<template>
  <div class="sidebar-item" 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)">
          <icon :icon="onlyOneChild.meta.icon"></icon>{{ onlyOneChild.meta.title }}
        </el-menu-item>
      </app-link>
    </template>

    <template v-else>
      <el-submenu ref="subMenu" :index="resolvePath(item.path)" popper-append-to-body>
        <template slot="title">
          <icon :icon="item.meta.icon"></icon>{{ item.meta.title }}
        </template>
        <navbar-item v-for="child in item.children"
                     :key="child.path" :item="child"
                     :base-path="resolvePath(child.path)"
                     class="nest-menu" />
      </el-submenu>
    </template>
  </div>
</template>

<script>
import path from 'path'
import AppLink from '../Sidebar/Link.vue'
import { isExternal } from '@/utils/validate'
import Icon from "./Icon.vue"

export default {
  name: 'NavbarItem',
  components: {
    AppLink,
    Icon
  },
  props: {
    item: {
      type: Object,
      required: true,
    },
    basePath: {
      type: String,
      default: "",
    },
  },
  data() {
    return {
      onlyOneChild: null,
    };
  },
  methods: {
    resolvePath(routePath) {
      if (isExternal(routePath)) {
        return routePath
      }
      if (isExternal(this.basePath)) {
        return this.basePath
      }
      return path.resolve(this.basePath, routePath)
    },

    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
    },
  },
  computed: {
  },
};
</script>

<style scoped lang="scss"></style>
