feat(WHE-18): implement money, billing period, and typed domain ids

packages/domain/src/settlement-primitives.ts

@@ -0,0 +1,44 @@
+import type { BillingPeriod } from './billing-period'
+import type { BillingCycleId, MemberId, PurchaseEntryId } from './ids'
+import type { Money } from './money'
+
+export type UtilitySplitMode = 'equal' | 'weighted_by_days'
+
+export interface SettlementMemberInput {
+  memberId: MemberId
+  active: boolean
+  utilityDays?: number
+}
+
+export interface SettlementPurchaseInput {
+  purchaseId: PurchaseEntryId
+  payerId: MemberId
+  amount: Money
+  description?: string
+}
+
+export interface SettlementInput {
+  cycleId: BillingCycleId
+  period: BillingPeriod
+  rent: Money
+  utilities: Money
+  utilitySplitMode: UtilitySplitMode
+  members: readonly SettlementMemberInput[]
+  purchases: readonly SettlementPurchaseInput[]
+}
+
+export interface SettlementMemberLine {
+  memberId: MemberId
+  rentShare: Money
+  utilityShare: Money
+  purchaseOffset: Money
+  netDue: Money
+  explanations: readonly string[]
+}
+
+export interface SettlementResult {
+  cycleId: BillingCycleId
+  period: BillingPeriod
+  lines: readonly SettlementMemberLine[]
+  totalDue: Money
+}