Relax validation on ChangeSchedule service for certain participants

app/models/participant_profile/ecf.rb

@@ -53,9 +53,11 @@ def self.ransackable_associations(_auth_object = nil)
     %w[cohort participant_identity school user teacher_profile induction_records]
   end
 
-  def self.eligible_to_change_cohort_and_continue_training(restrict_to_participant_ids: [])
+  def self.eligible_to_change_cohort_and_continue_training(cohort:, restrict_to_participant_ids: [])
     billable_states = %w[eligible payable paid].freeze
 
+    return none unless cohort == Cohort.active_registration_cohort
+
     completed_billable_declarations = ParticipantDeclaration.billable.for_declaration(:completed)
     completed_billable_declarations = completed_billable_declarations.where(participant_profile_id: restrict_to_participant_ids) if restrict_to_participant_ids.any?
 
@@ -70,6 +72,14 @@ def self.eligible_to_change_cohort_and_continue_training(restrict_to_participant
     query
   end
 
+  def eligible_to_change_cohort_back_to_their_payments_frozen_original?(cohort:, current_cohort:)
+    return false unless cohort_changed_after_payments_frozen?
+    return false unless cohort.payments_frozen?
+    return false if participant_declarations.billable_or_changeable.where(cohort: current_cohort).exists?
+
+    participant_declarations.billable.where(cohort:).exists?
+  end
+
   def self.archivable(restrict_to_participant_ids: [])
     unbillable_states = %i[ineligible voided submitted].freeze
 
@@ -92,8 +102,8 @@ def self.archivable(restrict_to_participant_ids: [])
   end
 
   # Instance Methods
-  def eligible_to_change_cohort_and_continue_training?
-    self.class.eligible_to_change_cohort_and_continue_training(restrict_to_participant_ids: [id]).exists?
+  def eligible_to_change_cohort_and_continue_training?(cohort:)
+    self.class.eligible_to_change_cohort_and_continue_training(cohort:, restrict_to_participant_ids: [id]).exists?
   end
 
   def archivable?

app/models/participant_profile/ect.rb

@@ -28,7 +28,7 @@ def role
     "Early career teacher"
   end
 
-  def self.eligible_to_change_cohort_and_continue_training(restrict_to_participant_ids: [])
-    super(restrict_to_participant_ids:).where(induction_completion_date: nil)
+  def self.eligible_to_change_cohort_and_continue_training(cohort:, restrict_to_participant_ids: [])
+    super(cohort:, restrict_to_participant_ids:).where(induction_completion_date: nil)
   end
 end

app/models/participant_profile/mentor.rb

@@ -49,7 +49,7 @@ def role
     "Mentor"
   end
 
-  def self.eligible_to_change_cohort_and_continue_training(restrict_to_participant_ids: [])
-    super(restrict_to_participant_ids:).where(mentor_completion_date: nil)
+  def self.eligible_to_change_cohort_and_continue_training(cohort:, restrict_to_participant_ids: [])
+    super(cohort:, restrict_to_participant_ids:).where(mentor_completion_date: nil)
   end
 end

app/services/change_schedule.rb

@@ -9,6 +9,7 @@ class ChangeSchedule
   attribute :course_identifier
   attribute :schedule_identifier
   attribute :cohort, :integer
+  attribute :allow_change_to_from_frozen_cohort, :boolean, default: false
 
   delegate :participant_profile_state, to: :participant_profile, allow_nil: true
   delegate :lead_provider, to: :cpd_lead_provider, allow_nil: true
@@ -80,6 +81,14 @@ def cohort
 
 private
 
+  def changing_cohort_due_to_payments_frozen?
+    return false unless participant_profile.ecf?
+    return false unless allow_change_to_from_frozen_cohort
+    return true if participant_profile.eligible_to_change_cohort_and_continue_training?(cohort:)
+
+    participant_profile.eligible_to_change_cohort_back_to_their_payments_frozen_original?(cohort:, current_cohort:)
+  end
+
   def user
     @user ||= participant_identity&.user
   end
@@ -114,6 +123,18 @@ def update_school_cohort_and_schedule!
     participant_profile.update!(school_cohort: target_school_cohort, schedule: new_schedule)
   end
 
+  def update_cohort_changed_after_payments_frozen!
+    changing_cohort = current_cohort.start_year != cohort&.start_year
+
+    if changing_cohort && changing_cohort_due_to_payments_frozen?
+      participant_profile.toggle(:cohort_changed_after_payments_frozen).save!
+    end
+  end
+
+  def current_cohort
+    relevant_induction_record.schedule.cohort
+  end
+
   def update_induction_records!
     return unless relevant_induction_record
 
@@ -129,6 +150,7 @@ def update_induction_records!
   def update_ecf_records!
     return unless participant_profile&.ecf?
 
