function flatten (parent, data = [], menusRaw = []) {
  return data.reduce((acc, { name, children }) => {
    const menu = menusRaw.filter(x => x.Url === name)[0]
    if (!menu) return acc

    const MenuName = menu.MenuName
    const item = { Url: name, MenuName, parent }

    if (children && children.length) {
      const p = parent.concat({ Url: name, MenuName })
      return acc.concat(item, flatten(p, children, menusRaw))
    }

    return acc.concat(item)
  }, [])
}

export default {
  state: {
    menusRaw: [],
    menus: [],
    breadcrumb: [],
  },
  mutations: {
    updateBread (state, { routerData, Url }) {
      // 扁平 routerData
      // 同时构造出 含有 title 的 parent 数据
      const routeList = flatten([], routerData, state.menusRaw)

      // 过滤出与 name 相同的 route 节点
      const currentRoute = routeList.filter(x => x.Url === Url)[0]

      // 获取 面包屑
      if (currentRoute) state.breadcrumb = currentRoute.parent.slice(1).concat(currentRoute)
    }
  }
}