From d6183594d65be80d929c25d2ddfe227feabdee21 Mon Sep 17 00:00:00 2001
From: "Yuyao Huang (Sam)" <huangyuyao@outlook.com>
Date: Sun, 29 Mar 2026 07:10:58 +0800
Subject: [PATCH] =?UTF-8?q?feat(handler):=20=E6=B7=BB=E5=8A=A0=E6=B6=88?=
 =?UTF-8?q?=E6=81=AF=E5=8E=BB=E9=87=8D=E5=8A=9F=E8=83=BD=E9=98=B2=E6=AD=A2?=
 =?UTF-8?q?=E9=A3=9E=E4=B9=A6=E9=87=8D=E5=A4=8D=E6=8A=95=E9=80=92?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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实现基于(user_id, content)的消息去重机制，避免飞书在网络抖动时重复投递相同消息。使用10秒时间窗口判断重复消息，超过窗口的旧记录会被自动清理。
---
 bot/handler.py | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/bot/handler.py b/bot/handler.py
index cc99990..60701a3 100644
--- a/bot/handler.py
+++ b/bot/handler.py
@@ -25,6 +25,26 @@ _ws_connected: bool = False
 _last_message_time: float = 0.0
 _reconnect_count: int = 0
 
+# Deduplication: drop Feishu re-deliveries by (user_id, content) within a short window.
+# Feishu retries on network hiccups within ~60s using the same payload.
+# We use a 10s window: identical content from the same user within 10s is a re-delivery,
+# not a deliberate repeat (user intentional repeats arrive after the bot has already replied).
+_recent_messages: dict[tuple[str, str], float] = {}  # key: (user_id, content) → timestamp
+_DEDUP_WINDOW = 10.0  # seconds
+
+
+def _is_duplicate(user_id: str, content: str) -> bool:
+    """Return True if this (user, content) pair arrived within the dedup window."""
+    now = time.time()
+    expired = [k for k, ts in _recent_messages.items() if now - ts > _DEDUP_WINDOW]
+    for k in expired:
+        del _recent_messages[k]
+    key = (user_id, content)
+    if key in _recent_messages:
+        return True
+    _recent_messages[key] = now
+    return False
+
 
 def get_ws_status() -> dict[str, Any]:
     """Return WebSocket connection status."""
@@ -79,10 +99,14 @@ def _handle_message(data: P2ImMessageReceiveV1) -> None:
             logger.info("Empty text after stripping, ignoring")
             return
 
-        logger.info("✉  ...%s → %r", open_id[-8:], text[:80])
-
         user_id = open_id or chat_id
 
+        if _is_duplicate(user_id, text):
+            logger.info("Dropping duplicate delivery: user=...%s text=%r", user_id[-8:], text[:60])
+            return
+
+        logger.info("✉  ...%s → %r", open_id[-8:], text[:80])
+
         if _main_loop is None:
             logger.error("Main event loop not set; cannot process message")
             return