1 files changed, 71 insertions, 0 deletions
diff --git a/lib/gitlab/analytics/cycle_analytics/stage_events.rb b/lib/gitlab/analytics/cycle_analytics/stage_events.rb
new file mode 100644
index 00000000000..d21f344f483
--- /dev/null
+++ b/lib/gitlab/analytics/cycle_analytics/stage_events.rb
@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Analytics
+    module CycleAnalytics
+      module StageEvents
+        # Convention:
+        # Issue: < 100
+        # MergeRequest: >= 100 && < 1000
+        # Custom events for default stages: >= 1000 (legacy)
+        ENUM_MAPPING = {
+          StageEvents::IssueCreated => 1,
+          StageEvents::IssueFirstMentionedInCommit => 2,
+          StageEvents::MergeRequestCreated => 100,
+          StageEvents::MergeRequestFirstDeployedToProduction => 101,
+          StageEvents::MergeRequestLastBuildFinished => 102,
+          StageEvents::MergeRequestLastBuildStarted => 103,
+          StageEvents::MergeRequestMerged => 104,
+          StageEvents::CodeStageStart => 1_000,
+          StageEvents::IssueStageEnd => 1_001,
+          StageEvents::PlanStageStart => 1_002
+        }.freeze
+
+        EVENTS = ENUM_MAPPING.keys.freeze
+
+        # Defines which start_event and end_event pairs are allowed
+        PAIRING_RULES = {
+          StageEvents::PlanStageStart => [
+            StageEvents::IssueFirstMentionedInCommit
+          ],
+          StageEvents::CodeStageStart => [
+            StageEvents::MergeRequestCreated
+          ],
+          StageEvents::IssueCreated => [
+            StageEvents::IssueStageEnd
+          ],
+          StageEvents::MergeRequestCreated => [
+            StageEvents::MergeRequestMerged
+          ],
+          StageEvents::MergeRequestLastBuildStarted => [
+            StageEvents::MergeRequestLastBuildFinished
+          ],
+          StageEvents::MergeRequestMerged => [
+            StageEvents::MergeRequestFirstDeployedToProduction
+          ]
+        }.freeze
+
+        def [](identifier)
+          events.find { |e| e.identifier.to_s.eql?(identifier.to_s) } || raise(KeyError)
+        end
+
+        # hash for defining ActiveRecord enum: identifier => number
+        def to_enum
+          ENUM_MAPPING.each_with_object({}) { |(k, v), hash| hash[k.identifier] = v }
+        end
+
+        # will be overridden in EE with custom events
+        def pairing_rules
+          PAIRING_RULES
+        end
+
+        # will be overridden in EE with custom events
+        def events
+          EVENTS
+        end
+
+        module_function :[], :to_enum, :pairing_rules, :events
+      end
+    end
+  end
+end