lib/Program.hs

   1 {-# LANGUAGE DeriveGeneric     #-}
   2 {-# LANGUAGE OverloadedStrings #-}
   3
   4 module Program where
   5
   6 import           Data.Aeson
   7 import           Data.Aeson.Encode.Pretty
   8 import qualified Data.ByteString.Lazy     as B
   9 import qualified Data.Text                as T
  10 import           GHC.Generics
  11
  12 instance FromJSON File where
  13   parseJSON (Object v) = File
  14     <$> v .: "path"
  15     <*> v .: "movable"
  16     <*> v .: "help"
  17
  18 data Program = Program
  19   { name  :: T.Text,
  20     files :: [File]
  21   }
  22   deriving (Generic, Show)
  23
  24 instance ToJSON Program where
  25   toJSON (Program name files) = object [ "name" .= name, "files" .= files ]
  26   toEncoding (Program name files) = pairs ("name" .= name <> "files" .= files)
  27 instance FromJSON Program
  28
  29 data File = File
  30   { path         :: String,
  31     supportLevel :: SupportLevel,
  32     help         :: String
  33   }
  34   deriving (Generic, Show)
  35
  36 instance ToJSON File where
  37   toJSON (File path supportLevel help) = object [ "path" .= path, "movable" .= supportLevel, "help" .= help ]
  38   toEncoding (File path supportLevel help) = pairs ("path" .= path <> "movable" .= supportLevel <> "help" .= help)
  39
  40 data SupportLevel = Unsupported | Alias | EnvVars | Supported
  41   deriving (Generic, Show)
  42
  43 instance ToJSON SupportLevel where
  44   toJSON Unsupported = toJSON (Bool False)
  45   toJSON _           = toJSON (Bool True)
  46   toEncoding Unsupported = toEncoding ( Bool False )
  47   toEncoding _           = toEncoding ( Bool True )
  48 instance FromJSON SupportLevel where
  49   parseJSON (Bool False) = return Unsupported
  50   parseJSON (Bool True)  = return EnvVars
  51
  52 makeFilename :: T.Text -> T.Text
  53 makeFilename s = T.pack ( "./programs/" ++ T.unpack s ++ ".json" )
  54
  55 save :: T.Text -> Program -> IO ()
  56 save filename program = do
  57   B.writeFile (T.unpack filename) (encodePretty program)
  58
  59 readProgram :: String -> IO ( Maybe Program )
  60 readProgram filename = do
  61     json_data <- B.readFile filename
  62     return (decode json_data)