import type { Listing, User } from "@prisma/client";

export type BillingConfig = {
  accountName: string | null;
  iban: string | null;
  includeVatLine: boolean;
};

type BillingUser = Pick<
  User,
  "billingAccountName" | "billingIban" | "billingIncludeVatLine"
>;
type BillingListing = Pick<
  Listing,
  "billingAccountName" | "billingIban" | "billingIncludeVatLine"
>;

export function normalizeOptionalString(
  input: unknown,
): string | null | undefined {
  if (input === undefined) return undefined;
  if (input === null) return null;
  const value = String(input).trim();
  return value ? value : null;
}

export function normalizeIban(input: unknown): string | null | undefined {
  if (input === undefined) return undefined;
  if (input === null) return null;
  const value = String(input).replace(/\s+/g, "").toUpperCase();
  return value ? value : null;
}

export function normalizeNullableBoolean(
  input: unknown,
): boolean | null | undefined {
  if (input === undefined) return undefined;
  if (input === null) return null;
  return Boolean(input);
}

export function resolveBillingDetails(
  user: BillingUser,
  listing?: BillingListing | null,
): BillingConfig {
  const accountName =
    listing?.billingAccountName ?? user.billingAccountName ?? null;
  const iban = listing?.billingIban ?? user.billingIban ?? null;
  const includeVatLine =
    listing?.billingIncludeVatLine !== null &&
    listing?.billingIncludeVatLine !== undefined
      ? Boolean(listing.billingIncludeVatLine)
      : Boolean(user.billingIncludeVatLine);

  return { accountName, iban, includeVatLine };
}