-- GENERATED by C->Haskell Compiler, version 0.28.6 Switcheroo, 25 November 2017 (Haskell)
-- Edit the ORIGNAL .chs file instead!


{-# LINE 1 "src/Evdev/LowLevel.chs" #-}
module Evdev.LowLevel where
import qualified Foreign.C.String as C2HSImp
import qualified Foreign.C.Types as C2HSImp
import qualified Foreign.ForeignPtr as C2HSImp
import qualified Foreign.Ptr as C2HSImp
import qualified Foreign.Storable as C2HSImp



import Data.Int
import Data.Time.Clock

import Foreign (Ptr)
import Foreign.C (CInt,CUInt,CLong)
import Foreign.C.Error (Errno(Errno))
import Foreign.ForeignPtr (mallocForeignPtrBytes,withForeignPtr)
import Foreign.Storable (peekByteOff)
import System.Posix.ByteString (RawFilePath)
import System.Posix.IO.ByteString (OpenMode(ReadOnly),defaultFileFlags,openFd)
import System.Posix.Types (Fd(Fd))




data ReadFlags = Sync
               | Normal
               | ForceSync
               | Blocking
  deriving (Eq,Ord,Show)
instance Enum ReadFlags where
  succ Sync = Normal
  succ Normal = ForceSync
  succ ForceSync = Blocking
  succ Blocking = error "ReadFlags.succ: Blocking has no successor"

  pred Normal = Sync
  pred ForceSync = Normal
  pred Blocking = ForceSync
  pred Sync = error "ReadFlags.pred: Sync has no predecessor"

  enumFromTo from to = go from
    where
      end = fromEnum to
      go v = case compare (fromEnum v) end of
                 LT -> v : go (succ v)
                 EQ -> [v]
                 GT -> []

  enumFrom from = enumFromTo from Blocking

  fromEnum Sync = 1
  fromEnum Normal = 2
  fromEnum ForceSync = 4
  fromEnum Blocking = 8

  toEnum 1 = Sync
  toEnum 2 = Normal
  toEnum 4 = ForceSync
  toEnum 8 = Blocking
  toEnum unmatched = error ("ReadFlags.toEnum: Cannot match " ++ show unmatched)

{-# LINE 23 "src/Evdev/LowLevel.chs" #-}


data GrabMode = LibevdevGrab
              | LibevdevUngrab
  deriving (Show)
instance Enum GrabMode where
  succ LibevdevGrab = LibevdevUngrab
  succ LibevdevUngrab = error "GrabMode.succ: LibevdevUngrab has no successor"

  pred LibevdevUngrab = LibevdevGrab
  pred LibevdevGrab = error "GrabMode.pred: LibevdevGrab has no predecessor"

  enumFromTo from to = go from
    where
      end = fromEnum to
      go v = case compare (fromEnum v) end of
                 LT -> v : go (succ v)
                 EQ -> [v]
                 GT -> []

  enumFrom from = enumFromTo from LibevdevUngrab

  fromEnum LibevdevGrab = 3
  fromEnum LibevdevUngrab = 4

  toEnum 3 = LibevdevGrab
  toEnum 4 = LibevdevUngrab
  toEnum unmatched = error ("GrabMode.toEnum: Cannot match " ++ show unmatched)

{-# LINE 25 "src/Evdev/LowLevel.chs" #-}


newtype Event = Event (C2HSImp.ForeignPtr (Event))
withEvent :: Event -> (C2HSImp.Ptr Event -> IO b) -> IO b
withEvent (Event fptr) = C2HSImp.withForeignPtr fptr
{-# LINE 27 "src/Evdev/LowLevel.chs" #-}


newtype Time = Time (C2HSImp.ForeignPtr (Time))
withTime :: Time -> (C2HSImp.Ptr Time -> IO b) -> IO b
withTime (Time fptr) = C2HSImp.withForeignPtr fptr
{-# LINE 29 "src/Evdev/LowLevel.chs" #-}


newtype Device = Device (C2HSImp.Ptr (Device))
{-# LINE 31 "src/Evdev/LowLevel.chs" #-}



