1 files changed, 95 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/user_mentions/models/concerns/isolated_mentionable.rb b/lib/gitlab/background_migration/user_mentions/models/concerns/isolated_mentionable.rb
new file mode 100644
index 00000000000..40aab896212
--- /dev/null
+++ b/lib/gitlab/background_migration/user_mentions/models/concerns/isolated_mentionable.rb
@@ -0,0 +1,95 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    module UserMentions
+      module Models
+        # == IsolatedMentionable concern
+        #
+        # Shortcutted for isolation version of Mentionable to be used in mentions migrations
+        #
+        module IsolatedMentionable
+          extend ::ActiveSupport::Concern
+
+          class_methods do
+            # Indicate which attributes of the Mentionable to search for GFM references.
+            def attr_mentionable(attr, options = {})
+              attr = attr.to_s
+              mentionable_attrs << [attr, options]
+            end
+          end
+
+          included do
+            # Accessor for attributes marked mentionable.
+            cattr_accessor :mentionable_attrs, instance_accessor: false do
+              []
+            end
+
+            if self < Participable
+              participant -> (user, ext) { all_references(user, extractor: ext) }
+            end
+          end
+
+          def all_references(current_user = nil, extractor: nil)
+            # Use custom extractor if it's passed in the function parameters.
+            if extractor
+              extractors[current_user] = extractor
+            else
+              extractor = extractors[current_user] ||= ::Gitlab::ReferenceExtractor.new(project, current_user)
+
+              extractor.reset_memoized_values
+            end
+
+            self.class.mentionable_attrs.each do |attr, options|
+              text    = __send__(attr) # rubocop:disable GitlabSecurity/PublicSend
+              options = options.merge(
+                cache_key: [self, attr],
+                author: author,
+                skip_project_check: skip_project_check?
+              ).merge(mentionable_params)
+
+              cached_html = self.try(:updated_cached_html_for, attr.to_sym)
+              options[:rendered] = cached_html if cached_html
+
+              extractor.analyze(text, options)
+            end
+
+            extractor
+          end
+
+          def extractors
+            @extractors ||= {}
+          end
+
+          def skip_project_check?
+            false
+          end
+
+          def build_mention_values
+            refs = all_references(author)
+
+            {
+              "#{self.user_mention_model.resource_foreign_key}": user_mention_resource_id,
+              note_id: user_mention_note_id,
+              mentioned_users_ids: array_to_sql(refs.mentioned_users.pluck(:id)),
+              mentioned_projects_ids: array_to_sql(refs.mentioned_projects.pluck(:id)),
+              mentioned_groups_ids: array_to_sql(refs.mentioned_groups.pluck(:id))
+            }
+          end
+
+          def array_to_sql(ids_array)
+            return unless ids_array.present?
+
+            '{' + ids_array.join(", ") + '}'
+          end
+
+          private
+
+          def mentionable_params
+            {}
+          end
+        end
+      end
+    end
+  end
+end