From 76953cc3561299d84931f0b77e5d99cd21f63f57 Mon Sep 17 00:00:00 2001
From: Joffrey JAFFEUX <j.jaffeux@gmail.com>
Date: Wed, 6 Mar 2024 12:03:42 +0100
Subject: [PATCH] FEATURE: allows to force a thread (#25987)

Forcing a thread will work even in channel which don't have `threading_enabled` or in direct message channels.

For now this feature is only available through the `ChatSDK`:

```ruby
ChatSDK::Message.create(in_reply_to_id: 1, guardian: guardian, raw: "foo bar baz", channel_id: 2, force_thread: true)
```
---
 lib/svg_sprite.rb                             |  1 -
 .../chat/api/channel_messages_controller.rb   |  3 ++
 plugins/chat/app/models/chat/message.rb       |  2 +-
 .../chat/app/queries/chat/messages_query.rb   | 40 +++++++++++++------
 .../app/queries/chat/thread_unreads_query.rb  |  2 +-
 .../serializers/chat/message_serializer.rb    | 12 +++---
 .../app/serializers/chat/thread_serializer.rb |  6 +--
 .../chat/app/services/chat/create_message.rb  |  4 +-
 .../services/chat/list_channel_messages.rb    |  7 ++--
 .../chat/list_channel_thread_messages.rb      |  2 +-
 .../chat/app/services/chat/lookup_thread.rb   |  2 +-
 plugins/chat/app/services/chat/publisher.rb   | 11 ++---
 .../discourse/components/chat-message.gjs     |  3 +-
 .../components/chat/thread/header.gjs         |  3 +-
 .../discourse/models/chat-thread.js           |  2 +
 .../discourse/routes/chat-channel-thread.js   | 31 +++++++-------
 .../discourse/routes/chat-channel.js          |  7 +++-
 .../services/chat-subscriptions-manager.js    |  2 +-
 .../stylesheets/common/chat-navbar.scss       |  4 ++
 .../20240301100413_add_force_to_threads.rb    |  7 ++++
 plugins/chat/lib/chat_sdk/message.rb          |  2 +
 .../chat/spec/lib/chat_sdk/message_spec.rb    | 10 +++++
 .../api/channel_messages_controller_spec.rb   | 19 +++++++++
 .../spec/services/chat/create_message_spec.rb | 15 +++++++
 .../chat/list_channel_messages_spec.rb        | 25 ++++++++++--
 .../chat/list_channel_thread_messages_spec.rb |  6 +++
 .../spec/services/chat/lookup_thread_spec.rb  |  6 +++
 .../chat/spec/services/chat/publisher_spec.rb |  1 +
 .../chat/spec/system/single_thread_spec.rb    | 13 ++++++
 .../assets/svg-icons/discourse-additional.svg |  3 --
 30 files changed, 191 insertions(+), 60 deletions(-)
 create mode 100644 plugins/chat/db/migrate/20240301100413_add_force_to_threads.rb

diff --git a/lib/svg_sprite.rb b/lib/svg_sprite.rb
index e099fc736ec..63fe74c0195 100644
--- a/lib/svg_sprite.rb
+++ b/lib/svg_sprite.rb
@@ -77,7 +77,6 @@ module SvgSprite
         discourse-other-tab
         discourse-sparkles
         discourse-threads
-        discourse-sidebar
         download
         ellipsis-h
         ellipsis-v
diff --git a/plugins/chat/app/controllers/chat/api/channel_messages_controller.rb b/plugins/chat/app/controllers/chat/api/channel_messages_controller.rb
index 80f614ca3b5..c57b52820a9 100644
--- a/plugins/chat/app/controllers/chat/api/channel_messages_controller.rb
+++ b/plugins/chat/app/controllers/chat/api/channel_messages_controller.rb
@@ -31,6 +31,9 @@ class Chat::Api::ChannelMessagesController < Chat::ApiController
   end
 
   def create
+    # users can't force a thread through JSON API
+    params[:force_thread] = false
+
     Chat::MessageRateLimiter.run!(current_user)
 
     with_service(Chat::CreateMessage) do
diff --git a/plugins/chat/app/models/chat/message.rb b/plugins/chat/app/models/chat/message.rb
index 8fd52263378..bd8d5b96955 100644
--- a/plugins/chat/app/models/chat/message.rb
+++ b/plugins/chat/app/models/chat/message.rb
@@ -279,7 +279,7 @@ module Chat
     end
 
