REFACTOR: Use `Topic#private_message?` to reduce duplication.

app/models/post.rb

@@ -164,7 +164,7 @@ class Post < ActiveRecord::Base
     }.merge(options)
 
     if Topic.visible_post_types.include?(post_type)
-      if topic.archetype == Archetype.private_message
+      if topic.private_message?
         user_ids = User.where('admin or moderator').pluck(:id)
         user_ids |= topic.allowed_users.pluck(:id)
         MessageBus.publish(channel, msg, user_ids: user_ids)

app/models/topic.rb

@@ -265,7 +265,7 @@ class Topic < ActiveRecord::Base
   end
 
   def advance_draft_sequence
-    if archetype == Archetype.private_message
+    if self.private_message?
       DraftSequence.next!(user, Draft::NEW_PRIVATE_MESSAGE)
     else
       DraftSequence.next!(user, Draft::NEW_TOPIC)

app/services/user_action_creator.rb

@@ -85,7 +85,7 @@ class UserActionCreator
     return unless model.user_id
 
     row = {
-      action_type: model.archetype == Archetype.private_message ? UserAction::NEW_PRIVATE_MESSAGE : UserAction::NEW_TOPIC,
+      action_type: model.private_message? ? UserAction::NEW_PRIVATE_MESSAGE : UserAction::NEW_TOPIC,
       user_id: model.user_id,
       acting_user_id: model.user_id,
       target_topic_id: model.id,
@@ -94,7 +94,7 @@ class UserActionCreator
     }
 
     UserAction.remove_action!(row.merge(
-      action_type: model.archetype == Archetype.private_message ? UserAction::NEW_TOPIC : UserAction::NEW_PRIVATE_MESSAGE
+      action_type: model.private_message? ? UserAction::NEW_TOPIC : UserAction::NEW_PRIVATE_MESSAGE
     ))
 
     rows = [row]

lib/composer_messages_finder.rb

@@ -20,7 +20,7 @@ class ComposerMessagesFinder
 
   # Determines whether to show the user education text
   def check_education_message
-    return if @topic && @topic.archetype == Archetype.private_message
+    return if @topic&.private_message?
 
     if creating_topic?
       count = @user.created_topic_count

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/advanced_user_narrative.rb

@@ -176,7 +176,7 @@ module DiscourseNarrativeBot
       }
 
       if @post &&
-         @post.archetype == Archetype.private_message &&
+         @post.topic.private_message? &&
          @post.topic.topic_allowed_users.pluck(:user_id).include?(@user.id)
 
         opts = opts.merge(topic_id: @post.topic_id)

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/new_user_narrative.rb

@@ -190,7 +190,7 @@ module DiscourseNarrativeBot
       }
 
       if @post &&
-         @post.archetype == Archetype.private_message &&
+         @post.topic.private_message? &&
          @post.topic.topic_allowed_users.pluck(:user_id).include?(@user.id)
 
         opts = opts.merge(topic_id: @post.topic_id)

plugins/discourse-presence/plugin.rb

@@ -58,7 +58,7 @@ after_initialize do
 
       topic = type == 'post' ? Post.find_by(id: id).topic : Topic.find_by(id: id)
 
-      if topic.archetype == Archetype.private_message
+      if topic.private_message?
         user_ids = User.where('admin OR moderator').pluck(:id) + topic.allowed_users.pluck(:id)
         group_ids = topic.allowed_groups.pluck(:id)