From 192fe89789cb8d35b0be990b7fb9eb4ae2be9d60 Mon Sep 17 00:00:00 2001
From: David Hill <dhill@mindcry.org>
Date: Sat, 15 Dec 2018 16:57:54 -0500
Subject: [PATCH] Populate user on channel join (slack) (#644)

---
 bridge/slack/handlers.go |  3 +++
 bridge/slack/helpers.go  | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/bridge/slack/handlers.go b/bridge/slack/handlers.go
index 89c800da..b9011c92 100644
--- a/bridge/slack/handlers.go
+++ b/bridge/slack/handlers.go
@@ -89,7 +89,10 @@ func (b *Bslack) handleSlackClient(messages chan *config.Message) {
 			b.Log.Fatalf("Invalid Token %#v", ev)
 		case *slack.ConnectionErrorEvent:
 			b.Log.Errorf("Connection failed %#v %#v", ev.Error(), ev.ErrorObj)
+		case *slack.MemberJoinedChannelEvent:
+			b.populateUser(ev.User)
 		default:
+			b.Log.Debugf("Unhandled incoming event: %T", ev)
 		}
 	}
 }
diff --git a/bridge/slack/helpers.go b/bridge/slack/helpers.go
index ff039c58..6f049561 100644
--- a/bridge/slack/helpers.go
+++ b/bridge/slack/helpers.go
@@ -63,6 +63,26 @@ func (b *Bslack) getChannelBy(lookupKey string, lookupMap map[string]*slack.Chan
 
 const minimumRefreshInterval = 10 * time.Second
 
+func (b *Bslack) populateUser(userID string) {
+	b.usersMutex.RLock()
+	_, exists := b.users[userID]
+	b.usersMutex.RUnlock()
+	if exists {
+		// already in cache
+		return
+	}
+
+	user, err := b.sc.GetUserInfo(userID)
+	if err != nil {
+		b.Log.Debugf("GetUserInfo failed for %v: %v", userID, err)
+		return
+	}
+
+	b.usersMutex.Lock()
+	b.users[userID] = user
+	b.usersMutex.Unlock()
+}
+
 func (b *Bslack) populateUsers() {
 	b.refreshMutex.Lock()
 	if time.Now().Before(b.earliestUserRefresh) || b.refreshInProgress {