import { cloneElement, useMemo } from 'react';
import classNames from 'classnames';

interface CloneElementProps {
  element: any | null;
  children?: any;
}

/**
 * CloneElement is a wrapper component for createElement function.
 * This allows you to describe your cloning element declaratively
 * which is a more natural API for React.
 */
export function CloneElement<T = any>({ element, children, ...rest }: CloneElementProps & Partial<T>) {
  const getProjectedProps = useMemo(() => props => {
    const childProps = element.props;

    return Object.keys(props).reduce((acc, key) => {
      const prop = props[key];
      const childProp = childProps[key];

      if (typeof prop === 'function' && typeof childProp === 'function') {
        acc[key] = args => {
          prop(args);
          childProp(args);
        };
      } else if (key === 'className') {
        acc[key] = classNames(prop, childProp);
      } else {
        acc[key] = prop;
      }

      return acc;
    }, {});
  }, [rest]);

  if (element === null) {
    return children;
  }

  const newProps = getProjectedProps(rest);
  return cloneElement(element, {
    ...element.props,
    ...newProps,
    children
  });
}