1 files changed, 48 insertions, 0 deletions
diff --git a/lib/gitlab/alert_management/payload.rb b/lib/gitlab/alert_management/payload.rb
new file mode 100644
index 00000000000..177d544d720
--- /dev/null
+++ b/lib/gitlab/alert_management/payload.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module AlertManagement
+    module Payload
+      MONITORING_TOOLS = {
+        prometheus: 'Prometheus'
+      }.freeze
+
+      class << self
+        # Instantiates an instance of a subclass of
+        # Gitlab::AlertManagement::Payload::Base. This can
+        # be used to create new alerts or read content from
+        # the payload of an existing AlertManagement::Alert
+        #
+        # @param project [Project]
+        # @param payload [Hash]
+        # @param monitoring_tool [String]
+        def parse(project, payload, monitoring_tool: nil)
+          payload_class = payload_class_for(
+            monitoring_tool: monitoring_tool || payload&.dig('monitoring_tool'),
+            payload: payload
+          )
+
+          payload_class.new(project: project, payload: payload)
+        end
+
+        private
+
+        def payload_class_for(monitoring_tool:, payload:)
+          if monitoring_tool == MONITORING_TOOLS[:prometheus]
+            if gitlab_managed_prometheus?(payload)
+              ::Gitlab::AlertManagement::Payload::ManagedPrometheus
+            else
+              ::Gitlab::AlertManagement::Payload::Prometheus
+            end
+          else
+            ::Gitlab::AlertManagement::Payload::Generic
+          end
+        end
+
+        def gitlab_managed_prometheus?(payload)
+          payload&.dig('labels', 'gitlab_alert_id').present?
+        end
+      end
+    end
+  end
+end