feat: add online presence tracking with last_seen column and configurable timeout

Add `last_seen` column to users table with index, implement `set_last_seen` and `get_online_users` database functions, expose presence config env vars (`PRESENCE_TIMEOUT_SECONDS`, `PRESENCE_ONLINE_LIMIT`, `PRESENCE_ONLINE_MARGIN_SECONDS`), include `last_seen` in follow list responses, and update profile docs to mention online indicator.

devplacepy/routers/docs/pages.py

@@ -117,6 +117,12 @@ DOCS_PAGES = [
         "kind": "prose",
         "section": SECTION_GENERAL,
     },
+    {
+        "slug": "presence",
+        "title": "Online presence",
+        "kind": "prose",
+        "section": SECTION_GENERAL,
+    },
     {
         "slug": "ai-correction",
         "title": "AI content correction",

devplacepy/routers/feed.py

@@ -19,6 +19,7 @@ from devplacepy.database import (
 )
 from devplacepy.attachments import get_attachments_batch
 from devplacepy.content import enrich_items
+from devplacepy.services import presence
 from devplacepy.utils import get_current_user
 from devplacepy.seo import list_page_seo, next_page_url
 from devplacepy.responses import respond
@@ -90,6 +91,7 @@ async def feed_page(
     stats = get_site_stats()
     top_authors = get_top_authors(5)
     daily_topic = get_daily_topic()
+    online_users = presence.online_users()
 
     post_uids_list = [item["post"]["uid"] for item in posts]
     attachments_map = get_attachments_batch("post", post_uids_list)
@@ -134,6 +136,7 @@ async def feed_page(
             "total_gists": stats["total_gists"],
             "top_authors": top_authors,
             "daily_topic": daily_topic,
+            "online_users": online_users,
             "next_cursor": next_cursor,
         },
         model=FeedOut,

devplacepy/routers/messages.py

@@ -26,6 +26,7 @@ from devplacepy.utils import (
 from devplacepy.seo import base_seo_context
 from devplacepy.responses import respond, action_result
 from devplacepy.schemas import MessagesOut
+from devplacepy.services import presence
 from devplacepy.services.audit import record as audit
 from devplacepy.services.correction import PENDING_SCOPE_KEY
 from devplacepy.dependencies import json_or_form
@@ -154,8 +155,8 @@ async def messages_page(request: Request, with_uid: str = None, search: str = ""
             user["uid"], f"/messages?with_uid={with_uid}"
         )
         current_conversation = with_uid
-        other_online = message_hub.is_online(with_uid)
-        other_last_seen = message_hub.last_seen(with_uid)
+        other_online = presence.is_online(other_user)
+        other_last_seen = other_user.get("last_seen") if other_user else None
         audit.record(
             request,
             "message.read_on_view",
@@ -261,18 +262,6 @@ def _resolve_ws_user(websocket: WebSocket):
         return _user_from_api_key(key)
     return None
 
-async def _announce_presence(user_uid: str, online: bool) -> None:
-    other_uids = {c["other_user"]["uid"] for c in get_conversations(user_uid) if c["other_user"]}
-    if not other_uids:
-        return
-    frame = {
-        "type": "presence",
-        "user_uid": user_uid,
-        "online": online,
-        "last_seen": None if online else message_hub.last_seen(user_uid),
-    }
-    await message_hub.send_to_users(list(other_uids), frame)
-
 @router.websocket("/ws")
 async def messages_ws(websocket: WebSocket):
     await websocket.accept()
@@ -282,12 +271,10 @@ async def messages_ws(websocket: WebSocket):
         return
 
     user_uid = user["uid"]
-    was_offline = message_hub.register(user_uid, websocket)
+    message_hub.register(user_uid, websocket)
     message_relay.start()
     try:
         await websocket.send_json({"type": "ready", "user_uid": user_uid})
-        if was_offline:
-            await _announce_presence(user_uid, True)
         while True:
             data = await websocket.receive_json()
             kind = data.get("type")
@@ -338,25 +325,9 @@ async def messages_ws(websocket: WebSocket):
                     await message_hub.send_to_user(
                         with_uid, {"type": "read", "by_uid": user_uid}
                     )
-            elif kind == "presence":
-                with_uid = str(data.get("with_uid", "")).strip()
-                if with_uid:
-                    await websocket.send_json(
-                        {
-                            "type": "presence",
-                            "user_uid": with_uid,
-                            "online": message_hub.is_online(with_uid),
-                            "last_seen": message_hub.last_seen(with_uid),
-                        }
-                    )
     except WebSocketDisconnect:
         pass
     except Exception:  # noqa: BLE001
         logger.exception("messages websocket loop failed for %s", user_uid)
     finally:
-        went_offline = message_hub.unregister(user_uid, websocket)
-        if went_offline:
-            try:
-                await _announce_presence(user_uid, False)
-            except Exception:  # noqa: BLE001
-                logger.debug("presence offline announce failed for %s", user_uid)
+        message_hub.unregister(user_uid, websocket)

devplacepy/routers/profile/index.py

@@ -49,6 +49,7 @@ from devplacepy.seo import (
     website_schema,
     profile_page_schema,
 )
+from devplacepy.services import presence
 from devplacepy.services.audit import record as audit
 from devplacepy.services.correction import schedule_correction
 from devplacepy.services.ai_modifier import schedule_modification
@@ -369,6 +370,7 @@ async def profile_page(
             "is_blocked": is_blocked,
             "is_muted": is_muted,
             "is_owner": is_owner,
+            "profile_online": presence.is_online(profile_user),
             "viewer_is_admin": viewer_is_admin,
             "media": media,
             "media_pagination": media_pagination,