class PlaidAccount::Liabilities::StudentLoanProcessor
  def initialize(plaid_account)
    @plaid_account = plaid_account
  end

  def process
    return unless student_loan_data.present?

    account.loan.update!(
      rate_type: "fixed",
      interest_rate: student_loan_data["interest_rate_percentage"],
      initial_balance: student_loan_data["origination_principal_amount"],
      term_months: term_months
    )
  end

  private
    attr_reader :plaid_account

    def account
      plaid_account.account
    end

    def term_months
      return nil unless origination_date && expected_payoff_date

      ((expected_payoff_date - origination_date).to_i / 30).to_i
    end

    def origination_date
      parse_date(student_loan_data["origination_date"])
    end

    def expected_payoff_date
      parse_date(student_loan_data["expected_payoff_date"])
    end

    def parse_date(value)
      return value if value.is_a?(Date)
      return nil unless value.present?

      Date.parse(value.to_s)
    rescue ArgumentError
      nil
    end

    def student_loan_data
      plaid_account.raw_liabilities_payload["student"]
    end
end