Integrating Taler.

doc/modules.rst

@@ -258,7 +258,7 @@ Example::
 This backend does not support fraud detection.
 
 Sofort.com
---------
+----------
 
 .. class:: payments.sofort.SofortProvider(key, id, project_id[, endpoint='https://api.sofort.com/api/xml'])
 
@@ -304,3 +304,30 @@ Example::
 
 
 This backend does not support fraud detection.
+
+Taler
+-----
+
+.. class:: payments.taler.TalerProvider(self, backend_url, address, name, jurisdiction, instance=None)
+
+   This backend implements payments using `Taler <https://taler/net/>`_.
+
+   :param backend_url: Backend's base URL.
+   :param instance: Merchant instance.
+   :param address: Merchant physical address.
+   :param name: Merchant/shop name.
+   :param jurisdiction: Jurisdiction where the merchant operates.
+
+Example::
+
+    PAYMENT_VARIANTS = {
+        'taler': ('payments.taler.TalerProvider',
+            {'backend_url': 'http://backend.test.taler.net/',
+             'address': 'US',
+             'jurisdiction': 'US',
+             'name': 'Taler tester shop'})
+    }
+
+.. This backend does not report fraud to Saleor, as fraud in
+   the classical sense is not possible with Taler.  Naturally,
+   protocol failures are detected and reported (to the wallet).

payments/locale/en/LC_MESSAGES/django.po

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2017-03-13 13:13+0100\n"
+"POT-Creation-Date: 2017-10-20 14:16+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <[email protected]>\n"
@@ -158,11 +158,11 @@ msgstr ""
 msgid "We were unable to complete the transaction. Please try again later."
 msgstr ""
 
-#: payments/cybersource/forms.py:51
+#: payments/cybersource/forms.py:52
 msgid "fingerprint"
 msgstr ""
 
-#: payments/cybersource/forms.py:68 payments/stripe/forms.py:52
+#: payments/cybersource/forms.py:69 payments/stripe/forms.py:52
 msgid "This payment has already been processed."
 msgstr ""
 
@@ -205,6 +205,24 @@ msgstr ""
 msgid "Total payment"
 msgstr ""
 
+#: payments/taler/__init__.py:89
+msgid ""
+"Taler wallet disabled, please go back and either enable the wallet or pick "
+"another payment method.  Please keep the wallet enabled if you pick Taler "
+"again!"
+msgstr ""
+
+#: payments/taler/__init__.py:117
+msgid ""
+"Your wallet seems to have been disabled while processing this payment; your "
+"coins didn't get spent though.  Please go back in the checkout page and "
+"restart the payment with the method  you desire."
+msgstr ""
+
+#: payments/templates/payments/taler_fallback.html:5
+msgid "Payment unsuccessful"
+msgstr ""
+
 #: payments/utils.py:8
 msgid "Month"
 msgstr ""

payments/locale/it/LC_MESSAGES/django.po

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2017-03-13 13:13+0100\n"
+"POT-Creation-Date: 2017-10-20 14:17+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: Marco Badan <[email protected]>, 2017\n"
 "Language-Team: Italian (https://www.transifex.com/mirumee/teams/34782/it/)\n"
@@ -179,11 +179,11 @@ msgstr ""
 msgid "We were unable to complete the transaction. Please try again later."
 msgstr "Non siamo riusciti a completare la transazione. Riprova più tardi."
 
-#: payments/cybersource/forms.py:51
+#: payments/cybersource/forms.py:52
 msgid "fingerprint"
 msgstr "fingerprint"
 
-#: payments/cybersource/forms.py:68 payments/stripe/forms.py:52
+#: payments/cybersource/forms.py:69 payments/stripe/forms.py:52
 msgid "This payment has already been processed."
 msgstr "Questo pagamento è già stato processato."
 
