feat(backend): watches report alert counts, alerts carry watch params and time away, webhooks their last delivery

backend/src/utils/read/watches.py

@@ -44,9 +44,15 @@ WITH alert AS (
 SELECT * FROM alert
 """  # noqa: S608
 
+_WATCH_STATS = """
+SELECT watch_id, count(*) AS count, max(ts) AS last FROM alerts
+WHERE watch_id = ANY($1::int[]) GROUP BY watch_id
+"""
+
 _ALERT_ROWS = """
 SELECT a.id, a.account_id, a.ts, a.seen, a.payload,
        w.id AS watch_id, w.kind AS watch_kind, w.name AS watch_name,
+       w.params AS watch_params,
        m.text AS stored_text,
        m.sender_id AS stored_sender, m.date AS stored_date,
        m.deleted_at IS NOT NULL AS stored_deleted,
@@ -225,9 +231,17 @@ async def describe_watches(
         {chat for chat, _ in targets if chat is not None},
         {person for _, person in targets if person is not None},
     )
+    stats = {
+        row["watch_id"]: row
+        for row in await pool.fetch(_WATCH_STATS, [watch.id for watch in watches])
+    }
     return [
         WatchItem(
-            **watch.model_dump(), chat=refs.chat(chat), person=refs.person(person)
+            **watch.model_dump(),
+            chat=refs.chat(chat),
+            person=refs.person(person),
+            alert_count=stats[watch.id]["count"] if watch.id in stats else 0,
+            last_alert_at=stats[watch.id]["last"] if watch.id in stats else None,
         )
         for watch, (chat, person) in zip(watches, targets, strict=True)
     ]
@@ -267,11 +281,15 @@ def _alert_item(row: asyncpg.Record, refs: Refs) -> AlertItem:
         seen=row["seen"],
         event=event,
         watch=AlertWatch(
-            id=row["watch_id"], kind=row["watch_kind"], name=row["watch_name"]
+            id=row["watch_id"],
+            kind=row["watch_kind"],
+            name=row["watch_name"],
+            params=json.loads(row["watch_params"]),
         ),
         chat=refs.chat(chat_id),
         message=message,
         peer=refs.person(peer_id),
+        away_since=payload.get("since"),
         path=_path(chat_id, message_id, peer_id),
     )