start implementing time machine mode (thread local)

src/pretix/base/models/event.py

@@ -76,6 +76,7 @@ from pretix.helpers.thumb import get_thumbnail
 
 from ..settings import settings_hierarkey
 from .organizer import Organizer, Team
+from ...presale.timemachine import time_machine_now
 
 logger = logging.getLogger(__name__)
 
@@ -243,11 +244,11 @@ class EventMixin:
         Is true, when ``presale_end`` is set and in the past.
         """
         if self.effective_presale_end:
-            return now() > self.effective_presale_end
+            return time_machine_now() > self.effective_presale_end
         elif self.date_to:
-            return now() > self.date_to
+            return time_machine_now() > self.date_to
         else:
-            return now().astimezone(self.timezone).date() > self.date_from.astimezone(self.timezone).date()
+            return time_machine_now().astimezone(self.timezone).date() > self.date_from.astimezone(self.timezone).date()
 
     @property
     def effective_presale_start(self):
@@ -267,7 +268,7 @@ class EventMixin:
         Is true, when ``presale_end`` is not set or in the future and ``presale_start`` is not
         set or in the past.
         """
-        if self.effective_presale_start and now() < self.effective_presale_start:
+        if self.effective_presale_start and time_machine_now() < self.effective_presale_start:
             return False
         return not self.presale_has_ended
 
@@ -315,11 +316,11 @@ class EventMixin:
         q_variation = (
             Q(active=True)
             & Q(sales_channels__contains=channel)
-            & Q(Q(available_from__isnull=True) | Q(available_from__lte=now()))
-            & Q(Q(available_until__isnull=True) | Q(available_until__gte=now()))
+            & Q(Q(available_from__isnull=True) | Q(available_from__lte=time_machine_now()))
+            & Q(Q(available_until__isnull=True) | Q(available_until__gte=time_machine_now()))
             & Q(item__active=True)
-            & Q(Q(item__available_from__isnull=True) | Q(item__available_from__lte=now()))
-            & Q(Q(item__available_until__isnull=True) | Q(item__available_until__gte=now()))
+            & Q(Q(item__available_from__isnull=True) | Q(item__available_from__lte=time_machine_now()))
+            & Q(Q(item__available_until__isnull=True) | Q(item__available_until__gte=time_machine_now()))
             & Q(Q(item__category__isnull=True) | Q(item__category__is_addon=False))
             & Q(item__sales_channels__contains=channel)
             & Q(item__require_bundling=False)
@@ -694,7 +695,7 @@ class Event(EventMixin, LoggedModel):
     @property
     def presale_has_ended(self):
         if self.has_subevents:
-            return self.presale_end and now() > self.presale_end
+            return self.presale_end and time_machine_now() > self.presale_end
         else:
             return super().presale_has_ended
 
@@ -1187,8 +1188,8 @@ class Event(EventMixin, LoggedModel):
             )
         ).filter(
             Q(active=True) & Q(is_public=True) & (
-                Q(Q(date_to__isnull=True) & Q(date_from__gte=now() - timedelta(hours=24)))
-                | Q(date_to__gte=now() - timedelta(hours=24))
+                Q(Q(date_to__isnull=True) & Q(date_from__gte=time_machine_now() - timedelta(hours=24)))
+                | Q(date_to__gte=time_machine_now() - timedelta(hours=24))
             )
         )  # order_by doesn't make sense with I18nField
         if ordering in ("date_ascending", "date_descending"):
@@ -1508,7 +1509,7 @@ class SubEvent(EventMixin, LoggedModel):
             disabled_items=Coalesce(
                 Subquery(
                     SubEventItem.objects.filter(
-                        Q(disabled=True) | Q(available_from__gt=now()) | Q(available_until__lt=now()),
+                        Q(disabled=True) | Q(available_from__gt=time_machine_now()) | Q(available_until__lt=time_machine_now()),
                         subevent=OuterRef('pk'),
                     ).order_by().values('subevent').annotate(items=GroupConcat('item_id', delimiter=',')).values('items'),
                     output_field=models.TextField(),
@@ -1519,7 +1520,7 @@ class SubEvent(EventMixin, LoggedModel):
             disabled_vars=Coalesce(
                 Subquery(
                     SubEventItemVariation.objects.filter(
-                        Q(disabled=True) | Q(available_from__gt=now()) | Q(available_until__lt=now()),
+                        Q(disabled=True) | Q(available_from__gt=time_machine_now()) | Q(available_until__lt=time_machine_now()),
                         subevent=OuterRef('pk'),
                     ).order_by().values('subevent').annotate(items=GroupConcat('variation_id', delimiter=',')).values('items'),
                     output_field=models.TextField(),

