feat: web UI chat render, panels, presence + analytics

backend/src/utils/events.py

@@ -0,0 +1,29 @@
+import json
+from typing import Literal
+
+import asyncpg
+
+BG_EVENTS_CHANNEL = "bg_events"
+
+EventKind = Literal["message", "edit", "delete", "reaction", "presence", "receipt"]
+
+
+async def notify_bg_event(  # noqa: PLR0913
+    pool: asyncpg.Pool,
+    kind: EventKind,
+    account_id: int,
+    *,
+    chat_id: int | None = None,
+    message_id: int | None = None,
+    message_ids: list[int] | None = None,
+) -> None:
+    payload: dict[str, object] = {"kind": kind, "account_id": account_id}
+    if chat_id is not None:
+        payload["chat_id"] = chat_id
+    if message_id is not None:
+        payload["message_id"] = message_id
+    if message_ids is not None:
+        payload["message_ids"] = message_ids
+    await pool.execute(
+        "SELECT pg_notify($1, $2)", BG_EVENTS_CHANNEL, json.dumps(payload)
+    )