Add cancel method to DispositionTask (#9823)

Resolves #9539

### Description
Adds a `cancel!` method to the `DispositionTask` that makes required changes on parent `HearingTask` and associated legacy/ama appeal.

app/models/tasks/disposition_task.rb

@@ -7,7 +7,10 @@
 # The task is marked complete when these children tasks are completed.
 class DispositionTask < GenericTask
   before_create :check_parent_type
+  after_update :update_appeal_location_after_cancel, if: :task_just_canceled_and_has_legacy_appeal?
+  after_update :create_ihp_tasks_after_cancel, if: :task_just_canceled_and_has_ama_appeal?
 
+  class HearingDispositionNotCanceled < StandardError; end
   class HearingDispositionNotNoShow < StandardError; end
 
   class << self
@@ -32,8 +35,16 @@ def check_parent_type
     end
   end
 
+  def cancel!
+    if hearing_disposition != Constants.HEARING_DISPOSITION_TYPES.cancelled
+      fail HearingDispositionNotCanceled
+    end
+
+    update!(status: Constants.TASK_STATUSES.cancelled)
+  end
+
   def mark_no_show!
-    if parent&.hearing_task_association&.hearing&.disposition != Constants.HEARING_DISPOSITION_TYPES.no_show
+    if hearing_disposition != Constants.HEARING_DISPOSITION_TYPES.no_show
       fail HearingDispositionNotNoShow
     end
 
@@ -48,4 +59,36 @@ def mark_no_show!
       on_hold_duration: 25.days
     )
   end
+
+  private
+
+  def task_just_canceled?
+    saved_change_to_attribute?("status") && cancelled?
+  end
+
+  def task_just_canceled_and_has_legacy_appeal?
+    task_just_canceled? && appeal.is_a?(LegacyAppeal)
+  end
+
+  def task_just_canceled_and_has_ama_appeal?
+    task_just_canceled? && appeal.is_a?(Appeal)
+  end
+
+  def create_ihp_tasks_after_cancel
+    RootTask.create_ihp_tasks!(appeal, parent)
+  end
+
+  def update_appeal_location_after_cancel
+    location = if appeal.vsos.empty?
+                 LegacyAppeal::LOCATION_CODES[:case_storage]
+               else
+                 LegacyAppeal::LOCATION_CODES[:service_organization]
+               end
+
+    AppealRepository.update_location!(appeal, location)
+  end
+
+  def hearing_disposition
+    parent&.hearing_task_association&.hearing&.disposition
+  end
 end

app/models/tasks/hearing_task.rb

@@ -7,4 +7,14 @@
 
 class HearingTask < GenericTask
   has_one :hearing_task_association
+
+  private
+
+  def update_status_if_children_tasks_are_complete
+    if children.select(&:active?).empty?
+      return update!(status: :cancelled) if children.select { |c| c.type == DispositionTask.name && c.cancelled? }.any?
+    end
+
+    super
+  end
 end

