/**
* Calcula la tarifa de un viaje considerando múltiples factores
*/
export class FareCalculator {
constructor(config = {}) {
this.baseFare = config.baseFare || parseFloat(process.env.BASE_FARE_BS) || 3;
this.perKm = config.perKm || parseFloat(process.env.PER_KM_BS) || 2;
this.perMin = config.perMin || parseFloat(process.env.PER_MIN_BS) || 0.5;
this.minFare = config.minFare || parseFloat(process.env.MIN_FARE_BS) || 5;
this.fuelPrice = config.fuelPrice || parseFloat(process.env.FUEL_PRICE_BS) || 0.50;
this.usdRate = config.usdRate || parseFloat(process.env.USD_EXCHANGE_RATE) || 45;
this.usdRateCache = null;
this.usdRateCacheTime = null;
this.CACHE_DURATION_MS = 3600000; // 1 hora
}
/**
* Obtiene la tasa de cambio oficial del BCV desde DolarAPI
* Implementa caché de 1 hora para evitar llamadas excesivas
*/
async getUsdRate() {
const now = Date.now();
// Usar caché si está disponible y no ha expirado
if (this.usdRateCache && this.usdRateCacheTime && (now - this.usdRateCacheTime < this.CACHE_DURATION_MS)) {
return this.usdRateCache;
}
try {
const response = await fetch('https://ve.dolarapi.com/v1/dolares/oficial');
if (!response.ok) {
throw new Error(`DolarAPI error: ${response.status}`);
}
const data = await response.json();
const rate = data.promedio || data.venta || this.usdRate;
// Actualizar caché
this.usdRateCache = rate;
this.usdRateCacheTime = now;
return rate;
} catch (error) {
console.warn('Error obteniendo tasa de cambio de DolarAPI, usando fallback:', error.message);
return this.usdRate; // Fallback a la tasa configurada
}
}
async calculate(distanceKm, durationMin, options = {}) {
const {
currency = 'BS',
surge = 1.0, // Multiplicador de demanda (1.0 = normal, 1.5 = alta demanda)
fuelSurcharge = true
} = options;
// Cálculo base
let fare = this.baseFare;
fare += distanceKm * this.perKm;
fare += durationMin * this.perMin;
// Recargo por gasolina si el precio subió
if (fuelSurcharge && this.fuelPrice > 0.50) {
const fuelExtra = (this.fuelPrice - 0.50) * 10;
fare += fuelExtra;
}
// Aplicar multiplicador de demanda
fare *= surge;
// Aplicar tarifa mínima
fare = Math.max(fare, this.minFare);
// Redondear a 2 decimales
fare = parseFloat(fare.toFixed(2));
const result = {
amount_bs: fare,
currency: 'BS',
breakdown: {
base_fare: this.baseFare,
distance_charge: parseFloat((distanceKm * this.perKm).toFixed(2)),
time_charge: parseFloat((durationMin * this.perMin).toFixed(2)),
surge_multiplier: surge,
fuel_surcharge: fuelSurcharge ? parseFloat(((this.fuelPrice - 0.50) * 10).toFixed(2)) : 0
}
};
// Convertir a USD si se solicita
if (currency === 'USD') {
const currentRate = await this.getUsdRate();
result.amount_usd = parseFloat((fare / currentRate).toFixed(2));
result.currency = 'USD';
result.exchange_rate = currentRate;
result.exchange_rate_source = 'DolarAPI (BCV Oficial)';
}
return result;
}
/**
* Calcula el estimado de comisión de la plataforma
*/
calculateCommission(fareAmount, commissionRate = 0.15) {
const commission = fareAmount * commissionRate;
const driverEarnings = fareAmount - commission;
return {
total_fare: fareAmount,
platform_commission: parseFloat(commission.toFixed(2)),
driver_earnings: parseFloat(driverEarnings.toFixed(2)),
commission_rate: commissionRate
};
}
}
