{-# INCLUDE <mpfr.h> #-}
{-# INCLUDE <chsmpfr.h> #-}
{-# LANGUAGE BangPatterns #-}

module Data.Number.MPFR.Internal (
       module FFIhelper, 
       withMPFRsBA, withMPFRBAui, withMPFRBAiu, withMPFRBAsi, withMPFRBAis, 
       withMPFRB, withMPFRP, withMPFR, withMPFRBB, withMPFRC, 
       withMPFRF, withMPFRUI, withMPFRR, checkPrec, getMantissa', binprec,
       unsafePerformIO, peek, Ptr, nullPtr, mallocForeignPtrBytes, with,
       withForeignPtr, CInt, CLong, CULong, withCString, peekCString, alloca,
       peekArray, shiftL, Word, minPrec,
       
       Precision
)
where

import Data.Number.MPFR.FFIhelper as FFIhelper

import Foreign.C(CInt, CLong, CULong, withCString, peekCString)
import Foreign.Marshal(alloca, peekArray)
import Foreign(unsafePerformIO, peek, Ptr, nullPtr, mallocForeignPtrBytes, with, withForeignPtr)
import Foreign.Storable(sizeOf)

import Data.Bits(shiftL)

import Data.Word(Word)

type Precision = Word


-- these are helper functions, only for internal use
{-# INLINE withMPFRsBA #-}
withMPFRsBA               :: RoundMode -> Precision -> MPFR -> MPFR
                               -> (Ptr MPFR -> Ptr MPFR -> Ptr MPFR -> CRoundMode -> IO CInt)
                               -> (MPFR, Int)
withMPFRsBA r p !mp1 !mp2 f = unsafePerformIO go
    where go = do withDummy p $ \p1 -> do
                    with mp1 $ \p2 -> do
                      with mp2 $ \p3 -> do
                          f p1 p2 p3 ((fromIntegral . fromEnum) r)
                          

{-# INLINE withMPFRBAui #-}
withMPFRBAui :: RoundMode -> Precision -> MPFR -> CULong
                  ->  (Ptr MPFR -> Ptr MPFR -> CULong -> CRoundMode -> IO CInt)
                  -> (MPFR, Int) 
withMPFRBAui r p !mp1 d f = unsafePerformIO go
    where go = do withDummy p $ \p1 -> do
                    with mp1 $ \p2 -> do
                      f p1 p2 d ((fromIntegral . fromEnum) r)
                                
{-# INLINE withMPFRBAsi #-}
withMPFRBAsi             :: RoundMode -> Precision -> MPFR -> CLong
                              -> (Ptr MPFR -> Ptr MPFR -> CLong -> CRoundMode -> IO CInt)
                              -> (MPFR, Int)
withMPFRBAsi r p !mp1 d f = unsafePerformIO go 
    where go = do withDummy p $ \ p1 -> do
                    with mp1 $ \ p2 -> do
                      f p1 p2 d ((fromIntegral . fromEnum) r)
                                  
{-# INLINE withMPFRBAiu #-}
withMPFRBAiu             :: RoundMode -> Precision -> CULong -> MPFR
                              -> (Ptr MPFR -> CULong -> Ptr MPFR -> CRoundMode -> IO CInt)
                              -> (MPFR, Int) 
withMPFRBAiu r p d !mp1 f = unsafePerformIO go 
    where go = do withDummy p $ \p1 -> do
                    with mp1 $ \p2 -> do
                      f p1 d p2 ((fromIntegral . fromEnum) r)
                      
{-# INLINE withMPFRBAis #-}
withMPFRBAis             :: RoundMode -> Precision -> CLong -> MPFR
                              -> (Ptr MPFR -> CLong -> Ptr MPFR -> CRoundMode -> IO CInt)
                              -> (MPFR, Int) 
withMPFRBAis r p d !mp1 f = unsafePerformIO go
    where go = do withDummy p $ \p1 -> do
                    with mp1 $ \p2 -> do
                      f p1 d p2 ((fromIntegral . fromEnum) r)
                     
