stats: Don't show analytics data unavailable error for new realms.

The value of start would be set to realm creation date or installation
date unless a value is explicitly provided by the user. We don't
want to show analytics data missing error in both these cases if
start is less than 24.5 hours from timezone_now() since some of the
stats are populated by a daily cron job that may take a couple of
minutes to run.

The same case applies if the value of the start is passed in the
request.

analytics/tests/test_views.py

@@ -5,6 +5,7 @@ import mock
 from django.utils.timezone import utc
 from django.http import HttpResponse
 import ujson
+from django.utils.timezone import now as timezone_now
 
 from analytics.lib.counts import COUNT_STATS, CountStat
 from analytics.lib.time_utils import time_range
@@ -286,13 +287,75 @@ class TestGetChartData(ZulipTestCase):
         self.assert_json_error_contains(result, 'Unknown chart name')
 
     def test_analytics_not_running(self) -> None:
-        # try to get data for a valid chart, but before we've put anything in the database
-        # (e.g. before update_analytics_counts has been run)
+        realm = get_realm("zulip")
+
+        self.assertEqual(FillState.objects.count(), 0)
+
+        realm.date_created = timezone_now() - timedelta(days=3)
+        realm.save(update_fields=["date_created"])
         with mock.patch('logging.warning'):
             result = self.client_get('/json/analytics/chart_data',
-                                     {'chart_name': 'number_of_humans'})
+                                     {'chart_name': 'messages_sent_over_time'})
         self.assert_json_error_contains(result, 'No analytics data available')
 
+        realm.date_created = timezone_now() - timedelta(days=1, hours=2)
+        realm.save(update_fields=["date_created"])
+        with mock.patch('logging.warning'):
+            result = self.client_get('/json/analytics/chart_data',
+                                     {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_error_contains(result, 'No analytics data available')
+
+        realm.date_created = timezone_now() - timedelta(days=1, minutes=10)
+        realm.save(update_fields=["date_created"])
+        result = self.client_get('/json/analytics/chart_data',
+                                 {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_success(result)
+
+        realm.date_created = timezone_now() - timedelta(hours=10)
+        realm.save(update_fields=["date_created"])
+        result = self.client_get('/json/analytics/chart_data',
+                                 {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_success(result)
+
+        end_time = timezone_now() - timedelta(days=5)
+        fill_state = FillState.objects.create(property='messages_sent:is_bot:hour', end_time=end_time,
+                                              state=FillState.DONE)
+
+        realm.date_created = timezone_now() - timedelta(days=3)
+        realm.save(update_fields=["date_created"])
+        with mock.patch('logging.warning'):
+            result = self.client_get('/json/analytics/chart_data',
+                                     {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_error_contains(result, 'No analytics data available')
+
+        realm.date_created = timezone_now() - timedelta(days=1, minutes=10)
+        realm.save(update_fields=["date_created"])
+        result = self.client_get('/json/analytics/chart_data',
+                                 {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_success(result)
+
+        end_time = timezone_now() - timedelta(days=2)
+        fill_state.end_time = end_time
+        fill_state.save(update_fields=["end_time"])
+
+        realm.date_created = timezone_now() - timedelta(days=3)
+        realm.save(update_fields=["date_created"])
+        result = self.client_get('/json/analytics/chart_data',
+                                 {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_success(result)
+
+        realm.date_created = timezone_now() - timedelta(days=1, hours=2)
+        realm.save(update_fields=["date_created"])
+        with mock.patch('logging.warning'):
+            result = self.client_get('/json/analytics/chart_data',
+                                     {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_error_contains(result, 'No analytics data available')
+
+        realm.date_created = timezone_now() - timedelta(days=1, minutes=10)
+        realm.save(update_fields=["date_created"])
+        result = self.client_get('/json/analytics/chart_data', {'chart_name': 'messages_sent_over_time'})
+        self.assert_json_success(result)
+
     def test_get_chart_data_for_realm(self) -> None:
         user = self.example_user('hamlet')
         self.login_user(user)

analytics/views.py

@@ -58,6 +58,8 @@ else:
     RemoteZulipServer = Mock()  # type: ignore # https://github.com/JukkaL/mypy/issues/1188
     RemoteRealmCount = Mock()  # type: ignore # https://github.com/JukkaL/mypy/issues/1188
 
+MAX_TIME_FOR_FULL_ANALYTICS_GENERATION = timedelta(days=1, minutes=30)
+
 def render_stats(request: HttpRequest, data_url_suffix: str, target_name: str,
                  for_installation: bool=False, remote: bool=False) -> HttpRequest:
     page_params = dict(
@@ -244,7 +246,8 @@ def get_chart_data(request: HttpRequest, user_profile: UserProfile, chart_name:
         if end is None:
             end = max(last_successful_fill(stat.property) or
                       datetime.min.replace(tzinfo=timezone_utc) for stat in stats)
-        if start > end:
+
+        if start > end and (timezone_now() - start > MAX_TIME_FOR_FULL_ANALYTICS_GENERATION):
             logging.warning("User from realm %s attempted to access /stats, but the computed "
                             "start time: %s (creation of realm or installation) is later than the computed "
                             "end time: %s (last successful analytics update). Is the "