<template>
    <div v-if="!item.hidden">
      <template v-if="hasOneShowingChild(item.children,item) && (!onlyOneChild.children||onlyOneChild.noShowingChildren)&&!item.alwaysShow">
        <app-link v-if="onlyOneChild.meta" :to="resolvePath(onlyOneChild.path)">
          <el-menu-item :index="resolvePath(onlyOneChild.path)" :class="{'submenu-title-noDropdown':!isNest}">

            <item :icon="onlyOneChild.meta.icon||(item.meta&&item.meta.icon)" :title="generateTitle(onlyOneChild.meta.title)" />

          </el-menu-item>
        </app-link>
      </template>
  
      <el-submenu v-else ref="subMenu" :index="resolvePath(item.path)" popper-append-to-body>
        <template slot="title">

          <item v-if="item.meta" :icon="item.meta && item.meta.icon" :title="generateTitle(item.meta.title)" />

        </template>
        <sidebar-item
          v-for="child in item.children"
          :key="child.path"
          :is-nest="true"
          :item="child"
          :base-path="resolvePath(child.path)"
          class="nest-menu"
        />
      </el-submenu>
    </div>
  </template>
  
  <script>
  import path from 'path'

  import { generateTitle } from '@/utils/i18n'

  import { isExternal } from '@/utils/validate'
  import Item from './Item'
  import AppLink from './Link'
  import FixiOSBug from './FixiOSBug'
  
  export default {
    name: 'SidebarItem',
    components: { Item, AppLink },
    mixins: [FixiOSBug],
    props: {
      // route object
      item: {
        type: Object,
        required: true
      },
      isNest: {
        type: Boolean,
        default: false
      },
      basePath: {
        type: String,
        default: ''
      }
    },
    data() {
      // To fix https://github.com/PanJiaChen/vue-admin-template/issues/237
      // TODO: refactor with render function
      this.onlyOneChild = null
      return {}
    },
    methods: {
      hasOneShowingChild(children = [], parent) {
        const showingChildren = children.filter(item => {
          if (item.hidden) {
            return false
          } else {
            // Temp set(will be used if only has one showing child)
            this.onlyOneChild = item
            return true
          }
        })
  
        // When there is only one child router, the child router is displayed by default
        if (showingChildren.length === 1) {
          return true
        }
  
        // Show parent if there are no child router to display
        if (showingChildren.length === 0) {
          this.onlyOneChild = { ... parent, path: '', noShowingChildren: true }
          return true
        }
  
        return false
      },
      resolvePath(routePath) {
        if (isExternal(routePath)) {
          return routePath
        }
        if (isExternal(this.basePath)) {
          return this.basePath
        }
        return path.resolve(this.basePath, routePath)

      },
  
      generateTitle

    }
  }
  </script>