Refactor ShareVisibilitesController

closes #7196

app/controllers/share_visibilities_controller.rb

@@ -7,17 +7,14 @@ class ShareVisibilitiesController < ApplicationController
   before_action :authenticate_user!
 
   def update
-    #note :id references a postvisibility
-    params[:shareable_id] ||= params[:post_id]
-    params[:shareable_type] ||= 'Post'
-
-    vis = current_user.toggle_hidden_shareable(accessible_post)
-    render :nothing => true, :status => 200
+    post = post_service.find!(params[:post_id])
+    current_user.toggle_hidden_shareable(post)
+    head :ok
   end
 
   private
 
-  def accessible_post
-    @post ||= params[:shareable_type].constantize.where(:id => params[:post_id]).select("id, guid, author_id, created_at").first
+  def post_service
+    @post_service ||= PostService.new(current_user)
   end
 end