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/models.py

@@ -1,8 +1,9 @@
 import time
 import uuid
 import datetime
-from flask import url_for
+from flask import url_for, current_app
 
+from sqlalchemy.ext.hybrid import hybrid_property
 from sqlalchemy.dialects.postgresql import (
     UUID,
     JSON
@@ -46,7 +47,12 @@ class HistoryModel:
 
     def update_from_original(self, original):
         for c in self.__table__.columns:
-            setattr(self, c.name, getattr(original, c.name))
+            # in some cases, columns may have different names to their underlying db column -  so only copy those
+            # that we can, and leave it up to subclasses to deal with any oddities/properties etc.
+            if hasattr(original, c.name):
+                setattr(self, c.name, getattr(original, c.name))
+            else:
+                current_app.logger.debug('{} has no column {} to copy from'.format(original, c.name))
 
 
 class User(db.Model):
@@ -621,6 +627,12 @@ NOTIFICATION_STATUS_TYPES = [
 NOTIFICATION_STATUS_TYPES_ENUM = db.Enum(*NOTIFICATION_STATUS_TYPES, name='notify_status_type')
 
 
+class NotificationStatusTypes(db.Model):
+    __tablename__ = 'notification_status_types'
+
+    name = db.Column(db.String(255), primary_key=True)
+
+
 class Notification(db.Model):
     __tablename__ = 'notifications'
 
@@ -656,7 +668,15 @@ class Notification(db.Model):
         unique=False,
         nullable=True,
         onupdate=datetime.datetime.utcnow)
-    status = db.Column(NOTIFICATION_STATUS_TYPES_ENUM, index=True, nullable=False, default='created')
+    _status_enum = db.Column('status', NOTIFICATION_STATUS_TYPES_ENUM, index=True, nullable=False, default='created')
+    _status_fkey = db.Column(
+        'notification_status',
+        db.String,
+        db.ForeignKey('notification_status_types.name'),
+        index=True,
+        nullable=True,
+        default='created'
+    )
     reference = db.Column(db.String, nullable=True, index=True)
     client_reference = db.Column(db.String, index=True, nullable=True)
     _personalisation = db.Column(db.String, nullable=True)
@@ -672,6 +692,15 @@ class Notification(db.Model):
     phone_prefix = db.Column(db.String, nullable=True)
     rate_multiplier = db.Column(db.Float(asdecimal=False), nullable=True)
 
+    @hybrid_property
+    def status(self):
+        return self._status_enum
+
+    @status.setter
+    def status(self, status):
+        self._status_fkey = status
+        self._status_enum = status
+
     @property
     def personalisation(self):
         if self._personalisation:
@@ -844,7 +873,15 @@ class NotificationHistory(db.Model, HistoryModel):
     sent_at = db.Column(db.DateTime, index=False, unique=False, nullable=True)
     sent_by = db.Column(db.String, nullable=True)
     updated_at = db.Column(db.DateTime, index=False, unique=False, nullable=True)
-    status = db.Column(NOTIFICATION_STATUS_TYPES_ENUM, index=True, nullable=False, default='created')
+    _status_enum = db.Column('status', NOTIFICATION_STATUS_TYPES_ENUM, index=True, nullable=False, default='created')
+    _status_fkey = db.Column(
+        'notification_status',
+        db.String,
+        db.ForeignKey('notification_status_types.name'),
+        index=True,
+        nullable=True,
+        default='created'
+    )
     reference = db.Column(db.String, nullable=True, index=True)
     client_reference = db.Column(db.String, nullable=True)
 
@@ -855,8 +892,18 @@ class NotificationHistory(db.Model, HistoryModel):
     @classmethod
     def from_original(cls, notification):
         history = super().from_original(notification)
+        history.status = notification.status
         return history
 
+    @hybrid_property
+    def status(self):
+        return self._status_enum
+
+    @status.setter
+    def status(self, status):
+        self._status_fkey = status
+        self._status_enum = status
+
 
 INVITED_USER_STATUS_TYPES = ['pending', 'accepted', 'cancelled']