export default {
  angleFromPositions (cx, cy, ex, ey) {
    const theta = Math.atan2(ey - cy, ex - cx) + Math.PI / 2;
    return theta * 180 / Math.PI;
  },

  angle360FromPositions (cx, cy, ex, ey) {
    const angle = this.angleFromPositions(cx, cy, ex, ey);
    return angle < 0 ? 360 + angle : angle;
  },

  range (start = 0, stop = null, step = 1) {
    let [_start, _stop] = [0, start];
    if (stop !== null) {
      [_start, _stop] = [start, stop];
    }
    const length = Math.max(Math.ceil((_stop - _start) / step), 0);
    const range = Array(length);

    for (let idx = 0; idx < length; idx++, _start += step) {
      range[idx] = _start;
    }

    return range;
  },

  round (number, decimals) {
    if (!isNaN(parseFloat(number)) && isFinite(number)) {
      const decimalPower = Math.pow(10, decimals);
      return Math.round(parseFloat(number) * decimalPower) / decimalPower;
    }
    return NaN;
  },

  getViewport () {
    return {
      height: window.innerHeight || document.documentElement.offsetHeight,
      width: window.innerWidth || document.documentElement.offsetWidth
    };
  },

  cloneObject (object) {
    return JSON.parse(JSON.stringify(object));
  },

  inputTypeForPrototype (prototype) {
    if (prototype === Date) return 'date';
    if (prototype === Number) return 'number';
    if (prototype === Boolean) return 'checkbox';
    return 'text';
  },

  prepareValueForInput (value, type) {
    if (type === 'date') return new Date(value).toISOString().slice(0, 10);
    if (type === 'checkbox') {
      return value ? 'on' : '';
    }
    return value;
  },

  removeObjectKey (key, object) {
    const newObject = {};
    Object.keys(object)
      .filter(k => k !== key)
      .forEach(k => { newObject[k] = object[k]; });
    return newObject;
  }
};