text: 'use strict'
  
  /**
   * static files (404.html, sw.js, conf.js)
   */
  const ASSET_URL = 'https://2096779623.github.io/gh-proxy/'
  // 前缀，如果自定义路由为example.com/gh/*，将PREFIX改为 '/gh/'，注意，少一个杠都会错！
  const PREFIX = '/'
  // git使用cnpmjs镜像、分支文件使用jsDelivr镜像的开关，0为关闭，默认开启
  const Config = {
      jsdelivr: 1,
      cnpmjs: 1
  }
  
  /** @type {RequestInit} */
  const PREFLIGHT_INIT = {
      status: 204,
      headers: new Headers({
          'access-control-allow-origin': '*',
          'access-control-allow-methods': 'GET,POST,PUT,PATCH,TRACE,DELETE,HEAD,OPTIONS',
          'access-control-max-age': '1728000',
      }),
  }
  
  /**
   * @param {any} body
   * @param {number} status
   * @param {Object<string, string>} headers
   */
  function makeRes(body, status = 200, headers = {}) {
      headers['access-control-allow-origin'] = '*'
      return new Response(body, {status, headers})
  }
  
  
  /**
   * @param {string} urlStr
   */
  function newUrl(urlStr) {
      try {
          return new URL(urlStr)
      } catch (err) {
          return null
      }
  }
  
  
  addEventListener('fetch', e => {
      const ret = fetchHandler(e)
          .catch(err => makeRes('cfworker error:\n' + err.stack, 502))
      e.respondWith(ret)
  })
  
  
  /**
   * @param {FetchEvent} e
   */
  async function fetchHandler(e) {
      const req = e.request
      const urlStr = req.url
      const urlObj = new URL(urlStr)
      let path = urlObj.searchParams.get('q')
      if (path) {
          return Response.redirect('https://' + urlObj.host + PREFIX + path, 301)
      }
      // cfworker 会把路径中的 `//` 合并成 `/`
      path = urlObj.href.substr(urlObj.origin.length + PREFIX.length).replace(/^https?:\/+/, 'https://')
      const exp1 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:releases|archive|suites)\/.*$/i
      const exp2 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:blob|raw)\/.*$/i
      const exp3 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:info|git-).*$/i
      const exp4 = /^(?:https?:\/\/)?raw\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+?\/.+$/i
      const exp5 = /^(?:https?:\/\/)?gist\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+$/i
      if (path.search(exp1) === 0 || path.search(exp5) === 0 || !Config.cnpmjs && (path.search(exp3) === 0 || path.search(exp4) === 0)) {
          return httpHandler(req, path)
      } else if (path.search(exp2) === 0) {
          if (Config.jsdelivr){
              const newUrl = path.replace('/blob/', '@').replace(/^(?:https?:\/\/)?github\.com/, 'https://cdn.jsdelivr.net/gh')
              return Response.redirect(newUrl, 302)
          }else{
              path = path.replace('/blob/', '/raw/')
              return httpHandler(req, path)
          }
      } else if (path.search(exp3) === 0) {
          const newUrl = path.replace(/^(?:https?:\/\/)?github\.com/, 'https://github.com.cnpmjs.org')
          return Response.redirect(newUrl, 302)
      } else if (path.search(exp4) === 0) {
          const newUrl = path.replace(/(?<=com\/.+?\/.+?)\/(.+?\/)/, '@$1').replace(/^(?:https?:\/\/)?raw\.(?:githubusercontent|github)\.com/, 'https://cdn.jsdelivr.net/gh')
          return Response.redirect(newUrl, 302)
      } else {
          return fetch(ASSET_URL + path)
      }
  }
  
  
  /**
   * @param {Request} req
   * @param {string} pathname
   */
  function httpHandler(req, pathname) {
      const reqHdrRaw = req.headers
  
      // preflight
      if (req.method === 'OPTIONS' &&
          reqHdrRaw.has('access-control-request-headers')
      ) {
          return new Response(null, PREFLIGHT_INIT)
      }
  
      let rawLen = ''
  
      const reqHdrNew = new Headers(reqHdrRaw)
  
      let urlStr = pathname
      if (urlStr.startsWith('github')) {
          urlStr = 'https://' + urlStr
      }
      const urlObj = newUrl(urlStr)
  
      /** @type {RequestInit} */
      const reqInit = {
          method: req.method,
          headers: reqHdrNew,
          redirect: 'follow',
          body: req.body
      }
      return proxy(urlObj, reqInit, rawLen, 0)
  }
  
  
  /**
   *
   * @param {URL} urlObj
   * @param {RequestInit} reqInit
   */
  async function proxy(urlObj, reqInit, rawLen) {
      const res = await fetch(urlObj.href, reqInit)
      const resHdrOld = res.headers
      const resHdrNew = new Headers(resHdrOld)
  
      // verify
      if (rawLen) {
          const newLen = resHdrOld.get('content-length') || ''
          const badLen = (rawLen !== newLen)
  
          if (badLen) {
              return makeRes(res.body, 400, {
                  '--error': `bad len: ${newLen}, except: ${rawLen}`,
                  'access-control-expose-headers': '--error',
              })
          }
      }
      const status = res.status
      resHdrNew.set('access-control-expose-headers', '*')
      resHdrNew.set('access-control-allow-origin', '*')
  
      resHdrNew.delete('content-security-policy')
      resHdrNew.delete('content-security-policy-report-only')
      resHdrNew.delete('clear-site-data')
  
      return new Response(res.body, {
          status,
          headers: resHdrNew,
      })
  }
  
  