1 files changed, 75 insertions, 0 deletions
diff --git a/app/services/projects/prometheus/alerts/create_events_service.rb b/app/services/projects/prometheus/alerts/create_events_service.rb
new file mode 100644
index 00000000000..a29240947ff
--- /dev/null
+++ b/app/services/projects/prometheus/alerts/create_events_service.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+module Projects
+  module Prometheus
+    module Alerts
+      # Persists a series of Prometheus alert events as list of PrometheusAlertEvent.
+      class CreateEventsService < BaseService
+        def execute
+          create_events_from(alerts)
+        end
+
+        private
+
+        def create_events_from(alerts)
+          Array.wrap(alerts).map { |alert| create_event(alert) }.compact
+        end
+
+        def create_event(payload)
+          parsed_alert = Gitlab::Alerting::Alert.new(project: project, payload: payload)
+
+          return unless parsed_alert.valid?
+
+          if parsed_alert.gitlab_managed?
+            create_managed_prometheus_alert_event(parsed_alert)
+          else
+            create_self_managed_prometheus_alert_event(parsed_alert)
+          end
+        end
+
+        def alerts
+          params['alerts']
+        end
+
+        def find_alert(metric)
+          Projects::Prometheus::AlertsFinder
+            .new(project: project, metric: metric)
+            .execute
+            .first
+        end
+
+        def create_managed_prometheus_alert_event(parsed_alert)
+          alert = find_alert(parsed_alert.metric_id)
+          payload_key = PrometheusAlertEvent.payload_key_for(parsed_alert.metric_id, parsed_alert.starts_at_raw)
+
+          event = PrometheusAlertEvent.find_or_initialize_by_payload_key(parsed_alert.project, alert, payload_key)
+
+          set_status(parsed_alert, event)
+        end
+
+        def create_self_managed_prometheus_alert_event(parsed_alert)
+          payload_key = SelfManagedPrometheusAlertEvent.payload_key_for(parsed_alert.starts_at_raw, parsed_alert.title, parsed_alert.full_query)
+
+          event = SelfManagedPrometheusAlertEvent.find_or_initialize_by_payload_key(parsed_alert.project, payload_key) do |event|
+            event.environment      = parsed_alert.environment
+            event.title            = parsed_alert.title
+            event.query_expression = parsed_alert.full_query
+          end
+
+          set_status(parsed_alert, event)
+        end
+
+        def set_status(parsed_alert, event)
+          persisted = case parsed_alert.status
+                      when 'firing'
+                        event.fire(parsed_alert.starts_at)
+                      when 'resolved'
+                        event.resolve(parsed_alert.ends_at)
+                      end
+
+          event if persisted
+        end
+      end
+    end
+  end
+end