CLDC-2163 add validations on whether buyers are living in the property (#1512)

* add several methods to the sales log to allow subsequent work to be human readable

* add a validation to prevent an inconsistent combination of values and tests for this validation

* handle derivation of values around buyers living in the property
- derive values where appropriate
- clear these values when the derived state no longer holds
- update the routing for pages holding questions about whether particular buyers will live in the property to reflect when they are derived
- test the deriving and associated clearing of values
- update tests on page routing and sales log factory

* update a page routing condition for human readability using an existing method and update test to reflect this change

* show related method in diff

* minor amendments after tech review

* simplify reset_derived_questions after tech review

* refactor on deriving and clearing invalid derived values on sales log

* correct linter complaints

* remove comment

* add validation to one more field with a new error message as it is in fact possible to tirgger the validation in the setup section

app/models/derived_variables/sales_log_variables.rb

@@ -1,5 +1,7 @@
 module DerivedVariables::SalesLogVariables
   def set_derived_fields!
+    reset_invalidated_derived_values!
+
     self.ethnic = 17 if ethnic_refused?
     self.mscharge = nil if no_monthly_leasehold_charges?
     if exdate.present?
@@ -13,9 +15,6 @@ module DerivedVariables::SalesLogVariables
       self.hoyear = hodate.year
     end
     self.deposit = value if outright_sale? && mortgage_not_used?
-    if mortgage_not_used?
-      self.mortgage = 0
-    end
     self.pcode1, self.pcode2 = postcode_full.split(" ") if postcode_full.present?
     self.totchild = total_child
     self.totadult = total_adult + total_elder
@@ -30,10 +29,74 @@ module DerivedVariables::SalesLogVariables
       self.uprn = nil
       self.uprn_known = 0
     end
+
+    set_encoded_derived_values!
   end
 
 private
 
+  DEPENDENCIES = [
+    {
+      conditions: {
+        buylivein: 2,
+      },
+      derived_values: {
+        buy1livein: 2,
+      },
+    },
+    {
+      conditions: {
+        buylivein: 2,
+        jointpur: 1,
+      },
+      derived_values: {
+        buy1livein: 2,
+        buy2livein: 2,
+      },
+    },
+    {
+      conditions: {
+        buylivein: 1,
+        jointpur: 2,
+      },
+      derived_values: {
+        buy1livein: 1,
+      },
+    },
+    {
+      conditions: {
+        mortgageused: 2,
+      },
+      derived_values: {
+        mortgage: 0,
+      },
+    },
+  ].freeze
+
+  def reset_invalidated_derived_values!
+    DEPENDENCIES.each do |dependency|
+      any_conditions_changed = dependency[:conditions].any? { |attribute, _value| send("#{attribute}_changed?") }
+      next unless any_conditions_changed
+
+      previously_in_derived_state = dependency[:conditions].all? { |attribute, value| send("#{attribute}_was") == value }
+      next unless previously_in_derived_state
+
+      dependency[:derived_values].each do |derived_attribute, _derived_value|
+        Rails.logger.debug("Cleared derived #{derived_attribute} value")
+        send("#{derived_attribute}=", nil)
+      end
+    end
+  end
+
+  def set_encoded_derived_values!
+    DEPENDENCIES.each do |dependency|
+      derivation_applies = dependency[:conditions].all? { |attribute, value| send(attribute) == value }
+      if derivation_applies
+        dependency[:derived_values].each { |attribute, value| send("#{attribute}=", value) }
+      end
+    end
+  end
+
   def number_of_household_members
     return unless hholdcount.present? && jointpur.present?
 

app/models/form/sales/pages/buyer1_live_in_property.rb

@@ -5,9 +5,21 @@ class Form::Sales::Pages::Buyer1LiveInProperty < ::Form::Page
     @depends_on = [
       {
         "buyer_has_seen_privacy_notice?" => true,
+        "outright_sale?" => false,
       },
       {
         "buyer_not_interviewed?" => true,
+        "outright_sale?" => false,
+      },
+      {
+        "buyer_has_seen_privacy_notice?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
+      },
+      {
+        "buyer_not_interviewed?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
       },
     ]
   end

app/models/form/sales/pages/buyer2_live_in_property.rb

@@ -4,12 +4,24 @@ class Form::Sales::Pages::Buyer2LiveInProperty < ::Form::Page
     @id = "buyer_2_live_in_property"
     @depends_on = [
       {
-        "joint_purchase?" => true,
         "buyer_has_seen_privacy_notice?" => true,
+        "outright_sale?" => false,
+        "joint_purchase?" => true,
+      },
+      {
+        "buyer_not_interviewed?" => true,
+        "outright_sale?" => false,
+        "joint_purchase?" => true,
       },
       {
+        "buyer_has_seen_privacy_notice?" => true,
         "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
+      },
+      {
         "buyer_not_interviewed?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
       },
     ]
   end

