1 files changed, 95 insertions, 0 deletions
diff --git a/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb b/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb
new file mode 100644
index 00000000000..11d59257ed9
--- /dev/null
+++ b/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb
@@ -0,0 +1,95 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module UsageDataCounters
+    module MergeRequestActivityUniqueCounter
+      MR_DIFFS_ACTION = 'i_code_review_mr_diffs'
+      MR_DIFFS_SINGLE_FILE_ACTION = 'i_code_review_mr_single_file_diffs'
+      MR_DIFFS_USER_SINGLE_FILE_ACTION = 'i_code_review_user_single_file_diffs'
+      MR_CREATE_ACTION = 'i_code_review_user_create_mr'
+      MR_CLOSE_ACTION = 'i_code_review_user_close_mr'
+      MR_REOPEN_ACTION = 'i_code_review_user_reopen_mr'
+      MR_MERGE_ACTION = 'i_code_review_user_merge_mr'
+      MR_CREATE_COMMENT_ACTION = 'i_code_review_user_create_mr_comment'
+      MR_EDIT_COMMENT_ACTION = 'i_code_review_user_edit_mr_comment'
+      MR_REMOVE_COMMENT_ACTION = 'i_code_review_user_remove_mr_comment'
+      MR_CREATE_REVIEW_NOTE_ACTION = 'i_code_review_user_create_review_note'
+      MR_PUBLISH_REVIEW_ACTION = 'i_code_review_user_publish_review'
+      MR_CREATE_MULTILINE_COMMENT_ACTION = 'i_code_review_user_create_multiline_mr_comment'
+      MR_EDIT_MULTILINE_COMMENT_ACTION = 'i_code_review_user_edit_multiline_mr_comment'
+      MR_REMOVE_MULTILINE_COMMENT_ACTION = 'i_code_review_user_remove_multiline_mr_comment'
+
+      class << self
+        def track_mr_diffs_action(merge_request:)
+          track_unique_action_by_merge_request(MR_DIFFS_ACTION, merge_request)
+        end
+
+        def track_mr_diffs_single_file_action(merge_request:, user:)
+          track_unique_action_by_merge_request(MR_DIFFS_SINGLE_FILE_ACTION, merge_request)
+          track_unique_action_by_user(MR_DIFFS_USER_SINGLE_FILE_ACTION, user)
+        end
+
+        def track_create_mr_action(user:)
+          track_unique_action_by_user(MR_CREATE_ACTION, user)
+        end
+
+        def track_close_mr_action(user:)
+          track_unique_action_by_user(MR_CLOSE_ACTION, user)
+        end
+
+        def track_merge_mr_action(user:)
+          track_unique_action_by_user(MR_MERGE_ACTION, user)
+        end
+
+        def track_reopen_mr_action(user:)
+          track_unique_action_by_user(MR_REOPEN_ACTION, user)
+        end
+
+        def track_create_comment_action(note:)
+          track_unique_action_by_user(MR_CREATE_COMMENT_ACTION, note.author)
+          track_multiline_unique_action(MR_CREATE_MULTILINE_COMMENT_ACTION, note)
+        end
+
+        def track_edit_comment_action(note:)
+          track_unique_action_by_user(MR_EDIT_COMMENT_ACTION, note.author)
+          track_multiline_unique_action(MR_EDIT_MULTILINE_COMMENT_ACTION, note)
+        end
+
+        def track_remove_comment_action(note:)
+          track_unique_action_by_user(MR_REMOVE_COMMENT_ACTION, note.author)
+          track_multiline_unique_action(MR_REMOVE_MULTILINE_COMMENT_ACTION, note)
+        end
+
+        def track_create_review_note_action(user:)
+          track_unique_action_by_user(MR_CREATE_REVIEW_NOTE_ACTION, user)
+        end
+
+        def track_publish_review_action(user:)
+          track_unique_action_by_user(MR_PUBLISH_REVIEW_ACTION, user)
+        end
+
+        private
+
+        def track_unique_action_by_merge_request(action, merge_request)
+          track_unique_action(action, merge_request.id)
+        end
+
+        def track_unique_action_by_user(action, user)
+          return unless user
+
+          track_unique_action(action, user.id)
+        end
+
+        def track_unique_action(action, value)
+          Gitlab::UsageDataCounters::HLLRedisCounter.track_usage_event(action, value)
+        end
+
+        def track_multiline_unique_action(action, note)
+          return unless note.is_a?(DiffNote) && note.multiline?
+
+          track_unique_action_by_user(action, note.author)
+        end
+      end
+    end
+  end
+end