+    update_cohort_changed_after_payments_frozen!
     update_school_cohort_and_schedule!
     update_induction_records!
   end
@@ -191,6 +213,7 @@ def not_already_withdrawn
   def validate_new_schedule_valid_with_existing_declarations
     return if user.blank? || participant_profile.blank?
     return unless new_schedule
+    return if changing_cohort_due_to_payments_frozen?
 
     applicable_declarations.each do |declaration|
       milestone = new_schedule.milestones.find_by!(declaration_type: declaration.declaration_type)
@@ -220,10 +243,11 @@ def validate_permitted_schedule_for_course
 
   def validate_cannot_change_cohort_ecf
     return unless participant_profile&.ecf?
+    return if changing_cohort_due_to_payments_frozen?
 
     if applicable_declarations.any? &&
         relevant_induction_record &&
-        relevant_induction_record.schedule.cohort.start_year != cohort&.start_year
+        current_cohort.start_year != cohort&.start_year
       errors.add(:cohort, I18n.t("cannot_change_cohort"))
     end
   end

spec/services/change_schedule_spec.rb

@@ -64,6 +64,90 @@
   end
 end
 
+RSpec.shared_examples "changing cohort and continuing training" do
+  %i[eligible payable paid].each do |state|
+    context "when there are #{state} declarations" do
+      let(:cohort) { new_cohort.previous }
+      let(:new_cohort) { Cohort.active_registration_cohort }
+
+      before { create(:participant_declaration, participant_profile:, cohort:, state:, course_identifier:, cpd_lead_provider:) }
+
+      it { expect(new_cohort).not_to eq(cohort) }
+
+      context "allow_change_to_from_frozen_cohort is true" do
+        let(:allow_change_to_from_frozen_cohort) { true }
+
+        context "when the participant is not eligible to transfer and continue training" do
+          it { is_expected.to be_invalid }
+        end
+
+        context "when the participant is eligible to transfer and continue training" do
+          before { cohort.update!(payments_frozen_at: Time.zone.now) }
+
+          it_behaves_like "changing the schedule of a participant"
+          it_behaves_like "reversing a change of schedule/cohort"
+
+          it { is_expected.to be_valid }
+          it { expect { service.call }.to change { participant_profile.reload.cohort_changed_after_payments_frozen }.to(true) }
+        end
+      end
+
+      context "when allow_change_to_from_frozen_cohort is false" do
+        let(:allow_change_to_from_frozen_cohort) { false }
+
+        context "when the participant is eligible to transfer and continue training" do
+          before { cohort.update!(payments_frozen_at: Time.zone.now) }
+
+          it { is_expected.to be_invalid }
+        end
+      end
+    end
+  end
+end
+
+RSpec.shared_examples "reversing a change of schedule/cohort" do
+  it "allows a change of schedule to be reversed" do
+    original_cohort = participant_profile.schedule.cohort
+
+    first_change_of_schedule = described_class.new(params)
+    expect(first_change_of_schedule).to be_valid
+    expect { first_change_of_schedule.call }.to change { ParticipantProfileSchedule.count }
+
+    second_change_of_schedule = described_class.new(params.merge({
+      cohort: original_cohort.start_year,
+    }))
+    expect(second_change_of_schedule).to be_valid
+    expect { second_change_of_schedule.call }.to change { ParticipantProfileSchedule.count }
+
+    expect(participant_profile.reload).not_to be_cohort_changed_after_payments_frozen
+  end
+
+  it "does not allow a change of schedule to be reversed if there are billable declarations in the new cohort" do
+    original_cohort = participant_profile.schedule.cohort
+
+    first_change_of_schedule = described_class.new(params)
+    expect(first_change_of_schedule).to be_valid
+    expect { first_change_of_schedule.call }.to change { ParticipantProfileSchedule.count }
+
+    second_change_of_schedule = described_class.new(params.merge({
+      cohort: original_cohort.start_year,
+    }))
+
+    travel_to(Date.new(new_cohort.start_year).end_of_year) do
+      create(:participant_declaration,
+             participant_profile: participant_profile.reload,
+             declaration_type: "retained-1",
+             state: :payable,
+             course_identifier:,
+             cpd_lead_provider:,
+             cohort: new_cohort)
+    end
+
+    expect(second_change_of_schedule).not_to be_valid
+    expect(second_change_of_schedule.errors.messages_for(:cohort)).to include("The property '#/cohort' cannot be changed")
+  end
+end
+
 RSpec.shared_examples "validating a participant is not already withdrawn for a change schedule" do
   it "is invalid and returns an error message" do
     is_expected.to be_invalid
@@ -122,6 +206,7 @@
       participant_id:,
       course_identifier:,
       schedule_identifier:,
+      allow_change_to_from_frozen_cohort:,
     }
   end
   let(:participant_identity) { create(:participant_identity) }
@@ -133,10 +218,12 @@
 
