From 4079cb908072deb443608284e9f3be969973184a Mon Sep 17 00:00:00 2001
From: Badgerbees <rapabelias@gmail.com>
Date: Fri, 27 Mar 2026 20:22:13 +0700
Subject: [PATCH] fix(slack): resolve mention race condition and unify chatID
 logic

---
 pkg/channels/slack/slack.go | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/pkg/channels/slack/slack.go b/pkg/channels/slack/slack.go
index f03283ea4..137c2f713 100644
--- a/pkg/channels/slack/slack.go
+++ b/pkg/channels/slack/slack.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/slack-go/slack"
 	"github.com/slack-go/slack/slackevents"
@@ -29,6 +30,7 @@ type SlackChannel struct {
 	ctx          context.Context
 	cancel       context.CancelFunc
 	pendingAcks  sync.Map
+	seenMessages sync.Map // "channel_id:ts" -> true (dedup message/app_mention race)
 }
 
 type slackMessageRef struct {
@@ -279,6 +281,14 @@ func (c *SlackChannel) handleMessageEvent(ev *slackevents.MessageEvent) {
 		return
 	}
 
+	// Deduplicate against app_mention events which Slack often sends in parallel.
+	dedupKey := ev.Channel + ":" + ev.TimeStamp
+	if _, loaded := c.seenMessages.LoadOrStore(dedupKey, true); loaded {
+		return
+	}
+	// Simple TTL: clean up from map after 1 minute (sufficient for Slack race)
+	time.AfterFunc(1*time.Minute, func() { c.seenMessages.Delete(dedupKey) })
+
 	// check allowlist to avoid downloading attachments for rejected users
 	sender := bus.SenderInfo{
 		Platform:    "slack",
@@ -307,12 +317,13 @@ func (c *SlackChannel) handleMessageEvent(ev *slackevents.MessageEvent) {
 		Timestamp: messageTS,
 	})
 
-	content := ev.Text
-	content = c.stripBotMention(content)
+	rawContent := ev.Text
+	content := c.stripBotMention(rawContent)
+	isMentioned := rawContent != content // Detect if bot was @mentioned
 
 	// In non-DM channels, apply group trigger filtering
 	if !strings.HasPrefix(channelID, "D") {
-		respond, cleaned := c.ShouldRespondInGroup(false, content)
+		respond, cleaned := c.ShouldRespondInGroup(isMentioned, content)
 		if !respond {
 			return
 		}
@@ -385,6 +396,14 @@ func (c *SlackChannel) handleAppMention(ev *slackevents.AppMentionEvent) {
 		return
 	}
 
+	// Deduplicate against message events which Slack often sends in parallel.
+	dedupKey := ev.Channel + ":" + ev.TimeStamp
+	if _, loaded := c.seenMessages.LoadOrStore(dedupKey, true); loaded {
+		return
+	}
+	// Simple TTL: clean up from map after 1 minute (sufficient for Slack race)
+	time.AfterFunc(1*time.Minute, func() { c.seenMessages.Delete(dedupKey) })
+
 	if !c.IsAllowedSender(bus.SenderInfo{
 		Platform:    "slack",
 		PlatformID:  ev.User,
@@ -406,11 +425,9 @@ func (c *SlackChannel) handleAppMention(ev *slackevents.AppMentionEvent) {
 	threadTS := ev.ThreadTimeStamp
 	messageTS := ev.TimeStamp
 
-	var chatID string
+	chatID := channelID
 	if threadTS != "" {
 		chatID = channelID + "/" + threadTS
-	} else {
-		chatID = channelID + "/" + messageTS
 	}
 
 	c.pendingAcks.Store(chatID, slackMessageRef{