app/models/form/sales/pages/buyer_company.rb

@@ -3,7 +3,7 @@ class Form::Sales::Pages::BuyerCompany < ::Form::Page
     super
     @id = "buyer_company"
     @depends_on = [{
-      "ownershipsch" => 3,
+      "outright_sale?" => true,
     }]
   end
 

app/models/sales_log.rb

@@ -26,7 +26,6 @@ class SalesLog < Log
 
   validates_with SalesLogValidator
   before_validation :recalculate_start_year!, if: :saledate_changed?
-  before_validation :reset_invalidated_dependent_fields!
   before_validation :process_postcode_changes!, if: :postcode_full_changed?
   before_validation :process_previous_postcode_changes!, if: :ppostcode_full_changed?
   before_validation :reset_location_fields!, unless: :postcode_known?
@@ -161,10 +160,26 @@ class SalesLog < Log
     inc1mort == 1
   end
 
+  def buyers_will_live_in?
+    buylivein == 1
+  end
+
+  def buyers_will_not_live_in?
+    buylivein == 2
+  end
+
   def buyer_two_will_live_in_property?
     buy2livein == 1
   end
 
+  def buyer_two_will_not_live_in_property?
+    buy2livein == 2
+  end
+
+  def buyer_one_will_not_live_in_property?
+    buy1livein == 2
+  end
+
   def buyer_two_not_already_living_in_property?
     buy2living == 2
   end
@@ -352,12 +367,9 @@ class SalesLog < Log
 
   def ownership_scheme
     case ownershipsch
-    when 1
+    when 1 then "shared ownership"
-      "shared ownership"
+    when 2 then "discounted ownership"
-    when 2
+    when 3 then "outright sale"
-      "discounted ownership"
-    when 3
-      "outright sale"
     end
   end
 end

app/models/validations/sales/household_validations.rb

@@ -20,6 +20,16 @@ module Validations::Sales::HouseholdValidations
     end
   end
 
+  def validate_buyers_living_in_property(record)
+    return unless record.form.start_date.year >= 2023
+
+    if record.buyers_will_live_in? && record.buyer_one_will_not_live_in_property? && record.buyer_two_will_not_live_in_property?
+      record.errors.add :buylivein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent_setup")
+      record.errors.add :buy1livein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
+      record.errors.add :buy2livein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
+    end
+  end
+
 private
 
   def validate_person_age_matches_relationship(record, person_num)

config/locales/en.yml

@@ -442,6 +442,9 @@ en:
         no_choices: "You cannot answer this question as you told us nobody in the household has a physical or mental health condition (or other illness) expected to last 12 months or more"
       postcode:
         discounted_ownership: "Last settled accommodation and discounted ownership property postcodes must match"
+      buylivein:
+        buyers_will_live_in_property_values_inconsistent_setup: "You have already told us that both buyer 1 and buyer 2 will not live in the property"
+        buyers_will_live_in_property_values_inconsistent: "You have already told us that the buyers will live in the property. Either buyer 1 or buyer 2 must live in the property"
 
     tenancy:
       length:

spec/models/form/sales/pages/buyer1_live_in_property_spec.rb

@@ -28,6 +28,25 @@ RSpec.describe Form::Sales::Pages::Buyer1LiveInProperty, type: :model do
   end
 
   it "has correct depends_on" do
-    expect(page.depends_on).to eq([{ "buyer_has_seen_privacy_notice?" => true }, { "buyer_not_interviewed?" => true }])
+    expect(page.depends_on).to eq([
+      {
+        "buyer_has_seen_privacy_notice?" => true,
+        "outright_sale?" => false,
+      },
+      {
+        "buyer_not_interviewed?" => true,
+        "outright_sale?" => false,
+      },
+      {
+        "buyer_has_seen_privacy_notice?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
+      },
+      {
+        "buyer_not_interviewed?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
+      },
+    ])
   end
 end

spec/models/form/sales/pages/buyer2_live_in_property_spec.rb

@@ -30,12 +30,24 @@ RSpec.describe Form::Sales::Pages::Buyer2LiveInProperty, type: :model do
   it "has correct depends_on" do
     expect(page.depends_on).to eq([
       {
-        "joint_purchase?" => true,
         "buyer_has_seen_privacy_notice?" => true,
+        "outright_sale?" => false,
+        "joint_purchase?" => true,
+      },
+      {
+        "buyer_not_interviewed?" => true,
+        "outright_sale?" => false,
+        "joint_purchase?" => true,
       },
       {
+        "buyer_has_seen_privacy_notice?" => true,
         "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
+      },
+      {
         "buyer_not_interviewed?" => true,
+        "joint_purchase?" => true,
+        "buyers_will_live_in?" => true,
       },
     ])
   end

spec/models/form/sales/pages/buyer_company_spec.rb

@@ -28,8 +28,6 @@ RSpec.describe Form::Sales::Pages::BuyerCompany, type: :model do
   end
 
