Adds a report for version mismatches.

refs #5074

app/reports/preservation_versions.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# Compare SDR versions against Preservation versions
+#  https://github.com/sul-dlss/dor-services-app/issues/5074
+# Invoke via:
+# bin/rails r -e production "PreservationVersions.report"
+class PreservationVersions
+  def self.report
+    output_file = 'preservation_versions_report.csv'
+
+    CSV.open(output_file, 'w') do |csv|
+      csv << %w[druid version preservation_version]
+      num_objs = RepositoryObject.count
+      RepositoryObject.joins(:head_version).call(:external_identifier, :version).each_with_index do |data, index|
+        druid, version = data
+        puts "#{index + 1} of #{num_objs} : #{druid}"
+        begin
+          preservation_version = Preservation::Client.objects.current_version(druid)
+        rescue Preservation::Client::NotFoundError
+          preservation_version = nil
+        end
+        csv << [druid, version, preservation_version] if preservation_version != version
+      end
+    end
+  end
+end