spec/models/tasks/disposition_task_spec.rb

@@ -36,6 +36,140 @@
     end
   end
 
+  describe ".cancel!" do
+    let(:disposition) { nil }
+    let(:appeal) { FactoryBot.create(:appeal) }
+    let(:root_task) { FactoryBot.create(:root_task, appeal: appeal) }
+    let(:hearing_task) { FactoryBot.create(:hearing_task, parent: root_task, appeal: appeal) }
+    let(:hearing) { FactoryBot.create(:hearing, appeal: appeal, disposition: disposition) }
+    let!(:hearing_task_association) do
+      FactoryBot.create(
+        :hearing_task_association,
+        hearing: hearing,
+        hearing_task: hearing_task
+      )
+    end
+    let!(:schedule_hearing_task) do
+      FactoryBot.create(
+        :schedule_hearing_task,
+        parent: hearing_task,
+        appeal: appeal,
+        assigned_to: HearingsManagement.singleton,
+        status: Constants.TASK_STATUSES.completed
+      )
+    end
+    let!(:disposition_task) do
+      FactoryBot.create(
+        :ama_disposition_task,
+        parent: hearing_task,
+        appeal: appeal,
+        status: Constants.TASK_STATUSES.in_progress
+      )
+    end
+
+    subject { disposition_task.cancel! }
+
+    context "the appeal is an AMA appeal" do
+      context "the task's hearing's disposition is canceled" do
+        let(:disposition) { Constants.HEARING_DISPOSITION_TYPES.cancelled }
+
+        it "cancels the disposition task and its parent hearing task" do
+          expect(disposition_task.cancelled?).to be_falsey
+          expect(hearing_task.on_hold?).to be_truthy
+
+          expect { subject }.to_not raise_error
+
+          expect(disposition_task.cancelled?).to be_truthy
+          expect(hearing_task.cancelled?).to be_truthy
+          expect(InformalHearingPresentationTask.where(appeal: appeal).length).to eq 0
+        end
+
+        context "the appeal has a VSO" do
+          let(:participant_id_with_pva) { "000000" }
+          let(:appeal) do
+            create(:appeal, claimants: [create(:claimant, participant_id: participant_id_with_pva)])
+          end
+
+          before do
+            Vso.create(
+              name: "Paralyzed Veterans Of America",
+              role: "VSO",
+              url: "paralyzed-veterans-of-america",
+              participant_id: "2452383"
+            )
+
+            allow_any_instance_of(BGSService).to receive(:fetch_poas_by_participant_ids)
+              .with([participant_id_with_pva]).and_return(
+                participant_id_with_pva => {
+                  representative_name: "PARALYZED VETERANS OF AMERICA, INC.",
+                  representative_type: "POA National Organization",
+                  participant_id: "2452383"
+                }
+              )
+          end
+
+          it "creates an IHP task" do
+            expect(InformalHearingPresentationTask.where(appeal: appeal).length).to eq 0
+
+            subject
+
+            expect(InformalHearingPresentationTask.where(appeal: appeal).length).to eq 1
+          end
+        end
+      end
+
+      context "the task's hearing's disposition is not canceled" do
+        let(:disposition) { Constants.HEARING_DISPOSITION_TYPES.postponed }
+
+        it "raises an error" do
+          expect(disposition_task.cancelled?).to be_falsey
+          expect { subject }.to raise_error(DispositionTask::HearingDispositionNotCanceled)
+          expect(disposition_task.cancelled?).to be_falsey
+        end
+      end
+    end
+
+    context "the appeal is a legacy appeal" do
+      let(:vacols_case) { FactoryBot.create(:case, bfcurloc: LegacyAppeal::LOCATION_CODES[:schedule_hearing]) }
+      let(:appeal) { create(:legacy_appeal, vacols_case: vacols_case) }
+      let(:hearing) { create(:legacy_hearing, appeal: appeal, disposition: disposition) }
+      let(:disposition) { Constants.HEARING_DISPOSITION_TYPES.cancelled }
+
+      context "there's no associated VSO" do
+        it "updates the case location to case storage (81)" do
+          subject
+
+          expect(vacols_case.reload.bfcurloc).to eq(LegacyAppeal::LOCATION_CODES[:case_storage])
+        end
+      end
+
+      context "there is an associated VSO" do
+        let(:participant_id) { "1234" }
+        let!(:vso) { create(:vso, name: "Gogozim", participant_id: participant_id) }
+
+        before do
+          allow(BGSService).to receive(:power_of_attorney_records).and_return(
+            appeal.veteran_file_number => {
+              file_number: appeal.veteran_file_number,
+              power_of_attorney: {
+                legacy_poa_cd: "3QQ",
+                nm: "Clarence Darrow",
+                org_type_nm: "POA Attorney",
+                ptcpnt_id: participant_id
+              }
+            }
+          )
+        end
+
+        it "updates the case location to service organization (55)" do
+          subject
+
+          expect(vacols_case.reload.bfcurloc).to eq(LegacyAppeal::LOCATION_CODES[:service_organization])
+        end
+      end
+    end
+  end
+
   describe ".mark_no_show!" do
     let(:disposition) { nil }
     let(:appeal) { FactoryBot.create(:appeal) }