{-# LANGUAGE OverloadedStrings #-}

module ACMS.API.REST where

#ifndef ghcjs_HOST_OS
import Network.HTTP.Simple
import Data.String (IsString(fromString))
#else
import Data.ByteString.Lazy.UTF8 qualified as LB
import Data.ByteString qualified as B
import Data.Maybe
import Data.String
import JavaScript.Web.XMLHttpRequest
import Miso.String qualified as J
#endif
import Control.Monad.Catch (MonadThrow)
import Data.Aeson qualified as A
import Data.ByteString.Lazy.Char8 qualified as LB
import Data.Function ((&))
import Miso (JSM)
import Miso.String (MisoString)

restRequest :: String -> Request
restRequest endpoint =
  fromString ("http://localhost:8081/api/rest" <> endpoint)

schemaVersion :: (APIMonad m, A.FromJSON a) => m a
schemaVersion =
  restRequest "/schemaVersion"
    & fetch
    >>= A.throwDecode

listCollections :: (APIMonad m) => m [MisoString]
listCollections =
  restRequest "/collection"
    & fetch
    >>= A.throwDecode

createCollection :: (APIMonad m) => MisoString -> m ()
createCollection collection =
  restRequest "/collections"
    & setRequestMethod "POST"
    & setRequestBodyLBS (A.encode (A.toJSON collection))
    & fetch
    >>= A.throwDecode

class (MonadThrow m) => APIMonad m where
  fetch :: Request -> m LB.ByteString

instance APIMonad JSM where
  fetch req = LB.fromStrict . getResponseBody <$> httpBS req

#ifdef ghcjs_HOST_OS
httpBS :: Request -> JSM (Response B.ByteString)
httpBS req = xhrByteString req

instance IsString Request where
  fromString uri =
    Request
      { reqMethod = GET,
        reqURI = J.pack uri,
        reqLogin = Nothing,
        reqHeaders = [],
        reqWithCredentials = False,
        reqData = NoData
      }

setRequestMethod :: B.ByteString -> Request -> Request
setRequestMethod "POST" req = req {reqMethod = POST}

setRequestBodyLBS :: LB.ByteString -> Request -> Request
setRequestBodyLBS body req = req {reqData = StringData (J.pack (LB.toString body))}

getResponseBody :: Response B.ByteString -> B.ByteString
getResponseBody = fromMaybe "" . contents
#else
instance APIMonad IO where
  fetch req = LB.fromStrict . getResponseBody <$> httpBS req
#endif