Validate voucher before creating user

aleksis/apps/paweljong/views.py

@@ -415,6 +415,13 @@ class RegisterEventWizardView(SessionWizardView):
         cleaned_data_financial = self.get_cleaned_data_for_step("financial")
         cleaned_data_consent = self.get_cleaned_data_for_step("consent")
 
+        if cleaned_data_financial["voucher_code"] != "":
+            vouchers = Voucher.objects.filter(person=person, event=event, used=False, code=cleaned_data_financial["voucher_code"])
+            if vouchers:
+                voucher = vouchers.first()
+            else:
+                messages.error(self.request, _("You entered an invalid voucher code!"))
+
         # Create email address
         if cleaned_data_email:
             _email = MailAddress.objects.create(