   context "ECT participant profile" do
     let(:cpd_lead_provider) { create(:cpd_lead_provider, :with_lead_provider) }
-    let(:participant_profile) { create(:ect, lead_provider: cpd_lead_provider.lead_provider, user:) }
+    let(:cohort) { Cohort.current }
+    let(:participant_profile) { create(:ect, lead_provider: cpd_lead_provider.lead_provider, user:, cohort:) }
     let(:schedule_identifier) { "ecf-standard-september" }
     let(:course_identifier) { "ecf-induction" }
-    let!(:schedule) { Finance::Schedule::ECF.find_by(schedule_identifier: "ecf-standard-september") }
+    let(:allow_change_to_from_frozen_cohort) { false }
+    let!(:schedule) { Finance::Schedule::ECF.find_by(schedule_identifier: "ecf-standard-september", cohort:) }
     let(:new_cohort) { Cohort.previous }
     let!(:new_schedule) { create(:ecf_schedule, cohort: new_cohort, schedule_identifier: "ecf-replacement-april") }
 
@@ -149,17 +236,20 @@
 
       context "when the cohort is changing" do
         let!(:new_schedule) { Finance::Schedule::ECF.find_by(schedule_identifier:, cohort: new_cohort) }
-        let!(:new_school_cohort) { create(:school_cohort, :cip, :with_induction_programme, cohort: new_cohort, lead_provider: cpd_lead_provider.lead_provider, school: participant_profile.school) }
+        let!(:new_school_cohort) { create(:school_cohort, :fip, :with_induction_programme, cohort: new_cohort, lead_provider: cpd_lead_provider.lead_provider, school: participant_profile.school) }
         let(:params) do
           {
             cpd_lead_provider:,
             participant_id:,
             course_identifier:,
             schedule_identifier:,
             cohort: new_cohort.start_year,
+            allow_change_to_from_frozen_cohort:,
           }
         end
 
+        it_behaves_like "reversing a change of schedule/cohort"
+
         %i[submitted eligible payable paid].each do |state|
           context "when there are #{state} declarations" do
             before { create(:participant_declaration, participant_profile:, state:, course_identifier:, cpd_lead_provider:) }
@@ -174,6 +264,10 @@
           end
         end
 
+        it_behaves_like "changing cohort and continuing training" do
+          let!(:new_schedule) { Finance::Schedule::ECF.find_by(cohort: new_cohort, schedule_identifier:) }
+        end
+
         context "when there are no submitted/eligible/payable/paid declarations" do
           context "when changing to another cohort" do
             describe ".call" do
@@ -298,6 +392,7 @@
             participant_id:,
             course_identifier:,
             schedule_identifier:,
+            allow_change_to_from_frozen_cohort:,
             cohort: new_cohort.start_year,
           }
         end
@@ -336,6 +431,7 @@
             participant_id:,
             course_identifier:,
             schedule_identifier: new_schedule.schedule_identifier,
+            allow_change_to_from_frozen_cohort:,
             cohort:,
           }
         end
@@ -381,11 +477,13 @@
 
   context "Mentor participant profile" do
     let(:cpd_lead_provider) { create(:cpd_lead_provider, :with_lead_provider) }
-    let!(:participant_profile) { create(:mentor, lead_provider: cpd_lead_provider.lead_provider, user:) }
+    let(:cohort) { Cohort.current }
+    let!(:participant_profile) { create(:mentor, lead_provider: cpd_lead_provider.lead_provider, user:, cohort:) }
     let(:schedule_identifier) { "ecf-extended-april" }
     let(:course_identifier) { "ecf-mentor" }
+    let(:allow_change_to_from_frozen_cohort) { false }
     let(:new_cohort) { Cohort.previous }
-    let!(:schedule) { create(:ecf_mentor_schedule, schedule_identifier: "ecf-extended-april") }
+    let!(:schedule) { create(:ecf_mentor_schedule, cohort:, schedule_identifier: "ecf-extended-april") }
 
