ECOM-1155 fix the date diff issue.

common/djangoapps/course_modes/admin.py

+"""
+Django admin page for course modes
+"""
+from django.conf import settings
+from pytz import timezone, UTC
 from ratelimitbackend import admin
 from course_modes.models import CourseMode
 from django import forms
@@ -6,6 +11,7 @@ from opaque_keys import InvalidKeyError
 from xmodule.modulestore.django import modulestore
 from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
+from util.date_utils import get_time_display
 
 
 class CourseModeForm(forms.ModelForm):
@@ -35,13 +41,37 @@ class CourseModeForm(forms.ModelForm):
 
         return course_key
 
+    def __init__(self, *args, **kwargs):
+        super(CourseModeForm, self).__init__(*args, **kwargs)
+        if self.instance.expiration_datetime:
+            default_tz = timezone(settings.TIME_ZONE)
+            # django admin is using default timezone. To avoid time conversion from db to form
+            # convert the UTC object to naive and then localize with default timezone.
+            expiration_datetime = self.instance.expiration_datetime.replace(tzinfo=None)
+            self.initial['expiration_datetime'] = default_tz.localize(expiration_datetime)
+
+    def clean_expiration_datetime(self):
+        """changing the tzinfo for a given datetime object"""
+        # django admin saving the date with default timezone to avoid time conversion from form to db
+        # changes its tzinfo to UTC
+        if self.cleaned_data.get("expiration_datetime"):
+            return self.cleaned_data.get("expiration_datetime").replace(tzinfo=UTC)
+
 
 class CourseModeAdmin(admin.ModelAdmin):
+    """Admin for course modes"""
     form = CourseModeForm
     search_fields = ('course_id',)
     list_display = (
         'id', 'course_id', 'mode_slug', 'mode_display_name', 'min_price',
-        'suggested_prices', 'currency', 'expiration_date', 'expiration_datetime'
+        'suggested_prices', 'currency', 'expiration_date', 'expiration_datetime_custom'
     )
 
+    def expiration_datetime_custom(self, obj):
+        """adding custom column to show the expiry_datetime"""
+        if obj.expiration_datetime:
+            return get_time_display(obj.expiration_datetime, '%B %d, %Y, %H:%M  %p')
+
+    expiration_datetime_custom.short_description = "Expiration Datetime"
+
 admin.site.register(CourseMode, CourseModeAdmin)

common/djangoapps/course_modes/tests/test_views.py

@@ -5,11 +5,14 @@ from mock import patch
 from django.conf import settings
 from django.test.utils import override_settings
 from django.core.urlresolvers import reverse
+from pytz import timezone
+from datetime import datetime
 
 from xmodule.modulestore.tests.django_utils import (
     ModuleStoreTestCase, mixed_store_config
 )
 
+from util.date_utils import get_time_display
 from util.testing import UrlResetMixin
 from embargo.test_utils import restrict_course
 from xmodule.modulestore.tests.factories import CourseFactory
@@ -314,3 +317,45 @@ class TrackSelectionEmbargoTest(UrlResetMixin, ModuleStoreTestCase):
     def test_embargo_allow(self):
         response = self.client.get(self.url)
         self.assertEqual(response.status_code, 200)
+
+
+class AdminCourseModePageTest(ModuleStoreTestCase):
+    """Test the django admin course mode form saving data in db without any conversion
+     properly converts the tzinfo from default zone to utc
+    """
+
+    def test_save_valid_data(self):
+        user = UserFactory.create(is_staff=True, is_superuser=True)
+        user.save()
+        course = CourseFactory.create()
+        expiration = datetime(2015, 10, 20, 1, 10, 23, tzinfo=timezone(settings.TIME_ZONE))
+
+        data = {
+            'course_id': unicode(course.id),
+            'mode_slug': 'professional',
+            'mode_display_name': 'professional',
+            'min_price': 10,
+            'currency': 'usd',
+            'expiration_datetime_0': expiration.date(),  # due to django admin datetime widget passing as seperate vals
+            'expiration_datetime_1': expiration.time(),
+
+        }
+
+        self.client.login(username=user.username, password='test')
+
+        # creating new course mode from django admin page
+        response = self.client.post(reverse('admin:course_modes_coursemode_add'), data=data)
+        self.assertRedirects(response, reverse('admin:course_modes_coursemode_changelist'))
+
+        # verifying that datetime is appearing on list page
+        response = self.client.get(reverse('admin:course_modes_coursemode_changelist'))
+        self.assertContains(response, get_time_display(expiration, '%B %d, %Y, %H:%M  %p'))
+
+        # verifiying the on edit page datetime value appearing without any modifications
+        resp = self.client.get(reverse('admin:course_modes_coursemode_change', args=(1,)))
+        self.assertContains(resp, expiration.date())
+        self.assertContains(resp, expiration.time())
+
+        # checking the values in db. comparing values without tzinfo
+        course_mode = CourseMode.objects.get(pk=1)
+        self.assertEqual(course_mode.expiration_datetime.replace(tzinfo=None), expiration.replace(tzinfo=None))