@@ -228,6 +228,24 @@ msgstr "controllo frode"
 msgid "Total payment"
 msgstr "Totale pagamento"
 
+#: payments/taler/__init__.py:89
+msgid ""
+"Taler wallet disabled, please go back and either enable the wallet or pick "
+"another payment method.  Please keep the wallet enabled if you pick Taler "
+"again!"
+msgstr ""
+
+#: payments/taler/__init__.py:117
+msgid ""
+"Your wallet seems to have been disabled while processing this payment; your "
+"coins didn't get spent though.  Please go back in the checkout page and "
+"restart the payment with the method  you desire."
+msgstr ""
+
+#: payments/templates/payments/taler_fallback.html:5
+msgid "Payment unsuccessful"
+msgstr ""
+
 #: payments/utils.py:8
 msgid "Month"
 msgstr "Mese"

payments/locale/ru/LC_MESSAGES/django.po

@@ -174,11 +174,11 @@ msgstr ""
 msgid "We were unable to complete the transaction. Please try again later."
 msgstr "Мы не смогли провести транзакцию. Пожалуйста, попробуйте позже."
 
-#: payments/cybersource/forms.py:51
+#: payments/cybersource/forms.py:52
 msgid "fingerprint"
 msgstr "отпечаток пальца"
 
-#: payments/cybersource/forms.py:68 payments/stripe/forms.py:52
+#: payments/cybersource/forms.py:69 payments/stripe/forms.py:52
 msgid "This payment has already been processed."
 msgstr "Этот платеж уже был обработан."
 
@@ -223,6 +223,20 @@ msgstr "проверка транзакции"
 msgid "Total payment"
 msgstr "Общая сумма"
 
+#: payments/taler/__init__.py:92
+msgid ""
+"Taler wallet disabled, please go back and either enable the wallet or pick "
+"another payment method.  Please keep the wallet enabled if you pick Taler "
+"again!"
+msgstr ""
+
+#: payments/taler/__init__.py:120
+msgid ""
+"Your wallet seems to have been disabled while processing this payment; your "
+"coins didn't get spent though.  Please go back in the checkout page and "
+"restart the payment with the method  you desire."
+msgstr ""
+
 #: payments/utils.py:8
 msgid "Month"
 msgstr "Месяц"

