priceValidator.ts

const priceValidator = ({ 
    products = [], 
    tax = 0, 
    deliveryFee = 0, 
    limitDeliveryFee = 0, 
    pointToDiscount = 0, 
    pointToDiscountRate = 10
}: IPriceValidator) => {
    const PRICE_OFFSET = 100

    let totalPrice = 0
    let totalPriceWithTax = 0
    let vat = tax / PRICE_OFFSET
    let totalDiscount = 0
    let totalQuantity = 0
    let totalDiscountPrice = 0

    products.map(({ variants: { price: { cents } }, quantity }) =>  { totalPrice += cents * quantity })
    products.map(({ quantity }) =>  { totalQuantity += quantity })
    totalDiscount = (Math.floor(pointToDiscount / pointToDiscountRate) * PRICE_OFFSET)

    const totalPriceInCent = totalPrice / PRICE_OFFSET
    const totalVat = Math.round((totalPriceInCent * vat) * PRICE_OFFSET) / PRICE_OFFSET

    totalPriceWithTax = totalPrice + (totalVat * PRICE_OFFSET)
    totalDiscountPrice  = totalPriceWithTax - totalDiscount

    if(limitDeliveryFee === 0 || limitDeliveryFee > totalDiscountPrice) { 
      totalDiscountPrice += deliveryFee
    }

    return { 
      totalPriceWithVatFee: totalDiscountPrice,
      totalPrice,
      totalQuantity,
      totalDiscount,
      totalDeliveryFee: deliveryFee / PRICE_OFFSET,
      totalVat,
      totalUsagePoint: pointToDiscount,
      totalDiscountPrice,
      vat,
      tax,
      deliveryFeeRate: deliveryFee,
    }
  }

  export default priceValidator