Split subject symbols by policy

Splits this method by policy so it's easier to break out LUP into it's
own journey.

app/models/academic_year.rb

@@ -67,6 +67,12 @@ def for(date)
         new(date.year)
       end
     end
+
+    def wrap(value)
+      return value if value.is_a? AcademicYear
+
+      new(value)
+    end
   end
 
   def initialize(year_or_academic_year_or_string = nil)

app/models/policies/early_career_payments.rb

@@ -109,5 +109,30 @@ def payment_and_deductions_info_url
     def auto_check_student_loan_plan_task?
       true
     end
+
+    def subject_symbols(claim_year:, itt_year:)
+      case AcademicYear.wrap(claim_year)
+      when AcademicYear.new(2022), AcademicYear.new(2024)
+        case AcademicYear.wrap(itt_year)
+        when AcademicYear.new(2019)
+          [:mathematics]
+        when AcademicYear.new(2020)
+          [:chemistry, :foreign_languages, :mathematics, :physics]
+        else
+          []
+        end
+      when AcademicYear.new(2023)
+        case AcademicYear.wrap(itt_year)
+        when AcademicYear.new(2018)
+          [:mathematics]
+        when AcademicYear.new(2020)
+          [:chemistry, :foreign_languages, :mathematics, :physics]
+        else
+          []
+        end
+      else
+        []
+      end
+    end
   end
 end

app/models/policies/levelling_up_premium_payments.rb

@@ -99,5 +99,17 @@ def payroll_file_name
     def auto_check_student_loan_plan_task?
       true
     end
+
+    def subject_symbols(claim_year:, itt_year:)
+      return [] unless (POLICY_START_YEAR..POLICY_END_YEAR).cover?(claim_year)
+
+      previous_five_years = (claim_year - 5)...claim_year
+
+      if previous_five_years.cover?(itt_year)
+        [:chemistry, :computing, :mathematics, :physics]
+      else
+        []
+      end
+    end
   end
 end

lib/journey_subject_eligibility_checker.rb

@@ -115,45 +115,6 @@ def none_of_the_above?(itt_year)
   def subject_symbols(policy:, claim_year:, itt_year:)
     raise "Unsupported policy: #{policy}" unless policy.in?(Journeys::AdditionalPaymentsForTeaching::POLICIES)
 
-    case policy
-    when Policies::EarlyCareerPayments
-      year = claim_year.is_a?(AcademicYear) ? claim_year : AcademicYear.new(claim_year)
-      case year
-      when AcademicYear.new(2022), AcademicYear.new(2024)
-        case itt_year
-        when AcademicYear.new(2019)
-          [:mathematics]
-        when AcademicYear.new(2020)
-          [:chemistry, :foreign_languages, :mathematics, :physics]
-        else
-          []
-        end
-      when AcademicYear.new(2023)
-        case itt_year
-        when AcademicYear.new(2018)
-          [:mathematics]
-        when AcademicYear.new(2020)
-          [:chemistry, :foreign_languages, :mathematics, :physics]
-        else
-          []
-        end
-      else
-        []
-      end
-    when Policies::LevellingUpPremiumPayments
-      case claim_year
-      when EligibilityCheckable::COMBINED_ECP_AND_LUP_POLICY_YEARS
-        year = itt_year.is_a?(AcademicYear) ? itt_year : AcademicYear.new(itt_year)
-
-        case year
-        when (claim_year - 5)...claim_year
-          [:chemistry, :computing, :mathematics, :physics]
-        else
-          []
-        end
-      else
-        []
-      end
-    end
+    policy.subject_symbols(claim_year: claim_year, itt_year: itt_year)
   end
 end