import type { Middleware } from './index'

/**
 * Sets a request header with the value of a cookie from document.cookie, if it exists
 */
export const CsrfMiddleware = (cookieName = 'csrfToken', headerName = 'x-csrf-token'): Middleware =>
  function CsrfMiddleware() {
    const REGEXP_COOKIE_NAME = new RegExp(cookieName + '[^;]+')
    const getCookie = () => {
      const cookieString = REGEXP_COOKIE_NAME.exec((document || {}).cookie || '')
      return cookieString
        ? decodeURIComponent(cookieString.toString().replace(/^[^=]+./, ''))
        : undefined
    }

    return {
      async prepareRequest(next) {
        const request = await next()
        if (typeof document === 'undefined') {
          return request
        }
        const csrf = getCookie()
        return !csrf
          ? request
          : request.enhance({
              headers: { [headerName]: csrf },
            })
      },
    }
  }
export default CsrfMiddleware