Simplify the code in the query.

The date in the notifications table should always be the most recent date for the template.
Removed the template_type param for the query as well.
Simplified the tests.

app/dao/notifications_dao.py

@@ -72,7 +72,18 @@ def dao_get_last_template_usage(template_id, template_type, service_id):
 
 
 @statsd(namespace="dao")
-def dao_get_last_date_template_was_used(template_id, template_type, service_id):
+def dao_get_last_date_template_was_used(template_id, service_id):
+    last_date_from_notifications = db.session.query(
+        functions.max(Notification.created_at)
+    ).filter(
+        Notification.service_id == service_id,
+        Notification.template_id == template_id,
+        Notification.key_type != KEY_TYPE_TEST
+    ).scalar()
+
+    if last_date_from_notifications:
+        return last_date_from_notifications
+
     last_date = db.session.query(
         functions.max(FactNotificationStatus.bst_date)
     ).filter(
@@ -80,26 +91,7 @@ def dao_get_last_date_template_was_used(template_id, template_type, service_id):
         FactNotificationStatus.key_type != KEY_TYPE_TEST
     ).scalar()
 
-    last_date_from_notifications = db.session.query(
+    return last_date
-        functions.max(Notification.created_at)
-    ).filter(
-        Notification.service_id == service_id,
-        Notification.notification_type == template_type,
-        Notification.template_id == template_id,
-        Notification.key_type != KEY_TYPE_TEST
-    ).scalar()
-
-    if last_date and last_date_from_notifications:
-        if datetime.combine(last_date, datetime.utcnow().min.time()) >= last_date_from_notifications:
-            return last_date
-        else:
-            return last_date_from_notifications
-    elif not last_date:
-        return last_date_from_notifications
-    elif not last_date_from_notifications:
-        return last_date
-    else:
-        return None
 
 
 @statsd(namespace="dao")

app/template_statistics/rest.py

@@ -58,10 +58,10 @@ def get_template_statistics_for_template_id(service_id, template_id):
 
 @template_statistics.route('/last-used/<uuid:template_id>')
 def get_last_used_datetime_for_template(service_id, template_id):
-    template = dao_get_template_by_id_and_service_id(template_id, service_id)
+    # Check the template and service exist
+    dao_get_template_by_id_and_service_id(template_id, service_id)
 
     last_date_used = dao_get_last_date_template_was_used(template_id=template_id,
-                                                         template_type=template.template_type,
                                                          service_id=service_id)
 
     return jsonify(last_date_used=last_date_used.strftime(DATETIME_FORMAT))

tests/app/dao/notification_dao/test_notification_dao_template_usage.py

@@ -56,54 +56,31 @@ def test_last_template_usage_should_be_able_to_get_no_template_usage_history_if_
     assert not results
 
 
-@pytest.mark.parametrize('last_status_date, last_notification_date',
-                         [((datetime.utcnow() - timedelta(days=2)).date(), None),
-                          ((datetime.utcnow() - timedelta(days=2)).date(), datetime.utcnow() - timedelta(days=3))]
-                         )
 def test_dao_get_last_date_template_was_used_returns_bst_date_from_stats_table(
-        sample_template, last_status_date, last_notification_date
+        sample_template
 ):
+    last_status_date = (datetime.utcnow() - timedelta(days=2)).date()
     create_ft_notification_status(bst_date=last_status_date,
                                   template=sample_template)
-    if last_notification_date:
+
-        create_notification(template=sample_template, created_at=last_notification_date)
     last_used_date = dao_get_last_date_template_was_used(template_id=sample_template.id,
-                                                         template_type='sms',
                                                          service_id=sample_template.service_id)
     assert last_used_date == last_status_date
 
 
-@pytest.mark.parametrize('last_notification_date, last_status_date',
-                         [(datetime.utcnow() - timedelta(hours=2), None),
-                          (datetime.utcnow() - timedelta(hours=2), (datetime.utcnow() - timedelta(days=2)).date())]
-                         )
 def test_dao_get_last_date_template_was_used_returns_created_at_from_notifications(
-        sample_template, last_status_date, last_notification_date
+        sample_template
 ):
+    last_notification_date = datetime.utcnow() - timedelta(hours=2)
     create_notification(template=sample_template, created_at=last_notification_date)
 
-    if last_status_date:
+    last_status_date = (datetime.utcnow() - timedelta(days=2)).date()
-        create_ft_notification_status(bst_date=last_status_date, template=sample_template)
+    create_ft_notification_status(bst_date=last_status_date, template=sample_template)
     last_used_date = dao_get_last_date_template_was_used(template_id=sample_template.id,
-                                                         template_type='sms',
                                                          service_id=sample_template.service_id)
     assert last_used_date == last_notification_date
 
 
 def test_dao_get_last_date_template_was_used_returns_none_if_never_used(sample_template):
     assert not dao_get_last_date_template_was_used(template_id=sample_template.id,
-                                                   template_type='sms',
                                                    service_id=sample_template.service_id)
-
-
-def test_dao_get_last_date_template_was_used_correct_date(sample_template):
-    date_from_notification = datetime.utcnow() - timedelta(hours=2)
-    create_notification(template=sample_template, created_at=date_from_notification)
-    date_from_ft_status = (datetime.utcnow() - timedelta(days=2)).date()
-    create_ft_notification_status(bst_date=date_from_ft_status,
-                                  template=sample_template)
-
-    actual_result = dao_get_last_date_template_was_used(template_id=sample_template.id,
-                                                        template_type='sms',
-                                                        service_id=sample_template.service_id)
-    assert actual_result == date_from_notification

tests/app/template_statistics/test_rest.py

@@ -221,7 +221,7 @@ def test_get_last_used_datetime_for_template_returns_400_if_service_does_not_exi
     )
 
 
-def test_get_last_used_datetime_for_template_returns_400_if_template_does_not_exist(
+def test_get_last_used_datetime_for_template_returns_404_if_template_does_not_exist(
     admin_request, sample_template
 ):
     admin_request.get(