Refactor ready_for_vaccinator?

This removes the usage of `ready_for_vaccinator?` with a database query
on the registration status to avoid unnecessary queries to the database.

Author: thomasleese

app/components/app_session_actions_component.rb

@@ -119,7 +119,19 @@ def ready_for_vaccinator_row
 
     counts_by_programme =
       session.programmes.index_with do |programme|
-        patient_sessions.count { it.ready_for_vaccinator?(programme:) }
+        patient_sessions
+          .where(
+            PatientSession::RegistrationStatus
+              .for_patient_session
+              .where(status: %w[attending completed])
+              .arel
+              .exists
+          )
+          .count do |patient_session|
+            patient_session.patient.consent_given_and_safe_to_vaccinate?(
+              programme:
+            )
+          end
       end
 
     return nil if counts_by_programme.values.all?(&:zero?)

app/controllers/sessions/record_controller.rb

@@ -16,20 +16,30 @@ class Sessions::RecordController < ApplicationController
 
   def show
     scope =
-      @session.patient_sessions.preload_for_status.in_programmes(
-        @session.programmes
-      )
+      @session
+        .patient_sessions
+        .preload_for_status
+        .in_programmes(@session.programmes)
+        .where(
+          PatientSession::RegistrationStatus
+            .for_patient_session
+            .where(status: %w[attending completed])
+            .arel
+            .exists
+        )
+
+    scope = @form.apply(scope)
 
     patient_sessions =
-      @form.apply(scope) do |filtered_scope|
-        filtered_scope.select { it.ready_for_vaccinator? }
+      scope.select do |patient_session|
+        patient_session.programmes.any? do |programme|
+          patient_session.patient.consent_given_and_safe_to_vaccinate?(
+            programme:
+          )
+        end
       end
 
-    if patient_sessions.is_a?(Array)
-      @pagy, @patient_sessions = pagy_array(patient_sessions)
-    else
-      @pagy, @patient_sessions = pagy(patient_sessions)
-    end
+    @pagy, @patient_sessions = pagy_array(patient_sessions)
 
     render layout: "full"
   end

app/forms/search_form.rb

@@ -40,10 +40,6 @@ def apply(scope, programme: nil)
 
     scope = scope.search_by_nhs_number(nil) if missing_nhs_number.present?
 
-    scope = scope.order_by_name
-
-    scope = yield(scope) if block_given?
-
     if (status = consent_status).present?
       scope =
         scope.where(
@@ -91,6 +87,6 @@ def apply(scope, programme: nil)
         )
     end
 
-    scope
+    scope.order_by_name
   end
 end

app/models/patient_session.rb

@@ -148,19 +148,6 @@ def todays_attendance
     end
   end
 
-  def ready_for_vaccinator?(programme: nil)
-    if registration_status.nil? || registration_status.unknown? ||
-         registration_status.not_attending?
-      return false
-    end
-
-    programmes_to_check = programme ? [programme] : programmes
-
-    programmes_to_check.any? do
-      patient.consent_given_and_safe_to_vaccinate?(programme: it)
-    end
-  end
-
   def next_activity(programme:)
     return :report if patient.vaccination_status(programme:).vaccinated?
 
@@ -176,6 +163,11 @@ def next_activity(programme:)
   end
 
   def outstanding_programmes
+    if registration_status.nil? || registration_status.unknown? ||
+         registration_status.not_attending?
+      return []
+    end
+
     # If this patient hasn't been seen yet by a nurse for any of the programmes,
     # we don't want to show the banner.
     all_programmes_none_yet =
@@ -185,7 +177,7 @@ def outstanding_programmes
 
     programmes.select do |programme|
       vaccination_status(programme:).none_yet? &&
-        ready_for_vaccinator?(programme:)
+        patient.consent_given_and_safe_to_vaccinate?(programme:)
     end
   end
 end

spec/models/patient_session_spec.rb

@@ -69,47 +69,6 @@
     end
   end
 
-  describe "#ready_for_vaccinator?" do
-    subject(:ready_for_vaccinator?) { patient_session.ready_for_vaccinator? }
-
-    it { should be(false) }
-
-    context "when attending the session" do
-      let(:patient_session) do
-        create(:patient_session, :in_attendance, session:)
-      end
-
-      it { should be(false) }
-    end
-
-    context "when attending the session and consent given and triaged as safe to vaccinate" do
-      let(:patient_session) do
-        create(
-          :patient_session,
-          :in_attendance,
-          :consent_given_triage_not_needed,
-          session:
-        )
-      end
-
-      it { should be(true) }
-
-      context "when already vaccinated" do
-        let(:patient_session) do
-          create(
-            :patient_session,
-            :in_attendance,
-            :consent_given_triage_not_needed,
-            :vaccinated,
-            session:
-          )
-        end
-
-        it { should be(false) }
-      end
-    end
-  end
-
   describe "#next_activity" do
     subject { patient_session.next_activity(programme:) }