PayID': refund.payment.info_data['PayID'][0],
+            'TransID': refund.full_id,
+            'RefNr': refund.full_id,
+            'OrderDesc': 'Order {}-{}'.format(self.event.slug.upper(), refund.full_id),
+        }
+        print(data)
+        encrypted_data = self._encrypt(urlencode(data))
+        payload = {
+            'MerchantID': self.settings.get('merchant_id'),
+            'Len': encrypted_data[1],
+            'Data': encrypted_data[0],
+        }
+
+        req = requests.post(
+            "https://www.computop-paygate.com/credit.aspx",
+            data=payload,
+        )
+
+        parsed = urllib.parse.parse_qs(req.text)
+        processed = self.parse_data(parsed['Data'][0])
+        refund.info = json.dumps(processed)
+        refund.save(update_fields=['info'])
+
+        if refund.info_data['Status'][0] == 'FAILED':
+            refund.state = OrderRefund.REFUND_STATE_FAILED
+            refund.save(update_fields=['state'])
+        elif refund.info_data['Status'][0] == 'AUTHORIZED':
+            refund.done()
+
     def check_hash(self, payload_parsed):
         mid = payload_parsed['mid'][0]
         mac = str(payload_parsed['MAC'][0]).lower().rstrip()
@@ -222,3 +272,7 @@ def get_paytypes(self):
             return "|".join(paytypes)
         else:
             return self.method
+
+    def parse_data(self, data):
+        payload = self.decrypt(str(data))
+        return urllib.parse.parse_qs(payload)
diff --git a/pretix_computop/views.py b/pretix_computop/views.py
@@ -1,6 +1,5 @@
 import hashlib
 import json
-import urllib.parse
 
 from cached_property import cached_property
 from django.contrib import messages
@@ -51,49 +50,42 @@ def _redirect_to_order(self):
     def pprov(self):
         return self.payment.payment_provider
 
-    def _handle_data(self, data):
-        try:
-            response = self._parse_data(data)
-        except TypeError as err:
-            self.payment.fail({'decryption_error': err, 'request': self.payment.info})
-        except ValueError as err:
-            self.payment.fail({'decryption_error': err, 'request': self.payment.info})
-        else:
-            if self.pprov.check_hash(response):
-                self.payment.info = json.dumps({'request': self.payment.info, 'response': response})
-                self.payment.save(update_fields=['info'])
-                self._set_status_code(response['Code'][0], response)
-
-    def _parse_data(self, data):
-        payload = self.pprov.decrypt(data)
-        return urllib.parse.parse_qs(payload)
-
-    def _set_status_code(self, code, response):
-        if code == '00000000':
-            self.payment.confirm()
-        else:
-            messages.error(self.request, _('Your payment failed. Please try again.'))
-            self.payment.fail(info={'request': self.payment.info, 'response': response})
-
 
 @method_decorator(csrf_exempt, name='dispatch')
 class ReturnView(ComputopOrderView, View):
     template_name = 'pretix_computop/return.html'
 
     def post(self, request, *args, **kwargs):
         if request.POST['Data']:
-            data = str(request.POST.get('Data'))
-            self._handle_data(data)
+            response = self.parse_data(request.POST.get('Data'))
+            if self.check_hash(response):
+                self.payment.info = json.dumps(response)
+                self.payment.save(update_fields=['info'])
+
+                if response['Code'][0] == '00000000':
+                    self.payment.confirm()
+                else:
+                    messages.error(request, _('Your payment failed. Please try again.'))
+                    self.payment.fail(info=response)
         return self._redirect_to_order()
 
     def get(self, request, *args, **kwargs):
         return self._redirect_to_order()
 
 
 @method_decorator(csrf_exempt, name='dispatch')
-class NotifyView(ReturnView, ComputopOrderView, View):
+class NotifyView(ComputopOrderView, View):
+    template_name = 'pretix_computop/return.html'
+
     def post(self, request, *args, **kwargs):
         if request.POST['Data']:
-            data = str(request.POST.get('Data'))
-            self._handle_data(data)
+            response = self.parse_data(request.POST.get('Data'))
+            if self.check_hash(response):
+                self.payment.info = json.dumps(response)
+                self.payment.save(update_fields=['info'])
+
+                if response['Code'][0] == '00000000':
+                    self.payment.confirm()
+                else:
+                    self.payment.fail(info=response)
         return HttpResponse('[accepted]', status=200)