// Costing methods supported by erp-kit's inventory valuation (0.48).
// Shared between the valuation-policy create form (options) and the list table
// (label lookup) so the two never drift.
export type CostingMethod = "STANDARD" | "FIFO" | "AVERAGE";

export interface CostingMethodOption {
  id: CostingMethod;
  name: string;
}

// Plain (mutable, uniform-element) array so it can be passed directly to the
// app-shell <Select> `items` prop, which rejects `readonly` tuple types.
export const COSTING_METHODS: CostingMethodOption[] = [
  { id: "STANDARD", name: "Standard Cost" },
  { id: "FIFO", name: "FIFO (First-In, First-Out)" },
  { id: "AVERAGE", name: "Moving Average" },
];

const LABELS: Record<string, string> = Object.fromEntries(
  COSTING_METHODS.map((m) => [m.id, m.name]),
);

/** Human-readable label for a costing-method enum value. */
export const costingMethodLabel = (value: string | null | undefined): string =>
  value ? (LABELS[value] ?? value) : "—";