{-# LANGUAGE OverloadedStrings #-}
module Blunt where
import Control.Exception (SomeException, evaluate, handle)
import Data.ByteString.Char8 (unpack)
import Data.ByteString.Lazy (fromStrict)
import Data.ByteString.Lazy.Char8 (pack)
import Network.HTTP.Types (notFound404, ok200)
import Network.Wai (Application, Request, Response, queryString, pathInfo,
requestMethod, responseLBS)
import Network.Wai.Handler.Warp (runEnv)
import Pointfree (pointfree')
main :: IO ()
main = runEnv 8080 application
application :: Application
application request respondWith = do
let action = route request
response <- action request
respondWith response
type Action = Request -> IO Response
route :: Request -> Action
route request = case (requestMethod request, pathInfo request) of
("GET", []) -> indexAction
("GET", ["pointfree"]) -> pointfreeAction
_ -> notFoundAction
indexAction :: Action
indexAction _request = do
let headers = [("Content-Type", "text/html; charset=utf-8")]
body = pack html
return (responseLBS ok200 headers body)
pointfreeAction :: Action
pointfreeAction request = do
let params = queryString request
input = case lookup "input" params of
Just (Just param) -> param
_ -> ""
maybeOutput <- safePointfree (unpack input)
let headers = [("Content-Type", "text/plain; charset=utf-8")]
body = case maybeOutput of
Just output -> pack output
Nothing -> fromStrict input
return (responseLBS ok200 headers body)
notFoundAction :: Action
notFoundAction _request = return (responseLBS notFound404 [] "")
safePointfree :: String -> IO (Maybe String)
safePointfree = handle handler . evaluate . pointfree' where
handler :: SomeException -> IO (Maybe String)
handler _ = return Nothing
html :: String
html = unlines
[ ""
, ""
, ""
, " "
, " "
, ""
, " Blunt"
, " "
, ""
, " "
, " Blunt
"
, ""
, " "
, " - Input
"
, " - "
, " "
, "
"
, ""
, " - Output
"
, " - "
, " "
, "
"
, "
"
, ""
, " "
, " "
, ""
]
js :: String
js = unlines
[ "'use strict';"
, ""
, "(function () {"
, " var input = document.getElementById('input');"
, " var output = document.getElementById('output');"
, ""
, " input.oninput = function (_event) {"
, " var request = new XMLHttpRequest();"
, ""
, " request.onreadystatechange = function () {"
, " if (request.readyState === 4 && request.status === 200) {"
, " output.value = request.response;"
, " }"
, " };"
, " request.open('GET', '/pointfree?input=' + encodeURIComponent(input.value));"
, " request.send();"
, " };"
, "}());"
]