From 722e330518df8ce4e2c2084ab453adab0660dc46 Mon Sep 17 00:00:00 2001
From: Erik Stein <erik@classlibrary.net>
Date: Tue, 19 Feb 2019 11:46:36 +0100
Subject: [PATCH] Mock datetime for preview.

---
 shared/utils/conf.py     |  4 ++++
 shared/utils/preview.py  | 25 +++++++++++++++++++++++++
 shared/utils/timezone.py | 14 +++++++++++---
 3 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 shared/utils/preview.py

diff --git a/shared/utils/conf.py b/shared/utils/conf.py
index 94492e7..1f01071 100644
--- a/shared/utils/conf.py
+++ b/shared/utils/conf.py
@@ -4,3 +4,7 @@ USE_TRANSLATABLE_FIELDS = (
     getattr(settings, 'CONTENT_PLUGINS_USE_TRANSLATABLE_FIELDS', False) or
     getattr(settings, 'USE_TRANSLATABLE_FIELDS', False)
 )
+
+
+USE_PREVIEW_DATETIME = getattr(settings, 'USE_PREVIEW_DATETIME', False)
+# You also have to set PREVIEW_DATETIME = datetime(...)
diff --git a/shared/utils/preview.py b/shared/utils/preview.py
new file mode 100644
index 0000000..082742f
--- /dev/null
+++ b/shared/utils/preview.py
@@ -0,0 +1,25 @@
+from django.conf import settings
+from django.utils import timezone
+
+from .conf import USE_PREVIEW_DATETIME
+from .timezone import smart_default_tz
+
+
+class datetime(timezone.datetime):
+    @classmethod
+    def now(klass):
+        if USE_PREVIEW_DATETIME:
+            if settings.DEBUG_PREVIEW_DATETIME:
+                now = timezone.datetime(*settings.DEBUG_PREVIEW_DATETIME)
+            else:
+                # TODO Get preview datetime from request user
+                now = timezone.now()
+            if settings.USE_TZ:
+                now = smart_default_tz(now)
+        else:
+            now = timezone.now()
+        return now
+
+    @classmethod
+    def today(klass):
+        return klass.now().date()
diff --git a/shared/utils/timezone.py b/shared/utils/timezone.py
index 0372fd6..06f6c0a 100644
--- a/shared/utils/timezone.py
+++ b/shared/utils/timezone.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-# Erik Stein <code@classlibrary.net>, 2015
 """
 
 Django and Timezones
@@ -17,6 +14,8 @@ A sample Django application illustrating some time zone traps for the unwary.
 
 """
 
+import datetime
+from django.conf import settings
 from django.utils import timezone
 
 
@@ -28,3 +27,12 @@ def smart_default_tz(datetime_value):
         datetime_value = timezone.make_aware(datetime_value, timezone=timezone.get_default_timezone())
     return timezone.localtime(datetime_value, timezone.get_default_timezone())
 
+
+def timezone_today():
+    """
+    Return the current date in the current time zone.
+    """
+    if settings.USE_TZ:
+        return timezone.localdate()
+    else:
+        return datetime.date.today()