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
//
// Assumes that `show` class is not required when
// the transition has finished the enter transition
// (show and fade classes are only applied during transition)


// --- 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)
};
const hasAnimateSupport = typeof Element !== 'undefined' && Boolean(Element.prototype.animate);

// --- 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,
      /*
       bootstrap-vue says: We always need `css` true
        @gitlab/ui says: OMG. THE FREAKING TRANSITIONS.
       So apparently jsdom doesn't implement animations (who can blame them)
       but a Vue Transition relies on the native animationend/transitionend
       events in order to fire onAfterLeave. jsdom will never fire the `onAfterLeave`
       which is relied on by e.g. the tooltip component to do it's `hidden` logic.
        So if in specs, we set `css: false`, everything will work as expected.
       The best way we have found is to do a feature detection on `Element.prototype.animate`
       */
      css: hasAnimateSupport
    };
    const dataCopy = {
      ...data
    };
    delete dataCopy.props;
    Object.keys(props).forEach(key => {
      delete dataCopy[key];
    });
    return h('transition',
    // Any transition event listeners will get merged here
    mergeData(dataCopy, {
      props: transProps
    }), children);
  }
});

export { BVTransition, props };
