-- TODO automate this sort of high level wrapper boilerplate
-- or look at upstream plans: https://github.com/well-typed/hs-bindgen/issues?q=state%3Aopen%20label%3A%22highlevel%22
module GarnetRs.Wrapped (
    T (..),
    Shape (..),
    hello,
    helloStruct,
    helloShape,
    add,
) where

import Data.ByteString
import Data.Word
import Foreign
import Foreign.C
import GarnetRs qualified as Raw
import GarnetRs.Safe qualified as Raw
import HsBindgen.Runtime.PtrConst
import Unsafe.Coerce

data T = T
    { a :: Bool
    , b :: Word8
    }
convertT :: T -> Raw.T
convertT T{a, b} = Raw.T{a = CBool $ fromBool a, b}

data Shape
    = Circle CDouble
    | Rectangle CDouble CDouble
convertShape :: Shape -> Raw.Shape
convertShape = \case
    Circle r -> Raw.Shape (Raw.Shape_Tag 0) $ Raw.set_shape_body_circle $ Raw.Circle_Body r
    Rectangle w h -> Raw.Shape (Raw.Shape_Tag 1) $ Raw.set_shape_body_rectangle $ Raw.Rectangle_Body w h

hello :: ByteString -> IO ()
hello s = useAsCString s $ Raw.hello . unsafeFromPtr

helloStruct :: T -> IO ()
helloStruct = Raw.hello_struct . convertT

helloShape :: Shape -> IO ()
helloShape = Raw.hello_shape . convertShape

add :: Int -> Int -> IO Int
add a b = from <$> Raw.add (to a) (to b)
  where
    -- these types should be the same in practice - both are pointer-sized
    to = unsafeCoerce @Int @CIntPtr
    from = unsafeCoerce @CIntPtr @Int