{- Conversions -}

convertEvent :: Event -> IO (Int,Int16,Int32,DiffTime)
convertEvent ev = (,,,)
    <$> getIntField (\ptr -> do {C2HSImp.peekByteOff ptr 16 :: IO C2HSImp.CUShort})
{-# LINE 38 "src/Evdev/LowLevel.chs" #-}

    <*> getIntField (\ptr -> do {C2HSImp.peekByteOff ptr 18 :: IO C2HSImp.CUShort})
{-# LINE 39 "src/Evdev/LowLevel.chs" #-}

    <*> getIntField (\ptr -> do {C2HSImp.peekByteOff ptr 20 :: IO C2HSImp.CInt})
{-# LINE 40 "src/Evdev/LowLevel.chs" #-}

    <*> withEvent ev getTime
    where
        convertTime s us = picosecondsToDiffTime $ 1000000000000 * fromIntegral s + 1000000 * fromIntegral us
        getIntField :: (Integral a,Integral b) => (Ptr Event -> IO a) -> IO b
        getIntField f = withEvent ev (fmap fromIntegral . f)
        getTime :: Ptr Event -> IO DiffTime
        getTime ptr =
            let sec, usec :: IO CLong
                sec = peekByteOff ptr 0
                usec = peekByteOff ptr 8
{-# LINE 50 "src/Evdev/LowLevel.chs" #-}

            in  convertTime <$> sec <*> usec

nextEvent :: Device -> CUInt -> IO (Errno, Event)
nextEvent dev flags = do
    ptr <- mallocForeignPtrBytes 24
{-# LINE 55 "src/Evdev/LowLevel.chs" #-}

    err <- withForeignPtr ptr $ libevdev_next_event dev flags
    return (Errno err, Event ptr)

libevdev_grab :: (Device) -> (GrabMode) -> IO ((CInt))
libevdev_grab a1 a2 =
  let {a1' = id a1} in
  let {a2' = (fromIntegral . fromEnum) a2} in
  libevdev_grab'_ a1' a2' >>= \res ->
  let {res' = fromIntegral res} in
  return (res')

{-# LINE 59 "src/Evdev/LowLevel.chs" #-}

grabDevice :: Device -> GrabMode -> IO (Errno, ())
grabDevice dev mode = do
    err <- libevdev_grab dev mode
    return (Errno err, ())

newDevice :: RawFilePath -> IO (Errno, Device)
newDevice path = do
    Fd n <- openFd path ReadOnly Nothing $ defaultFileFlags
    dev <- libevdev_new
{-# LINE 68 "src/Evdev/LowLevel.chs" #-}

    err <- libevdev_set_fd dev n
    return (Errno err, dev)


{- Simpler functions -}

deviceFd :: (Device) -> IO ((Fd))
deviceFd a1 =
  let {a1' = id a1} in
  deviceFd'_ a1' >>= \res ->
  let {res' = Fd res} in
  return (res')

{-# LINE 75 "src/Evdev/LowLevel.chs" #-}

deviceName :: (Device) -> IO ((String))
deviceName a1 =
  let {a1' = id a1} in
  deviceName'_ a1' >>= \res ->
  C2HSImp.peekCString res >>= \res' ->
  return (res')

{-# LINE 76 "src/Evdev/LowLevel.chs" #-}

--TODO should really be ByteString


{- Util -}

convertEnum :: (Enum a, Integral b) => a -> b
convertEnum = fromIntegral . fromEnum

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_next_event"
  libevdev_next_event :: ((Device) -> (C2HSImp.CUInt -> ((C2HSImp.Ptr (Event)) -> (IO C2HSImp.CInt))))

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_grab"
  libevdev_grab'_ :: ((Device) -> (C2HSImp.CInt -> (IO C2HSImp.CInt)))

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_new"
  libevdev_new :: (IO (Device))

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_set_fd"
  libevdev_set_fd :: ((Device) -> (C2HSImp.CInt -> (IO C2HSImp.CInt)))

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_get_fd"
  deviceFd'_ :: ((Device) -> (IO C2HSImp.CInt))

foreign import ccall safe "Evdev/LowLevel.chs.h libevdev_get_name"
  deviceName'_ :: ((Device) -> (IO (C2HSImp.Ptr C2HSImp.CChar)))