feishu inbound: dedupe repeated message_id within TTL to prevent duplicate sends

pkg/channels/feishu.go

@@ -41,6 +41,9 @@ type FeishuChannel struct {
 	tenantAccessToken string
 	tenantTokenExpire time.Time
 	tenantTokenErr    error
+
+	recentMsgMu sync.Mutex
+	recentMsg   map[string]time.Time
 }
 
 func (c *FeishuChannel) SupportsAction(action string) bool {
@@ -59,6 +62,7 @@ func NewFeishuChannel(cfg config.FeishuConfig, bus *bus.MessageBus) (*FeishuChan
 		BaseChannel: base,
 		config:      cfg,
 		client:      lark.NewClient(cfg.AppID, cfg.AppSecret),
+		recentMsg:   map[string]time.Time{},
 	}, nil
 }
 
@@ -222,6 +226,12 @@ func (c *FeishuChannel) handleMessageReceive(ctx context.Context, event *larkim.
 	if sender != nil && sender.TenantKey != nil {
 		metadata["tenant_key"] = *sender.TenantKey
 	}
+	if messageID := metadata["message_id"]; messageID != "" {
+		if c.isDuplicateInboundMessage(messageID) {
+			logger.WarnCF("feishu", "Duplicate Feishu inbound message skipped", map[string]interface{}{"message_id": messageID, logger.FieldChatID: chatID})
+			return nil
+		}
+	}
 
 	logger.InfoCF("feishu", "Feishu message received", map[string]interface{}{
 		logger.FieldSenderID: senderID,
@@ -322,6 +332,29 @@ func (c *FeishuChannel) isAllowedChat(chatID, chatType string) bool {
 	return false
 }
 
+func (c *FeishuChannel) isDuplicateInboundMessage(messageID string) bool {
+	messageID = strings.TrimSpace(messageID)
+	if messageID == "" {
+		return false
+	}
+	now := time.Now()
+	const ttl = 10 * time.Minute
+	c.recentMsgMu.Lock()
+	defer c.recentMsgMu.Unlock()
+	for id, ts := range c.recentMsg {
+		if now.Sub(ts) > ttl {
+			delete(c.recentMsg, id)
+		}
+	}
+	if ts, ok := c.recentMsg[messageID]; ok {
+		if now.Sub(ts) <= ttl {
+			return true
+		}
+	}
+	c.recentMsg[messageID] = now
+	return false
+}
+
 func (c *FeishuChannel) shouldHandleGroupMessage(chatType, content string) bool {
 	chatType = strings.ToLower(strings.TrimSpace(chatType))
 	isGroup := chatType != "" && chatType != "p2p"