module Web.Routes.Wai where
import qualified Data.ByteString.Char8 as S
import qualified Data.ByteString.Lazy.Char8 as L
import Data.Text (Text)
import qualified Data.Text as Text
import qualified Data.Text.Encoding as Text
import Control.Monad.Trans.Resource (ResourceT)
import Network.Wai ( Application, Request, Response, rawPathInfo
, responseLBS)
import Network.HTTP.Types (status404)
import Web.Routes.Base (decodePathInfo, encodePathInfo)
import Web.Routes.PathInfo (PathInfo(..), fromPathInfo, stripOverlapBS
, toPathInfoParams)
import Web.Routes.RouteT (RouteT, unRouteT)
import Web.Routes.Site (Site(..))
-- | a low-level function for convert a parser, printer, and routing function into an 'Application'
handleWaiError :: (url -> [(Text, Maybe Text)] -> Text) -- ^ function to convert a 'url' + params into path info + query string
-> (S.ByteString -> Either String url) -- ^ function to parse path info into 'url'
-> S.ByteString -- ^ app root
-> (String -> Application) -- ^ function to call if there is a decoding error, argument is the parse error
-> ((url -> [(Text, Maybe Text)] -> Text) -> url -> Application) -- ^ routing function
-> Application
handleWaiError fromUrl toUrl approot handleError handler =
\request ->
do let fUrl = toUrl $ stripOverlapBS approot $ rawPathInfo request
case fUrl of
(Left parseError) -> handleError parseError request
(Right url) -> handler (\url params -> (Text.decodeUtf8 approot) `Text.append` (fromUrl url params)) url request
-- | a low-level function for convert a parser, printer, and routing function into an 'Application'
--
-- returns 404 if the url parse fails.
handleWai_ :: (url -> [(Text, Maybe Text)] -> Text) -- ^ function to convert a 'url' + params into path info + query string
-> (S.ByteString -> Either String url) -- ^ function to parse path info into 'url'
-> S.ByteString -- ^ app root
-> ((url -> [(Text, Maybe Text)] -> Text) -> url -> Application) -- ^ routing function
-> Application
handleWai_ fromUrl toUrl approot handler =
handleWaiError fromUrl toUrl approot handleError handler
where
handleError :: String -> Application
handleError parseError = \_request -> return $ responseLBS status404 [] (L.pack parseError)
-- | function to convert a routing function into an Application by
-- leveraging 'PathInfo' to do the url conversion
handleWai :: (PathInfo url) =>
S.ByteString -- ^ approot
-> ((url -> [(Text, Maybe Text)] -> Text) -> url -> Application) -- ^ routing function
-> Application
handleWai approot handler = handleWai_ toPathInfoParams fromPathInfo approot handler
-- | a function to convert a parser, printer and routing function into an 'Application'.
--
-- This is similar to 'handleWai_' expect that it expects the routing function to use 'RouteT'.
handleWaiRouteT_ :: (url -> [(Text, Maybe Text)] -> Text) -- ^ function to convert a 'url' + params into path info + query string
-> (S.ByteString -> Either String url) -- ^ function to parse path info into 'url'
-> S.ByteString -- ^ app root
-> (url -> Request -> RouteT url (ResourceT IO) Response) -- ^ routing function
-> Application
handleWaiRouteT_ toPathInfo fromPathInfo approot handler =
handleWai_ toPathInfo fromPathInfo approot (\toPathInfo' url request -> unRouteT (handler url request) toPathInfo')
-- | convert a 'RouteT' based routing function into an 'Application' using 'PathInfo' to do the url conversion
handleWaiRouteT :: (PathInfo url) =>
S.ByteString -- ^ app root
-> (url -> Request -> RouteT url (ResourceT IO) Response) -- ^ routing function
-> Application
handleWaiRouteT approot handler = handleWaiRouteT_ toPathInfoParams fromPathInfo approot handler
-- |convert a 'Site url Application' into a plain-old 'Application'
waiSite :: Site url Application -- ^ Site
-> S.ByteString -- ^ approot, e.g. http://www.example.org/app
-> Application
waiSite site approot = handleWai_ formatURL (parsePathSegments site . decodePathInfo) approot (handleSite site)
where
formatURL url params =
let (paths, moreParams) = formatPathSegments site url
in encodePathInfo paths (params ++ moreParams)