import FingerprintJS from '@fingerprintjs/fingerprintjs';

let fpPromise = null;
let cachedFingerprint = null;
let cachedDeviceInfo = null;

/**
 * Inicializa FingerprintJS (solo una vez)
 */
function initFingerprintJS() {
  if (!fpPromise) {
    fpPromise = FingerprintJS.load();
  }
  return fpPromise;
}

/**
 * Obtiene el fingerprint del dispositivo
 * @returns {Promise<{fingerprint: string, deviceInfo: Object}>}
 */
export async function getDeviceFingerprint() {
  // Si ya tenemos el fingerprint en caché, devolverlo
  if (cachedFingerprint && cachedDeviceInfo) {
    return {
      fingerprint: cachedFingerprint,
      deviceInfo: cachedDeviceInfo,
    };
  }

  try {
    const fp = await initFingerprintJS();
    const result = await fp.get();

    // Extraer información del dispositivo desde los componentes
    const deviceInfo = extractDeviceInfo(result.components);

    cachedFingerprint = result.visitorId;
    cachedDeviceInfo = deviceInfo;

    return {
      fingerprint: result.visitorId,
      deviceInfo: deviceInfo,
    };
  } catch (error) {
    console.error('Error obteniendo fingerprint:', error);
    // Fallback: generar un fingerprint básico
    return {
      fingerprint: generateFallbackFingerprint(),
      deviceInfo: {
        browser: navigator.userAgent.includes('Chrome') ? 'Chrome' : 
                 navigator.userAgent.includes('Firefox') ? 'Firefox' : 
                 navigator.userAgent.includes('Safari') ? 'Safari' : 'Unknown',
        os: navigator.platform,
        device: 'Unknown',
      },
    };
  }
}

/**
 * Extrae información legible del dispositivo desde los componentes de FingerprintJS
 * @param {Object} components - Componentes de FingerprintJS
 * @returns {Object} Información del dispositivo
 */
function extractDeviceInfo(components) {
  const info = {
    browser: 'Unknown',
    browserVersion: '',
    os: 'Unknown',
    osVersion: '',
    device: 'Unknown',
    screenResolution: '',
    timezone: '',
    language: navigator.language || '',
  };

  // Información del navegador
  if (components.browserName) {
    info.browser = components.browserName.value || 'Unknown';
  }
  if (components.browserVersion) {
    info.browserVersion = components.browserVersion.value || '';
  }

  // Información del sistema operativo
  if (components.os) {
    info.os = components.os.value || 'Unknown';
  }
  if (components.osVersion) {
    info.osVersion = components.osVersion.value || '';
  }

  // Información del dispositivo
  if (components.deviceMemory) {
    info.device = components.deviceMemory.value ? 'Desktop' : 'Mobile';
  }
  if (components.platform) {
    const platform = components.platform.value?.toLowerCase() || '';
    if (platform.includes('mobile') || platform.includes('android') || platform.includes('iphone')) {
      info.device = 'Mobile';
    } else if (platform.includes('tablet') || platform.includes('ipad')) {
      info.device = 'Tablet';
    } else {
      info.device = 'Desktop';
    }
  }

  // Resolución de pantalla
  if (components.screenResolution) {
    const res = components.screenResolution.value;
    if (res && res.length >= 2) {
      info.screenResolution = `${res[0]}x${res[1]}`;
    }
  }

  // Zona horaria
  if (components.timezone) {
    info.timezone = components.timezone.value || '';
  }

  return info;
}

/**
 * Genera un fingerprint básico como fallback
 * @returns {string} Hash del fingerprint
 */
function generateFallbackFingerprint() {
  const data = [
    navigator.userAgent,
    navigator.language,
    navigator.platform,
    screen.width + 'x' + screen.height,
    new Date().getTimezoneOffset(),
  ].join('|');

  // Simple hash (no usar en producción, solo como fallback)
  let hash = 0;
  for (let i = 0; i < data.length; i++) {
    const char = data.charCodeAt(i);
    hash = ((hash << 5) - hash) + char;
    hash = hash & hash; // Convert to 32bit integer
  }
  return Math.abs(hash).toString(36);
}

/**
 * Limpia el caché del fingerprint (útil para testing)
 */
export function clearFingerprintCache() {
  cachedFingerprint = null;
  cachedDeviceInfo = null;
}