{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DeriveLift #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TypeFamilies #-}
module Frames.Streamly.Streaming.Class where

import Frames.Streamly.Streaming.Common (Separator, QuotingMode)
import           Control.Monad.Catch                     ( MonadThrow(..))
import Control.Foldl (PrimMonad)

class Monad m => StreamFunctions (s :: (Type -> Type) -> Type -> Type) (m :: Type -> Type) where
  type FoldType s ::  (Type -> Type) -> Type -> Type -> Type
  sThrowIfEmpty :: forall x. MonadThrow m => s m x -> m ()
  -- ^ throw an exception if the stream is empty
  sLength :: s m a -> m Int
  -- ^ return the length of the stream
  sCons :: forall a. a -> s m a -> s m a
  -- ^ add an element to the head of a stream
  sUncons :: forall a . s m a -> m (Maybe (a, s m a))
  -- ^ split a stream into it's head and tail, returning @m Nothing@ if the stream was empty
  sHead :: forall a . s m a -> m (Maybe a)
  -- ^ return the first item of a (possibly empty) stream. @m Nothing@ if the stream was empty
  sMap :: forall x y. (x -> y) -> s m x -> s m y
  -- ^ map each element of the stream using the given function
  sMapMaybe :: forall x y. (x -> Maybe y) -> s m x -> s m y
  -- ^ map each element of the stream using the given function
  sScanM :: forall a x.(x -> a -> m x) -> m x -> s m a -> s m x
  -- ^ map each item along with a running state to produce a new stream
  sDrop :: forall a.Int -> s m a -> s m a
  -- ^ drop n items from the head of the stream
  sTake :: forall a.Int -> s m a -> s m a
  -- ^ take first n elemens of the stream and drop the rest
  sFolder :: forall x b. (x -> b -> x) -> x -> s m b -> m x
  -- ^ fold the stream using the given step function and starting value
  sBuildFold :: forall x a b.(x -> a -> x) -> x -> (x -> b) -> FoldType s m a b
  -- ^ Build a fold from (pure) step, start and extract functions
  sBuildFoldM :: forall x a b.(x -> a -> m x) -> m x -> (x -> m b) -> FoldType s m a b
  -- ^ Build a fold from (monadic) step, start and extract functions
  sMapFoldM :: forall a b c. (b -> m c) -> FoldType s m a b -> FoldType s m a c
  -- ^ map the output of a fold
  sLMapFoldM :: forall a b c. (c -> m a) -> FoldType s m a b -> FoldType s m c b
  -- ^ map the output of a fold
  sFoldMaybe :: forall a b. FoldType s m a b -> FoldType s m (Maybe a) b
  -- ^ fold only over Justs
  sFold :: forall a b.FoldType s m a b -> s m a -> m b
  -- ^ run a fold on a stream
  sToList :: forall x. s m x -> m [x]
  -- ^ stream to (lazy) list
  sFromFoldable :: forall f a.Foldable f => f a -> s m a
  -- ^ build a stream of @a@ from a foldable of @a@

class (StreamFunctions s (IOSafe s m), MonadThrow (IOSafe s m), PrimMonad (IOSafe s m)) => StreamFunctionsIO (s :: (Type -> Type) -> Type -> Type) m where
  type IOSafe s m :: Type -> Type
  runSafe :: forall a.IOSafe s m a ->  m a
  -- ^ Unwrap computation fram a resource management monad layer, if present.
  sReadTextLines :: FilePath -> s (IOSafe s m) Text
  -- ^ create a stream of lines of text by reading the given file
  sTokenized :: Separator -> QuotingMode -> FilePath -> s (IOSafe s m) [Text]
  -- ^ read lines of text, split them by a separator, handle quotation.
{-
  sTokenizedRaw :: Separator -> FilePath -> s (IOSafe s m) [Text]
  -- ^ read lines of text, split them by a separator
-}
  sReadScanMAndFold :: forall x b.FilePath -> (x -> Text -> (IOSafe s m) x) -> (IOSafe s m) x -> FoldType s (IOSafe s m) x b -> (IOSafe s m) b
  sWriteTextLines :: FilePath -> s (IOSafe s m) Text -> m ()
    -- ^ streamly version handles invalid characters





{-
data StreamFunctions (s :: (Type -> Type) -> Type -> Type) (m :: Type -> Type) = StreamFunctions
  { sThrowIfEmpty :: forall x. s m x -> m ()
    -- ^ throw an exception if the stream is empty
  , sCons :: forall a. a -> s m a -> s m a
  -- ^ add an element to the head of a stream
  , sUncons :: forall a . s m a -> m (Maybe (a, s m a))
    -- ^ split a stream into it's head and tail, returning @m Nothing@ if the stream was empty
  , sHead :: forall a . s m a -> m (Maybe a)
    -- ^ return the first item of a (possibly empty) stream. @m Nothing@ if the stream was empty
  , sMap :: forall x y. (x -> y) -> s m x -> s m y
    -- ^ map each element of the stream using the given function
  , sMapMaybe :: forall x y. (x -> Maybe y) -> s m x -> s m y
    -- ^ map each element of the stream using the given function
  , sScanM :: forall a x.(x -> a -> m x) -> m x -> s m a -> s m x
    -- ^ map each item along with a running state to produce a new stream
  , sDrop :: forall a.Int -> s m a -> s m a
    -- ^ drop n items from the head of the stream
  , sTake :: forall a.Int -> s m a -> s m a
  -- ^ take first n elemens of the stream and drop the rest
  , sFolder :: forall x b. (x -> b -> x) -> x -> s m b -> m x
    -- ^ fold the stream using the given step function and starting value
  , sBuildFold :: forall x a b.(x -> a -> x) -> x -> (x -> b) -> FoldType s m a b
    -- ^ Build a fold from (pure) step, start and extract functions
  , sBuildFoldM :: forall x a b.(x -> a -> m x) -> m x -> (x -> m b) -> FoldType s m a b
    -- ^ Build a fold from (monadic) step, start and extract functions
  , sMapFold :: forall a b c. (b -> m c) -> FoldType s m a b -> FoldType s m a c
    -- ^ map the output of a fold
  , sFold :: forall a b.FoldType s m a b -> s m a -> m b
  -- ^ run a fold on a stream
  , sToList :: forall x. s m x -> m [x]
  -- ^ stream to (lazy) list
  , sFromFoldable :: forall f a.Foldable f => f a -> s m a
    -- ^ build a stream of @a@ from a foldable of @a@
  }

data StreamFunctionsIO (s :: (Type -> Type) -> Type -> Type) (m :: Type -> Type) = StreamFunctionsIO
  {
    sReadTextLines :: FilePath -> s m Text
    -- ^ create a stream of lines of text by reading the given file
  , sWriteTextLines :: FilePath -> s m Text -> m ()
    -- ^ streamly version handles invalid characters
  }

data StreamFunctionsWithIO (s :: (Type -> Type) -> Type -> Type) (m :: Type -> Type) = StreamFunctionsWithIO
  {
    streamFunctions :: StreamFunctions s m
  , streamFunctionsIO :: StreamFunctionsIO s m
  }
-}