{-# LANGUAGE OverloadedStrings #-}
module JS (
    generate
  ) where

import Blog (Blog(..), Path(..))
import Control.Monad.IO.Class (MonadIO(..))
import Control.Monad.Reader (ReaderT, asks)
import Data.ByteString.Lazy (ByteString, concat, readFile, writeFile)
import Data.ByteString.Lazy.Char8 (pack)
import qualified Files (find)
import JSON (exportBlog)
import Paths_hablo (getDataDir)
import Pretty ((.$))
import System.Directory (createDirectoryIfMissing)
import System.FilePath ((</>))
import Prelude hiding (concat, readFile, writeFile)

compile :: [ByteString] -> ByteString
compile sources = concat (header:sources ++ [footer])
  where
    header = "(function() {\n"
    footer = "})();"

var :: (String, ByteString) -> ByteString
var (varName, content) = concat ["var ", pack varName, " = ", content, ";\n"]

generate :: ReaderT Blog IO ()
generate = do
  destinationDir <- (</> "js") <$> (asks $path.$root)
  blogJSON <- exportBlog
  remarkablePath <- asks $path.$remarkableConfig
  liftIO $ do
    remarkableJSON <- maybe (return "{html: true}") readFile remarkablePath
    let jsVars = var <$> [("blog", blogJSON), ("remarkableConfig", remarkableJSON)]
    jsFiles <- (</> "js") <$> getDataDir >>= Files.find
    jsCode <- mapM readFile jsFiles
    createDirectoryIfMissing False destinationDir
    writeFile (destinationDir </> "hablo.js") $ compile (jsVars ++ jsCode )