tighten ai_auto_response participation and spam guard

plugins/ai_auto_response/safety/dedup.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+import re
 import time
-from typing import Dict, Set
+from typing import Dict, List, Set, Tuple
 
 
 class DedupManager:
@@ -9,6 +10,7 @@ class DedupManager:
         self.inflight_message_keys: Set[str] = set()
         self.recent_message_keys: Dict[str, float] = {}
         self.recent_reply_signatures: Dict[str, float] = {}
+        self.recent_room_content_hits: Dict[str, List[Tuple[float, str]]] = {}
 
     def begin_message_processing(self, message_key: str, expiry_sec: int) -> bool:
         if not message_key:
@@ -51,3 +53,31 @@ class DedupManager:
             return True
         self.recent_reply_signatures[signature] = now
         return False
+
+    def should_skip_repeated_room_content(
+        self,
+        *,
+        room_id: str,
+        content: str,
+        window_sec: int,
+        repeat_threshold: int,
+        min_length: int = 4,
+    ) -> bool:
+        text = self._normalize_room_content(content)
+        if not room_id or not text or len(text) < max(int(min_length or 4), 1):
+            return False
+        now = time.time()
+        window_sec = max(int(window_sec or 0), 1)
+        repeat_threshold = max(int(repeat_threshold or 0), 2)
+        room_items = self.recent_room_content_hits.get(room_id, [])
+        room_items = [(ts, item_text) for ts, item_text in room_items if now - ts <= window_sec]
+        same_count = sum(1 for _, item_text in room_items if item_text == text)
+        room_items.append((now, text))
+        self.recent_room_content_hits[room_id] = room_items[-80:]
+        return same_count + 1 >= repeat_threshold
+
+    @staticmethod
+    def _normalize_room_content(content: str) -> str:
+        text = str(content or "").strip().lower()
+        text = re.sub(r"\s+", "", text)
+        return text