Allow users to list their notifications

This is in very early stage, but at least it works.

calsocial/models.py

@@ -18,6 +18,7 @@
 """
 
 from datetime import datetime
+from enum import Enum
 from warnings import warn
 
 from flask_babelex import lazy_gettext
@@ -41,6 +42,24 @@ def generate_uuid():
     return uuid4().hex
 
 
+def _(translate):  # pylint: disable=invalid-name
+    """Function to mark strings as translatable
+
+    The actual translation will be fetched later in `:meth:AuditLog.get_message`.
+    """
+
+    return translate
+
+
+class NotificationAction(Enum):
+    follow = 1
+
+
+notification_action_messages = {
+    NotificationAction.follow: (_('%(actor)s followed you'), _('%(actor)s followed %(item)s'))
+}
+
+
 class SettingsProxy:
     """Proxy object to get settings for a user
     """
@@ -184,6 +203,15 @@ class Profile(db.Model):  # pylint: disable=too-few-public-methods
     #: The display name
     display_name = db.Column(db.Unicode(length=80), nullable=False)
 
+    @property
+    def fqdn(self):
+        ret = ''
+
+        if self.user:
+            return f'@{self.user.username}'
+
+        return f'@{self.username}@{self.domain}'
+
     def __repr__(self):
         if self.user:
             username = self.user.username
@@ -194,6 +222,16 @@ class Profile(db.Model):  # pylint: disable=too-few-public-methods
 
         return f'<Profile {self.id}(@{username}{domain})>'
 
+    def __str__(self):
+        ret = ''
+
+        if self.display_name:
+            ret = self.display_name + ' '
+
+        ret += f'({self.fqdn})'
+
+        return ret
+
     @property
     def followed_list(self):
         """List of profiles this profile is following
@@ -313,15 +351,6 @@ class UserSetting(db.Model):  # pylint: disable=too-few-public-methods
         return f'<UserSetting of {self.user}, {self.key}="{self.value}">'
 
 
-def _(translate):  # pylint: disable=invalid-name
-    """Function to mark strings as translatable
-
-    The actual translation will be fetched later in `:meth:AuditLog.get_message`.
-    """
-
-    return translate
-
-
 class AuditLog(db.Model):
     """Database model for audit log records
     """
@@ -442,3 +471,62 @@ class UserFollow(db.Model):
 
     #: The timestamp when the follow was accepted
     accepted_at = db.Column(db.DateTime(), nullable=True)
+
+
+class Notification(db.Model):
+    """Database model for notifications
+    """
+
+    __tablename__ = 'notifications'
+    # pylint: disable=invalid-name
+    id = db.Column(db.Integer(), primary_key=True)
+
+    #: The recipient of the notification
+    profile_id = db.Column(db.Integer(), db.ForeignKey('profiles.id'), nullable=False)
+
+    profile = db.relationship('Profile',
+                              backref=db.backref('notifications', lazy='dynamic'),
+                              foreign_keys=[profile_id])
+
+    #: The profile that generated the notification
+    actor_id = db.Column(db.Integer(), db.ForeignKey('profiles.id'), nullable=True)
+
+    actor = db.relationship('Profile', foreign_keys=[actor_id])
+
+    #: The item (e.g. event) that generated the notification
+    item_id = db.Column(db.Integer(), nullable=True)
+
+    #: The type of the item that generated the notification
+    item_type = db.Column(db.String(length=40))
+
+    #: The type of action
+    action = db.Column(db.Enum(NotificationAction))
+
+    #: The timestamp when the notification was created
+    created_at = db.Column(db.DateTime(), default=datetime.utcnow, nullable=False)
+
+    #: The timestamp when the notification was read
+    read_at = db.Column(db.DateTime(), nullable=True)
+
+    @property
+    def item(self):
+        item_class = self._decl_class_registry.get(self.item_type)
+
+        if item_class is None:
+            warn(f'Unknown item type {self.item_type}')
+
+            return None
+
+        return item_class.query.get(self.item_id)
+
+    @property
+    def message(self):
+        """Get the translated message for ``key``
+        """
+
+        from flask_security import current_user
+
+        messages = notification_action_messages.get(self.action)
+        message = messages[0 if self.item == current_user.profile else 1]
+
+        return lazy_gettext(message, actor=self.actor, item=self.item)