     describe "validations" do
       it_behaves_like "validating a participant for a change schedule"
@@ -395,18 +493,21 @@
       end
 
       context "when the cohort is changing" do
-        let!(:new_school_cohort) { create(:school_cohort, :cip, :with_induction_programme, cohort: new_cohort, lead_provider: cpd_lead_provider.lead_provider, school: participant_profile.school) }
+        let!(:new_school_cohort) { create(:school_cohort, :fip, :with_induction_programme, cohort: new_cohort, lead_provider: cpd_lead_provider.lead_provider, school: participant_profile.school) }
         let!(:new_schedule) { create(:ecf_mentor_schedule, schedule_identifier:, cohort: new_cohort) }
         let(:params) do
           {
             cpd_lead_provider:,
             participant_id:,
             course_identifier:,
             schedule_identifier:,
+            allow_change_to_from_frozen_cohort:,
             cohort: new_cohort.start_year,
           }
         end
 
+        it_behaves_like "reversing a change of schedule/cohort"
+
         %i[submitted eligible payable paid].each do |state|
           context "when there are #{state} declarations" do
             before { create(:participant_declaration, participant_profile:, state:, course_identifier:, cpd_lead_provider:) }
@@ -421,6 +522,10 @@
           end
         end
 
+        it_behaves_like "changing cohort and continuing training" do
+          let!(:new_schedule) { create(:ecf_mentor_schedule, cohort: new_cohort, schedule_identifier:) }
+        end
+
         context "when there are no submitted/eligible/payable/paid declarations" do
           context "when changing to another cohort" do
             describe ".call" do
@@ -539,10 +644,12 @@
     let(:cpd_lead_provider) { create(:cpd_lead_provider, :with_npq_lead_provider) }
     let(:npq_lead_provider) { cpd_lead_provider.npq_lead_provider }
     let(:npq_course) { create(:npq_course, identifier: "npq-senior-leadership") }
-    let(:schedule) { Finance::Schedule::NPQ.find_by(cohort: Cohort.current, schedule_identifier: "npq-specialist-spring") }
-    let(:participant_profile) { create(:npq_participant_profile, npq_lead_provider:, npq_course:, schedule:, user:) }
+    let(:schedule) { Finance::Schedule::NPQ.find_by(cohort:, schedule_identifier: "npq-specialist-spring") }
+    let(:cohort) { Cohort.current }
+    let(:participant_profile) { create(:npq_participant_profile, npq_lead_provider:, npq_course:, schedule:, user:, cohort:) }
     let(:course_identifier) { npq_course.identifier }
     let(:schedule_identifier) { new_schedule.schedule_identifier }
+    let(:allow_change_to_from_frozen_cohort) { false }
     let(:new_cohort) { Cohort.previous }
     let(:new_schedule) { Finance::Schedule::NPQ.find_by(cohort: new_cohort, schedule_identifier: "npq-leadership-spring") }
     let!(:npq_contract) { create(:npq_contract, :npq_senior_leadership, npq_lead_provider:, npq_course:) }
@@ -564,9 +671,12 @@
             course_identifier:,
             schedule_identifier:,
             cohort: new_cohort.start_year,
+            allow_change_to_from_frozen_cohort:,
           }
         end
 
+        it_behaves_like "reversing a change of schedule/cohort"
+
         %i[submitted eligible payable paid].each do |state|
           context "when there are #{state} declarations" do
             before { create(:participant_declaration, participant_profile:, state:, course_identifier:, cpd_lead_provider:) }
@@ -583,6 +693,23 @@
           end
         end
 
+        %i[eligible payable paid].each do |state|
+          context "when there are #{state} declarations" do
+            let(:new_cohort) { Cohort.active_registration_cohort }
+            let!(:new_schedule) { create(:npq_leadership_schedule, cohort: new_cohort) }
+
+            before { create(:participant_declaration, participant_profile:, state:, course_identifier:, cpd_lead_provider:) }
+
+            context "allow_change_to_from_frozen_cohort is true" do
+              let(:allow_change_to_from_frozen_cohort) { true }
+
+              before { participant_profile.schedule.cohort.update!(payments_frozen_at: Time.zone.now) }
+
+              it { is_expected.not_to be_valid }
+            end
+          end
+        end
+
         context "when there are no submitted/eligible/payable/paid declarations" do
           context "when changing to another cohort" do
             let(:new_cohort) { Cohort.previous }