This module is part of Chatty.
  Copyleft (c) 2014 Marvin Cohrs

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  Please share Antisplice with everyone you like.

  Chatty is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  Chatty is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with Chatty. If not, see <http://www.gnu.org/licenses/>.

-- | Provides an ExtendedPrinter that handles colours using standardized ANSI codes.
module Text.Chatty.Extended.ANSI where

import qualified System.Console.ANSI as A
import Control.Monad
import Control.Monad.Trans.Class
import Control.Monad.IO.Class
import Text.Chatty.Printer
import Text.Chatty.Extended.Printer
import Text.Chatty.Expansion

-- | An ExtendedPrinter that uses ANSI colour codes.
newtype AnsiPrinterT m a = AnsiPrinter { runAnsiPrinterT :: [Colour] -> m (a,[Colour]) }

instance Monad m => Monad (AnsiPrinterT m) where
  return a = AnsiPrinter $ \s -> return (a,s)
  (AnsiPrinter p) >>= f = AnsiPrinter $ \s -> do (a,s') <- p s; runAnsiPrinterT (f a) s'

instance MonadTrans AnsiPrinterT where
  lift m = AnsiPrinter $ \c -> do a <- m; return (a,c)

instance Monad m => Functor (AnsiPrinterT m) where
  fmap f a = AnsiPrinter $ \s -> do (a',s') <- runAnsiPrinterT a s; return (f a',s')

instance MonadIO m => MonadIO (AnsiPrinterT m) where
  liftIO = lift . liftIO

instance MonadPrinter m => MonadPrinter (AnsiPrinterT m) where
  mprint = lift . mprint
  mnoecho = lift . mnoecho
  mflush = lift mflush
  mnomask = lift . mnomask

instance MonadPrinter m => ExtendedPrinter (AnsiPrinterT m) where
  estart c = AnsiPrinter $ \c1 -> do
    mprint $ A.setSGRCode [A.SetColor A.Foreground (mkColourInt c) (mkColourCode c)]
    return ((),c:c1)
  efin = AnsiPrinter $ \c1 ->
    case c1 of
      (_:c:cx) -> do
        mprint $ A.setSGRCode [A.SetColor A.Foreground (mkColourInt c) (mkColourCode c)]
        return ((),c:cx)
      _ -> do
        mprint $ A.setSGRCode [A.Reset]
        return ((),[])

instance (Functor m,MonadExpand m) => MonadExpand (AnsiPrinterT m) where
  expand s = AnsiPrinter $ \cx -> do
    s1 <- (expand =<<) $ liftM (replay.snd) $ runRecorderT $ liftM fst $ flip runAnsiPrinterT cx $ expandClr s
    return (s1, cx)

-- | Convert Chatty's colour intensity to ansi-terminal's one
mkColourInt (Dull _) = A.Dull
mkColourInt (Vivid _) = A.Vivid

-- | Convert Chatty's colour tone to ansi-terminal's one
mkColourCode (Dull c) = mkColourCode (Vivid c)
mkColourCode (Vivid c) = case c of
  Green -> A.Green
  Red -> A.Red
  Yellow -> A.Yellow
  Blue -> A.Blue
  Black -> A.Black
  White -> A.White
  Cyan -> A.Cyan
  Magenta -> A.Magenta