     def thread_om?
-      in_thread? && self.thread.original_message_id == self.id
+      in_thread? && self.thread&.original_message_id == self.id
     end
 
     def parsed_mentions
diff --git a/plugins/chat/app/queries/chat/messages_query.rb b/plugins/chat/app/queries/chat/messages_query.rb
index b96b2be24cd..ff4f48242d9 100644
--- a/plugins/chat/app/queries/chat/messages_query.rb
+++ b/plugins/chat/app/queries/chat/messages_query.rb
@@ -52,13 +52,23 @@ module Chat
         include_thread_messages = true
         messages = messages.where(thread_id: thread_id)
       end
-      messages = messages.where(<<~SQL, channel_id: channel.id) if !include_thread_messages
-        chat_messages.thread_id IS NULL OR chat_messages.id IN (
-          SELECT original_message_id
-          FROM chat_threads
-          WHERE chat_threads.channel_id = :channel_id
-        )
-      SQL
+
+      if include_thread_messages
+        if !thread_id.present?
+          messages =
+            messages.left_joins(:thread).where(
+              "chat_threads.id IS NULL OR chat_threads.force = false OR chat_messages.id = chat_threads.original_message_id",
+            )
+        end
+      else
+        messages = messages.where(<<~SQL, channel_id: channel.id)
+          chat_messages.thread_id IS NULL OR chat_messages.id IN (
+            SELECT original_message_id
+            FROM chat_threads
+            WHERE chat_threads.channel_id = :channel_id
+          )
+        SQL
+      end
 
       if target_message_id.present? && direction.blank?
         query_around_target(target_message_id, channel, messages)
@@ -100,14 +110,14 @@ module Chat
 
       past_messages =
         messages
-          .where("created_at < ?", target_message.created_at)
+          .where("chat_messages.created_at < ?", target_message.created_at)
           .order(created_at: :desc)
           .limit(PAST_MESSAGE_LIMIT)
           .to_a
 
       future_messages =
         messages
-          .where("created_at > ?", target_message.created_at)
+          .where("chat_messages.created_at > ?", target_message.created_at)
           .order(created_at: :asc)
           .limit(FUTURE_MESSAGE_LIMIT)
           .to_a
@@ -135,11 +145,15 @@ module Chat
 
       if target_message_id.present?
         condition = direction == PAST ? "<" : ">"
-        messages = messages.where("id #{condition} ?", target_message_id.to_i)
+        messages = messages.where("chat_messages.id #{condition} ?", target_message_id.to_i)
       end
 
       order = direction == FUTURE ? "ASC" : "DESC"
-      messages = messages.order("created_at #{order}, id #{order}").limit(page_size).to_a
+      messages =
+        messages
+          .order("chat_messages.created_at #{order}, chat_messages.id #{order}")
+          .limit(page_size)
+          .to_a
 
       if direction == FUTURE
         can_load_more_future = messages.size == page_size
@@ -161,14 +175,14 @@ module Chat
     def self.query_by_date(target_date, channel, messages)
       past_messages =
         messages
-          .where("created_at <= ?", target_date.to_time.utc)
+          .where("chat_messages.created_at <= ?", target_date.to_time.utc)
           .order(created_at: :desc)
           .limit(PAST_MESSAGE_LIMIT)
           .to_a
 
       future_messages =
         messages
-          .where("created_at > ?", target_date.to_time.utc)
+          .where("chat_messages.created_at > ?", target_date.to_time.utc)
           .order(created_at: :asc)
           .limit(FUTURE_MESSAGE_LIMIT)
           .to_a
diff --git a/plugins/chat/app/queries/chat/thread_unreads_query.rb b/plugins/chat/app/queries/chat/thread_unreads_query.rb
index 503f63edfdb..73841f09721 100644
--- a/plugins/chat/app/queries/chat/thread_unreads_query.rb
+++ b/plugins/chat/app/queries/chat/thread_unreads_query.rb
@@ -53,7 +53,7 @@ module Chat
           AND chat_messages.deleted_at IS NULL
           AND chat_messages.thread_id IS NOT NULL
           AND chat_messages.id != chat_threads.original_message_id
-          AND chat_channels.threading_enabled
+          AND (chat_channels.threading_enabled OR chat_threads.force = true)
           AND user_chat_thread_memberships.notification_level NOT IN (:quiet_notification_levels)
           AND original_message.deleted_at IS NULL
           AND user_chat_channel_memberships.muted = false
diff --git a/plugins/chat/app/serializers/chat/message_serializer.rb b/plugins/chat/app/serializers/chat/message_serializer.rb
index acccb091432..5c43a6062f9 100644
--- a/plugins/chat/app/serializers/chat/message_serializer.rb
+++ b/plugins/chat/app/serializers/chat/message_serializer.rb
@@ -182,20 +182,20 @@ module Chat
       end
     end
 
