import { h } from 'vue';
// eslint-disable-next-line
import Swiper from '../../core';

function calcLoopedSlides(slides, swiperParams) {
  let slidesPerViewParams = swiperParams.slidesPerView;
  if (swiperParams.breakpoints) {
    const breakpoint = Swiper.prototype.getBreakpoint(swiperParams.breakpoints);
    const breakpointOnlyParams =
      breakpoint in swiperParams.breakpoints ? swiperParams.breakpoints[breakpoint] : undefined;
    if (breakpointOnlyParams && breakpointOnlyParams.slidesPerView) {
      slidesPerViewParams = breakpointOnlyParams.slidesPerView;
    }
  }
  let loopedSlides = Math.ceil(parseFloat(swiperParams.loopedSlides || slidesPerViewParams, 10));

  loopedSlides += swiperParams.loopAdditionalSlides;

  if (loopedSlides > slides.length) {
    loopedSlides = slides.length;
  }
  return loopedSlides;
}

function renderLoop(swiperRef, slides, swiperParams) {
  const modifiedSlides = slides.map((child, index) => {
    if (!child.props) child.props = {};
    child.props.swiperRef = swiperRef;
    child.props['data-swiper-slide-index'] = index;
    return child;
  });

  function duplicateSlide(child, index, position) {
    if (!child.props) child.props = {};
    return h(
      child.type,
      {
        ...child.props,
        key: `${child.key}-duplicate-${index}-${position}`,
        class: `${child.props.className || ''} ${swiperParams.slideDuplicateClass} ${
          child.props.class || ''
        }`,
      },
      child.children,
    );
  }

  if (swiperParams.loopFillGroupWithBlank) {
    const blankSlidesNum =
      swiperParams.slidesPerGroup - (modifiedSlides.length % swiperParams.slidesPerGroup);
    if (blankSlidesNum !== swiperParams.slidesPerGroup) {
      for (let i = 0; i < blankSlidesNum; i += 1) {
        const blankSlide = h('div', {
          class: `${swiperParams.slideClass} ${swiperParams.slideBlankClass}`,
        });
        modifiedSlides.push(blankSlide);
      }
    }
  }

  if (swiperParams.slidesPerView === 'auto' && !swiperParams.loopedSlides) {
    swiperParams.loopedSlides = modifiedSlides.length;
  }

  const loopedSlides = calcLoopedSlides(modifiedSlides, swiperParams);

  const prependSlides = [];
  const appendSlides = [];
  modifiedSlides.forEach((child, index) => {
    if (index < loopedSlides) {
      appendSlides.push(duplicateSlide(child, index, 'prepend'));
    }
    if (index < modifiedSlides.length && index >= modifiedSlides.length - loopedSlides) {
      prependSlides.push(duplicateSlide(child, index, 'append'));
    }
  });
  if (swiperRef.value) {
    swiperRef.value.loopedSlides = loopedSlides;
  }

  return [...prependSlides, ...modifiedSlides, ...appendSlides];
}

export { calcLoopedSlides, renderLoop };
