Validate against multiple reblogs of same status by same account

app/models/status.rb

@@ -16,6 +16,7 @@ class Status < ApplicationRecord
   validates :account, presence: true
   validates :uri, uniqueness: true, unless: 'local?'
   validates :text, presence: true, length: { maximum: 500 }, if: proc { |s| s.local? && !s.reblog? }
+  validates :reblog, uniqueness: { scope: :account, message: 'of status already exists' }, if: 'reblog?'
 
   scope :with_counters, -> { select('statuses.*, (select count(r.id) from statuses as r where r.reblog_of_id = statuses.id) as reblogs_count, (select count(f.id) from favourites as f where f.status_id = statuses.id) as favourites_count') }
   scope :with_includes, -> { includes(:account, :media_attachments, :stream_entry, mentions: :account, reblog: [:account, mentions: :account], thread: :account) }