{-# LANGUAGE FlexibleContexts #-}
module Text.Trifecta.Diagnostic.Prim
  ( Diagnostic(..)
  , tellDiagnostic
  ) where

import Control.Applicative
import Control.Comonad
import Control.Monad (guard)
import Control.Monad.Writer.Class
import Data.Functor.Apply
import Data.Foldable
import Data.Traversable
import Data.Monoid
import Data.List.NonEmpty hiding (map)
import Data.Semigroup
import Data.Semigroup.Reducer
import Data.Semigroup.Foldable
import Data.Semigroup.Traversable
import Text.Trifecta.Rope.Bytes
import Text.Trifecta.Rope.Delta
import Text.Trifecta.Diagnostic.Rendering.Prim
import Text.Trifecta.Diagnostic.Level
import Text.PrettyPrint.Free
import System.Console.Terminfo.PrettyPrint
import Prelude hiding (log)

data Diagnostic m = Diagnostic !Rendering !DiagnosticLevel m [Diagnostic m]
  deriving Show

tellDiagnostic :: (MonadWriter t m, Reducer (Diagnostic e) t) => Diagnostic e -> m ()
tellDiagnostic = tell . unit

instance Renderable (Diagnostic m) where
  render (Diagnostic r _ _ _) = r

instance HasDelta (Diagnostic m) where
  delta (Diagnostic r _ _ _) = delta r

instance HasBytes (Diagnostic m) where
  bytes = bytes . delta

instance Extend Diagnostic where
  extend f d@(Diagnostic r l _ xs) = Diagnostic r l (f d) (map (extend f) xs)

instance Comonad Diagnostic where
  extract (Diagnostic _ _ m _) = m

instance Pretty m => Pretty (Diagnostic m) where
  pretty (Diagnostic r l m xs) = vsep $
     [ pretty (delta r) <> char ':' <+> pretty l <> char ':' <+> nest 4 (pretty m) ] 
     <> (pretty r <$ guard (not (nullRendering r)))
     <> (indent 2 (prettyList xs) <$ guard (not (null xs)))
  prettyList = vsep . Prelude.map pretty

instance PrettyTerm m => PrettyTerm (Diagnostic m) where
  prettyTerm (Diagnostic r l m xs) = vsep $ 
     [ prettyTerm (delta r) <> char ':' <+> prettyTerm l <> char ':' <+> nest 4 (prettyTerm m) ]
     <> (prettyTerm r <$ guard (not (nullRendering r)))
     <> (indent 2 (prettyTermList xs) <$ guard (not (null xs)))
  prettyTermList = vsep . Prelude.map prettyTerm

instance Functor Diagnostic where
  fmap f (Diagnostic r l m xs) = Diagnostic r l (f m) $ map (fmap f) xs

instance Foldable Diagnostic where
  foldMap f (Diagnostic _ _ m xs) = f m `mappend` foldMap (foldMap f) xs

instance Traversable Diagnostic where
  traverse f (Diagnostic r l m xs) = Diagnostic r l <$> f m <*> traverse (traverse f) xs

instance Foldable1 Diagnostic where
  foldMap1 f (Diagnostic _ _ m []) = f m
  foldMap1 f (Diagnostic _ _ m (x:xs)) = f m <> foldMap1 (foldMap1 f) (x:|xs)

instance Traversable1 Diagnostic where
  traverse1 f (Diagnostic r l m [])     = fmap (\fm -> Diagnostic r l fm []) (f m)
  traverse1 f (Diagnostic r l m (x:xs)) = (\fm (y:|ys) -> Diagnostic r l fm (y:ys)) 
                                      <$> f m 
                                      <.> traverse1 (traverse1 f) (x:|xs)