Implement follower-only threads

Author: luap42

app/models/comment_thread.rb

@@ -1,6 +1,7 @@
 class CommentThread < ApplicationRecord
-  include PostRelated
-
+  include CommunityRelated
+  
+  belongs_to :post, optional: true
   has_many :comments
   has_many :thread_follower
   belongs_to :locked_by, class_name: 'User', optional: true
@@ -9,8 +10,8 @@ class CommentThread < ApplicationRecord
 
   scope :deleted, -> { where(deleted: true) }
   scope :undeleted, -> { where(deleted: false) }
-  scope :initially_visible, -> { where(deleted: false, archived: false).where('reply_count > 0') }
-  scope :publicly_available, -> { where(deleted: false).where('reply_count > 0') }
+  scope :initially_visible, -> { where(deleted: false, archived: false, is_private: false).where('reply_count > 0') }
+  scope :publicly_available, -> { where(deleted: false, is_private: false).where('reply_count > 0') }
   scope :archived, -> { where(archived: true) }
 
   after_create :create_follower
@@ -29,7 +30,7 @@ def followed_by?(user)
 
   def can_access?(user)
     (!deleted? || user&.privilege?('flag_curate') || user&.has_post_privilege?('flag_curate', post)) &&
-      post.can_access?(user)
+      (!post || post&.can_access?(user)) && (!is_private || followed_by?(user))
   end
 
   private