<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, onlyOneChild.query)">
        <el-menu-item :index="resolvePath(onlyOneChild.path)" :class="{'submenu-title-noDropdown':!isNest}">
          <item :icon="onlyOneChild.meta.icon||(item.meta&&item.meta.icon)" :title="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="item.meta.title" />
      </template>
      <sidebar-item
        v-for="child in item.children"
        :key="child.path"
        :is-nest="true"
        :item="child"
        :base-path="resolvePath(item.path)"
        class="nest-menu"
      />
    </el-submenu>
  </div>
</template>

<script>
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() {
    this.onlyOneChild = null
    return {}
  },
  methods: {
    hasOneShowingChild(children = [], parent) {
      if (!children) {
        children = [];
      }
      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
      }

      // 扁平路由（完整 path 如 /crm/line）无 children 时须保留 parent.path，
      // 否则 el-menu-item index 全为空字符串，点击一项会全部高亮
      if (showingChildren.length === 0) {
        this.onlyOneChild = { ...parent, path: parent.path || '', noShowingChildren: true }
        return true
      }

      return false
    },
    resolvePath(routePath, routeQuery) {
      if (isExternal(routePath)) {
        return routePath
      }
      if (isExternal(this.basePath)) {
        return this.basePath
      }
      const fullPath = this.joinPath(this.basePath, routePath)
      if (routeQuery) {
        const query = JSON.parse(routeQuery)
        return { path: fullPath, query: query }
      }
      return fullPath
    },
    joinPath(base, routePath) {
      if (!routePath) {
        return base || ''
      }
      const seg = String(routePath)
      if (seg.startsWith('/') || seg.startsWith('http://') || seg.startsWith('https://')) {
        return seg
      }
      const basePath = base || ''
      if (!basePath) {
        return '/' + seg.replace(/^\//, '')
      }
      const left = basePath.endsWith('/') ? basePath.slice(0, -1) : basePath
      return left + '/' + seg.replace(/^\//, '')
    }
  }
}
</script>
