<template>
  <transition
    name="vc-collapse-transition"
    v-on="hooks"
  >
    <slot />
  </transition>
</template>

<script lang="ts">
import { defineComponent } from 'vue'
import type { RendererElement } from '@vue/runtime-core'

export default defineComponent({
  name: 'VcCollapseTransition',
  computed: {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    hooks (): {[key: string]: any} {
      return {
        beforeEnter: this.beforeEnter,
        enter: this.enter,
        afterEnter: this.afterEnter,
        beforeLeave: this.beforeLeave,
        leave: this.leave,
        afterLeave: this.afterLeave
      }
    }
  },
  methods: {
    beforeEnter (el: RendererElement): void {
      if (!el.dataset) el.dataset = {}
      el.dataset.oldPaddingTop = el.style.paddingTop
      el.dataset.oldPaddingBottom = el.style.paddingBottom
      el.style.maxHeight = 0
      el.style.paddingTop = 0
      el.style.paddingBottom = 0
    },
    enter (el: RendererElement): void {
      el.dataset.oldOverflow = el.style.overflow
      if (el.scrollHeight !== 0) {
        el.style.maxHeight = `${el.scrollHeight}px`
        el.style.paddingTop = el.dataset.oldPaddingTop
        el.style.paddingBottom = el.dataset.oldPaddingBottom
      } else {
        el.style.maxHeight = 0
        el.style.paddingTop = el.dataset.oldPaddingTop
        el.style.paddingBottom = el.dataset.oldPaddingBottom
      }
      el.style.overflow = 'hidden'
    },
    afterEnter (el: RendererElement): void {
      el.style.maxHeight = ''
      el.style.overflow = el.dataset.oldOverflow
    },
    beforeLeave (el: RendererElement): void {
      if (!el.dataset) el.dataset = {}
      el.dataset.oldPaddingTop = el.style.paddingTop
      el.dataset.oldPaddingBottom = el.style.paddingBottom
      el.dataset.oldOverflow = el.style.overflow
      el.style.maxHeight = `${el.scrollHeight}px`
      el.style.overflow = 'hidden'
    },
    leave (el: RendererElement): void {
      if (el.scrollHeight !== 0) {
        el.style.maxHeight = 0
        el.style.paddingTop = 0
        el.style.paddingBottom = 0
      }
    },
    afterLeave (el: RendererElement): void {
      el.style.maxHeight = ''
      el.style.overflow = el.dataset.oldOverflow
      el.style.paddingTop = el.dataset.oldPaddingTop
      el.style.paddingBottom = el.dataset.oldPaddingBottom
    }
  }
})
</script>
