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module Main where
#ifndef ghcjs_HOST_OS
import Data.String
import Language.Javascript.JSaddle.Warp as JSaddle
import Network.HTTP.Simple
#else
import Data.ByteString.Char8 qualified as B
import Data.Maybe
import Data.String
import JavaScript.Web.XMLHttpRequest
import Miso.String qualified as J
#endif
import Data.Aeson qualified as A
import Data.ByteString.Lazy.Char8 qualified as LB
import Data.Default
import Data.Function
import Data.Map qualified as M
import GHC.Generics (Generic)
import Miso
import Miso.String (toMisoString)
data Model = Model
{ schema :: Maybe (Either String Schema),
posts :: Maybe (Either String [A.Value])
}
deriving (Show, Eq, Generic, Default)
data Schema = Schema
{ id :: String,
schema :: String,
title :: String,
type_ :: SchemaType
}
deriving (Show, Eq)
instance A.FromJSON Schema where
parseJSON =
A.withObject
"Schema"
( \v ->
Schema
<$> v A..: "$id"
<*> v A..: "$schema"
<*> v A..: "title"
<*> A.parseJSON (A.Object v)
)
data SchemaType = Object (M.Map String String)
deriving (Show, Eq)
instance A.FromJSON SchemaType where
parseJSON =
A.withObject
"SchemaType"
( \v ->
v A..: "type" >>= \case
("object" :: String) -> Object <$> v A..: "properties"
)
data Action
= NoOp
| Init
| FetchSchema
| SetSchema (Either String Schema)
| FetchPosts
| SetPosts (Either String [A.Value])
deriving (Show, Eq)
#ifndef ghcjs_HOST_OS
runApp :: JSM () -> IO ()
runApp f = JSaddle.debugOr 8080 (f >> syncPoint) JSaddle.jsaddleApp
#else
runApp :: IO () -> IO ()
runApp app = app
#endif
main :: IO ()
main = runApp $ startApp App {..}
where
initialAction = Init
model = def
update = updateModel
view = viewModel
events = defaultEvents
subs = []
mountPoint = Nothing
logLevel = Off
updateModel :: Action -> Model -> Effect Action Model
updateModel action m =
case action of
NoOp -> noEff m
Init -> batchEff m [pure FetchSchema, pure FetchPosts]
FetchSchema -> m <# do SetSchema <$> fetchSchema
SetSchema schema ->
let setSchema :: Either String Schema -> Model -> Model
setSchema schema m = m {schema = Just schema}
in noEff (setSchema schema m)
FetchPosts -> m <# do SetPosts <$> fetchPosts
SetPosts posts ->
let setPosts :: Either String [A.Value] -> Model -> Model
setPosts posts m = m {posts = Just posts}
in noEff (setPosts posts m)
fetchSchema :: JSM (Either String Schema)
fetchSchema =
A.eitherDecode <$> fetch (fromString "http://localhost:8081/posts.schema.json")
fetchPosts :: JSM (Either String [A.Value])
fetchPosts =
A.eitherDecode
<$> fetch
( fromString "http://localhost:8081"
& setRequestMethod "POST"
& setRequestBodyLBS "SELECT posts FROM posts"
)
fetch :: Request -> JSM LB.ByteString
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.unpack body))}
getResponseBody :: Response B.ByteString -> B.ByteString
getResponseBody = fromMaybe "" . contents
#endif
viewModel :: Model -> View Action
viewModel model =
div_ [] $
[ maybe (text "..") (either err viewSchema) model.schema,
maybe (text "..") (either err viewPosts) model.posts
]
err :: String -> View Action
err = text . toMisoString . ("err! " <>)
viewSchema :: Schema -> View Action
viewSchema schema =
case schema.type_ of
Object properties ->
ol_ [] $
( \(k, v) ->
li_ [] $
[ text (toMisoString k),
text ":",
text (toMisoString v)
]
)
<$> (M.toList properties)
viewPosts :: [A.Value] -> View Action
viewPosts posts = ol_ [] (viewPost <$> posts)
where
viewPost post = pre_ [] [text (toMisoString (A.encode post))]
|
