1 files changed, 57 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/set_default_iteration_cadences.rb b/lib/gitlab/background_migration/set_default_iteration_cadences.rb
new file mode 100644
index 00000000000..530608144aa
--- /dev/null
+++ b/lib/gitlab/background_migration/set_default_iteration_cadences.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # rubocop:disable Style/Documentation
+    class SetDefaultIterationCadences
+      class Iteration < ApplicationRecord
+        self.table_name = 'sprints'
+      end
+
+      class IterationCadence < ApplicationRecord
+        self.table_name = 'iterations_cadences'
+
+        include BulkInsertSafe
+      end
+
+      class Group < ApplicationRecord
+        self.table_name = 'namespaces'
+      end
+
+      def perform(*group_ids)
+        create_iterations_cadences(group_ids)
+        assign_iterations_cadences(group_ids)
+      end
+
+      private
+
+      def create_iterations_cadences(group_ids)
+        groups_with_cadence = IterationCadence.select(:group_id)
+        new_cadences = Group.where(id: group_ids).where.not(id: groups_with_cadence).map do |group|
+          last_iteration = Iteration.where(group_id: group.id).order(:start_date)&.last
+
+          next unless last_iteration
+
+          time = Time.now
+          IterationCadence.new(
+            group_id: group.id,
+            title: "#{group.name} Iterations",
+            start_date: last_iteration.start_date,
+            last_run_date: last_iteration.start_date,
+            automatic: false,
+            created_at: time,
+            updated_at: time
+          )
+        end
+
+        IterationCadence.bulk_insert!(new_cadences.compact)
+      end
+
+      def assign_iterations_cadences(group_ids)
+        IterationCadence.where(group_id: group_ids).each do |cadence|
+          Iteration.where(iterations_cadence_id: nil).where(group_id: cadence.group_id).update_all(iterations_cadence_id: cadence.id)
+        end
+      end
+    end
+  end
+end