/* global WebSocket */

const internals = {
  kSocketLocation: 'ws://localhost:1987',

  data: {
    state: 0,
    runningAverages: {},
    winner: null
  },

  initSocket() {

    internals.socket = new WebSocket(internals.kSocketLocation);
    internals.socket.addEventListener('message', (data) => {

      Object.assign(internals.data, JSON.parse(data.data));
    });
  }
};

/**
 * The data structure representing the sorting hat data
 *
 * @typedef tSortingHatData
 * @type object
 * @param {number} state the current state: 0 for waiting, 1 for
 * polling, 2 for cool down.
 * @param {string} [winner] the winner after polling, might be null if
 * no winner is detected
 * @param {Object.<string,tRunningAverages>} runningAverages the running averages for
 * the different categories, used to render the waves
 */

/**
 * The running averages, including the current sum and count
 *
 * @typedef tRunningAverages
 * @type object
 * @param {number} sum the current total
 * @param {number} count the number of samples
 * @param {number} average the average (sum / count)
 */

/**
 * The main data service, connects to a socket and updates the internal
 * data structure
 *
 * @class DataService
 */
export default {

  /**
   * Returns the internal data structure, intended to be used as the data
   * property in vue components
   *
   * @memberof DataService
   * @method data
   * @return tSortingHatData
   */
  data() {

    if (!internals.socket) {
      internals.initSocket();
    }

    return internals.data;
  }
};