import {Ticker} from '@avocado/timing';

const MAGIC_TO_FIT_HOUR_INTO_USHORT = 2730;

export class WorldTime {

  constructor() {
    this._hour = 0;
    this.ticker = new Ticker(1);
    this._state = 0;
    this.ticker.on('tick', () => {
      this._state = (this._hour * MAGIC_TO_FIT_HOUR_INTO_USHORT) >> 0;
    });
  }

  static format(time) {
    const rawHour = (time + 12) % 12;
    const hour = Math.floor(0 === Math.floor(rawHour) ? 12 : rawHour);
    const minutes = String(Math.floor((rawHour - Math.floor(rawHour)) * 60)).padStart(2, '0');
    if (time >= 12) {
      return `${hour}:${minutes} pm`;
    }
    else {
      return `${hour}:${minutes} am`;
    }
  }

  get hour() {
    return this._hour;
  }

  set hour(hour) {
    this._hour = hour;
    this._state = (this._hour * MAGIC_TO_FIT_HOUR_INTO_USHORT) >> 0;
  }

  patchState(steps) {
    for (const step of steps) {
      const {path, value} = step;
      if ('/' === path) {
        this._hour = value / MAGIC_TO_FIT_HOUR_INTO_USHORT;
      }
    }
  }

  secondsPerHour() {
    return 60;
  }

  get state() {
    return this._state;
  }

  tick(elapsed) {
    this._hour += (elapsed / this.secondsPerHour());
    this._hour = this._hour % 24;
    this.ticker.tick(elapsed);
  }

}