Show MMR 2nd dose delay hint only after 1st dose administered

Previously, the hint text about when the 2nd MMR dose is due was shown
even when triaging patients who hadn't received their 1st dose yet.

Now, the hint only displays when the patient has already been vaccinated
with their 1st dose, making the message contextually relevant and
preventing confusion during triage delays for unvaccinated patients.

Author: jhenderson

app/components/app_triage_form_component.rb

@@ -19,11 +19,7 @@ def initialize(form, url:, method: :post, heading: true, continue: false)
   def builder = GOVUKDesignSystemFormBuilder::FormBuilder
 
   def hint_text
-    if programme.mmr? &&
-         !patient.vaccination_status(
-           programme:,
-           academic_year: session.academic_year
-         ).vaccinated?
+    if programme.mmr? && patient_eligible_for_additional_dose?
       "2nd dose is not due until #{form.next_mmr_dose_date.to_fs(:long)}"
     else
       "For example, #{hint_date.to_fs(:long)} "
@@ -54,4 +50,14 @@ def fieldset_options
       { legend: { text: }, hint: { text: hint } }
     end
   end
+
+  def patient_eligible_for_additional_dose?
+    next_dose =
+      patient.vaccination_status(
+        programme: programme,
+        academic_year: session.academic_year
+      ).dose_sequence
+
+    next_dose == programme.maximum_dose_sequence
+  end
 end

spec/components/app_triage_form_component_spec.rb

@@ -118,4 +118,28 @@
       expect(rendered).not_to have_text("The parent has consented to")
     end
   end
+
+  context "hint text for delayed triage when programme is MMR" do
+    context "when the patient has not received any dose" do
+      let(:programme) { create(:programme, :mmr) }
+
+      it "doesn't show the specific hint text about the 2nd dose" do
+        expect(rendered).not_to have_text("2nd dose is not due until")
+      end
+    end
+
+    context "when the patient has received the 1st dose" do
+      let(:programme) { create(:programme, :mmr) }
+
+      before do
+        create(:vaccination_record, patient:, programme:, session:)
+
+        StatusUpdater.call(patient:)
+      end
+
+      it "doesn't show the specific hint text about the 2nd dose" do
+        expect(rendered).to have_text("2nd dose is not due until")
+      end
+    end
+  end
 end