gistfile1.rb

module StaticInstructions::Meta
  class BasicFederalTax < Base
    include PayPeriods

    def calculate(result)
      tr = TaxRates.new(result.annual_taxable_income)
      zero_or_positive tr.rate * result.annual_taxable_income - tr.constant - k1 - k2(result) - k3 - k4(result)
    end

    def k4(result)
      [bd(0.15) * result.annual_taxable_income, bd(0.15) * bd(1_117)].min
    end

    def k3
      0
    end

    def k2(result)
      bd(0.15) * [pay_periods * result.canada_pension_plan, bd(2_356.20)].min
      + bd(0.15) * [pay_periods * result.employment_insurance, bd(891.12)].min
    end

    def k1
      employee.td1_form.total_claim * 0.15
    end

    def calculation_dependencies
      [ :annual_taxable_income, :canada_pension_plan, :employment_insurance ]
    end
  end
end