-    def include_thread?
-      include_thread_id? && object.thread_om? && object.thread.present?
+    def include_thread_id?
+      channel.threading_enabled || object.thread&.force
     end
 
-    def include_thread_id?
-      channel.threading_enabled
+    def include_thread?
+      include_thread_id? && object.thread_om? && object.thread.present?
     end
 
     def thread
       Chat::ThreadSerializer.new(
         object.thread,
         scope: scope,
-        membership: @options[:thread_memberships]&.find { |m| m.thread_id == object.thread.id },
-        participants: @options[:thread_participants]&.dig(object.thread.id),
+        membership: @options[:thread_memberships]&.find { |m| m.thread_id == object.thread&.id },
+        participants: @options[:thread_participants]&.dig(object.thread&.id),
         include_thread_preview: true,
         include_thread_original_message: @options[:include_thread_original_message],
         root: false,
diff --git a/plugins/chat/app/serializers/chat/thread_serializer.rb b/plugins/chat/app/serializers/chat/thread_serializer.rb
index 77bae3375c3..b123a08c779 100644
--- a/plugins/chat/app/serializers/chat/thread_serializer.rb
+++ b/plugins/chat/app/serializers/chat/thread_serializer.rb
@@ -13,14 +13,14 @@ module Chat
                :reply_count,
                :current_user_membership,
                :preview,
-               :last_message_id
+               :last_message_id,
+               :force
 
     def initialize(object, opts)
       super(object, opts)
       @opts = opts
-
       # Avoids an N1 to re-load the thread in the serializer for original_message.
-      object.original_message&.thread = object
+      object&.original_message&.thread = object
       @current_user_membership = opts[:membership]
     end
 
diff --git a/plugins/chat/app/services/chat/create_message.rb b/plugins/chat/app/services/chat/create_message.rb
index a0e06cd0437..8fcb13c26cc 100644
--- a/plugins/chat/app/services/chat/create_message.rb
+++ b/plugins/chat/app/services/chat/create_message.rb
@@ -62,6 +62,7 @@ module Chat
       attribute :enforce_membership, :boolean, default: false
       attribute :incoming_chat_webhook
       attribute :process_inline, :boolean, default: Rails.env.test?
+      attribute :force_thread, :boolean, default: false
 
       validates :chat_channel_id, presence: true
       validates :message, presence: true, if: -> { upload_ids.blank? }
@@ -112,6 +113,7 @@ module Chat
           original_message: reply,
           original_message_user: reply.user,
           channel: channel,
+          force: contract.force_thread,
         )
     end
 
@@ -185,7 +187,7 @@ module Chat
     end
 
     def publish_new_thread(reply:, contract:, channel:, thread:, **)
-      return unless channel.threading_enabled?
+      return unless channel.threading_enabled? || thread&.force
       return unless reply&.thread_id_previously_changed?(from: nil)
       Chat::Publisher.publish_thread_created!(channel, reply, thread.id)
     end
diff --git a/plugins/chat/app/services/chat/list_channel_messages.rb b/plugins/chat/app/services/chat/list_channel_messages.rb
index e5faca0095e..30d5fcce1f0 100644
--- a/plugins/chat/app/services/chat/list_channel_messages.rb
+++ b/plugins/chat/app/services/chat/list_channel_messages.rb
@@ -115,7 +115,8 @@ module Chat
       context.target_message_id = messages_data[:target_message_id]
 
       messages_data[:target_message] = (
-        if enabled_threads && messages_data[:target_message]&.thread_reply?
+        if messages_data[:target_message]&.thread_reply? &&
+             (enabled_threads || messages_data[:target_message].thread&.force)
           []
         else
           [messages_data[:target_message]]
@@ -130,10 +131,10 @@ module Chat
       ].flatten.compact
     end
 
-    def fetch_tracking(guardian:, enabled_threads:, **)
+    def fetch_tracking(guardian:, **)
       context.tracking = {}
 
