Discount

Source: src/data/discount/

Service

createDiscountService / DiscountService

Factory: createDiscountService(repository: DiscountRepository) — returns DiscountService.

Owns discount lifecycle and deterministic price calculations. Framework-agnostic; talks to persistence through DiscountRepository.

Method	Parameters	Returns	Description
getById	(ctx: RequestContext, id: string)	Promise<DiscountRecord | null>	Returns a discount by id
listByTenant	(ctx: RequestContext)	Promise<DiscountRecord[]>	Lists all discounts for the tenant
create	(ctx: RequestContext, input: DiscountCreateInput)	Promise<DiscountRecord>	Creates a new discount; normalizes code to uppercase
update	(ctx: RequestContext, id: string, patch: DiscountPatchInput)	Promise<DiscountRecord>	Updates a discount; normalizes code to uppercase
remove	(ctx: RequestContext, id: string)	Promise<void>	Deletes a discount by id
evaluateEligibility	(ctx: RequestContext, input: DiscountEvaluationInput)	Promise<DiscountEvaluationResult>	Evaluates discount eligibility, enforcing lifecycle, scope, and usage-limit rules; computes final pricing
consumeUsage	(ctx: RequestContext, input: { discountId: string, orderId: string })	Promise<DiscountUsageConsumeResult>	Records usage of a discount for an order
resolveBestForCustomer	(ctx: RequestContext, input: ResolveBestForCustomerInput)	Promise<ResolveBestForCustomerResult>	Finds the highest-value eligible discount for a customer from assignments + global pool
consumeAssignmentUsage	(ctx: RequestContext, assignmentId: string)	Promise<void>	Increments usedCount on an assignment; no-op for forever rule
assignToCustomer	(ctx: RequestContext, input: DiscountAssignmentCreateInput)	Promise<DiscountAssignment>	Creates or upserts a discount assignment for a customer (idempotent)
revokeAssignment	(ctx: RequestContext, assignmentId: string)	Promise<DiscountAssignment | null>	Soft-revokes an assignment by setting expiresAt to the past; returns null if not found

DiscountEvaluationInput

Field	Type
code	string
items	DiscountEvaluationItem[]
customerId	string (optional)
roleIds	string[] (optional)
now	Date (optional)

DiscountEvaluationResult

Field	Type
discountId	string
discountCode	string (optional)
subtotalCents	number
discountAmountCents	number
totalCents	number

Repository

DiscountRepository

Method	Parameters	Returns
getById	(ctx: RequestContext, id: string)	Promise<DiscountRecord | null>
findByCode	(ctx: RequestContext, code: string)	Promise<DiscountRecord | null>
listByTenant	(ctx: RequestContext)	Promise<DiscountRecord[]>
create	(ctx: RequestContext, input: DiscountCreateInput)	Promise<DiscountRecord>
update	(ctx: RequestContext, id: string, patch: DiscountPatchInput)	Promise<DiscountRecord>
delete	(ctx: RequestContext, id: string)	Promise<void>
consumeUsage	(ctx: RequestContext, input: DiscountUsageConsumeInput)	Promise<DiscountUsageConsumeResult>
findActiveGlobalDiscounts	(ctx: RequestContext)	Promise<DiscountRecord[]> — all active, non-expired, globally-scoped discounts within the usage limit

DiscountUsageConsumeResult

Union type with status:

• consumed — includes discount: DiscountRecord
• already_consumed — includes discount: DiscountRecord
• limit_reached
• not_found

Validators

discountTypeSchema

Enum: PERCENT, AMOUNT

discountSchema

Field	Type	Required	Default
tenantId	string	Yes	—
code	string	No	—
type	discountTypeSchema	Yes	—
percent	number (1–100)	No	—
amountCents	number (int, ≥ 0)	No	—
scope.appliesToAll	boolean	No	true
scope.productIds	string[]	No	[]
scope.roleIds	string[]	No	[]
scope.customerIds	string[]	No	[]
lifecycle.isActive	boolean	No	true
lifecycle.startsAt	Date	No	—
lifecycle.endsAt	Date	No	—
lifecycle.usageLimit	number (int, positive)	No	—
lifecycle.usageCount	number (int, ≥ 0)	No	0
lifecycle.consumedOrderIds	string[]	No	[]
createdAt	Date (coerced)	Yes	—
updatedAt	Date (coerced)	Yes	—

Refinements:

• percent is required when type is PERCENT
• amountCents is required when type is AMOUNT
• endsAt must be after startsAt

discountCreateInputSchema

Same as discountSchema but omits tenantId (from base), subtotalCents/totalCents, and lifecycle.usageCount/lifecycle.consumedOrderIds. Lifecycle is optional.

discountPatchInputSchema

All fields from discountSchema except tenantId, made partial. Includes same refinements.

discountEligibilityInputSchema

Field	Type	Required	Default
code	string	Yes	—
items	Array<{ productId, quantity, unitPriceCents }>	Yes	—
customerId	string	No	—
roleIds	string[]	No	[]
now	Date	No	—

discountErrorResponseSchema

Field	Type	Required
code	string	Yes
message	string	Yes

Inferred Types

• Discount — z.infer<typeof discountSchema>
• DiscountCreateInput — z.infer<typeof discountCreateInputSchema>
• DiscountPatchInput — z.infer<typeof discountPatchInputSchema>
• DiscountEligibilityInput — z.infer<typeof discountEligibilityInputSchema>
• DiscountType — z.infer<typeof discountTypeSchema>

Assignment Repository

Additional DiscountRepository Methods (Assignments)

Method	Parameters	Returns
findAssignmentsForCustomer	(ctx, customerId)	Promise<DiscountAssignment[]>
createAssignment	(ctx, input: DiscountAssignmentCreateInput)	Promise<DiscountAssignment>
incrementAssignmentUsage	(ctx, assignmentId)	Promise<DiscountAssignment>
findAssignment	(ctx, assignmentId)	Promise<DiscountAssignment | null>
updateAssignment	(ctx, assignmentId, patch)	Promise<DiscountAssignment>
findActiveGlobalDiscounts	(ctx)	Promise<DiscountRecord[]> — active, non-expired, scope.appliesToAll=true discounts within usage limit

DiscountAssignment

Field	Type
id	string
tenantId	string
discountId	string
customerId	string
rule	'one_time' | 'next_n' | 'forever'
totalAllowed	number | null
usedCount	number
expiresAt	Date | null
createdAt	Date
updatedAt	Date