payments/taler/__init__.py

@@ -0,0 +1,159 @@
+#  This file is part of DJANGO-PAYMENTS
+#  (C) 2017 Taler Systems SA
+#
+#  This library is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2.1 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library; if not, write to the Free Software
+#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#  @author Marcello Stanisci
+
+from django.utils.translation import ugettext as _
+from django.template.loader import render_to_string
+import json
+from django.shortcuts import redirect
+from ..core import BasicProvider, get_base_url
+from .. import RedirectNeeded, PaymentStatus
+import re
+from django.http import HttpResponse, JsonResponse
+import requests
+try:
+    from urllib.parse import urljoin
+except ImportError:
+    from urlparse import urljoin
+import logging
+from django.conf import settings
+from .amount import Amount, BadAmount
+
+logger = logging.getLogger(__name__)
+
+class TalerProvider(BasicProvider):
+    '''
+    GNU Taler payment provider
+    '''
+
+    def __init__(self, backend_url, address, name, jurisdiction, instance=None):
+
+        # The backend URL is served by the C backend, it is
+        # used to sign data coming from the frontend and to
+        # communicate with the exchange.
+        # Its URL must end with a slash, like 'http://backend.demo.taler.net/'.
+        self.backend_url = backend_url
+        # Token which identifies this frontend to the backend.  In fact,
+        # any backend can support multiple frontends, and 'None' is the
+        # default one.
+        self.instance = instance
+        # Physical address and jurisdiction, and shop name
+        self.address = address
+        self.name = name
+        self.jurisdiction = jurisdiction
+        super(TalerProvider, self)
+
+    # This function gets called when the user chooses the
+    # payment method to use.  It will redirect the user to
+    # the page returning 402+contract_url.
+    def get_form(self, payment, data=None):
+        raise RedirectNeeded(self.get_return_url(payment))
+
+    # Design note: in django-payments, there is usually ONE URL that
+    # processes the payment, thus decisions are taken on the basis of
+    # the _state_ of the payment, rather than a particular endpoint.
+    # For example, it is perfectly normal having fulfillment and pay
+    # URL being the same thing.
+
+    def process_data(self, payment, request):
+
+        # Very first branch taken.  It returns the 402 status
+        # plus the contract generation URL.
+        if payment.status == PaymentStatus.WAITING:
+            wallet_not_found_msg = _('Taler wallet disabled.  Please' \
+                ' either enable the wallet or pick another payment method.')
+            data = render_to_string('payments/taler_fallback.html',
+                                   {'msg': wallet_not_found_msg})
+            response = HttpResponse(data, status=402)
+
+            response['X-Taler-Contract-Url'] = self.get_return_url(payment)
+            payment.change_status(PaymentStatus.INPUT)
+            return response
+
+        # Listen for contract generation.
+        if payment.status == PaymentStatus.INPUT:
+            try:
+                total_amount = Amount.parse('%s:%0.2f' % (payment.currency, payment.total)).dump()
+                order = {
+                    'summary': payment.message,
+                    'nonce': request.GET.get('nonce'),
+                    'amount': total_amount,
+                    'products': [{'description': payment.description,
+                                  'quantity': 1,
+                                  'product_id': 0,
+                                  'price': total_amount}],
+                    'fulfillment_url': self.get_return_url(payment),
+                    'pay_url': self.get_return_url(payment),
+                    'merchant': {
+                        'instance': self.instance,
+                        'address': self.address,
+                        'name': self.name,
+                        'jurisdiction': self.jurisdiction},
+                    'extra': {}}
+            except BadAmount as e:
+                logger.error('Malformed amount: %s' % e.faulty_str)
+                data = {'error': _('Internal error generating contract'),
+                                   'detail': _('Could not parse amount')}
+                return JsonResponse(data, status=500)
+
+            try:
+                r = requests.post(urljoin(self.backend_url, 'proposal'),
+                                  json={'order': order})
+            except requests.RequestException as e:
+                logger.error(e)
+                return JsonResponse({'error': 'Internal server error',
+                    'detail': 'Could not reach the backend'}, status=500)
+            if r.status_code == 200:
+                payment.change_status(PaymentStatus.PREAUTH)
+            return JsonResponse(r.json(), status=r.status_code)
+
+        # This is responsible to both execute the payment and receive it.
+        # When the wallet attempts to GET it, it returns the 402 which
+        # executes the payment, whereas POSTing to it triggers the /pay behaviour.
+        if payment.status == PaymentStatus.PREAUTH:
+            if request.method == 'POST':
+                try:
+                    r = requests.post(urljoin(self.backend_url, 'pay'),
+                                      json=json.loads(request.body.decode('utf-8')))
+                except requests.RequestException as e:
+                    logger.error(e)
+                    return JsonResponse({'error': 'Internal server error',
+                        'detail': 'Could not reach the backend'}, status=500)
+                if r.status_code == 200:
+                    payment.change_status(PaymentStatus.CONFIRMED)
+                return JsonResponse(r.json(), status=r.status_code)
+
+            if request.method == 'GET':
+                wallet_not_found_msg = _('Taler wallet disabled.  Please' \
+                    ' either enable the wallet or pick another payment method.')
+                data = render_to_string('payments/taler_fallback.html',
+                                       {'msg': wallet_not_found_msg})
+                response = HttpResponse(data, status=402)
+                response['X-Taler-Contract-Url'] = self.get_return_url(payment)
+                response['X-Taler-Offer-Url'] = get_base_url()
+                return response
+
+        # Taken when the payment has gone through, redirect to persistent
+        # fulfillment page.
+        if payment.status == PaymentStatus.CONFIRMED:
+            # returns absolute url
+            return redirect(payment.get_success_url())
+
+        # This should _never_ happen
+        return JsonResponse({'error': 'Internal server error',
+            'detail': 'Unknown payment status!'}, status=500)