import Prelude hiding (getContents, readFile, writeFile, putStrLn)
import Svg
import Glyphs (doGlyphs, lineHeight')
import Split
import Options.Applicative
import Data.Functor
import Data.Text.IO (readFile, getContents)
import Data.Text.Lazy.IO (writeFile, putStrLn)


data Options =
  Opts {
    width, size, stroke :: {-# UNPACK #-} !Double,
    inFile, outFile     :: Maybe FilePath,
    text                :: Maybe Text,
    color               :: Text
  }
  deriving Show

options :: IO Options
options = execParser desc where
  desc = info (opts <**> helper) $
    fullDesc <> header "render lántas text as svg"
  opts =
    Opts <$> dimOpt  'W' "width" 1000
         <*> (dimOpt' 'S' "size" "text size" 60 <&> (/ lineHeight'))
         <*> dimOpt'  'K' "stroke" "line thickness" 2
         <*> filePath 'i' "input"
         <*> filePath 'o' "output"
         <*> text
         <*> color
  dimOpt s l d = dimOpt' s l l d
  dimOpt' s l n d = option auto $ mconcat
    [short s, long l, help $ n <> " in pixels", metavar "SIZE", value d]
  filePath s n = optional $ option str $ mconcat
    [short s, long n, help $ n <> " file", metavar "FILE"]
  text = optional $ option str $ mconcat
    [short 't', long "text", help $ "use given text instead of a file",
     metavar "TEXT"]
  color = option str $ mconcat
    [short 'C', long "color", help $ "set stroke color (any css syntax)",
     metavar "COLOR", value "black"]

main :: IO ()
main = do
  Opts {..} <- options
  txt <- split <$> if
    | Just t   <- text   -> pure t
    | Just "-" <- inFile -> getContents
    | Just i   <- inFile -> readFile i
    | otherwise          -> fail "no input given"
  let res = prettyText $ doGlyphs txt (E {..})
  case outFile of
    Just o | o /= "-" -> writeFile o res
    _                 -> putStrLn res