return all zeros when NotificationStatistics dont exist

app/dao/notifications_dao.py

@@ -1,4 +1,4 @@
-from sqlalchemy import (desc, func, Integer, and_, asc)
+from sqlalchemy import (desc, func, Integer, and_, or_, asc)
 from sqlalchemy.sql.expression import cast
 
 from datetime import (
@@ -12,6 +12,7 @@ from werkzeug.datastructures import MultiDict
 
 from app import db
 from app.models import (
+    Service,
     Notification,
     Job,
     NotificationStatistics,
@@ -57,6 +58,51 @@ def dao_get_notification_statistics_for_day(day):
     ).all()
 
 
+def dao_get_potential_notification_statistics_for_day(day):
+    all_services = db.session.query(
+        Service.id,
+        NotificationStatistics
+    ).outerjoin(
+        Service.service_notification_stats
+    ).filter(
+        or_(
+            NotificationStatistics.day == day,
+            NotificationStatistics.day == None  # noqa
+        )
+    ).order_by(
+        asc(Service.created_at)
+    )
+
+    notification_statistics = []
+    for service_notification_stats_pair in all_services:
+        if service_notification_stats_pair.NotificationStatistics:
+            notification_statistics.append(
+                service_notification_stats_pair.NotificationStatistics
+            )
+        else:
+            notification_statistics.append(
+                create_notification_statistics_dict(
+                    service_notification_stats_pair,
+                    day
+                )
+            )
+    return notification_statistics
+
+
+def create_notification_statistics_dict(service_id, day):
+    return {
+        'id': None,
+        'emails_requested': 0,
+        'emails_delivered': 0,
+        'emails_failed': 0,
+        'sms_requested': 0,
+        'sms_delivered': 0,
+        'sms_failed': 0,
+        'day': day.isoformat(),
+        'service': service_id
+    }
+
+
 def dao_get_7_day_agg_notification_statistics_for_service(service_id,
                                                           date_from,
                                                           week_count=52):