-      return if !enabled_threads || !context.thread_ids.present?
+      return if !context.thread_ids.present?
 
       context.tracking =
         ::Chat::TrackingStateReportQuery.call(
diff --git a/plugins/chat/app/services/chat/list_channel_thread_messages.rb b/plugins/chat/app/services/chat/list_channel_thread_messages.rb
index 5fedc020474..9aa02ef4ee5 100644
--- a/plugins/chat/app/services/chat/list_channel_thread_messages.rb
+++ b/plugins/chat/app/services/chat/list_channel_thread_messages.rb
@@ -61,7 +61,7 @@ module Chat
     end
 
     def ensure_thread_enabled(thread:, **)
-      thread.channel.threading_enabled
+      thread.channel.threading_enabled || thread.force
     end
 
     def can_view_thread(guardian:, thread:, **)
diff --git a/plugins/chat/app/services/chat/lookup_thread.rb b/plugins/chat/app/services/chat/lookup_thread.rb
index 789665ae588..b9fffe21769 100644
--- a/plugins/chat/app/services/chat/lookup_thread.rb
+++ b/plugins/chat/app/services/chat/lookup_thread.rb
@@ -46,7 +46,7 @@ module Chat
     end
 
     def threading_enabled_for_channel(thread:, **)
-      thread.channel.threading_enabled
+      thread.channel.threading_enabled || thread.force
     end
 
     def fetch_membership(thread:, guardian:, **)
diff --git a/plugins/chat/app/services/chat/publisher.rb b/plugins/chat/app/services/chat/publisher.rb
index f960f679abe..a368fa2f041 100644
--- a/plugins/chat/app/services/chat/publisher.rb
+++ b/plugins/chat/app/services/chat/publisher.rb
@@ -15,7 +15,7 @@ module Chat
     end
 
     def self.calculate_publish_targets(channel, message)
-      return [root_message_bus_channel(channel.id)] if !allow_publish_to_thread?(channel)
+      return [root_message_bus_channel(channel.id)] if !allow_publish_to_thread?(channel, message)
 
       if message.thread_om?
         [
@@ -30,8 +30,8 @@ module Chat
       end
     end
 
-    def self.allow_publish_to_thread?(channel)
-      channel.threading_enabled
+    def self.allow_publish_to_thread?(channel, message)
+      channel.threading_enabled || message.thread&.force
     end
 
     def self.publish_new!(chat_channel, chat_message, staged_id)
@@ -42,7 +42,7 @@ module Chat
         serialize_message_with_type(chat_message, :sent).merge(staged_id: staged_id),
       )
 
-      if !chat_message.thread_reply? || !allow_publish_to_thread?(chat_channel)
+      if !chat_message.thread_reply? || !allow_publish_to_thread?(chat_channel, chat_message)
         MessageBus.publish(
           self.new_messages_message_bus_channel(chat_channel.id),
           {
@@ -59,13 +59,14 @@ module Chat
         )
       end
 
-      if chat_message.thread_reply? && allow_publish_to_thread?(chat_channel)
+      if chat_message.thread_reply? && allow_publish_to_thread?(chat_channel, chat_message)
         MessageBus.publish(
           self.new_messages_message_bus_channel(chat_channel.id),
           {
             type: "thread",
             channel_id: chat_channel.id,
             thread_id: chat_message.thread_id,
+            force_thread: chat_message.thread&.force,
             message:
               Chat::MessageSerializer.new(
                 chat_message,
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs b/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
index 8a127734b4e..085aee51338 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-message.gjs
@@ -466,7 +466,8 @@ export default class ChatMessage extends Component {
 
   get threadingEnabled() {
     return (
-      this.args.message?.channel?.threadingEnabled &&
+      (this.args.message?.channel?.threadingEnabled ||
+        this.args.message?.thread?.force) &&
       !!this.args.message?.thread
     );
   }
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat/thread/header.gjs b/plugins/chat/assets/javascripts/discourse/components/chat/thread/header.gjs
index 8a7ac4fba5b..b1c2e2ac979 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat/thread/header.gjs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat/thread/header.gjs
@@ -3,6 +3,7 @@ import { inject as service } from "@ember/service";
 import replaceEmoji from "discourse/helpers/replace-emoji";
 import icon from "discourse-common/helpers/d-icon";
 import I18n from "discourse-i18n";
+import and from "truth-helpers/helpers/and";
 import Navbar from "discourse/plugins/chat/discourse/components/chat/navbar";
 import ChatThreadHeaderUnreadIndicator from "discourse/plugins/chat/discourse/components/chat/thread/header-unread-indicator";
 
