{-# LANGUAGE LambdaCase #-}
module PuppetDB.Remote (pdbConnect) where

import Puppet.Utils
import Puppet.PP

import Puppet.Interpreter.Types

import Network.HTTP.Conduit
import qualified Network.HTTP.Types as W
import qualified Data.ByteString.Lazy.Char8 as L
import qualified Data.ByteString.Char8 as BC
import Data.Aeson
import qualified Codec.Text.IConv as IConv
import qualified Control.Exception as X
import Control.Monad.Error
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Data.Either.Strict as S

runRequest req = do
    let doRequest = withManager (fmap responseBody . httpLbs req) :: IO L.ByteString
        eHandler :: X.SomeException -> IO (Either Doc L.ByteString)
        eHandler e = return $ Left $ string (show e) <> ", with queryString " <+> string (BC.unpack (queryString req))
    liftIO (fmap Right doRequest `X.catch` eHandler) >>= \case
        Right o -> do
            let utf8 = IConv.convert "LATIN1" "UTF-8" o
            case decode' utf8 of
                Just x                   -> return x
                Nothing                  -> throwError ("Json decoding has failed " <> string (show utf8))
        Left err -> throwError err

pdbRequest :: (FromJSON a, ToJSON b) => T.Text -> T.Text -> b -> IO (S.Either Doc a)
pdbRequest url querytype query = fmap strictifyEither $ runErrorT $ do
    let jsonquery = L.toStrict (encode query)
        q = case toJSON query of
                Null -> ""
                _ -> T.decodeUtf8 $ "?" <> W.renderSimpleQuery False [("query", jsonquery)]
    let fullurl = url <> "/v3/" <> querytype <> q
    initReq <- case parseUrl (T.unpack fullurl) of
            Right r -> return (r :: Request)
            Left rr -> throwError ("Something failed when parsing the PuppetDB URL" <+> string (show (rr :: HttpException)))
    let req = initReq { requestHeaders = [("Accept", "application/json")] }
    runRequest req

-- | Given an URL (ie. @http://localhost:8080@), will return an incomplete 'PuppetDBAPI'.
pdbConnect :: T.Text -> IO (S.Either Doc PuppetDBAPI)
pdbConnect url = return $ S.Right $ PuppetDBAPI
    (return (ttext url))
    (const (return (S.Left "operation not supported")))
    (const (return (S.Left "operation not supported")))
    (const (return (S.Left "operation not supported")))
    (pdbRequest url "facts")
    (pdbRequest url "resources")
    (pdbRequest url "nodes")
    (return (S.Left "operation not supported"))
    (\ndename -> pdbRequest url ("nodes/" <> ndename <> "/resources"))