Enhanc`searchable` in `annotations`

app/models/annotation.rb

@@ -35,9 +35,17 @@ class Annotation < ApplicationRecord
     integer :document_id
     integer :doctrine_id
 
-    join(:library_rank, target: Cdao::Document, type: :integer, join: { from: :id, to: :document_id })
-    join(:search_year, target: Cdao::Document, type: :integer, join: { from: :id, to: :document_id })
-    join(:search_doc_date, target: Cdao::Document, type: :date, join: { from: :id, to: :document_id })
+    integer :library_rank do
+      document.library.rank
+    end
+
+    integer :search_year do
+      document.year.present? && document.year > 0 ? document.year : (document.doc_date.try :year)
+    end
+
+    date :search_doc_date do
+      document.doc_date.presence || Date.new(year.presence || 0)
+    end
 
     date :created_at
     date :updated_at