@@ -54,7 +55,7 @@ export default class ChatThreadHeader extends Component {
 
   <template>
     <Navbar @showFullTitle={{@showFullTitle}} as |navbar|>
-      {{#if @thread}}
+      {{#if (and this.channel.threadingEnabled @thread)}}
         <navbar.BackButton
           @route={{this.backLink.route}}
           @routeModels={{this.backLink.models}}
diff --git a/plugins/chat/assets/javascripts/discourse/models/chat-thread.js b/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
index 99be405c604..33c79abf50e 100644
--- a/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
+++ b/plugins/chat/assets/javascripts/discourse/models/chat-thread.js
@@ -32,6 +32,7 @@ export default class ChatThread {
   @tracked tracking;
   @tracked currentUserMembership;
   @tracked preview;
+  @tracked force;
 
   messagesManager = new ChatMessagesManager(getOwnerWithFallback(this));
 
@@ -41,6 +42,7 @@ export default class ChatThread {
     this.status = args.status;
     this.staged = args.staged;
     this.replyCount = args.reply_count;
+    this.force = args.force;
 
     this.originalMessage = args.original_message
       ? ChatMessage.create(channel, args.original_message)
diff --git a/plugins/chat/assets/javascripts/discourse/routes/chat-channel-thread.js b/plugins/chat/assets/javascripts/discourse/routes/chat-channel-thread.js
index b0623e038a9..4abf81bdf5c 100644
--- a/plugins/chat/assets/javascripts/discourse/routes/chat-channel-thread.js
+++ b/plugins/chat/assets/javascripts/discourse/routes/chat-channel-thread.js
@@ -8,20 +8,31 @@ export default class ChatChannelThread extends DiscourseRoute {
   @service chat;
   @service chatThreadPane;
 
+  redirectToChannel(channel, transition) {
+    transition.abort();
+    this.chatStateManager.closeSidePanel();
+    this.router.transitionTo("chat.channel", ...channel.routeModels);
+  }
+
   model(params, transition) {
     const channel = this.modelFor("chat.channel");
     return channel.threadsManager
       .find(channel.id, params.threadId)
       .catch(() => {
-        transition.abort();
-        this.chatStateManager.closeSidePanel();
-        this.router.transitionTo("chat.channel", ...channel.routeModels);
+        this.redirectToChannel(channel, transition);
         return;
       });
   }
 
-  afterModel(model) {
-    this.chat.activeChannel.activeThread = model;
+  afterModel(thread, transition) {
+    const channel = this.modelFor("chat.channel");
+
+    if (!channel.threadingEnabled && !thread.force) {
+      this.redirectToChannel(channel, transition);
+      return;
+    }
+
+    this.chat.activeChannel.activeThread = thread;
   }
 
   @action
@@ -36,15 +47,7 @@ export default class ChatChannelThread extends DiscourseRoute {
     }
   }
 
-  beforeModel(transition) {
-    const channel = this.modelFor("chat.channel");
-
-    if (!channel.threadingEnabled) {
-      transition.abort();
-      this.router.transitionTo("chat.channel", ...channel.routeModels);
-      return;
-    }
-
+  beforeModel() {
     const { messageId } = this.paramsFor(this.routeName + ".near-message");
     if (
       !messageId &&
diff --git a/plugins/chat/assets/javascripts/discourse/routes/chat-channel.js b/plugins/chat/assets/javascripts/discourse/routes/chat-channel.js
index 2b282350dfb..43892ac3e58 100644
--- a/plugins/chat/assets/javascripts/discourse/routes/chat-channel.js
+++ b/plugins/chat/assets/javascripts/discourse/routes/chat-channel.js
@@ -15,7 +15,12 @@ export default class ChatChannelRoute extends DiscourseRoute {
     const messageId = this.paramsFor("chat.channel.near-message").messageId;
     const threadId = this.paramsFor("chat.channel.thread").threadId;
 
