module Main where

import System.Directory
import Options.Applicative
import Data.List

data CgiState = CgiSuccess
instance Show CgiState where
    show CgiSuccess = "20 text/gemini; lang=en; charset=utf-8\r"

data Args = Args
    { title :: String
    , directory :: FilePath
    , fileHead :: FilePath
    , verbose :: Bool
    , names :: Bool
    , cgi :: Bool
    }

args :: Parser Args
args = Args
    <$> strOption ( long "title" <> short 't' <> value "Title Left Blank" <> help "Document title" )
    <*> strOption ( long "directory" <> short 'd' <> value "./" <> help "Directory to parse" )
    <*> strOption ( long "header" <> short 'H' <> value "" <> help "Header text" )
    <*> switch ( long "verbose" <> short 'v' <> help "Verbose mode")
    <*> switch ( long "names" <> short 'n' <> help "Generate link names based on first of each document" )
    <*> switch ( long "cgi" <> help "Output gemini file header")

main :: IO ()
main = parseArgs =<< execParser opts
  where
    opts = info ( args <**> helper)
        ( fullDesc
       <> progDesc "Generate  gemini page index"
       <> header "Generate a gemini page index")

parseArgs :: Args -> IO()
parseArgs (Args t dir h v r c) = do
    if c then do
            print CgiSuccess
            putStrLn $ "# " ++ t
        else putStrLn $ "# " ++ t
    if not (null h)
        then putStr $ "\n" ++ h ++ "\n\n"
        else putStr "\n"
    mapM_ (mkIndex r dir) . filter (isSuffixOf ".gmi") =<< getDirectoryContents dir

mkIndex :: Bool -> FilePath -> FilePath -> IO ()
mkIndex True d l = do
    line <- readFile $ d++"/"++l
    putStrLn $ "=> " ++ path ++ (head . lines $ line)
        where path = d++"/"++l++" "

mkIndex False d l = putStrLn $ "=> " ++ path
    where path = d++"/"++l

--compose = (++) <$> ("=> " ++) <*> (show . length) <*> (head . lines =<< readFile)