import React from 'react';
import loadable from 'react-loadable';
import isFunction from 'lodash/isFunction';
import { delayedComponent } from './components';

/**
 * @callback dynamicLoader~importComponent
 * @return {Promise<React.Component>}
 */

/**
 * Returns a component that will perform the given dynamic import and render
 * `Components.DynamicLoading` in the meantime.
 *
 * @example Register a component with a dynamic import
 *  registerComponent('MyComponent', dynamicComponent(() => import('./path/to/MyComponent')));
 *
 * @example Pass a dynamic component to a route
 *  import { addRoute, dynamicLoader, getDynamicComponent } from 'meteor/vulcan:core';
 *
 *  addRoute({
 *    name: 'home',
 *    path: '/',
 *    component: dynamicLoader(() => import('./path/to/HomeComponent')),
 *  });
 *
 * @param {dynamicLoader~importComponent|Promise<React.Component>} importComponent
 *  Function where the dynamic import is performed
 * @return {React.Component}
 *  Component that will load the dynamic import on mount
 */
export const dynamicLoader = importComponent => loadable({
  loader: isFunction(importComponent)
    ? importComponent
    : () => importComponent, // backwards compatibility,
  // use delayedComponent, as this function can be used when Components is not populated yet
  loading: delayedComponent('DynamicLoading'),
});

/**
 * Renders a dynamic component with the given props.
 *
 * @param {dynamicLoader~importComponent|Promise<React.Component>} importComponent
 * @param {Object} props
 */
export const renderDynamicComponent = (importComponent, props = {}) =>
  React.createElement(dynamicLoader(importComponent), props);

export const getDynamicComponent = componentImport => {
  console.warn(
    'getDynamicComponent is deprecated, use renderDynamicComponent instead.',
    'If you want to retrieve the component instead that of just rendering it,',
    'use dynamicLoader. See this issue to know how to do it: https://github.com/VulcanJS/Vulcan/issues/1997',
  );
  return renderDynamicComponent(componentImport);
};