import { extend, mergeData } from '../../vue';
import { NAME_TRANSITION } from '../../constants/components';
import { PROP_TYPE_BOOLEAN, PROP_TYPE_STRING, PROP_TYPE_OBJECT } from '../../constants/props';
import { isPlainObject } from '../../utils/inspect';
import { makeProp } from '../../utils/props';

// Generic Bootstrap v4 fade (no-fade) transition component

// --- Constants ---

const NO_FADE_PROPS = {
  name: '',
  enterClass: '',
  enterActiveClass: '',
  enterToClass: 'show',
  leaveClass: 'show',
  leaveActiveClass: '',
  leaveToClass: ''
};
const FADE_PROPS = {
  ...NO_FADE_PROPS,
  enterActiveClass: 'fade',
  leaveActiveClass: 'fade'
};

// --- Props ---

const props = {
  // Has no effect if `trans-props` provided
  appear: makeProp(PROP_TYPE_BOOLEAN, false),
  // Can be overridden by user supplied `trans-props`
  mode: makeProp(PROP_TYPE_STRING),
  // Only applicable to the built in transition
  // Has no effect if `trans-props` provided
  noFade: makeProp(PROP_TYPE_BOOLEAN, false),
  // For user supplied transitions (if needed)
  transProps: makeProp(PROP_TYPE_OBJECT)
};

// --- Main component ---

// @vue/component
const BVTransition = /*#__PURE__*/extend({
  name: NAME_TRANSITION,
  functional: true,
  props,
  render(h, _ref) {
    let {
      children,
      data,
      props
    } = _ref;
    let transProps = props.transProps;
    if (!isPlainObject(transProps)) {
      transProps = props.noFade ? NO_FADE_PROPS : FADE_PROPS;
      if (props.appear) {
        // Default the appear classes to equal the enter classes
        transProps = {
          ...transProps,
          appear: true,
          appearClass: transProps.enterClass,
          appearActiveClass: transProps.enterActiveClass,
          appearToClass: transProps.enterToClass
        };
      }
    }
    transProps = {
      mode: props.mode,
      ...transProps,
      // We always need `css` true
      css: true
    };
    const dataCopy = {
      ...data
    };
    delete dataCopy.props;
    return h('transition',
    // Any transition event listeners will get merged here
    mergeData(dataCopy, {
      props: transProps
    }), children);
  }
});

export { BVTransition, props };
