Intercept received messages and queue them

- Exposes behavior under QUEUE_MESSAGE_ENABLED flag that is turned off in
production.

- Delays messages to allow for reordering of latecoming messages up to 500ms

.env

@@ -7,3 +7,4 @@ OFFLINE_INBOX_ENABLED=1
 LOG_LEVEL=debug
 LOG_LEVEL_STATUS_GO=info
 JSC_ENABLED=1
+QUEUE_MESSAGE_ENABLED=1

.env.jenkins

@@ -7,3 +7,4 @@ OFFLINE_INBOX_ENABLED=1
 LOG_LEVEL=debug
 LOG_LEVEL_STATUS_GO=info
 JSC_ENABLED=0
+QUEUE_MESSAGE_ENABLED=1

.env.prod

@@ -7,3 +7,4 @@ OFFLINE_INBOX_ENABLED=0
 LOG_LEVEL=info
 LOG_LEVEL_STATUS_GO=
 JSC_ENABLED=0
+QUEUE_MESSAGE_ENABLED=0

src/status_im/chat/events.cljs

@@ -20,6 +20,7 @@
             status-im.chat.events.commands
             status-im.chat.events.requests
             status-im.chat.events.animation
+            status-im.chat.events.queue-message
             status-im.chat.events.receive-message
             status-im.chat.events.sign-up
             status-im.chat.events.console

src/status_im/chat/events/queue_message.cljs

@@ -0,0 +1,30 @@
+(ns status-im.chat.events.queue-message
+  (:require-macros [cljs.core.async.macros :as async-macros])
+  (:require [cljs.core.async :as async]
+            [re-frame.core :as re-frame]
+            [status-im.utils.config :as config]
+            [status-im.utils.pre-receiver :as pre-receiver]
+            [status-im.utils.handlers :as handlers]))
+
+;; We queue messaged before receiving them to allow lagging messages to catch up.
+;; This ensures proper ordering from a user's POV the vast majority of the time.
+
+;; XXX(oskarth): Hacky def, consider better encapsulation
+(when config/queue-message-enabled?
+  (def in-ch (pre-receiver/start!
+              {:delay-ms 500
+               :reorder? true
+               :add-fn   #(re-frame/dispatch [:chat-received-message/add %])})))
+
+;; NOTE(oskarth): in-ch is assumed to exist
+(re-frame/reg-fx
+ ::queue-message
+ (fn [message]
+   (async/put! in-ch message)))
+
+(handlers/register-handler-fx
+ :pre-received-message
+ (fn [_ [_ message]]
+   (if config/queue-message-enabled?
+     {::queue-message message}
+     {:dispatch [:chat-received-message/add message]})))

src/status_im/protocol/handlers.cljs

@@ -316,7 +316,7 @@
               route-fx (case type
                          (:message
                           :group-message
-                          :public-group-message) {:dispatch [:chat-received-message/add (transform-protocol-message message)]} 
+                          :public-group-message) {:dispatch [:pre-received-message (transform-protocol-message message)]}
                          :pending                (cond-> {::pending-messages-save message}
                                                    chat-message
                                                    (assoc :dispatch

src/status_im/utils/config.cljs

@@ -30,3 +30,4 @@
       keyword))
 
 (def jsc-enabled? (enabled? (get-config :JSC_ENABLED 0)))
+(def queue-message-enabled? (enabled? (get-config :QUEUE_MESSAGE_ENABLED 0)))