<template>
  <Dropdown ref="dropdown" @on-click="handleClick" :class="hideTitle ? '' : 'collased-menu-dropdown'"
    :transfer="hideTitle" :placement="placement">
    <a class="drop-menu-a" type="text" @mouseover="handleMousemove($event, children)"
      :style="{textAlign: !hideTitle ? 'left' : ''}">
      <Icon :size="rootIconSize" color="#fff" :type="parentItem.icon" />
      <span class="menu-title" v-if="!hideTitle">{{ showTitle(parentItem) }}</span>
      <Icon style="float: right;" v-if="!hideTitle" type="ios-arrow-forward" :size="16" />
    </a>
    <DropdownMenu ref="dropdown" slot="list">
      <template v-for="child in children">
        <collapsed-menu v-if="showChildren(child)" :icon-size="iconSize" :parent-item="child" :theme="theme"
          :key="`drop-${child.name}`"></collapsed-menu>
        <DropdownItem v-else :key="`drop-${child.name}`" :name="child.name">
          <Icon :size="iconSize" :type="child.icon" />
          <span class="menu-title">{{ showTitle(child) }}</span>
        </DropdownItem>
      </template>
    </DropdownMenu>
  </Dropdown>
</template>
<script>
import mixin from './mixin'
import itemMixin from './item.mixin'
import { findNodeUpperByClasses } from '@/utils'

export default {
  name: 'CollapsedMenu',
  mixins: [mixin, itemMixin],
  props: {
    hideTitle: {
      type: Boolean,
      default: false
    },
    rootIconSize: {
      type: Number,
      default: 16
    },
    theme: {
      type: String,
      required: true
    }
  },
  data () {
    return {
      placement: 'right-end'
    }
  },
  methods: {
    handleClick (name) {
      this.$emit('on-click', name)
    },
    handleMousemove (event, children) {
      const { pageY } = event
      const height = children.length * 38
      const isOverflow = pageY + height < window.innerHeight
      this.placement = isOverflow ? 'right-start' : 'right-end'
    }
  },
  mounted () {
    let dropdown = findNodeUpperByClasses(this.$refs.dropdown.$el, ['ivu-select-dropdown', 'ivu-dropdown-transfer'])
    if (dropdown) dropdown.style.overflow = 'visible'
  }
}
</script>
