{-# LANGUAGE OverloadedStrings #-}

module HsDev.Cache (
	escapePath,
	cabalCache,
	projectCache,
	standaloneCache,
	dump,
	load,
	) where

import Control.DeepSeq (force)
import Data.Aeson (eitherDecode)
import Data.Aeson.Encode.Pretty (encodePretty)
import qualified Data.ByteString.Lazy.Char8 as BS
import Data.Char (isAlphaNum)
import Data.List (intercalate)
import System.FilePath

import HsDev.Symbols (Cabal(..))
import HsDev.Project
import HsDev.Database (Database)

-- | Escape path
escapePath :: FilePath -> FilePath
escapePath = intercalate "." . map (filter isAlphaNum) . splitDirectories

-- | Name of cache for cabal
cabalCache :: Cabal -> FilePath
cabalCache Cabal = "cabal" <.> "json"
cabalCache (Sandbox p) = escapePath p <.> "json"

-- | Name of cache for projects
projectCache :: Project -> FilePath
projectCache p = (escapePath . projectPath $ p) <.> "json"

-- | Name of cache for standalone files
standaloneCache :: FilePath
standaloneCache = "standalone" <.> "json"

-- | Dump database to file
dump :: FilePath -> Database -> IO ()
dump file = BS.writeFile file . encodePretty

-- | Load database from file, strict
load :: FilePath -> IO (Either String Database)
load file = do
	cts <- BS.readFile file
	return $ force $ eitherDecode cts