// TODO: refactoriza este código — extrae constantes, mejora nombres y crea funciones auxiliares

const DAILY_RATE_BY_CAR_TYPE = {
  economy: 35,
  standard: 55,
  premium: 90
} as const

type CarType = keyof typeof DAILY_RATE_BY_CAR_TYPE

const SHORT_RENTAL_DISCOUNT = 0.1
const LONG_RENTAL_DISCOUNT = 0.2
const INSURANCE_DAILY_PRICE = 15

function applyRentalDiscount(totalCost: number, rentalDays: number): number {
  if (rentalDays >= 14) {
    return totalCost * (1 - LONG_RENTAL_DISCOUNT)
  } else if (rentalDays >= 7) {
    return totalCost * (1 - SHORT_RENTAL_DISCOUNT)
  }

  return totalCost
}

function isValidCarType(carType: unknown): carType is CarType {
  return (
    typeof carType === 'string' 
    && carType in DAILY_RATE_BY_CAR_TYPE
  )
}

export function calculateCarRentalCost(days: number, carType: CarType, hasInsurance: boolean): number {
  // Verificar que los días sean válidos
  if (days <= 0) return -1;
  if (!isValidCarType(carType)) return -1
  
  // Determinar la tarifa base según el tipo de auto
  const dailyRate = DAILY_RATE_BY_CAR_TYPE[carType];

  // Aplicar descuento según los días rentados
  const baseCost = dailyRate * days;
  let totalCost = applyRentalDiscount(baseCost, days)

  // Agregar costo del seguro si aplica
  if (hasInsurance) {
    totalCost += INSURANCE_DAILY_PRICE * days;
  }

  return totalCost;
}