-    if (!messageId && !threadId && model.threadsManager.unreadThreadCount > 0) {
+    if (
+      model.threadingEnabled &&
+      !messageId &&
+      !threadId &&
+      model.threadsManager.unreadThreadCount > 0
+    ) {
       this.router.transitionTo("chat.channel.threads", ...model.routeModels);
     }
   }
diff --git a/plugins/chat/assets/javascripts/discourse/services/chat-subscriptions-manager.js b/plugins/chat/assets/javascripts/discourse/services/chat-subscriptions-manager.js
index eff4aa14a98..23ae3673bc0 100644
--- a/plugins/chat/assets/javascripts/discourse/services/chat-subscriptions-manager.js
+++ b/plugins/chat/assets/javascripts/discourse/services/chat-subscriptions-manager.js
@@ -226,7 +226,7 @@ export default class ChatSubscriptionsManager extends Service {
 
   _onNewThreadMessage(busData) {
     this.chatChannelsManager.find(busData.channel_id).then((channel) => {
-      if (!channel.threadingEnabled) {
+      if (!channel.threadingEnabled && !busData.force_thread) {
         return;
       }
 
diff --git a/plugins/chat/assets/stylesheets/common/chat-navbar.scss b/plugins/chat/assets/stylesheets/common/chat-navbar.scss
index 7b3b1c9660b..f714b38bb13 100644
--- a/plugins/chat/assets/stylesheets/common/chat-navbar.scss
+++ b/plugins/chat/assets/stylesheets/common/chat-navbar.scss
@@ -36,6 +36,10 @@
   .single-select-header {
     padding: 0.3675rem 0.584rem;
   }
+
+  > .c-navbar__title:first-child {
+    margin-left: 1rem;
+  }
 }
 
 .c-navbar__back-button {
diff --git a/plugins/chat/db/migrate/20240301100413_add_force_to_threads.rb b/plugins/chat/db/migrate/20240301100413_add_force_to_threads.rb
new file mode 100644
index 00000000000..b496dd05844
--- /dev/null
+++ b/plugins/chat/db/migrate/20240301100413_add_force_to_threads.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddForceToThreads < ActiveRecord::Migration[7.0]
+  def change
+    add_column :chat_threads, :force, :boolean, null: false, default: false
+  end
+end
diff --git a/plugins/chat/lib/chat_sdk/message.rb b/plugins/chat/lib/chat_sdk/message.rb
index e89451ae556..ea6c7f8889f 100644
--- a/plugins/chat/lib/chat_sdk/message.rb
+++ b/plugins/chat/lib/chat_sdk/message.rb
@@ -113,6 +113,7 @@ module ChatSDK
       upload_ids: nil,
       streaming: false,
       enforce_membership: false,
+      force_thread: false,
       &block
     )
       message =
@@ -126,6 +127,7 @@ module ChatSDK
           upload_ids: upload_ids,
           streaming: streaming,
           enforce_membership: enforce_membership,
+          force_thread: force_thread,
         ) do
           on_model_not_found(:channel) { raise "Couldn't find channel with id: `#{channel_id}`" }
           on_model_not_found(:channel_membership) do
diff --git a/plugins/chat/spec/lib/chat_sdk/message_spec.rb b/plugins/chat/spec/lib/chat_sdk/message_spec.rb
index fb712c7e1af..c1ca1172548 100644
--- a/plugins/chat/spec/lib/chat_sdk/message_spec.rb
+++ b/plugins/chat/spec/lib/chat_sdk/message_spec.rb
@@ -27,6 +27,16 @@ describe ChatSDK::Message do
       end
     end
 
