add new notification_status column to models.py

We now have a new column in the database, but it isn't being
populated. The first step is to make sure we update this column,
while still keeping the old enum based column up to date as well.

A couple of changes have had to happen to support this - one irritating
thing is that if we're ever querying columns individually, including
`Notification.status`, then we'll need to give that column a label,
since under the hood it translates to `Notification._status_enum`.
Accessing status through the ORM (i.e., my_noti.status = 'sending' or
similar) will work fine.

app/dao/services_dao.py

@@ -127,7 +127,8 @@ def dao_update_service(service):
     db.session.add(service)
 
 
-def dao_add_user_to_service(service, user, permissions=[]):
+def dao_add_user_to_service(service, user, permissions=None):
+    permissions = permissions or []
     try:
         from app.dao.permissions_dao import permission_dao
         service.users.append(user)
@@ -214,7 +215,8 @@ def fetch_todays_total_message_count(service_id):
 def _stats_for_service_query(service_id):
     return db.session.query(
         Notification.notification_type,
-        Notification.status,
+        # see dao_fetch_todays_stats_for_all_services for why we have this label
+        Notification.status.label('status'),
         func.count(Notification.id).label('count')
     ).filter(
         Notification.service_id == service_id,
@@ -232,13 +234,13 @@ def dao_fetch_monthly_historical_stats_by_template_for_service(service_id, year)
     start_date, end_date = get_financial_year(year)
     sq = db.session.query(
         NotificationHistory.template_id,
-        NotificationHistory.status,
+        # see dao_fetch_todays_stats_for_all_services for why we have this label
+        NotificationHistory.status.label('status'),
         month.label('month'),
         func.count().label('count')
     ).filter(
         NotificationHistory.service_id == service_id,
         NotificationHistory.created_at.between(start_date, end_date)
-
     ).group_by(
         month,
         NotificationHistory.template_id,
@@ -249,7 +251,7 @@ def dao_fetch_monthly_historical_stats_by_template_for_service(service_id, year)
         Template.id.label('template_id'),
         Template.name,
         Template.template_type,
-        sq.c.status,
+        sq.c.status.label('status'),
         sq.c.count.label('count'),
         sq.c.month
     ).join(
@@ -267,7 +269,8 @@ def dao_fetch_monthly_historical_stats_for_service(service_id, year):
     start_date, end_date = get_financial_year(year)
     rows = db.session.query(
         NotificationHistory.notification_type,
-        NotificationHistory.status,
+        # see dao_fetch_todays_stats_for_all_services for why we have this label
+        NotificationHistory.status.label('status'),
         month,
         func.count(NotificationHistory.id).label('count')
     ).filter(
@@ -306,7 +309,9 @@ def dao_fetch_monthly_historical_stats_for_service(service_id, year):
 def dao_fetch_todays_stats_for_all_services(include_from_test_key=True):
     query = db.session.query(
         Notification.notification_type,
-        Notification.status,
+        # this label is necessary as the column has a different name under the hood (_status_enum / _status_fkey),
+        # if we query the Notification object there is a hybrid property to translate, but here there isn't anything.
+        Notification.status.label('status'),
         Notification.service_id,
         func.count(Notification.id).label('count')
     ).filter(
@@ -336,7 +341,8 @@ def fetch_stats_by_date_range_for_all_services(start_date, end_date, include_fro
 
     query = db.session.query(
         table.notification_type,
-        table.status,
+        # see dao_fetch_todays_stats_for_all_services for why we have this label
+        table.status.label('status'),
         table.service_id,
         func.count(table.id).label('count')
     ).filter(