// Price math in öre (1 SEK = 100 öre) to avoid float drift.

export function formatOre(ore: number, locale: 'sv' | 'en' = 'sv'): string {
  const sek = ore / 100;
  return new Intl.NumberFormat(locale === 'sv' ? 'sv-SE' : 'en-SE', {
    style: 'currency',
    currency: 'SEK',
    minimumFractionDigits: 2,
    maximumFractionDigits: 2,
  }).format(sek);
}

export function vatAmountOre(netOre: number, vatBp: number): number {
  return Math.round((netOre * vatBp) / 10000);
}

/** Net price + VAT, rounded the same way as billing. */
export function priceInclVatOre(netOre: number, vatBp: number): number {
  return netOre + vatAmountOre(netOre, vatBp);
}

export function computeTotals(
  items: Array<{ unitPriceOre: number; quantity: number; vatBp: number }>,
) {
  let subtotal = 0;
  let vat = 0;
  for (const i of items) {
    const line = i.unitPriceOre * i.quantity;
    subtotal += line;
    vat += vatAmountOre(line, i.vatBp);
  }
  return { subtotalOre: subtotal, vatOre: vat, totalOre: subtotal + vat };
}