+    context "when force_thread is present" do
+      it "creates the message in a thread" do
+        message_1 = described_class.create(**params)
+        message_2 =
+          described_class.create(**params, in_reply_to_id: message_1.id, force_thread: true)
+
+        expect(message_2.thread.force).to eq(true)
+      end
+    end
+
     context "when channel doesn’t exist" do
       it "fails" do
         expect { described_class.create(**params, channel_id: -999) }.to raise_error(
diff --git a/plugins/chat/spec/requests/chat/api/channel_messages_controller_spec.rb b/plugins/chat/spec/requests/chat/api/channel_messages_controller_spec.rb
index a31ab9e5ce7..47e83919c8e 100644
--- a/plugins/chat/spec/requests/chat/api/channel_messages_controller_spec.rb
+++ b/plugins/chat/spec/requests/chat/api/channel_messages_controller_spec.rb
@@ -67,4 +67,23 @@ RSpec.describe Chat::Api::ChannelMessagesController do
       end
     end
   end
+
+  describe "#create" do
+    context "when force_thread param is given" do
+      it "removes it from params" do
+        sign_in(current_user)
+
+        message_1 = Fabricate(:chat_message, chat_channel: channel)
+
+        expect {
+          post "/chat/#{channel.id}.json",
+               params: {
+                 in_reply_to_id: message_1.id,
+                 message: "test",
+                 force_thread: true,
+               }
+        }.to change { Chat::Thread.where(force: false).count }.by(1)
+      end
+    end
+  end
 end
diff --git a/plugins/chat/spec/services/chat/create_message_spec.rb b/plugins/chat/spec/services/chat/create_message_spec.rb
index a84ffec17bf..54e9bd7f47e 100644
--- a/plugins/chat/spec/services/chat/create_message_spec.rb
+++ b/plugins/chat/spec/services/chat/create_message_spec.rb
@@ -42,6 +42,7 @@ RSpec.describe Chat::CreateMessage do
         upload_ids: [upload.id],
         context_topic_id: context_topic_id,
         context_post_ids: context_post_ids,
+        force_thread: false,
       }
     end
     let(:message) { result[:message_instance].reload }
@@ -323,6 +324,20 @@ RSpec.describe Chat::CreateMessage do
                           Chat::Publisher.expects(:publish_thread_created!).never
                           result
                         end
+
+                        context "when thread is forced" do
+                          before { params[:force_thread] = true }
+
+                          it "publishes the new thread" do
+                            Chat::Publisher.expects(:publish_thread_created!).with(
+                              channel,
+                              reply_to,
+                              instance_of(Integer),
+                              nil,
+                            )
+                            result
+                          end
+                        end
                       end
                     end
                   end
diff --git a/plugins/chat/spec/services/chat/list_channel_messages_spec.rb b/plugins/chat/spec/services/chat/list_channel_messages_spec.rb
index 794519c502f..8f50bd783c4 100644
--- a/plugins/chat/spec/services/chat/list_channel_messages_spec.rb
+++ b/plugins/chat/spec/services/chat/list_channel_messages_spec.rb
@@ -159,10 +159,29 @@ RSpec.describe Chat::ListChannelMessages do
     context "when threads are disabled" do
       fab!(:thread_1) { Fabricate(:chat_thread, channel: channel) }
 
-      before { channel.update!(threading_enabled: false) }
+      before do
+        channel.update!(threading_enabled: false)
+        thread_1.add(user)
+      end
 
-      it "returns empty tracking" do
-        expect(result.tracking).to eq({})
+      it "returns tracking" do
+        Fabricate(:chat_message, chat_channel: channel, thread: thread_1)
+
+        expect(result.tracking.thread_tracking).to eq(
+          { thread_1.id => { channel_id: channel.id, mention_count: 0, unread_count: 0 } },
+        )
+      end
+
+      context "when thread is forced" do
+        before { thread_1.update!(force: true) }
+
+        it "returns tracking" do
+          Fabricate(:chat_message, chat_channel: channel, thread: thread_1)
+
+          expect(result.tracking.thread_tracking).to eq(
+            { thread_1.id => { channel_id: channel.id, mention_count: 0, unread_count: 1 } },
+          )
+        end
       end
     end
 
diff --git a/plugins/chat/spec/services/chat/list_channel_thread_messages_spec.rb b/plugins/chat/spec/services/chat/list_channel_thread_messages_spec.rb
index eeaf2958b2e..8533f97b479 100644
--- a/plugins/chat/spec/services/chat/list_channel_thread_messages_spec.rb
+++ b/plugins/chat/spec/services/chat/list_channel_thread_messages_spec.rb
@@ -42,6 +42,12 @@ RSpec.describe Chat::ListChannelThreadMessages do
       before { thread.channel.update!(threading_enabled: false) }
 
       it { is_expected.to fail_a_policy(:ensure_thread_enabled) }
+
+      context "when the thread is forced" do
+        before { thread.update!(force: true) }
+
+        it { is_expected.to be_a_success }
+      end
     end
 
     context "when channel and site setting are enabling threading" do
diff --git a/plugins/chat/spec/services/chat/lookup_thread_spec.rb b/plugins/chat/spec/services/chat/lookup_thread_spec.rb
index a6c806a394e..873d30e0a4f 100644
--- a/plugins/chat/spec/services/chat/lookup_thread_spec.rb
+++ b/plugins/chat/spec/services/chat/lookup_thread_spec.rb
@@ -56,6 +56,12 @@ RSpec.describe Chat::LookupThread do
       before { channel.update!(threading_enabled: false) }
 
