{-# LANGUAGE OverloadedStrings, FlexibleContexts #-}

module Network.Wai.Application.Classic.Header where

import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as BS (tail,break)
import Network.HTTP.Types.Header
import Network.Wai

----------------------------------------------------------------

-- | Look-up key for If-Unmodified-Since:.
hIfUnmodifiedSince :: HeaderName
hIfUnmodifiedSince = "if-unmodified-since"

-- | Look-up key for Status.
hStatus :: HeaderName
hStatus = "status"

-- | Look-up key for X-Forwarded-For.
hXForwardedFor :: HeaderName
hXForwardedFor = "x-forwarded-for"

-- | Look-up key for Via.
hVia :: HeaderName
hVia = "via"

-- | Lookup key for Transfer-Encoding.
hTransferEncoding :: HeaderName
hTransferEncoding = "transfer-encoding"

-- | Lookup key for Accept-Encoding.
hAcceptEncoding :: HeaderName
hAcceptEncoding = "accept-encoding"

----------------------------------------------------------------

hostPort :: Request -> (ByteString, ByteString)
hostPort req = case requestHeaderHost req of
    Nothing -> ("Unknown","80")
    Just hostport -> case BS.break (== ':') hostport of
        (host,"")   -> (host,"80")
        (host,port) -> (host, BS.tail port)