const TAB_KEYS = ['nav.home', 'nav.ai', 'nav.message', 'nav.mine']

/** 与 pages.json tabBar.list[].pagePath 一致（无开头 /） */
const TAB_PAGE_PATHS = new Set([
  'pages/home/index',
  'pages/ai/index',
  'pages/message/index',
  'pages/mine/index'
])

/** 运行时会改 TabBar 的 uni API（非 Tab 页调用会报 not TabBar page） */
const TABBAR_API_NAMES = [
  'setTabBarStyle',
  'setTabBarItem',
  'setTabBarBadge',
  'removeTabBarBadge',
  'showTabBarRedDot',
  'hideTabBarRedDot',
  'showTabBar',
  'hideTabBar',
  'setTabBarMidButton'
]

/** 首次安装时缓存的原始 API（避免重复 bind 已包装函数） */
const TABBAR_RAW_APIS = {}

let tabBarEntryTask = null

function readUniTabPagePaths() {
  try {
    const list =
      (typeof __uniConfig !== 'undefined' &&
        __uniConfig.tabBar &&
        __uniConfig.tabBar.list) ||
      []
    list.forEach((item) => {
      const path = normalizePageRoute(item.pagePath || '')
      if (path) {
        TAB_PAGE_PATHS.add(path)
      }
    })
  } catch (e) {
    // ignore
  }
}

function getPublicPathPrefixes() {
  const prefixes = ['bqH5/', 'bqjy/']
  try {
    const envPath = String(import.meta.env.VITE_APP_PUBLIC_PATH || '')
      .trim()
      .replace(/^\/|\/$/g, '')
    if (envPath) {
      const withSlash = `${envPath}/`
      if (!prefixes.includes(withSlash)) {
        prefixes.unshift(withSlash)
      }
    }
  } catch (e) {
    // ignore
  }
  return prefixes
}

function normalizePageRoute(route) {
  if (!route) {
    return ''
  }
  let r = String(route).split('?')[0].replace(/^\//, '')
  if (r.endsWith('.html')) {
    r = r.slice(0, -5)
  }
  for (const prefix of getPublicPathPrefixes()) {
    if (r.startsWith(prefix)) {
      r = r.slice(prefix.length)
    }
  }
  return r
}

function getCurrentPageRoute() {
  const stack = getCurrentPages()
  if (stack.length) {
    const cur = stack[stack.length - 1]
    return cur.route || cur.$page?.route || cur.$page?.fullPath || ''
  }
  if (typeof window !== 'undefined' && window.location && window.location.pathname) {
    return window.location.pathname
  }
  return ''
}

function getCurrentPageMeta() {
  const stack = getCurrentPages()
  if (!stack.length) {
    return null
  }
  const cur = stack[stack.length - 1]
  return cur.$page?.meta || cur.$vm?.$page?.meta || null
}

/**
 * 路由是否对应 tabBar.list 中的页面（不等于当前栈顶一定是 Tab 上下文）
 */
export function isTabBarRoute(route) {
  const normalized = normalizePageRoute(route || getCurrentPageRoute())
  return !!normalized && TAB_PAGE_PATHS.has(normalized)
}

/**
 * 当前栈顶是否为原生 TabBar 页
 * 须同时满足：meta.isTabBar === true 且 route 在 tabBar.list 内
 * （仅 meta 或仅 route 在 H5 生产环境都可能误判，导致 setTabBarStyle:fail）
 */
export function isTabBarPage() {
  if (!isTabBarRoute()) {
    return false
  }
  const meta = getCurrentPageMeta()
  return !!(meta && meta.isTabBar === true)
}

