{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE QuantifiedConstraints #-}
{-# LANGUAGE ImpredicativeTypes #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE UndecidableInstances #-}

module Conftrack.Source.Yaml (YamlSource(..), mkYamlSource, mkYamlSourceWith, mkYamlFileSource) where

import Conftrack.Source (SomeSource(..), ConfigSource (..))
import Conftrack.Source.Aeson

import Prelude hiding (readFile)
import qualified Data.Aeson as A
import qualified Data.Yaml as Y
import Data.Text (Text)
import qualified Data.Aeson.Text as A
import qualified Data.Text.Lazy as LT
import Data.Functor ((<&>))
import System.OsPath (OsPath)
import qualified System.OsPath as OS
import System.File.OsPath (readFile)
import qualified Data.ByteString as BS

newtype YamlSource = YamlSource JsonSource
  deriving newtype (ConfigSource, Show)

mkYamlSource :: A.Value -> SomeSource
mkYamlSource value = mkYamlSourceWith ("Yaml string " <> LT.toStrict (A.encodeToLazyText value)) value

mkYamlSourceWith :: Text -> A.Value -> SomeSource
mkYamlSourceWith description value = SomeSource (source, [])
  where source = YamlSource (JsonSource value description)

mkYamlFileSource :: OsPath -> IO (Either Y.ParseException SomeSource)
mkYamlFileSource path = do
  bytes <- readFile path <&> BS.toStrict
  pathAsText <- OS.decodeUtf path <&> LT.toStrict . LT.pack
  pure $ Y.decodeEither' bytes
    <&> mkYamlSourceWith ("YAML file " <> pathAsText)