{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes        #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeOperators #-}
{-|
Module      : Frames.Streamly.InCore
Description : Support for transformations between streamly streams and Frames Array of Structures (SoA).
Copyright   : (c) Adam Conner-Sax 2020
License     : BSD-3-Clause
Maintainer  : adam_conner_sax@yahoo.com
Stability   : experimental

This module can be used in-place of Frames.InCore.  The pipes functions are all replaced by equivalent streamly functions.
Relevant classes and type-families are re-exported for convenience.
-}
module Frames.Streamly.InCore
    (
      inCoreSoA
    , inCoreAoS
    , inCoreAoS'
    , inCoreSoA_F
    , inCoreAoS_F
    , inCoreAoS'_F
    -- * Re-exports from Frames
    , toAoS
    , VectorFor
    , VectorMFor
    , VectorMs
    , Vectors
    , RecVec(..)

    )
where

import qualified Frames
import qualified Frames.InCore                          as Frames
import           Frames.InCore                           (VectorFor, VectorMFor, VectorMs, Vectors, RecVec(..), toAoS)

import Frames.Streamly.Streaming.Class (StreamFunctions(..)) --, FoldType)
import qualified Control.Monad.Primitive                as Prim

import qualified Data.Vinyl                             as Vinyl


-- | Fold a stream of 'Vinyl' records into SoA (Structure-of-Arrays) form.
-- Here as a 'streamly' fold, so it may be deployed along with other folds or on only part of a stream.
inCoreSoA_F :: forall rs s m. (Prim.PrimMonad m, Frames.RecVec rs, StreamFunctions s m)
             => FoldType s m (Frames.Record rs) (Int, Vinyl.Rec (((->) Int) Frames.:. Frames.ElField) rs)
inCoreSoA_F = sBuildFoldM @s feed initial fin where
  feed (!i, !sz, !mvs') row
    | i == sz = Frames.growRec (Proxy::Proxy rs) mvs'
                >>= flip feed row . (i, sz*2,)
    | otherwise = do Frames.writeRec (Proxy::Proxy rs) i mvs' row
                     return (i+1, sz, mvs')

  initial = do
    mvs <- Frames.allocRec (Proxy :: Proxy rs) Frames.initialCapacity
    return (0, Frames.initialCapacity, mvs)

  fin (n, _, mvs') =
    do vs <- Frames.freezeRec (Proxy::Proxy rs) n mvs'
       return . (n,) $ Frames.produceRec (Proxy::Proxy rs) vs
{-# INLINEABLE inCoreSoA_F #-}

-- | Perform the 'inCoreSoA_F' fold on a stream of records.
inCoreSoA :: forall rs s m. (Prim.PrimMonad m, Frames.RecVec rs, StreamFunctions s m)
          => s m (Frames.Record rs)
          -> m (Int, Vinyl.Rec (((->) Int) Frames.:. Frames.ElField) rs)
inCoreSoA = sFold (inCoreSoA_F @rs @s)
{-# INLINEABLE inCoreSoA #-}

-- | Fold a stream of 'Vinyl' records into AoS (Array-of-Structures) form.
inCoreAoS_F :: forall rs s m. (Prim.PrimMonad m, Frames.RecVec rs, StreamFunctions s m)
          => FoldType s m (Frames.Record rs) (Frames.FrameRec rs)
inCoreAoS_F = sMapFoldM @s (return . uncurry Frames.toAoS) $ inCoreSoA_F @rs @s
{-# INLINE inCoreAoS_F #-}

-- | Perform the 'inCoreAoS_F' fold on a stream of records.
inCoreAoS :: forall m rs s. (Prim.PrimMonad m, Frames.RecVec rs, StreamFunctions s m)
          => s m (Frames.Record rs)
          -> m (Frames.FrameRec rs)
inCoreAoS = sFold (inCoreAoS_F @rs @s)
{-# INLINEABLE inCoreAoS #-}


-- | More general AoS fold, allowing for a, possible column changing, transformation of the records while in SoA form.
inCoreAoS'_F ::  forall ss rs s m. (Prim.PrimMonad m, Frames.RecVec rs, StreamFunctions s m)
             => (Frames.Rec ((->) Int Frames.:. Frames.ElField) rs -> Frames.Rec ((->) Int Frames.:. Frames.ElField) ss)
             -> FoldType s m (Frames.Record rs) (Frames.FrameRec ss)
inCoreAoS'_F f  = sMapFoldM @s (return . uncurry Frames.toAoS . aux) (inCoreSoA_F @rs @s)
  where aux (x,y) = (x, f y)
{-# INLINEABLE inCoreAoS'_F #-}

-- | Perform the more general AoS fold on a stream of records.
inCoreAoS' ::  forall ss rs s m. (Prim.PrimMonad m, Frames.RecVec rs,  StreamFunctions s m)
           => (Frames.Rec ((->) Int Frames.:. Frames.ElField) rs -> Frames.Rec ((->) Int Frames.:. Frames.ElField) ss)
           -> s m (Frames.Record rs)
           -> m (Frames.FrameRec ss)
inCoreAoS' f = sFold (inCoreAoS'_F @ss @rs @s f)
{-# INLINEABLE inCoreAoS' #-}