Improve notifications

- Keep track of unread count
 - "follow back" action

utils/__init__.py

@@ -3,6 +3,7 @@ from datetime import datetime
 from datetime import timezone
 
 from dateutil import parser
+from little_boxes import activitypub as ap
 
 logger = logging.getLogger(__name__)
 
@@ -25,3 +26,7 @@ def parse_datetime(s: str) -> datetime:
         dt = dt.replace(tzinfo=timezone.utc)
 
     return dt
+
+
+def now() -> str:
+    ap.format_datetime(datetime.now(timezone.utc))

utils/meta.py

@@ -0,0 +1,50 @@
+from enum import Enum
+from typing import Any
+from typing import Dict
+
+from little_boxes import activitypub as ap
+
+_SubQuery = Dict[str, Any]
+
+
+class Box(Enum):
+    INBOX = "inbox"
+    OUTBOX = "outbox"
+    REPLIES = "replies"
+
+
+class MetaKey(Enum):
+    NOTIFICATION = "notification"
+    NOTIFICATION_UNREAD = "notification_unread"
+    NOTIFICATION_FOLLOWS_BACK = "notification_follows_back"
+    ACTOR_ID = "actor_id"
+    UNDO = "undo"
+    PUBLISHED = "published"
+
+
+def _meta(mk: MetaKey) -> str:
+    return f"meta.{mk.value}"
+
+
+def by_remote_id(remote_id: str) -> _SubQuery:
+    return {"remote_id": remote_id}
+
+
+def in_inbox() -> _SubQuery:
+    return {"box": Box.INBOX.value}
+
+
+def in_outbox() -> _SubQuery:
+    return {"box": Box.OUTBOX.value}
+
+
+def by_type(type_: ap.ActivityType) -> _SubQuery:
+    return {"type": type_.value}
+
+
+def not_undo() -> _SubQuery:
+    return {_meta(MetaKey.UNDO): False}
+
+
+def by_actor(actor: ap.BaseActivity) -> _SubQuery:
+    return {_meta(MetaKey.ACTOR_ID): actor.id}

utils/notifications.py

@@ -0,0 +1,84 @@
+import logging
+from functools import singledispatch
+from typing import Any
+from typing import Dict
+
+from little_boxes import activitypub as ap
+
+from config import DB
+from config import MetaKey
+from config import _meta
+from utils.meta import by_actor
+from utils.meta import by_type
+from utils.meta import in_inbox
+from utils.meta import not_undo
+
+_logger = logging.getLogger(__name__)
+
+_NewMeta = Dict[str, Any]
+
+
+@singledispatch
+def set_inbox_flags(activity: ap.BaseActivity, new_meta: _NewMeta) -> None:
+    return None
+
+
+@set_inbox_flags.register
+def _accept_set_inbox_flags(activity: ap.Accept, new_meta: _NewMeta) -> None:
+    """Handle notifications for "accepted" following requests."""
+    _logger.info(f"set_inbox_flags activity={activity!r}")
+    # Check if this actor already follow us back
+    follows_back = False
+    follow_query = {
+        **in_inbox(),
+        **by_type(ap.ActivityType.FOLLOW),
+        **by_actor(activity.get_actor()),
+        **not_undo(),
+    }
+    raw_follow = DB.activities.find_one(follow_query)
+    if raw_follow:
+        follows_back = True
+
+        DB.activities.update_many(
+            follow_query, {"$set": {_meta(MetaKey.NOTIFICATION_FOLLOWS_BACK): True}}
+        )
+
+    # This Accept will be a "You started following $actor" notification
+    new_meta.update(
+        **{
+            _meta(MetaKey.NOTIFICATION): True,
+            _meta(MetaKey.NOTIFICATION_UNREAD): True,
+            _meta(MetaKey.NOTIFICATION_FOLLOWS_BACK): follows_back,
+        }
+    )
+    return None
+
+
+@set_inbox_flags.register
+def _follow_set_inbox_flags(activity: ap.Follow, new_meta: _NewMeta) -> None:
+    """Handle notification for new followers."""
+    # Check if we're already following this actor
+    follows_back = False
+    accept_query = {
+        **in_inbox(),
+        **by_type(ap.ActivityType.ACCEPT),
+        **by_actor(activity.get_actor()),
+        **not_undo(),
+    }
+    raw_accept = DB.activities.find_one(accept_query)
+    if raw_accept:
+        follows_back = True
+
+        DB.activities.update_many(
+            accept_query, {"$set": {_meta(MetaKey.NOTIFICATION_FOLLOWS_BACK): True}}
+        )
+
+    # This Follow will be a "$actor started following you" notification
+    new_meta.update(
+        **{
+            _meta(MetaKey.NOTIFICATION): True,
+            _meta(MetaKey.NOTIFICATION_UNREAD): True,
+            _meta(MetaKey.NOTIFICATION_FOLLOWS_BACK): follows_back,
+        }
+    )
+    return None