fix(userbot): a deletion that arrives before its message is applied once the message is stored

backend/src/userbot/handlers/deletes.py

@@ -20,6 +20,9 @@ async def on_deleted_messages(client: PyroClient, messages: list[Message]) -> No
             box.append(message.id)
         else:
             channels.setdefault(chat_id, []).append(message.id)
+    ctx.pending_deletes.remember(None, box)
+    for chat_id, ids in channels.items():
+        ctx.pending_deletes.remember(chat_id, ids)
     if box:
         await repository.mark_deleted_box(ctx.pool, ctx.account_id, box)
         await notify_bg_event(ctx.pool, "delete", ctx.account_id, message_ids=box)

backend/src/userbot/modules/capture/context.py

@@ -2,6 +2,7 @@ import asyncpg
 from pyrogram import Client
 
 from userbot.modules.capture.identity import ChatMetaCache, PeerIdentityCache
+from userbot.modules.capture.pending import PendingDeletes
 from userbot.modules.contacts import ContactCache
 from userbot.modules.folders import FolderCache
 from userbot.modules.watches import WatchCache
@@ -28,6 +29,7 @@ class CaptureContext:
         self.watches = WatchCache(pool, account_id)
         self.peer_identity = PeerIdentityCache()
         self.chat_meta = ChatMetaCache()
+        self.pending_deletes = PendingDeletes()
         self.policies = PolicySet()
 
     async def reload_policies(self) -> None:

backend/src/userbot/modules/capture/message.py

@@ -61,6 +61,10 @@ async def capture_message(
     current = await repository.upsert_message(
         ctx.pool, ctx.account_id, message_row(message, chat_id, message.date)
     )
+    if ctx.pending_deletes.take(chat_id, message.id):
+        await repository.mark_deleted_late(
+            ctx.pool, ctx.account_id, chat_id, message.id
+        )
     from userbot.modules.capture.identity import capture_identity  # noqa: PLC0415
 
     await capture_identity(message, ctx)

backend/src/userbot/modules/capture/pending.py

@@ -0,0 +1,36 @@
+import time
+
+from userbot.modules.capture.repository import CHANNEL_ID_THRESHOLD
+
+PENDING_DELETE_SECONDS = 120.0
+PENDING_DELETE_LIMIT = 10_000
+
+DeleteKey = tuple[int | None, int]
+
+
+def _key(chat_id: int | None, message_id: int) -> DeleteKey:
+    if chat_id is None or chat_id > CHANNEL_ID_THRESHOLD:
+        return None, message_id
+    return chat_id, message_id
+
+
+class PendingDeletes:
+    def __init__(self) -> None:
+        self._expires: dict[DeleteKey, float] = {}
+
+    def remember(self, chat_id: int | None, message_ids: list[int]) -> None:
+        now = time.monotonic()
+        while self._expires:
+            oldest = next(iter(self._expires))
+            fresh = self._expires[oldest] > now
+            if fresh and len(self._expires) < PENDING_DELETE_LIMIT:
+                break
+            del self._expires[oldest]
+        for message_id in message_ids:
+            key = _key(chat_id, message_id)
+            self._expires.pop(key, None)
+            self._expires[key] = now + PENDING_DELETE_SECONDS
+
+    def take(self, chat_id: int, message_id: int) -> bool:
+        expires = self._expires.pop(_key(chat_id, message_id), None)
+        return expires is not None and expires > time.monotonic()

backend/src/userbot/modules/capture/repository.py

@@ -47,6 +47,11 @@ UPDATE messages SET deleted_at = now()
 WHERE account_id = $1 AND chat_id = $2 AND message_id = $3 AND date = $4
 """
 
+_MARK_DELETED_LATE = """
+UPDATE messages SET deleted_at = now()
+WHERE account_id = $1 AND chat_id = $2 AND message_id = $3 AND deleted_at IS NULL
+"""
+
 _INSERT_VERSION = """
 INSERT INTO message_versions
     (account_id, chat_id, message_id, observed_at, edit_date, text, raw)
@@ -310,6 +315,12 @@ async def add_version(pool: asyncpg.Pool, account_id: int, row: MessageRow) -> b
     return True
 
 
+async def mark_deleted_late(
+    pool: asyncpg.Pool, account_id: int, chat_id: int, message_id: int
+) -> None:
+    await pool.execute(_MARK_DELETED_LATE, account_id, chat_id, message_id)
+
+
 async def current_media(
     pool: asyncpg.Pool, account_id: int, chat_id: int, message_id: int
 ) -> asyncpg.Record | None: