Cleanup Protocols/Objects that display or calculate totals

gistfile1.txt

// MARK: Refundable
protocol Refundable {
    var canBeRefunded: Bool { get }
    var isRefunded: Bool { get }
    var isARefund: Bool { get }
}

extension Bill: Refundable {
    var canBeRefunded: Bool {
        return isClosed && !isRefunded && !isARefund
    }
}

// MARK: OrderTotals
protocol OrderTotals {

    /// Amount the customer has to pay
    func totalAmountDue(whenPayingBy paymentType: PaymentType?) -> Int64

    /**
     Remaining amount the customer has to pay
     
     Calculation:
     ```
     totalOutstandingBalance = totalAmountPaid - totalAmountDue
     ````
     */
    func totalOutstandingBalance(whenPayingBy paymentType: PaymentType?) -> Int64

    /// Tips received
    var totalTips: Int64 { get }

    /// Total rounding adjustments made to the BillEngineBillRepresentable.total
    var totalRoundingAdjustments: Int64 { get }

    /// Total amount tendered in cash, credit/debit, or non-integrated payment
    var totalAmountTendered: Int64 { get }

    /// The excess amount that is returned to the customer
    var totalChange: Int64 { get }

    /**
    Total amount paid by the customer. It excludes the change returned to the customer.
     
     Calculation:
     ```
     totalAmountPaid = totalAmountTendered - totalChange
     ````
    */
    var totalAmountPaid: Int64 { get }
}

extension OrderTotals where Self: BillEngineBillRepresentable & NSManagedObject {
    func calculateTotal(whenPayingBy paymentType: PaymentType?) -> ZeroDecimalAmount {
        guard let managedObjectContext = managedObjectContext,
            let paymentType = paymentType else {
                return total
        }
        switch paymentType {
        case .cash: return PennyRoundingCalculator.round(total, in: managedObjectContext)
        case .card: return total
        case .nonIntegrated: return total
        }
    }
}

// MARK: Bill extension
extension Bill: OrderTotals {
    func totalAmountDue(whenPayingBy paymentType: PaymentType? = nil) -> Int64 {
        if isClosed {
            return total + totalRoundingAdjustments
        } else {
            return calculateTotal(whenPayingBy: paymentType)
        }
    }

    func totalOutstandingBalance(whenPayingBy paymentType: PaymentType? = nil) -> Int64 {
        return totalAmountPaid - totalAmountDue(whenPayingBy: paymentType)
    }

    var totalTips: Int64 {
        return payments?.reduce(ZeroDecimalAmount.zero) { $0 + $1.tip } ?? ZeroDecimalAmount.zero
    }

    var totalRoundingAdjustments: Int64 {
        if isClosed {
            return payments?.reduce(ZeroDecimalAmount.zero) { $0 + $1.roundingDifference } ?? ZeroDecimalAmount.zero
        } else {
            return calculateTotal(whenPayingBy: .cash) - total
        }
    }

    var totalAmountTendered: Int64 {
        return totalAmountPaid + totalTips + totalChange
    }

    var totalChange: Int64 {
        return payments?.reduce(ZeroDecimalAmount.zero) {
            return $0 + ($1.cashPayments?.reduce(ZeroDecimalAmount.zero) { $0 + $1.change } ?? ZeroDecimalAmount.zero)
        } ?? ZeroDecimalAmount.zero
    }

    var totalAmountPaid: Int64 {
        return payments?.reduce(ZeroDecimalAmount.zero) { $0 + $1.amount } ?? ZeroDecimalAmount.zero
    }
}

// MARK: Order extension
extension Order: OrderTotals {
    func totalAmountDue(whenPayingBy paymentType: PaymentType? = nil) -> Int64 {
        return calculateTotal(whenPayingBy: paymentType)
    }

    func totalOutstandingBalance(whenPayingBy paymentType: PaymentType? = nil) -> Int64 {
        return totalAmountDue(whenPayingBy: paymentType)
    }

    var totalTips: Int64 {
        return ZeroDecimalAmount.zero
    }

    var totalRoundingAdjustments: Int64 {
        return calculateTotal(whenPayingBy: .cash) - total
    }

    var totalAmountTendered: Int64 {
        return totalAmountPaid + totalTips + totalChange
    }

    var totalChange: Int64 {
        return ZeroDecimalAmount.zero
    }

    var totalAmountPaid: Int64 {
        return ZeroDecimalAmount.zero
    }
}