--  Copyright 2012 Wolfgang Thaller.
--
--  This file is part of Retro68.
--
--  Retro68 is free software: you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation, either version 3 of the License, or
--  (at your option) any later version.
--
--  Retro68 is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with Retro68.  If not, see <http://www.gnu.org/licenses/>.

module Main where

import Text.ParserCombinators.Parsec
import Text.ParserCombinators.Parsec.Language
import Text.ParserCombinators.Parsec.Token
import System.Directory
import System.FilePath
import Control.Monad(guard)
import Data.List(isSuffixOf)
import qualified Control.Exception
import System.IO
import qualified Text.PrettyPrint.HughesPJ as PP
import Text.PrettyPrint.HughesPJ((<+>),(<>),($$),($+$))
import Data.Char
import Numeric
import Data.Maybe(isJust)
import Control.Monad.State
import qualified Data.Map as Map
import System.Environment(getArgs)

data CallingConvention = Pascal | CCall
                       deriving(Show, Eq)

data Item = CharItem Char
          | IgnoredItem
          | FunctionItem CallingConvention String String [String] [String] [Integer] (Maybe ParameterRegs)
          | PragmaParameterItem String ParameterRegs
          deriving(Show)

type Register = String
data ParameterRegs = ParameterRegs (Maybe Register) [Register]
    deriving(Show)

tp = makeTokenParser javaStyle

item  =   (char '\r' >> return (CharItem '\n'))
      <|> try externApiDeclaration
      <|> try (string "= 0x4E90" >> return IgnoredItem)
      <|> try (string "= 0x4E91" >> return IgnoredItem)
      <|> try pragmaParameter
      <|> fmap CharItem anyChar

balancedText stopAtComma = fmap (foldr ($) "") $
        many (fmap (++) paranthesized <|> fmap (:) (noneOf (if stopAtComma then "()," else "()")))
    where paranthesized = char '(' >> balancedText False >>= \xs -> char ')' >> return ('(' : xs ++ ")")

isIDChar '_' = True
isIDChar c = isAlphaNum c

trim = dropWhile isSpace . reverse . dropWhile isSpace . reverse
cleanup = unwords . words . trim

returnType = do
    t <- identifier tp
    ptrs <- many (reservedOp tp "*" >> return '*')
    return $ t ++ ptrs

externApiDeclaration = do  
    (cconv, rettype) <- 
            (reserved tp "EXTERN_API" >> (fmap ((,) Pascal) $ fmap trim $ parens tp (balancedText False)))
            <|> (reserved tp "EXTERN_API_C" >> (fmap ((,) CCall) $ fmap trim $ parens tp (balancedText False)))
            <|> (reserved tp "pascal" >> fmap ((,) Pascal) returnType)
    name <- identifier tp
    arguments <- fmap (map cleanup) $ parens tp (commaSep tp $ balancedText True)
    
    let hexwords = commaSep tp hexword
        macroinline = do
            inlinekey <- identifier tp
            guard ("WORDINLINE" `isSuffixOf` inlinekey)
            parens tp hexwords
        plaininline = do
            reservedOp tp "="
            braces tp hexwords
          
    inlines <- macroinline <|> plaininline <|> return []
    
    semi tp
    let arguments' | arguments == ["void"] = []
                   | otherwise = arguments
        argumentNames = map (trim . reverse . takeWhile isIDChar . reverse . trim) arguments'
        argumentTypes = map (trim . reverse . dropWhile isIDChar . reverse . trim) arguments'
    return $ FunctionItem cconv rettype name argumentTypes argumentNames inlines Nothing

pragmaParameter = do
    reservedOp tp "#"
    reserved tp "pragma"
    reserved tp "parameter"
    retval <- optionMaybe reg
    name <- identifier tp
    args <- parens tp (commaSep tp reg)
    -- args <- option [] $ parens tp (fmap return $ reg)
    -- let args = []
    return $ PragmaParameterItem name (ParameterRegs retval args)

reg = (reserved tp "__A0" >> return "%%a0")
   <|>(reserved tp "__A1" >> return "%%a1")
   <|>(reserved tp "__A2" >> return "%%a2")
   <|>(reserved tp "__D0" >> return "%%d0")
   <|>(reserved tp "__D1" >> return "%%d1")
   

data TypeCategory = ByteType | WordType | LongType | PointerType | VoidType
   deriving(Show, Eq)
classifyType tm t | "Ptr" `isSuffixOf` t = Just PointerType
                  | "*" `isSuffixOf` t = Just PointerType
                  | "Handle" `isSuffixOf` t = Just PointerType
                  | "UPP" `isSuffixOf` t = Just PointerType
                  | "Ref" `isSuffixOf` t = Just PointerType
classifyType tm "unsigned char" = Just ByteType
classifyType tm "signed char" = Just ByteType
classifyType tm "char" = Just ByteType
classifyType tm "short" = Just WordType
classifyType tm "long" = Just LongType
classifyType tm "void" = Just VoidType
classifyType tm t = Map.lookup t tm

