/**
 * 跨域中间件
 * @author yutent<yutent.io@gmail.com>
 * @date 2020/09/18 14:55:49
 */

import { parse } from 'node:url'

export function createCors() {
  return function (req, res, next) {
    let opts = this.get('cors')

    if (opts.enabled) {
      let origin = req.headers['origin'] || req.headers['referer'] || ''
      let headers = req.headers['access-control-request-headers']
      let { hostname, host, protocol } = parse(origin)

      if (opts.origin.length && hostname) {
        let pass = false
        for (let it of opts.origin) {
          if (hostname.endsWith(it)) {
            pass = true
            break
          }
        }
        if (pass === false) {
          return (res.body = null)
        }
      }
      if (opts.credentials) {
        res.set('Access-Control-Allow-Credentials', 'true')
      }

      res.set('Access-Control-Allow-Origin', `${protocol}//${host}`)
      res.set('Access-Control-Allow-Methods', req.method)

      if (headers) {
        res.set('Access-Control-Allow-Headers', headers)
      }

      if (opts.maxAge) {
        res.set('Access-Control-Max-Age', opts.maxAge)
      }

      if (req.method === 'OPTIONS') {
        return (res.body = null)
      }
    }
    next()
  }
}