{- |Description: Provide a combinator to give handlers access to the
 raw WAI request.
-}
module Servant.API.RawRequest where

import Network.Wai
import Servant
import Servant.Server.Internal.Delayed (passToServer)

{- |
  @RawRequest@ provides the `Network.Wai.Request` field from the WAI request.

  Example:

@
import Control.Monad.IO.Class (liftIO)
import Network.Wai
import Servant
import ServantExtras.RawRequest

type MyAPI = "my-request-endpoint"
           :> RawRequest
           :> Get '[JSON] NoContent

myServer :: Server MyAPI
myServer = requestEndpointHandler
  where
    requestEndpointHandler :: Request -> Handler NoContent
    requestEndpointHandler req =
      -- Do something clever with the request
      pure NoContent
@
-}
data RawRequest

instance HasServer api ctx => HasServer (RawRequest :> api) ctx where
  type ServerT (RawRequest :> api) m = Request -> ServerT api m

  hoistServerWithContext :: forall (m :: * -> *) (n :: * -> *).
Proxy (RawRequest :> api)
-> Proxy ctx
-> (forall x. m x -> n x)
-> ServerT (RawRequest :> api) m
-> ServerT (RawRequest :> api) n
hoistServerWithContext Proxy (RawRequest :> api)
_ Proxy ctx
ctx forall x. m x -> n x
nt ServerT (RawRequest :> api) m
server =
    forall {k} (api :: k) (context :: [*]) (m :: * -> *) (n :: * -> *).
HasServer api context =>
Proxy api
-> Proxy context
-> (forall x. m x -> n x)
-> ServerT api m
-> ServerT api n
hoistServerWithContext (forall {k} (t :: k). Proxy t
Proxy @api) Proxy ctx
ctx forall x. m x -> n x
nt forall b c a. (b -> c) -> (a -> b) -> a -> c
. ServerT (RawRequest :> api) m
server
  route :: forall env.
Proxy (RawRequest :> api)
-> Context ctx
-> Delayed env (Server (RawRequest :> api))
-> Router env
route Proxy (RawRequest :> api)
_ Context ctx
ctx Delayed env (Server (RawRequest :> api))
server =
    forall {k} (api :: k) (context :: [*]) env.
HasServer api context =>
Proxy api
-> Context context -> Delayed env (Server api) -> Router env
route (forall {k} (t :: k). Proxy t
Proxy @api) Context ctx
ctx forall a b. (a -> b) -> a -> b
$
      Delayed env (Server (RawRequest :> api))
server forall env a b.
Delayed env (a -> b) -> (Request -> a) -> Delayed env b
`passToServer` \Request
req ->
        Request
req