Hack.hs

module Bird.Translator.Hack(
  fromBirdReply
, toBirdRequest
) where

import qualified Hack as Hack
import qualified Data.Map as Hash
import Bird.Translator
import Bird.Request
import Bird.Reply
import Bird.Request.QueryStringParser
import Bird.Request.UrlencodedFormParser
import Data.ByteString.Lazy.Char8 (pack, unpack)

instance BirdReplyTranslator Hack.Response where
  fromBirdReply r = 
    Hack.Response {
      Hack.status = replyStatus r,
      Hack.headers = (Hash.toList $ Hash.insertWith insertUnlessPresent "Content-Type" "text/html" $ replyHeaders r),
      Hack.body = pack $ replyBody r
    }
    where
      insertUnlessPresent = flip const

instance BirdRequestTranslator Hack.Env where
  toBirdRequest e = 
    Request {
      verb = hackRequestMethodToBirdRequestMethod $ Hack.requestMethod e
    , path = split '/' $ Hack.pathInfo e
    , params = parsedParams
    , rawRequestUri = (Hack.pathInfo e) ++ maybeQueryString
    }
    where
      maybeQueryString =
        if Hack.queryString e /= ""
        then "?" ++ Hack.queryString e
        else ""
      parsedQueryString = parseQueryString (Hack.queryString e)
      parsedUrlencodedForm = 
        if   (Hack.requestMethod e == Hack.POST || Hack.requestMethod e == Hack.PUT) && 
             lookup "Content-Type" (Hack.http e) == Just "application/x-www-form-urlencoded"
        then parseQueryString (unpack $ Hack.hackInput e)
        else []
      parsedParams = parsedQueryString ++ parsedUrlencodedForm


hackRequestMethodToBirdRequestMethod rm = 
  case rm of 
    Hack.GET -> GET
    Hack.PUT -> PUT
    Hack.POST -> POST
    Hack.DELETE -> DELETE
    _ -> error "unknown request method!"

split :: Char -> String -> [String]
split d s
  | findSep == [] = []
  | otherwise     = t : split d s''
    where
      (t, s'') = break (== d) findSep
      findSep = dropWhile (== d) s