From 41276481a66e22a747527fa6a886a27f04e42b0e Mon Sep 17 00:00:00 2001
From: Midgard <midgard@zeus.ugent.be>
Date: Wed, 8 Nov 2023 14:40:13 +0100
Subject: [PATCH] Support new multiple_channels_viewed event

---
 js/controller.js | 16 ++++++++++++++--
 js/mm_client.js  |  9 ++++++++-
 js/pubsub.js     |  2 +-
 js/store.js      |  7 +++++++
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/js/controller.js b/js/controller.js
index 52eb7cd..4182a26 100644
--- a/js/controller.js
+++ b/js/controller.js
@@ -223,8 +223,20 @@ pubsub.subscribe("MESSAGES_NEW", post => {
 	client.channelStore.updateLastPostTime(post.channel_id, post["create_at"]);
 });
 
-pubsub.subscribe("CHANNEL_READ", ({endpoint, channel_id}) => {
-	mm_client.getOrCreate(endpoint).channelStore.setUnread(channel_id, 0, 0);
+pubsub.subscribe("CHANNEL_READ", ({endpoint, channel_id, time}) => {
+	const chanStore = mm_client.getOrCreate(endpoint).channelStore;
+	const store = chanStore.getNoFetch();
+	if (
+		store !== null && channel_id in store.channels &&
+		time !== null && time < store.channels[channel_id]["last_post_at"]
+	) {
+		// We don't keep track of messages, immediately writing them to the DOM instead, so we don't
+		// know how many unread messages there are when we get a "channel read up to a certain
+		// timestamp" if there are newer messages than that. So refetch the channel list.
+		chanStore.fetch();
+	} else {
+		mm_client.getOrCreate(endpoint).channelStore.setUnread(channel_id, 0, 0);
+	}
 });
 
 pubsub.subscribe("WINDOW_FOCUSED", () => {
diff --git a/js/mm_client.js b/js/mm_client.js
index f70a036..e13a641 100644
--- a/js/mm_client.js
+++ b/js/mm_client.js
@@ -245,7 +245,14 @@ class MattermostClient {
 				pubsub.publish("MESSAGES_NEW", {...post, endpoint: this.endpoint});
 
 			} else if (data.event === "channel_viewed") {
-				pubsub.publish("CHANNEL_READ", {endpoint: this.endpoint, channel_id: data.data.channel_id});
+				pubsub.publish("CHANNEL_READ", {endpoint: this.endpoint, channel_id: data.data.channel_id, time: null});
+
+			} else if (data.event === "multiple_channels_viewed") {
+				console.log(data.data.channel_times);
+				for (let channel_id in data.data.channel_times) {
+					const time = data.data.channel_times[channel_id];
+					pubsub.publish("CHANNEL_READ", {endpoint: this.endpoint, channel_id, time});
+				}
 
 			} else if (
 					data.event === "user_added" ||
diff --git a/js/pubsub.js b/js/pubsub.js
index 603acf3..fd53287 100644
--- a/js/pubsub.js
+++ b/js/pubsub.js
@@ -11,7 +11,7 @@ const topics = [
 	"USERS_CHANGED",
 	"CHANNEL_MEMBERS_NEW",
 	"CHANNEL_MEMBERS_REMOVED",
-	"CHANNEL_READ", // {endpoint, channel_id}
+	"CHANNEL_READ", // {endpoint, channel_id, time}
 	"WINDOW_FOCUSED",
 ];
 
diff --git a/js/store.js b/js/store.js
index 213b08f..f6d3b29 100644
--- a/js/store.js
+++ b/js/store.js
@@ -62,6 +62,13 @@ class ChannelStore {
 		return {teams: this._teams, channels: this._channels, unread: this._unread};
 	}
 
+	getNoFetch() {
+		if (this._promise === null) {
+			return null;
+		}
+		return {teams: this._teams, channels: this._channels, unread: this._unread};
+	}
+
 	async updateChannel(channel) {
 		if (this._promise === null) {
 			// Data does not exist yet and is not being requested