{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE BlockArguments #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# OPTIONS_GHC -Wall -fno-warn-tabs #-}

module Gpu.Vulkan.PhysicalDevice.Struct.Th (
	vkPhysicalDeviceLimits, vkPhysicalDeviceFeatures,
	DeviceSize(..), Size(..),

	vkPhysicalDeviceData, vkPhysicalDeviceFromFunBody ) where

import Language.Haskell.TH
import Control.Arrow
import Control.Monad
import Data.Foldable
import Data.Maybe
import Data.List.Length
import Data.Word
import Data.Int
import Data.Char

import Gpu.Vulkan.Middle.Types
import Gpu.Vulkan.Base.Middle.Internal

import qualified Gpu.Vulkan.Sample.Enum as Sample

import qualified Gpu.Vulkan.Device.Middle.Types as Device

newtype DeviceSize = DeviceSize { unDeviceSize :: Word64 }
	deriving (Show, Eq, Ord, Enum, Num, Real, Integral)

vkPhysicalDeviceLimits :: DecsQ
vkPhysicalDeviceLimits = makeData "Limits"

vkPhysicalDeviceFeatures :: DecsQ
vkPhysicalDeviceFeatures = makeData "Features"

makeData :: String -> DecsQ
makeData dtnm = (\dt sg bd tsg tbd -> [dt, sg, bd, tsg, tbd])
	<$> vkPhysicalDeviceData dtnm
	<*> vkPhysicalDeviceFromFunSig dtnm
	<*> vkPhysicalDeviceFromFunBody dtnm
	<*> vkPhysicalDeviceToFunSig dtnm
	<*> vkPhysicalDeviceToFunBody dtnm

vkPhysicalDeviceData :: String -> DecQ
vkPhysicalDeviceData dtnm = do
	ds <- runIO $ readStructData dtnm
	dataD (cxt []) (mkName dtnm) [] Nothing [recC (mkName dtnm)
		(uncurry (member dtnm) <$> ds)] [derivClause Nothing [conT ''Show]]

dict :: Dict
dict = dictGenToDict dictGen

dictGenToDict :: DictGen -> Dict
dictGenToDict = map \(tp, tfr, _to) -> (tp, tfr)

dict2 :: Dict2
dict2 = dictGenToDict2 dictGen

dictGenToDict2 :: DictGen -> Dict2
dictGenToDict2 = map \(tp, _tfr, to) -> (tp, to)

type Dict = [(String, (TypeQ, Name -> ExpQ))]
type Dict2 = [(String, (Name -> PatQ, Name -> ExpQ))]
type DictGen = [(String, (TypeQ, Name -> ExpQ), (Name -> PatQ, Name -> ExpQ))]

dictGen :: [(String, (TypeQ, Name -> ExpQ), (Name -> PatQ, Name -> ExpQ))]
dictGen = [
	("uint32_t", (conT ''Word32, varE), (varP, varE)),
	("int32_t", (conT ''Int32, varE), (varP, varE)),
	("float", (conT ''Float, varE), (varP, varE)),
	("VkBool32", (conT ''Bool, appE (varE 'bool32ToBool) . varE),
		(varP, appE (varE 'boolToBool32) . varE)),
	("size_t", (conT ''Size, appE (conE 'Size) . varE),
		(conP 'Size . (: []) . varP, varE)),
	("VkDeviceSize", (conT ''Device.Size, appE (conE 'Device.Size) . varE),
		(conP 'Device.Size . (: []) . varP, varE)),
	("VkSampleCountFlags",
		(conT ''Sample.CountFlags,
			appE (conE 'Sample.CountFlagBits) . varE),
		(conP 'Sample.CountFlagBits . (: []) . varP, varE)) ]

noBang :: BangQ
noBang = bang noSourceUnpackedness noSourceStrictness

member :: String -> String -> FieldName -> VarBangTypeQ
member dtnm tp_ fn = varBangType (mkName nm) $ bangType noBang tp
	where
	pfx = map toLower dtnm
	(nm, tp) = getNameType pfx tp_ fn

getNameType :: String -> String -> FieldName -> (String, TypeQ)
getNameType pfx tp (Atom fn) = (pfx ++ capitalize fn, fst $ lookup' tp dict)
getNameType pfx tp (List fn nb) = (pfx ++ capitalize fn,
	conT ''LengthL `appT` litT (numTyLit nb) `appT` fst (lookup' tp dict))

lookup' :: (Show a, Eq a) => a -> [(a, b)] -> b
lookup' x d = case lookup x d of
	Nothing -> error $ "no such key: " ++ show x
	Just y -> y

capitalize :: String -> String
capitalize "" = ""
capitalize (c : cs) = toUpper c : cs

readStructData :: String -> IO [(String, FieldName)]
readStructData dtnm = map ((id *** readName) . (separate '|')) . lines <$>
	(readFile $ "th/vkPhysicalDevice" ++ dtnm ++ ".txt")

data FieldName = Atom String | List String Integer deriving Show

readName :: String -> FieldName
readName ('A' : ' ' : nm) = Atom nm
readName ('L' : ' ' : nmnb) = let [nm, nb] = words nmnb in List nm (read nb)
readName _ = error "bad"

separate :: Eq a => a -> [a] -> ([a], [a])
separate c str = case span (/= c) str of
	(pre, _ : pst) -> (pre, pst)
	_ -> error "no separater"

vkPhysicalDeviceFromFunSig :: String -> DecQ
vkPhysicalDeviceFromFunSig dtnm = sigD (mkName $ map toLower dtnm ++ "FromCore")
	$ (conT =<< (fromJustMsg "vkPhysicalDeviceFromFunSig" <$> lookupTypeName ("C." ++ dtnm))) `arrT` conT (mkName dtnm)

