{-|
Module      : Main
Description : The "glue" between spreadsheets and GraphViz
Copyright   : (c) OleksandrZhabenko, 2017-2022
License     : MIT
Maintainer  : olexandr543@yahoo.com
Stability   : Experimental

A program @mmsyn4@ converts a specially formated @.csv@ file with a colon as a field separator obtained from the electronic table 
into a visualized by GraphViz graph in the one of the supported by GraphViz format. The proper GraphViz installation is required.
-}

module Main where

import GVTI (process2)
import System.Environment (getArgs)
import System.Directory
import Data.List (isPrefixOf)
import Data.Char (isLetter, isDigit) 
import Formatting (formatLines)

main :: IO ()
main = do 
  args00 <- getArgs
  let args = filter (/= "-g") args00
      arg0 = concat . take 1 $ args
      arggs = drop 1 args
      xxs = take 1 . drop 2 . concat . filter ("-c" `isPrefixOf`) $ arggs
      yys = take 2 . drop 2 . concat . filter ("-f" `isPrefixOf`) $ arggs
      bnames = drop 2 . concat . filter ("-b" `isPrefixOf`) $ arggs
      splines = take 1 . drop 2 . concat . filter ("-s" `isPrefixOf`) $ arggs
      remAts = take 1 . drop 1 . concat . filter ("-y" `isPrefixOf`) $ arggs
      gvti = any (== "-g") args00
      delims 
        | any ("-d" `isPrefixOf`) arggs =  drop 2 . concat . filter ("-d" `isPrefixOf`) $ arggs
        | otherwise = ":"
  exI <- doesFileExist arg0
  if exI 
    then do 
      text2 <- readFile arg0 -- well, in the future  this can be extended to also stdin.
      let txt 
           | gvti = unlines  . formatLines (head delims) . filter (any (\x -> isLetter x || isDigit x)) . lines $ text2
           | otherwise =  unlines . filter (any (\x -> isLetter x || isDigit x)) . lines $ text2
      process2 delims xxs yys bnames splines remAts txt
    else error "Main: No file specified exists in the current directory! "