import { defineStore } from 'pinia'
import { ref } from 'vue'
import axios from 'axios'
import { httpGet } from '@/utils/request'
import { transformMenu, MENU_LABELS, type ResolvedMenu, type BackendMenuItem } from '@/config/menu-labels'

/**
 * 菜单 Store
 * W3.7 改用 httpGet 统一封装
 * W2 D3 改造:从后端 /sys/menu/nav 拉真实菜单树
 * - 后端返回 name=null,改前端 MENU_LABELS 映射表(详见 config/menu-labels.ts)
 * - 用 transformMenu 转后端结构 -> 前端 ResolvedMenu
 * - 同 menu store 暴露给 AppLayout 渲染
 */
export type MenuItem = ResolvedMenu

export const useMenuStore = defineStore('menu', () => {
  const list = ref<MenuItem[]>([])
  const loading = ref(false)
  const error = ref<string | null>(null)
  const collapsed = ref<boolean>(false)
  /** 上次拉取时间(毫秒) */
  const fetchedAt = ref<number>(0)

  function toggleCollapsed() {
    collapsed.value = !collapsed.value
  }

  /**
   * F006 W2 D3:调 /sys/menu/nav 拿后端菜单树
   * 走 vite proxy 转发到 gateway,header 带 Bearer(token 由 httpGet 拦截器自动加)
   * 5 分钟内不重复拉
   */
  /**
   * 过滤无效菜单项(测试数据、数字名称等)
   * super_admin=1 会返回所有菜单,包含很多测试/占位数据
   */
  function filterInvalidMenus(items: ResolvedMenu[]): ResolvedMenu[] {
    return items.filter(item => {
      const title = item.title?.trim() || ''
      // 过滤纯数字标题(如 "2", "70", "1111111111")
      if (/^\d+$/.test(title)) return false
      // 过滤"未知菜单"
      if (title === '未知菜单') return false
      // 过滤过长的数字串(超过8位)
      if (/^\d{8,}$/.test(title)) return false
      // 递归过滤子菜单
      if (item.children?.length) {
        item.children = filterInvalidMenus(item.children)
      }
      return true
    })
  }

  /**
   * V2 R2 (方案 B 实施): 后端拉到的菜单, url 不在 MENU_LABELS 里的全砍
   * 父菜单(无 url 但有 children): 递归砍子菜单, 若砍光连父也删
   * 极致干净: 前端 MENU_LABELS 是真实意图, 后端 super_admin 全集只是临时数据
   */
  function filterByFrontendTruth(items: ResolvedMenu[]): ResolvedMenu[] {
    const allowedUrls = new Set(MENU_LABELS.map(m => m.url))
    const seenUrls = new Set<string>()  // W5.x.x+3.1: 跨父菜单去重 (老 vue 一个 url 可能在多个父菜单下重复)
    return items
      .map(item => {
        // 父菜单: 无 url, 递归处理 children
        if (!item.url) {
          if (!item.children?.length) return null
          const filtered = filterByFrontendTruth(item.children)
          if (!filtered.length) return null
          return { ...item, children: filtered }
        }
        // F002-W18 修: 后端 url 可能带 / 前缀 (如 /user/enterprise/enterprise),
        // MENU_LABELS 不带 / (如 user/enterprise/enterprise), 规范化后匹配
        const normalizedUrl = item.url.replace(/^\//, '')
        if (!allowedUrls.has(item.url) && !allowedUrls.has(normalizedUrl)) return null
        if (seenUrls.has(normalizedUrl)) return null
        seenUrls.add(normalizedUrl)
        return item
      })
      .filter((item): item is ResolvedMenu => item !== null)
  }

  async function fetchMenu(force = false) {
    if (loading.value) return
    if (!force && fetchedAt.value && Date.now() - fetchedAt.value < 5 * 60 * 1000) {
      return
    }
    loading.value = true
    error.value = null
    try {
      const data = await httpGet<BackendMenuItem[]>('/sys/menu/nav')
      const transformed = transformMenu(Array.isArray(data) ? data : [])
      const frontendTruth = filterByFrontendTruth(transformed)
      list.value = filterInvalidMenus(frontendTruth)
      fetchedAt.value = Date.now()
    } catch (e: any) {
      error.value = e?.msg || e?.message || '菜单加载失败'
    } finally {
      loading.value = false
    }
  }

  function clear() {
    list.value = []
    fetchedAt.value = 0
    error.value = null
  }

  return { list, loading, error, collapsed, fetchedAt, toggleCollapsed, fetchMenu, clear }
})