<template>
  <div v-if="!item.meta || !item.meta.hidden">
    <!-- 显示具有单个子路由的菜单项或没有子路由的父路由 -->
    <template
      v-if="
        hasOneShowingChild(item.children, item as RouteRecordRaw) &&
        (!onlyOneChild.children || onlyOneChild.noShowingChildren) &&
        !item.meta?.alwaysShow
      "
    >
      <AppLink v-if="onlyOneChild.meta" :to="resolvePath(onlyOneChild.path)">
        <el-menu-item
          :index="resolvePath(onlyOneChild.path)"
          :class="{ 'submenu-title-noDropdown': !isNest }"
        >
          <SidebarMenuItemTitle
            :icon="onlyOneChild.meta.icon || (item.meta && item.meta.icon)"
            :title="onlyOneChild.meta.title"
          />
        </el-menu-item>
      </AppLink>
    </template>

    <!-- 显示具有多个子路由的父菜单项 -->
    <el-sub-menu v-else :index="resolvePath(item.path)" teleported>
      <template #title>
        <SidebarMenuItemTitle
          v-if="item.meta"
          :icon="item.meta && item.meta.icon"
          :title="item.meta.title"
        />
      </template>

      <SidebarMenuItem
        v-for="child in item.children"
        :key="child.path"
        :is-nest="true"
        :item="child"
        :base-path="resolvePath(child.path)"
      />
    </el-sub-menu>
  </div>
</template>
<script setup lang="ts">
defineOptions({
  name: "SidebarMenuItem",
  inheritAttrs: false,
});

import path from "path-browserify";
import { isExternal } from "@/utils/index";
import { RouteRecordRaw } from "vue-router";

const props = defineProps({
  /**
   * 路由(eg:user)
   */
  item: {
    type: Object,
    required: true,
  },

  /**
   * 父层级完整路由路径(eg:/system)
   */
  basePath: {
    type: String,
    required: true,
  },
  isNest: {
    type: Boolean,
    default: false,
  },
});

const onlyOneChild = ref(); // 临时变量，唯一子路由

/**
 * 判断当前路由是否只有一个子路由
 *
 * 1：如果只有一个子路由： 返回 true
 * 2：如果无子路由 ：返回 true
 *
 * @param children 子路由数组
 * @param parent 当前路由
 */
function hasOneShowingChild(
  children: RouteRecordRaw[] = [],
  parent: RouteRecordRaw
) {
  // 子路由集合
  const showingChildren = children.filter((route: RouteRecordRaw) => {
    if (route.meta?.hidden) {
      // 过滤不显示的子路由
      return false;
    } else {
      route.meta!.hidden = false;
      // 临时变量（多个子路由 onlyOneChild 变量是用不上的）
      onlyOneChild.value = route;
      return true;
    }
  });

  // 如果只有一个子路由, 返回 true
  if (showingChildren.length === 1) {
    return true;
  }

  // 如果没有子路由，显示父级路由
  if (showingChildren.length === 0) {
    onlyOneChild.value = { ...parent, path: "", noShowingChildren: true };
    return true;
  }
  return false;
}

/**
 *  解析路由路径(相对路径 → 绝对路径)
 *
 * @param routePath 路由路径
 */
function resolvePath(routePath: string) {
  if (isExternal(routePath)) {
    return routePath;
  }
  if (isExternal(props.basePath)) {
    return props.basePath;
  }

  // 完整路径(/system/user) = 父级路径(/system) + 路由路径(user)
  const fullPath = path.resolve(props.basePath, routePath);
  return fullPath;
}
</script>

<style lang="scss">
.hideSidebar {
  .submenu-title-noDropdown {
    position: relative;
    padding: 0 !important;

    .el-tooltip {
      padding: 0 !important;

      .sub-el-icon {
        margin-left: 19px;
      }
    }

    & > span {
      display: inline-block;
      width: 0;
      height: 0;
      overflow: hidden;
      visibility: hidden;
    }
  }

  .el-sub-menu {
    overflow: hidden;

    & > .el-sub-menu__title {
      padding: 0 !important;

      .sub-el-icon {
        margin-left: 19px;
      }

      .el-sub-menu__icon-arrow {
        display: none;
      }
    }
  }

  .el-menu--collapse {
    width: $sidebar-width-collapsed;

    .el-sub-menu {
      & > .el-sub-menu__title {
        & > span {
          display: inline-block;
          width: 0;
          height: 0;
          overflow: hidden;
          visibility: hidden;
        }
      }
    }
  }
}
</style>
