Spec.hs

{-# LANGUAGE CPP                 #-}
{-# LANGUAGE NoImplicitPrelude   #-}

{-# LANGUAGE ScopedTypeVariables #-}
module System.Etc.Spec (
    module Types
  , module Errors
  , parseConfigSpec
  , readConfigSpecTH
  , readConfigSpec
  ) where

import qualified Data.Text.IO as Text (readFile)
import           RIO
import qualified RIO.Text     as Text

import Data.Proxy (Proxy)

import Language.Haskell.TH        (ExpQ)
import Language.Haskell.TH.Syntax (Lift)

import System.Etc.Internal.Errors     as Errors
import System.Etc.Internal.Spec.Types as Types (ConfigSpec, ConfigValue)

import qualified Data.Aeson as JSON

#ifdef WITH_YAML
import qualified System.Etc.Internal.Spec.YAML    as YAML
import qualified System.Etc.Internal.Spec.YAML.TH as YAML
#else
import qualified System.Etc.Internal.Spec.JSON    as JSONSpec
import qualified System.Etc.Internal.Spec.JSON.TH as JSONSpec
#endif

{-|

Parses a text input into a @ConfigSpec@, input can be JSON or YAML (if cabal
flag is set).

-}
#ifdef WITH_CLI
parseConfigSpec
  :: (MonadThrow m, JSON.FromJSON cmd)
    => Text               -- ^ Text to be parsed
    -> m (ConfigSpec cmd) -- ^ returns ConfigSpec
#else
parseConfigSpec
  :: (MonadThrow m)
  => Text               -- ^ Text to be parsed
  -> m (ConfigSpec ()) -- ^ returns ConfigSpec
#endif

#ifdef WITH_YAML
parseConfigSpec = YAML.parseConfigSpec
#else
parseConfigSpec = JSONSpec.parseConfigSpec
#endif

{-|

Reads contents of a file and parses into a @ConfigSpec@, file contents can be
either JSON or YAML (if cabal flag is set).

-}
#ifdef WITH_CLI
readConfigSpec
  :: JSON.FromJSON cmd
  => Text -- ^ Filepath where contents are going to be read from and parsed
  -> IO (ConfigSpec cmd) -- ^ returns ConfigSpec
#else
readConfigSpec
  :: Text -- ^ Filepath where contents are going to be read from and parsed
  -> IO (ConfigSpec ()) -- ^ returns ConfigSpec
#endif
readConfigSpec filepath = do
  contents <- Text.readFile $ Text.unpack filepath
  parseConfigSpec contents


-- | Reads a specified 'FilePath' and parses a 'ConfigSpec' at compilation time.
readConfigSpecTH :: (Lift k, JSON.FromJSON k) => Proxy k -> Text -> ExpQ
#ifdef WITH_YAML
readConfigSpecTH = YAML.readConfigSpecTH
#else
readConfigSpecTH = JSONSpec.readConfigSpecTH
#endif