export nominal OrderId = string
export nominal Cents = int
export type Count = int
export type Bool = boolean
export type Text = string
export type StateName = "pending" | "paid" | "shipped" | "cancelled"

export type Receipt = { number: Text }
export type Tracking = { code: Text }
export type Reason = { note: Text }

export nominal Pending = { id: OrderId, total: Cents }
export nominal Paid = { id: OrderId, total: Cents, receipt: Receipt }
export nominal Shipped = { id: OrderId, receipt: Receipt, tracking: Tracking }
export nominal Cancelled = { id: OrderId, reason: Reason }
export type Order = Pending | Paid | Shipped | Cancelled

export error InvalidTransition = { id: OrderId, state: StateName }

export nominal Fixed = { amount: Cents }
export nominal Times = { factor: Count }
export nominal Capped = { rule: Rule, cap: Cents }
export nominal Sum = { parts: Rule[] }
export type Rule = Fixed | Times | Capped | Sum

export type OrderInput = { id: Text, total: Count }