{-# LANGUAGE OverloadedStrings #-}

import  Data.Default                    (Default (..))
import  Network.HTTP.Client.TLS         (newTlsManager)
import  Network.HTTP.Types              (status500)
import  Network.Wai
import  Network.Wai.Handler.Warp        (run)
import  Network.Wai.Middleware.Delegate (ProxySettings (..), delegateToProxy)

demoSettings :: ProxySettings
demoSettings = def { proxyHost = "httpbin.org" }

-- | An trivial app that proxies every request to httpbin.org
httpBin :: ProxySettings -> IO Application
httpBin s = do

  -- delegate everything!
  let takeItAll = const True
      dummyApp _ respond = respond $
        responseLBS status500 [] "I should have been proxied"

  manager <- newTlsManager
  return $ delegateToProxy s manager takeItAll dummyApp

main :: IO ()
main = httpBin demoSettings >>= run 3000