haskell/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 import           System.Directory
  12
  13 instance FromJSON File where
  14   parseJSON (Object v) = File
  15     <$> v .: "path"
  16     <*> v .: "movable"
  17     <*> v .: "help"
  18
  19 data Program = Program
  20   { name  :: T.Text,
  21     files :: [File]
  22   }
  23   deriving (Generic, Show)
  24
  25 instance ToJSON Program where
  26   toJSON (Program name files) = object [ "name" .= name, "files" .= files ]
  27   toEncoding (Program name files) = pairs ("name" .= name <> "files" .= files)
  28 instance FromJSON Program
  29
  30 data File = File
  31   { path         :: String,
  32     supportLevel :: SupportLevel,
  33     help         :: String
  34   }
  35   deriving (Generic, Show)
  36
  37 instance ToJSON File where
  38   toJSON (File path supportLevel help) = object [ "path" .= path, "movable" .= supportLevel, "help" .= help ]
  39   toEncoding (File path supportLevel help) = pairs ("path" .= path <> "movable" .= supportLevel <> "help" .= help)
  40
  41 data SupportLevel = Unsupported | Alias | EnvVars | Supported
  42   deriving (Generic, Show)
  43
  44 instance ToJSON SupportLevel where
  45   toJSON Unsupported = toJSON (Bool False)
  46   toJSON _           = toJSON (Bool True)
  47   toEncoding Unsupported = toEncoding ( Bool False )
  48   toEncoding _           = toEncoding ( Bool True )
  49 instance FromJSON SupportLevel where
  50   parseJSON (Bool False) = return Unsupported
  51   parseJSON (Bool True)  = return EnvVars
  52
  53 makeFilename :: T.Text -> T.Text
  54 makeFilename s = T.pack ( "./programs/" ++ T.unpack s ++ ".json" )
  55
  56 save :: T.Text -> Program -> IO ()
  57 save filename program = do
  58   createDirectoryIfMissing False "./programs/"
  59   B.writeFile (T.unpack filename) (encodePretty program)
  60
  61 readProgram :: String -> IO ( Maybe Program )
  62 readProgram filename = do
  63     json_data <- B.readFile filename
  64     return (decode json_data)