src/pretix/presale/middleware.py

@@ -79,3 +79,4 @@ class EventMiddleware:
                 response = response.render()
 
         return response
+

src/pretix/presale/templates/pretixpresale/event/base.html

@@ -33,6 +33,17 @@
             </div>
         </div>
     {% endif %}
+    {% if request.now_dt_is_fake %}
+        <div class="offline-banner">
+            <div class="container">
+                <span class="fa fa-user-secret" aria-hidden="true"></span>
+                {% trans "You are currently using the time machine. The ticket shop is rendered as if it were" %} {{ request.now_dt }}
+                <a href="#">
+                    {% trans "Go back to current time" %}
+                </a>
+            </div>
+        </div>
+    {% endif %}
     <div class="container page-header-links {% if event.settings.theme_color_background|upper != "#FFFFFF" or event_logo_image_large %}page-header-links-outside{% endif %}">
         {% if event.settings.locales|length > 1 or request.organizer.settings.customer_accounts %}
             {% if event.settings.theme_color_background|upper != "#FFFFFF" or event_logo_image_large %}

src/pretix/presale/timemachine.py

@@ -0,0 +1,74 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program 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 Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+# This file is based on an earlier version of pretix which was released under the Apache License 2.0. The full text of
+# the Apache License 2.0 can be obtained at <http://www.apache.org/licenses/LICENSE-2.0>.
+#
+# This file may have since been changed and any changes are released under the terms of AGPLv3 as described above. A
+# full history of changes and contributors is available at <https://github.com/pretix/pretix>.
+#
+# This file contains Apache-licensed contributions copyrighted by: Tobias Kunze
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the Apache License 2.0 is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under the License.
+
+import threading
+from dateutil.parser import parse
+from django.utils.timezone import now
+
+
+class TimeMachineMiddleware:
+    tls = threading.local()
+
+    def __init__(self, get_response=None):
+        self.get_response = get_response
+        super().__init__()
+
+    def __call__(self, request):
+        if hasattr(request, 'event') and hasattr(request, '_namespace') and request._namespace == 'presale' and \
+                'time_machine' in request.COOKIES and \
+                request.user.has_event_permission(request.organizer, request.event, 'can_change_event_settings', request):
+            print("setting now_dt from cookie")
+            request.now_dt = parse(request.COOKIES['time_machine'])
+            request.now_dt_is_fake = True
+        else:
+            print("setting now_dt to now",
+                  "hasevent?",hasattr(request, 'event') ,
+                  "namespace?",hasattr(request, '_namespace') and request._namespace,
+                  "cookies?",request.COOKIES)
+            request.now_dt = now()
+            request.now_dt_is_fake = False
+
+        try:
+            TimeMachineMiddleware.tls.now_dt = request.now_dt
+            TimeMachineMiddleware.tls.now_dt_is_fake = request.now_dt_is_fake
+
+            return self.get_response(request)
+        finally:
+            TimeMachineMiddleware.tls.now_dt = None
+            TimeMachineMiddleware.tls.now_dt_is_fake = None
+
+
+def time_machine_now():
+    return TimeMachineMiddleware.tls.now_dt or now()
+

src/pretix/settings.py

@@ -454,6 +454,7 @@ MIDDLEWARE = [
     'pretix.base.middleware.LocaleMiddleware',
     'pretix.base.middleware.SecurityMiddleware',
     'pretix.presale.middleware.EventMiddleware',
+    'pretix.presale.timemachine.TimeMachineMiddleware',
     'pretix.api.middleware.ApiScopeMiddleware',
 ]