   it "has correct depends_on" do
-    expect(page.depends_on).to eq([{
+    expect(page.depends_on).to eq([{ "outright_sale?" => true }])
-      "ownershipsch" => 3,
-    }])
   end
 end

spec/models/sales_log_spec.rb

@@ -220,6 +220,70 @@ RSpec.describe SalesLog, type: :model do
       record_from_db = ActiveRecord::Base.connection.execute("select mortgage from sales_logs where id=#{sales_log.id}").to_a[0]
       expect(record_from_db["mortgage"]).to eq(0.0)
     end
+
+    it "clears mortgage value if mortgage used is changed from no to yes" do
+      # to avoid log failing validations when mortgage value is removed:
+      new_grant_value = sales_log.grant + sales_log.mortgage
+      sales_log.update!(mortgageused: 2, grant: new_grant_value)
+      sales_log.update!(mortgageused: 1)
+      record_from_db = ActiveRecord::Base.connection.execute("select mortgage from sales_logs where id=#{sales_log.id}").to_a[0]
+      expect(record_from_db["mortgage"]).to eq(nil)
+    end
+
+    context "when outright sale and buyers will live in the property" do
+      let(:sales_log) { create(:sales_log, :outright_sale_setup_complete, buylivein: 1, jointpur:) }
+
+      context "and the sale is not a joint purchase" do
+        let(:jointpur) { 2 }
+
+        it "derives that buyer 1 will live in the property" do
+          expect(sales_log.buy1livein).to be 1
+        end
+
+        it "does not derive a value for whether buyer 2 will live in the property" do
+          expect(sales_log.buy2livein).to be nil
+        end
+
+        it "clears that buyer 1 will live in the property if joint purchase is updated" do
+          sales_log.update!(jointpur: 1)
+          expect(sales_log.buy1livein).to be nil
+        end
+      end
+
+      context "and the sale is a joint purchase" do
+        let(:jointpur) { 1 }
+
+        it "does not derive values for whether buyer 1 or buyer 2 will live in the property" do
+          expect(sales_log.buy1livein).to be nil
+          expect(sales_log.buy2livein).to be nil
+        end
+      end
+    end
+
+    context "when outright sale and buyers will not live in the property" do
+      let(:sales_log) { create(:sales_log, :outright_sale_setup_complete, buylivein: 2, jointpur:) }
+
+      context "and the sale is not a joint purchase" do
+        let(:jointpur) { 2 }
+
+        it "derives that buyer 1 will not live in the property" do
+          expect(sales_log.buy1livein).to be 2
+        end
+
+        it "does not derive a value for whether buyer 2 will live in the property" do
+          expect(sales_log.buy2livein).to be nil
+        end
+      end
+
+      context "and the sale is a joint purchase" do
+        let(:jointpur) { 1 }
+
+        it "derives that neither buyer 1 nor buyer 2 will live in the property" do
+          expect(sales_log.buy1livein).to be 2
+          expect(sales_log.buy2livein).to be 2
+        end
+      end
+    end
   end
 
   context "when saving addresses" do

spec/models/validations/sales/household_validations_spec.rb

@@ -201,4 +201,61 @@ RSpec.describe Validations::Sales::HouseholdValidations do
       end
     end
   end
+
+  describe "validating fields about buyers living in the property" do
+    let(:sales_log) { FactoryBot.create(:sales_log, :outright_sale_setup_complete, noint: 1, companybuy: 2, buylivein:, jointpur:, jointmore:, buy1livein:) }
+
+    context "when buyers will live in the property and the sale is a joint purchase" do
+      let(:buylivein) { 1 }
+      let(:jointpur) { 1 }
+      let(:jointmore) { 2 }
+
+      context "and buyer one will live in the property" do
+        let(:buy1livein) { 1 }
+
+        it "does not add validations regardless of whether buyer two will live in the property" do
+          sales_log.buy2livein = 1
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+          sales_log.buy2livein = 2
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+        end
+      end
+
+      context "and buyer one will not live in the property" do
+        let(:buy1livein) { 2 }
+
+        it "does not add validations if buyer two will live in the property or if we do not yet know" do
+          sales_log.buy2livein = 1
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+          sales_log.buy2livein = nil
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+        end
+
+        it "triggers a validation if buyer two will also not live in the property" do
+          sales_log.buy2livein = 2
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors[:buylivein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent_setup")
+          expect(sales_log.errors[:buy2livein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
+          expect(sales_log.errors[:buy1livein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
+        end
+      end
+
+      context "and we don't know whether buyer one will live in the property" do
+        let(:buy1livein) { nil }
+
+        it "does not add validations regardless of whether buyer two will live in the property" do
+          sales_log.buy2livein = 1
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+          sales_log.buy2livein = 2
+          household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors).to be_empty
+        end
+      end
+    end
+  end
 end