Add notification to curators when an intem is marked complete

fixes #505

app/models/work.rb

@@ -25,7 +25,7 @@ class Work < ApplicationRecord
     end
 
     event :complete_submission do
-      transitions from: :draft, to: :awaiting_approval, guard: :valid_to_submit
+      transitions from: :draft, to: :awaiting_approval, guard: :valid_to_submit, after: :notify_collection_curators
     end
 
     event :request_changes do
@@ -723,5 +723,11 @@ def publish_precurated_files
 
       delete_pre_curation_s3_dir
     end
+
+    def notify_collection_curators(current_user)
+      curators = collection.administrators.map { |admin| "@#{admin.uid}" }.join(", ")
+      notification = "#{curators} The [work](#{work_path(self)}) is ready for review."
+      WorkActivity.add_system_activity(id, notification, current_user.id)
+    end
 end
 # rubocop:ensable Metrics/ClassLength

spec/models/work_spec.rb

@@ -548,6 +548,15 @@
     it "can not transition from awaiting_approval to draft" do
       expect { awaiting_approval_work.draft!(user) }.to raise_error AASM::InvalidTransition
     end
+
+    it "notifies the curators it is ready for review" do
+      curator = FactoryBot.create(:research_data_moderator)
+      expect { awaiting_approval_work }.to change { WorkActivity.where(activity_type: "SYSTEM").count }.by(2)
+      expect(WorkActivity.where(activity_type: "SYSTEM").last.message).to eq("marked as awaiting_approval")
+      curator_notification = WorkActivity.where(activity_type: "SYSTEM").first.message
+      expect(curator_notification).to include("@#{curator.uid}")
+      expect(curator_notification). to include(Rails.application.routes.url_helpers.work_path(awaiting_approval_work))
+    end
   end
 
   describe "#approve" do