vkPhysicalDeviceToFunSig :: String -> DecQ
vkPhysicalDeviceToFunSig dtnm = sigD (mkName $ map toLower dtnm ++ "ToCore")
	$ conT (mkName dtnm) `arrT` (conT =<< (fromJustMsg "vkPhysicalDeviceToFunSig" <$> lookupTypeName ("C." ++ dtnm)))

arrT :: TypeQ -> TypeQ -> TypeQ
arrT t1 t2 = arrowT `appT` t1 `appT` t2

vkPhysicalDeviceFromFunBody :: String -> DecQ
vkPhysicalDeviceFromFunBody dtnm = do
	ds <- runIO $ readStructData dtnm
	xs <- replicateM (length ds) $ newName "x"
	let	fs = (\(tp, _) -> typeToFun tp) <$> ds
		nvs = zip (map snd ds) xs
		nws = zip (zip (map snd ds) xs) fs
	funD (mkName $ map toLower dtnm ++ "FromCore") [
		clause [(`recP` exFieldPats dtnm nvs) =<< fromJustMsg "vkPhysicalDeviceFromFunBody" <$> lookupValueName' ("C." ++ dtnm)]
			(normalB $ recConE (mkName dtnm) (exFieldExps dtnm nws)) []
		]

vkPhysicalDeviceToFunBody :: String -> DecQ
vkPhysicalDeviceToFunBody dtnm = do
	ds <- runIO $ readStructData dtnm
	xs <- replicateM (length ds) $ newName "x"
	let	pes = (\(tp, _) -> typeToPatExp tp) <$> ds
		nvs = zip (zip (map snd ds) xs) pes
	funD (mkName $ map toLower dtnm ++ "ToCore") [
		clause [(recP (mkName dtnm) $ toFieldPats dtnm nvs)]
			(normalB $ (`recConE` toFieldExps dtnm nvs) =<< fromJustMsg "vkPhysicalDeviceToFunBody" <$> lookupValueName' ("C." ++ dtnm)) []]

typeToFun :: String -> (Name -> ExpQ)
typeToFun nm = let Just (_, f) = lookup nm dict in f

exFieldPats :: String -> [(FieldName, Name)] -> [Q FieldPat]
exFieldPats dtnm = map $ uncurry (exFieldPat1 $ map toLower dtnm)

exFieldPat1 :: String -> FieldName -> Name -> Q FieldPat
exFieldPat1 pfx fn x = do
	let	nm = case fn of
			Atom n -> n
			List n _ -> n
	n <- fromJustMsg (mkMsg pfx nm) <$> lookupValueName' ("C." ++ pfx ++ capitalize nm)
	fieldPat n (varP x)
	where
	mkMsg p n = "exFieldPat1: pfx = " ++ show p ++ " nm = " ++ show n

exFieldExps :: String -> [((FieldName, Name), Name -> ExpQ)] -> [Q (Name, Exp)]
exFieldExps dtnm = map . uncurry $ uncurry (exFieldExp1 $ map toLower dtnm)

listToLengthL :: ListToLengthL n => [a] -> LengthL n a
listToLengthL xs = case splitL xs of
	Right (ln, []) -> ln
	_ -> error "bad"

exFieldExp1 :: String -> FieldName -> Name -> (Name -> ExpQ) -> Q (Name, Exp)
exFieldExp1 pfx (Atom nm) x f = fieldExp (mkName $ pfx ++ capitalize nm) (f x)
exFieldExp1 pfx (List nm _) x f = do
	y <- newName "y"
	fieldExp (mkName $ pfx ++ capitalize nm)
		. appE (varE 'listToLengthL) $ lam1E (varP y) (f y) .<$> varE x

(.<$>) :: ExpQ -> ExpQ -> ExpQ
f .<$> x = infixApp f (varE '(<$>)) x

typeToPatExp :: String -> (Name -> PatQ, Name -> ExpQ)
typeToPatExp = fromJustMsg "typeToPatExp" . (`lookup` dict2)

toFieldPats :: String -> [((FieldName, Name), (Name -> PatQ, a))] -> [Q FieldPat]
toFieldPats dtnm = map . uncurry $ uncurry (toFieldPat1 $ map toLower dtnm)

toFieldPat1 :: String -> FieldName -> Name -> ((Name -> PatQ), a) -> Q FieldPat
toFieldPat1 pfx (Atom nm) x (f, _) = fieldPat (mkName $ pfx ++ capitalize nm) (f x)
toFieldPat1 pfx (List nm _) x _ = fieldPat (mkName $ pfx ++ capitalize nm) (varP x)

toFieldExps :: String -> [((FieldName, Name), (Name -> PatQ, Name -> ExpQ))] -> [Q (Name, Exp)]
toFieldExps dtnm = map . uncurry $ uncurry (toFieldExp1 $ map toLower dtnm)

toFieldExp1 :: String -> FieldName -> Name -> (Name -> PatQ, Name -> ExpQ) -> Q (Name, Exp)
toFieldExp1 pfx (Atom nm) x (_, f) = do
	n <- fromJustMsg "toFieldExp1" <$> lookupValueName' ("C." ++ pfx ++ capitalize nm)
	fieldExp n (f x)
toFieldExp1 pfx (List nm _) x (pf, f) = do
	n <- fromJustMsg "toFieldExp1" <$> lookupValueName' ("C." ++ pfx ++ capitalize nm)
	y <- newName "y"
	fieldExp n $ lam1E (pf y) (f y) .<$> (varE 'toList `appE` varE x)

fromJustMsg :: String -> Maybe a -> a
fromJustMsg msg Nothing = error msg
fromJustMsg _ (Just x) = x

lookupValueName' :: String -> Q (Maybe Name)
lookupValueName' = pure . Just . mkName