{-|
Module      : Gargantext.Prelude.Utils
Description : Useful Tools near Prelude of the project
Copyright   : (c) CNRS, 2017-Present
License     : AGPL + CECILL v3
Maintainer  : team@gargantext.org
Stability   : experimental
Portability : POSIX

-}

{-# OPTIONS_GHC -fno-warn-orphans   #-}

module Gargantext.Prelude.Utils
  where

import Control.Lens (view)
import Control.Monad.Random.Class (MonadRandom)
import Control.Monad.Reader (MonadReader)
import Control.Monad.Reader (ask)
import Data.Text (Text)
import GHC.IO (FilePath)
import Gargantext.Config
import Gargantext.API.Admin.Settings
import Gargantext.Database.Admin.Types.Node (NodeId, NodeType)
import Gargantext.Prelude
import Gargantext.Core.Crypto.Hash
import System.Directory (createDirectoryIfMissing)
import System.Random (newStdGen)
import qualified Data.Text             as Text
import qualified System.Random.Shuffle as SRS

--------------------------------------------------------------------------
shuffle :: MonadRandom m => [a] -> m [a]
shuffle ns = SRS.shuffleM ns 

--------------------------------------------------------------------------
data NodeToHash = NodeToHash { nodeType :: NodeType
                             , nodeId   :: NodeId
                             }

type FolderPath = FilePath
type FileName   = FilePath

-- | toPath example of use:
-- toPath 2 "gargantexthello"
-- ("ga/rg","antexthello")
-- 
-- toPath 3 "gargantexthello"
-- ("gar/gan","texthello")


toPath :: Int -> Text -> (FolderPath,FileName)
toPath n x = (Text.unpack $ Text.intercalate "/" [x1,x2], Text.unpack xs)
  where
    (x1,x') = Text.splitAt n x
    (x2,xs) = Text.splitAt n x'

class SaveFile a where
  saveFile' :: FilePath -> a -> IO ()

class ReadFile a where
  readFile' :: FilePath -> IO a


writeFile :: (MonadReader env m, MonadBase IO m, HasSettings env, SaveFile a)
         => a -> m FilePath
writeFile a = do
  dataPath <- view (settings . config . gc_datafilepath) <$> ask
  (fp,fn)  <- liftBase $ (toPath 3) . hash . show <$> newStdGen

  let foldPath = dataPath <> "/" <> fp
      filePath = foldPath <> "/" <> fn

  _ <- liftBase $ createDirectoryIfMissing True foldPath
  _ <- liftBase $ saveFile' filePath a

  pure filePath


readFile :: (MonadReader env m, MonadBase IO m, HasSettings env, ReadFile a)
         => FilePath -> m a
readFile fp = do
  dataPath <- view (settings . config . gc_datafilepath) <$> ask
  liftBase $ readFile' $ dataPath <> "/" <> fp