const Service = require("moleculer").Service;
const DetectDetector = require('node-device-detector');
const MemCache = require("../mixins/memcache");
const crypto = require('crypto');

const DEVICE_TYPE = require('node-device-detector/parser/const/device-type');

/**
 * @typedef {Object} DetectCtxParams
 * @property {String} userAgent
 */

class DeviceDetectorService extends Service {

  #cache = true;
  #detector;

  constructor(broker) {
	super(broker);

	this.parseServiceSchema({
	  name: 'device-detector',
	  mixins: [
		MemCache({})
	  ],
	  actions: {
		"detect": this.detectHandler,
		"detect-bot": this.detectBotHandler
	  },
	  created: this.serviceCreated,
	  started: this.serviceStarted,
	  stopped: this.serviceStopped,
	});
  }

  /**
   * @param {DetectCtxParams} ctx.params
   * @returns {Promise<Object>}
   */
  async detectHandler(ctx) {
	const {userAgent} = ctx.params;
	let detectData = null;
	let cacheData = null;
	let keyCache = null;

	if (this.#cache) {
	  keyCache = crypto.createHash('md5').update(userAgent).digest('hex');
	  cacheData = await this.memcache.getCache(keyCache);

	  if (cacheData) {
		detectData = cacheData;
	  }
	}

	if (!detectData) {
	  let resultOs = this.#detector.parseOs(userAgent);
	  let resultClient = this.#detector.parseClient(userAgent);
	  let resultDeviceType = this.#detector.parseDeviceType(userAgent, resultOs, resultClient, {});
	  detectData = Object.assign({os: resultOs}, {client: resultClient}, {device: resultDeviceType});
	}

	if (this.#cache && !cacheData) {
	  await this.memcache.setCache(keyCache, detectData, 3600);
	}

	let mixData = this.detectType(userAgent, detectData);

	return Object.assign({}, detectData, mixData);
  }

  // public

  /**
   * @param {DetectCtxParams} ctx.params
   * @returns {Promise<Object>}
   */
  detectBotHandler(ctx) {
	const {userAgent} = ctx.params;
	return this.#detector.parseBot(userAgent);
  }

  // private

  detectType(userAgent, detectData) {
	let isTabled = detectData.device && [DEVICE_TYPE.TABLET].indexOf(detectData.device.type) !== -1;
	let isMobile = detectData.device && [DEVICE_TYPE.SMARTPHONE, DEVICE_TYPE.FEATURE_PHONE].indexOf(detectData.device.type) !== -1;
	let isPhablet = detectData.device && [DEVICE_TYPE.PHABLET].indexOf(detectData.device.type) !== -1;
	let isIOS = detectData.os && detectData.os.family === 'iOS';
	let isIPhone = '';
	let isAndroid = detectData.os && detectData.os.family === 'Android';
	let isDesktop = !isTabled && !isMobile && !isPhablet;
	let isYaBrowser = /(Yandex.Browser|YaBrowser)/i.test(userAgent);

	return {
	  isDesktop: isDesktop,
	  isTabled: isTabled,
	  isMobile: isMobile,
	  isPhablet: isPhablet,
	  isIOS: isIOS,
	  isIPhone: isIPhone,
	  isAndroid: isAndroid,
	  isYaBrowser: isYaBrowser
	};
  }


  serviceCreated() {
	this.#detector = new DetectDetector();
  }

  serviceStarted() {
  }

  serviceStopped() {
  }

}

module.exports = DeviceDetectorService;