Add more metadata when tracking PDF share event

We need to track a few fields in order to give us metrics on how mayn
accounts are linked, as well as the number of paystubs and account
descriptions.

This logic gets me worried for bugs, since it's in a critical place, so
I'm putting it in a rescue block so it doesn't break the sending of the
actual documents.

app/app/controllers/cbv/summaries_controller.rb

@@ -74,11 +74,21 @@ def transmit_to_caseworker
       @cbv_flow.touch(:transmitted_at)
     end
 
+    track_transmitted_event(@cbv_flow, @payments)
+  end
+
+  def track_transmitted_event(cbv_flow, payments)
     NewRelicEventTracker.track("IncomeSummarySharedWithCaseworker", {
       timestamp: Time.now.to_i,
-      site_id: @cbv_flow.site_id,
-      cbv_flow_id: @cbv_flow.id
+      site_id: cbv_flow.site_id,
+      cbv_flow_id: cbv_flow.id,
+      account_count: payments.map { |p| p[:account_id] }.uniq.count,
+      paystub_count: payments.count,
+      account_count_with_additional_information:
+        cbv_flow.additional_information.values.count { |info| info["comment"].present? }
     })
+  rescue => ex
+    Rails.logger.error "Failed to track NewRelic event: #{ex.message}"
   end
 
   def generate_confirmation_code(prefix = nil)

app/spec/controllers/cbv/summaries_controller_spec.rb

@@ -140,6 +140,19 @@
         patch :update
         expect(response).to redirect_to({ controller: :successes, action: :show })
       end
+
+      it "sends a NewRelic event" do
+        allow(NewRelicEventTracker).to receive(:track)
+        patch :update
+        expect(NewRelicEventTracker).to have_received(:track).with("IncomeSummarySharedWithCaseworker", {
+          timestamp: be_a(Integer),
+          site_id: cbv_flow.site_id,
+          cbv_flow_id: cbv_flow.id,
+          account_count: 1,
+          paystub_count: 1,
+          account_count_with_additional_information: 0
+        })
+      end
     end
   end
 end