module Main where

import ALTO (Collection, collection)
import Control.Monad.Except.IOH (handle)
import Control.Monad.State (MonadState(..), execStateT)
import qualified Data.ByteString.Char8 as BS (readFile)
import qualified Data.ByteString.Lazy as Lazy (writeFile)
import qualified Data.Map as Map (keys)
import PDF (Document, UnifiedLayers(..), parseDocument, render)
import PDF.Box (Box(..), at)
import PDF.Pages (Pages(..), withFonts)
import Scoria (Scoriae)
import qualified Scoria (fromCSV)
import System.Environment (getArgs)
import System.Exit (die)

clean :: Document -> Collection -> Scoriae -> IO Document
clean pdf alto scoriae =
  (at UnifiedLayers $ withFonts cleanLayer) pdf `handle` die
  where
    cleanLayer = execStateT $ do
      pages <- get >>= r Pages
      return ()

processFiles :: FilePath -> FilePath -> FilePath -> IO ()
processFiles inputFile altoDir outputFile = do
  pdf <- either die return . parseDocument =<< BS.readFile inputFile
  alto <- collection altoDir
  scoriae <- Scoria.fromCSV <$> getContents
  Lazy.writeFile outputFile . render =<< clean pdf alto scoriae

main :: IO ()
main = do
  args <- getArgs
  case args of
    [inputFile, altoDir, outputFile] ->
      processFiles inputFile altoDir outputFile 
    _ -> die "Syntax: pdfcleaner INPUT_PDF_FILE ALTO_DIR OUTPUT_FILE"