       it { is_expected.to fail_a_policy(:threading_enabled_for_channel) }
+
+      context "when thread is forced" do
+        before { thread.update!(force: true) }
+
+        it { is_expected.to be_a_success }
+      end
     end
   end
 end
diff --git a/plugins/chat/spec/services/chat/publisher_spec.rb b/plugins/chat/spec/services/chat/publisher_spec.rb
index e0517643d96..697ddf8f044 100644
--- a/plugins/chat/spec/services/chat/publisher_spec.rb
+++ b/plugins/chat/spec/services/chat/publisher_spec.rb
@@ -281,6 +281,7 @@ describe Chat::Publisher do
               type: "thread",
               channel_id: channel.id,
               thread_id: thread.id,
+              force_thread: false,
               message:
                 Chat::MessageSerializer.new(
                   message_1,
diff --git a/plugins/chat/spec/system/single_thread_spec.rb b/plugins/chat/spec/system/single_thread_spec.rb
index 382d70d7915..d38a20da396 100644
--- a/plugins/chat/spec/system/single_thread_spec.rb
+++ b/plugins/chat/spec/system/single_thread_spec.rb
@@ -82,6 +82,19 @@ describe "Single thread in side panel", type: :system do
       expect(chat_drawer_page).to have_open_channel(channel)
     end
 
+    context "when thread is forced and threading disabled" do
+      before do
+        channel.update!(threading_enabled: false)
+        thread.update!(force: true)
+      end
+
+      it "doesn’t show back button " do
+        chat_page.visit_thread(thread)
+
+        expect(page).to have_no_css(".c-routes-channel-thread .c-navbar__back-button")
+      end
+    end
+
     it "highlights the message in the channel when clicking original message link" do
       chat_page.visit_thread(thread)
 
diff --git a/vendor/assets/svg-icons/discourse-additional.svg b/vendor/assets/svg-icons/discourse-additional.svg
index 3ba19815c0b..2cc3846994c 100644
--- a/vendor/assets/svg-icons/discourse-additional.svg
+++ b/vendor/assets/svg-icons/discourse-additional.svg
@@ -73,7 +73,4 @@ Additional SVG icons
     <path d="M26 46.5156C37.3305 46.5156 46.5156 37.3305 46.5156 26C46.5156 14.6695 37.3305 5.48438 26 5.48438C14.6695 5.48438 5.48438 14.6695 5.48438 26C5.48438 37.3305 14.6695 46.5156 26 46.5156ZM26 52C40.3594 52 52 40.3594 52 26C52 11.6406 40.3594 0 26 0C11.6406 0 0 11.6406 0 26C0 40.3594 11.6406 52 26 52Z"/>
     <path d="M33.3125 22.75H18.6875C16.8926 22.75 15.4375 24.2051 15.4375 26C15.4375 27.7949 16.8926 29.25 18.6875 29.25H33.3125C35.1074 29.25 36.5625 27.7949 36.5625 26C36.5625 24.2051 35.1074 22.75 33.3125 22.75Z"/>
   </symbol>
-  <symbol id="discourse-sidebar" viewBox="0 0 513 513">
-    <path fill-rule="evenodd" clip-rule="evenodd" d="M64.125 0C28.0547 0 0 29.0566 0 64.125V399.75C0 435.82 28.0547 463.875 64.125 463.875H448.875C483.943 463.875 513 435.82 513 399.75V64.125C513 29.0566 483.943 0 448.875 0H64.125ZM219.375 407.75H56.125V56.1875H219.375V407.75ZM272.5 56.1875H455.875V407.75H272.5V56.1875ZM96 96C91.5817 96 88 99.5817 88 104V128C88 132.418 91.5817 136 96 136H184C188.418 136 192 132.418 192 128V104C192 99.5817 188.418 96 184 96H96ZM88 184C88 179.582 91.5817 176 96 176H184C188.418 176 192 179.582 192 184V208C192 212.418 188.418 216 184 216H96C91.5817 216 88 212.418 88 208V184ZM96 256C91.5817 256 88 259.582 88 264V288C88 292.418 91.5817 296 96 296H184C188.418 296 192 292.418 192 288V264C192 259.582 188.418 256 184 256H96Z"/>
-  </symbol>
 </svg>