Redirect.hs

{-# LANGUAGE OverloadedStrings #-}

module Network.Wai.Application.Classic.Redirect (
    redirectApp,
) where

import qualified Data.ByteString.Char8 as BS
import Network.HTTP.Types
import Network.Wai
import Network.Wai.Application.Classic.Field
import Network.Wai.Application.Classic.FileInfo (matchRoute)
import Network.Wai.Application.Classic.Path
import Network.Wai.Application.Classic.Types

redirectApp :: ClassicAppSpec -> RedirectRoute -> Application
redirectApp _ route req respond
    | matchRoute src path = respond $ responseLBS status hdr ""
    | otherwise = respond $ responseLBS notFound404 textPlainHeader "Not Found\r\n"
  where
    path = rawPathInfo req
    src = redirectSrc route
    dst = redirectDst route
    -- Scheme must not be included because of no way to tell
    -- http or https.
    rurl = BS.concat ["//", dst </> (path <\> src), rawQueryString req]
    hdr = locationHeader rurl
    status = movedPermanently301