import assoc from 'ramda/src/assoc';
import compose from 'ramda/src/compose';
import keys from 'ramda/src/keys';
import reduce from 'ramda/src/reduce';
import pickBy from 'ramda/src/pickBy';

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

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

export const 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 += 1, _start += step) {
    _range[idx] = _start;
  }

  return _range;
};

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

export const getViewport = () => ({
  height: window.innerHeight || document.documentElement.offsetHeight,
  width: window.innerWidth || document.documentElement.offsetWidth,
});

export const cloneObject = object =>
  JSON.parse(JSON.stringify(object));

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

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

export const transformKeys = fn => (obj) => {
  const addTransformedKey = (result, key) => assoc(fn(key), obj[key], result);
  return reduce(addTransformedKey, {}, keys(obj));
};

export const removeNamespace = namespace => (key) => {
  const capitalized = key.substr(namespace.length);
  return capitalized.slice(0, 1).toLowerCase() + capitalized.slice(1);
};

export const getAnimationModule = (animation, theme) => compose(
  transformKeys(removeNamespace(animation)),
  pickBy((v, k) => k.startsWith(animation)),
)(theme);

export const isValuePresent = value => (
  value !== null
    && value !== undefined
    && value !== ''
    && !(typeof value === 'number' && isNaN(value))
);