1 files changed, 59 insertions, 0 deletions
diff --git a/app/services/ci/pipeline_schedules/calculate_next_run_service.rb b/app/services/ci/pipeline_schedules/calculate_next_run_service.rb
new file mode 100644
index 00000000000..9978b2d4775
--- /dev/null
+++ b/app/services/ci/pipeline_schedules/calculate_next_run_service.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+module Ci
+  module PipelineSchedules
+    class CalculateNextRunService < BaseService
+      include Gitlab::Utils::StrongMemoize
+
+      def execute(schedule, fallback_method:)
+        @schedule = schedule
+
+        return fallback_method.call unless ::Feature.enabled?(:ci_daily_limit_for_pipeline_schedules, project, default_enabled: :yaml)
+        return fallback_method.call unless plan_cron&.cron_valid?
+
+        now = Time.zone.now
+
+        schedule_next_run = schedule_cron.next_time_from(now)
+        return schedule_next_run if worker_cron.match?(schedule_next_run) && plan_cron.match?(schedule_next_run)
+
+        plan_next_run = plan_cron.next_time_from(now)
+        return plan_next_run if worker_cron.match?(plan_next_run)
+
+        worker_next_run = worker_cron.next_time_from(now)
+        return worker_next_run if plan_cron.match?(worker_next_run)
+
+        worker_cron.next_time_from(plan_next_run)
+      end
+
+      private
+
+      def schedule_cron
+        strong_memoize(:schedule_cron) do
+          Gitlab::Ci::CronParser.new(@schedule.cron, @schedule.cron_timezone)
+        end
+      end
+
+      def worker_cron
+        strong_memoize(:worker_cron) do
+          Gitlab::Ci::CronParser.new(worker_cron_expression, Time.zone.name)
+        end
+      end
+
+      def plan_cron
+        strong_memoize(:plan_cron) do
+          daily_limit = @schedule.daily_limit
+
+          next unless daily_limit
+
+          every_x_minutes = (1.day.in_minutes / daily_limit).to_i
+
+          Gitlab::Ci::CronParser.parse_natural("every #{every_x_minutes} minutes", Time.zone.name)
+        end
+      end
+
+      def worker_cron_expression
+        Settings.cron_jobs['pipeline_schedule_worker']['cron']
+      end
+    end
+  end
+end