/**
 * H5 生产环境直开/刷新 Tab URL 时，用 switchTab 切回真正的 Tab 上下文
 * @returns {Promise<boolean>} 切换后是否为 TabBar 页
 */
export function ensureTabBarEntry() {
  if (isTabBarPage()) {
    return Promise.resolve(true)
  }
  if (!isTabBarRoute()) {
    return Promise.resolve(false)
  }
  if (tabBarEntryTask) {
    return tabBarEntryTask
  }
  const route = normalizePageRoute(getCurrentPageRoute())
  tabBarEntryTask = new Promise((resolve) => {
    uni.switchTab({
      url: `/${route}`,
      complete: () => {
        tabBarEntryTask = null
        resolve(isTabBarPage())
      }
    })
  })
  return tabBarEntryTask
}

function noopTabBarResult(name) {
  return { errMsg: `${name}:ok` }
}

function finishNoopTabBarCall(name, options) {
  const result = noopTabBarResult(name)
  if (options && typeof options.success === 'function') {
    options.success(result)
  }
  if (options && typeof options.complete === 'function') {
    options.complete(result)
  }
  return Promise.resolve(result)
}

function isTabBarFailMsg(msg) {
  return String(msg || '').includes('TabBar') && String(msg || '').includes('fail')
}

function rememberRawTabBarApi(target, name) {
  if (TABBAR_RAW_APIS[name]) {
    return TABBAR_RAW_APIS[name]
  }
  const fn = target[name]
  if (typeof fn !== 'function') {
    return null
  }
  if (fn._tabBarGuardRaw) {
    TABBAR_RAW_APIS[name] = fn._tabBarGuardRaw
    return TABBAR_RAW_APIS[name]
  }
  TABBAR_RAW_APIS[name] = fn.bind(target)
  return TABBAR_RAW_APIS[name]
}

/**
 * H5 生产包中框架 / uview 可能在我们安装守卫后又写回 uni API，故每次启动 / 切页都重装
 */
function wrapTabBarApi(target, name) {
  if (!target || typeof target[name] !== 'function') {
    return
  }
  const raw = rememberRawTabBarApi(target, name)
  if (!raw) {
    return
  }
  function patchedTabBarApi(options) {
    const opts = options || {}
    if (!isTabBarPage()) {
      return finishNoopTabBarCall(name, opts)
    }
    try {
      const ret = raw(opts)
      if (ret && typeof ret.catch === 'function') {
        ret.catch((err) => {
          if (isTabBarFailMsg(err && err.errMsg)) {
            return finishNoopTabBarCall(name, opts)
          }
          throw err
        })
      }
      if (ret && typeof ret.then === 'function') {
        return ret.then(
          (res) => {
            if (res && isTabBarFailMsg(res.errMsg)) {
              return noopTabBarResult(name)
            }
            return res
          },
          (err) => {
            if (isTabBarFailMsg(err && err.errMsg)) {
              return noopTabBarResult(name)
            }
            throw err
          }
        )
      }
      return ret
    } catch (err) {
      if (isTabBarFailMsg(err && err.errMsg)) {
        return finishNoopTabBarCall(name, opts)
      }
      throw err
    }
  }
  patchedTabBarApi._tabBarGuardPatched = true
  patchedTabBarApi._tabBarGuardRaw = raw
  target[name] = patchedTabBarApi
}

function patchTabBarApis(target) {
  if (!target) {
    return
  }
  TABBAR_API_NAMES.forEach((name) => wrapTabBarApi(target, name))
}

function installTabBarInterceptors() {
  if (typeof uni === 'undefined' || !uni.addInterceptor) {
    return
  }
  TABBAR_API_NAMES.forEach((name) => {
    if (typeof uni[name] !== 'function') {
      return
    }
    uni.addInterceptor(name, {
      invoke() {
        if (!isTabBarPage()) {
          return false
        }
      }
    })
  })
}

export function installTabBarApiGuard() {
  readUniTabPagePaths()
  if (typeof uni !== 'undefined') {
    patchTabBarApis(uni)
    installTabBarInterceptors()
  }
  if (typeof wx !== 'undefined') {
    patchTabBarApis(wx)
  }
}

installTabBarApiGuard()

/**
 * 原生 tabBar 的 text 不能写进 pages.json 的 i18n，需在运行时按当前语言更新（仅 Tab 页）
 * @param {(key: string) => string} t  如 (k) => this.$t(k)
 */
export function syncTabBarText(t) {
  if (!isTabBarPage()) {
    return
  }
  TAB_KEYS.forEach((key, index) => {
    uni.setTabBarItem({
      index,
      text: t(key)
    })
  })
}