com.neurosys.ecom.strategy.service

Interface PromotionStrategy<P extends Product,U extends User>

All Superinterfaces:

ChargeStrategy<P,U>, CumulativeChargeStrategy<P,U>, Strategy

All Known Implementing Classes:

DefaultPromotionStrategy

public interface PromotionStrategy<P extends Product,U extends User>
extends CumulativeChargeStrategy<P,U>

What are the possible payment options for an Order
Note: Because Promotions are linked to users being eligible, this Strategies methods may throw ValidationException that should be explicitly handled.

Note: The fundamental difference between DefaultDiscountStrategy and PromotionStrategy is that this is applicable @ a product level only; while PromotionStrategy is applicable @ the cart level and also supports product level.

Author:

Arjun Dhar

Method Summary

Modifier and Type	Method and Description
<CONTEXT> Amount	calculate(Map<P,Number> productQtyMap, U user, String currency, List<PromotionForUser> promotions, Amount subTotal, Number totalQuantity, CONTEXT context) Note: Discounts are DEDUCTED in main / API calcs, so total can be (+), discount part (-) ...
void	commitPromotionsForOrder(Order order) Update Promotions persisted state; to track count, usage of promotion etc.
<CONTEXT> List<PromotionForUser>	getPromotions(Map<P,Number> productQtyMap, U user, Amount subTotal, Number quantityTotal, CONTEXT context) Get a List of PromotionForUser for the Order of a user

Methods inherited from interface com.neurosys.ecom.strategy.service.ChargeStrategy

calculate

Methods inherited from interface com.neurosys.ecom.strategy.service.Strategy

getVersion

Method Detail

getPromotions

<CONTEXT> List<PromotionForUser> getPromotions(Map<P,Number> productQtyMap,
                                               U user,
                                               Amount subTotal,
                                               Number quantityTotal,
                                               CONTEXT context)
                                        throws javax.validation.ValidationException

Get a List of PromotionForUser for the Order of a user

Parameters:

productQtyMap - as Map of Product to Number (Quantity)

user - as U @NUllable true

subTotal - as Amount; many scenarios use the Sub-Total of products to calculate other params. So provide that as a defined context variable. @nullable true

quantityTotal - as Number; many scenarios use the quantityTotal of products to calculate other params @nullable true

context - as additional case driven params that can be supplied @nullable true

Returns:

List of PromotionForUser . @Nulable true; No promotions available

Throws:

javax.validation.ValidationException

calculate

<CONTEXT> Amount calculate(Map<P,Number> productQtyMap,
                           U user,
                           String currency,
                           List<PromotionForUser> promotions,
                           Amount subTotal,
                           Number totalQuantity,
                           CONTEXT context)
                    throws javax.validation.ValidationException

Note: Discounts are DEDUCTED in main / API calcs, so total can be (+), discount part (-) ... [inverse]

Specified by:

calculate in interface CumulativeChargeStrategy<P extends Product,U extends User>

Parameters:

productQtyMap - as Map of Product to Number (Quantity)

user - as U @NUllable true

currency - as String @nullable true. A null implies default currency. Note: If not null then this will override subTotal Amount.getCurrency().

subTotal - as Amount; many scenarios use the Sub-Total of products to calculate other params. So provide that as a defined context variable. @nullable true

totalQuantity - as Number; many scenarios use the quantityTotal of products to calculate other params @nullable true

context - as additional case driven params that can be supplied @nullable true

Returns:

Amount @nullable true (implementation dependent) For Promotions; if there is a discount then Amount.getTotal() should be positive; while Amount.getDiscount() should be negative number. This is because a Discount is DEDUCTED. So while it makes sense to DEDUCT a positive value from TOTAL; the discount itself should be ADDED hence = > Existing Total - (This Discount as Total) Existing Discount - (-This Discount) = Existing Discount + This Discount

Throws:

javax.validation.ValidationException

See Also:

Amount.deduct(Amount)

commitPromotionsForOrder

void commitPromotionsForOrder(Order order)

Update Promotions persisted state; to track count, usage of promotion etc. by user/order. If there are any Promotion's mentioned in the Order then commit them to Data Store.
For example if a COUPON is to be used only N times; then ensure after the Order is successful the validity is reduced to N-1