{-# INLINE withMPFRB #-}
withMPFRB       :: MPFR -> (Ptr MPFR -> IO CInt) -> CInt 
withMPFRB !mp1 f = unsafePerformIO go
    where go = with mp1 $ \p1 -> f p1

withMPFRP       :: MPFR -> (Ptr MPFR -> IO CPrecision) -> CPrecision 
withMPFRP !mp1 f = unsafePerformIO go
    where go = with mp1 $ \p1 -> f p1

{-# INLINE withMPFR #-}
withMPFR           :: RoundMode -> Precision -> MPFR 
                        -> (Ptr MPFR -> Ptr MPFR -> CRoundMode -> IO CInt) 
                        -> (MPFR, Int)
withMPFR r p !mp1 f = unsafePerformIO go 
    where go = do withDummy p $ \p1 -> do
                    with mp1 $ \p2 -> do
                      f p1 p2 ((fromIntegral . fromEnum) r)
                      
{-# INLINE withMPFRBB #-}
withMPFRBB           :: MPFR -> MPFR 
                          -> (Ptr MPFR -> Ptr MPFR -> IO CInt) 
                          -> CInt  
withMPFRBB !mp1 !mp2 f = unsafePerformIO go
    where go = do with mp1 $ \p1 -> do 
                    with mp2 $ \p2 -> do 
                                      f p1 p2
                              
{-# INLINE withMPFRC #-}
withMPFRC       :: RoundMode -> Precision ->
                     (Ptr MPFR -> CRoundMode -> IO CInt) -> (MPFR, Int)
withMPFRC r p f = unsafePerformIO go
    where go = do withDummy p $ \p1 -> do
                    f p1 ((fromIntegral . fromEnum) r)
   
withMPFRF         :: MPFR -> RoundMode
                       -> (Ptr MPFR -> CRoundMode -> IO CInt)
                       -> Int
withMPFRF !mp1 r f = (fromIntegral . unsafePerformIO) go
    where go = do with mp1 $ \p1 -> f p1 ((fromIntegral . fromEnum) r)

{-# INLINE withMPFRUI #-}
withMPFRUI         :: RoundMode -> Precision -> Word
                        -> (Ptr MPFR -> CULong -> CRoundMode -> IO CInt)
                        -> (MPFR, Int)
withMPFRUI r p d f = unsafePerformIO go 
    where go = do withDummy p $ \p1 -> do
                    f p1 (fromIntegral d) ((fromIntegral . fromEnum) r)
                    
{-# INLINE withMPFRR #-}
withMPFRR       :: Precision -> MPFR
                     -> (Ptr MPFR -> Ptr MPFR -> IO CInt)
                     -> (MPFR, Int)
withMPFRR p !d f = unsafePerformIO go
    where go = do withDummy p $ \p1 -> do
                    with d $ \p2 -> do
                      f p1 p2

                        
{-# INLINE checkPrec #-}
checkPrec :: Precision -> Precision
checkPrec = max minPrec

getMantissa'     :: MPFR -> [Limb]
getMantissa' (MP p _ _ p1) = unsafePerformIO go
    where go = do withForeignPtr p1 $ \pt -> do 
                    arr <- peekArray (Prelude.ceiling ((fromIntegral p ::Double) / fromIntegral bitsPerMPLimb)) pt ;
                    return arr 

{- TODO: this is inefficient 
binprec   :: Integer -> Precision
binprec i = length (takeWhile (/= 0) (iterate (flip shiftR 1) i)
-}
-- TODO
{-# INLINE binprec #-}
binprec   :: Integer -> Precision
binprec d | d == 0 = minPrec
          | otherwise = Prelude.floor (logBase 2 (abs . fromInteger $ d) :: Double) + 1

--one ::  MPFR              
--one = fromWord Near minPrec 1

--zero :: MPFR              
--ggzero = fromWord Near minPrec 0

minPrec :: Precision
minPrec = fromIntegral $ 8 * sizeOf (undefined :: Int)