hexword = integer tp
outputItem typeMap (CharItem c) = [c]
-- outputItem (FunctionItem cconv rettype name argumentTypes argumentNames words) = "<fun>"

outputItem typeMap (FunctionItem cconv rettype name argumentTypes argumentNames words Nothing)
    | True, not (null words), Just retcat <- classifyType typeMap rettype
    = let
        helper = PP.text "__magic_inline_" <> PP.text name
        magic = PP.text "__magic_inline_" <> PP.hcat (PP.punctuate (PP.char '_') (map (PP.text . hexword) words'))
        hexword w = replicate (4 - length s) '0' ++ s where s = showHex w ""
        magicArgTypes = case retcat of
            ByteType -> reverse $ "char" : argumentTypes
            WordType -> reverse $ "short" : argumentTypes
            LongType -> reverse $ "long" : argumentTypes
            PointerType -> reverse $ "long" : argumentTypes                           
            VoidType -> reverse argumentTypes
        magicArgValues = case retcat of
            VoidType -> reverse argumentNames
            _ -> reverse $ "0" : argumentNames
        words' = case retcat of
            VoidType -> words
            _ | cconv == CCall -> words
            ByteType -> words ++ [ 0x101f ] -- move.b (a7)+,d0
            WordType -> words ++ [ 0x301f ] -- move.w (a7)+,d0
            LongType -> words ++ [ 0x201f ] -- move.l (a7)+,d0
            PointerType -> words ++ [ 0x201f ] -- move.l (a7)+,d0   
        cconvAttr = case cconv of
            Pascal -> PP.text "__attribute__((stdcall))" 
            CCall -> PP.empty
    in PP.render $
       PP.text rettype <+> cconvAttr <+> helper
            <> PP.parens (PP.hsep $ PP.punctuate PP.comma $ map PP.text magicArgTypes)
            <+> PP.text("__asm__") <> PP.parens ( PP.doubleQuotes magic )
            <> PP.semi
       $+$
       PP.text "static inline" <+> PP.text rettype <+> PP.text name
            <+> PP.parens (PP.hsep $ PP.punctuate PP.comma $ zipWith (\t n -> PP.text t <+> PP.text n) argumentTypes argumentNames) $$
            PP.text "{" $+$ (PP.nest 4 $
                (if retcat == VoidType then PP.empty else PP.text "return") <+>
                helper <> PP.parens (PP.hsep $ PP.punctuate PP.comma $ map PP.text magicArgValues) <> PP.semi
            ) $+$ PP.text "}\n\n"


      

outputItem typeMap (FunctionItem cconv rettype name argumentTypes argumentNames words mbParamRegs) = 
    PP.render $
        linkage <+> PP.text rettype <+> PP.text name
            <+> PP.parens (PP.hsep $ PP.punctuate PP.comma $ zipWith (\t n -> PP.text t <+> PP.text n) argumentTypes argumentNames) $$
        if isJust mbCategories && not (null words)
            then
                PP.text "{" $+$ (PP.nest 4 $
                    addReturnValue $
                    PP.text "__asm__ __volatile__ (" $+$
                    PP.nest 4 (
                        PP.nest 4 (PP.vcat asmStatements) $+$
                        showConstraints outs $+$
                        showConstraints ins $+$
                        PP.text ": \"%a0\", \"%a1\", \"%d0\", \"%d1\", \"%d2\", \"memory\", \"cc\""
                        <> (if tooltrap then PP.text ", \"%a5\"" else PP.empty)
                    )
                    $+$ PP.text ");"
                ) $+$ PP.text "}\n\n"
            else
                PP.semi $+$ 
                PP.text "//" <+> PP.text (show words) $+$
                PP.text "//" <+> PP.text rettype <+> PP.text (show $ (classifyType typeMap) rettype) $+$
                PP.text "//" <+> PP.text (show argumentTypes) <+> PP.text (show $ map (classifyType typeMap) argumentTypes) $+$
                PP.text "\n" -- couldn't convert type
    where
        tooltrap = True -- trapnum >= 0xA800
        linkage | null words = PP.text "extern"
                | otherwise = PP.text "static inline"
 
 
        mbCategories = do
            retcat <- classifyType typeMap rettype
            argcats <- mapM (classifyType typeMap) argumentTypes
            return (retcat, argcats)
  
        Just (returnCategory, argumentCategories) = mbCategories
  
        returnsValue = returnCategory /= VoidType
        addReturnValue body 
            | returnsValue = (PP.text rettype <+> PP.text "_ret;") $+$
                             body $+$
                             PP.text "return _ret;"
            | otherwise = body
        outs | returnsValue = [PP.text "\"=g\"(_ret)"]
             | otherwise = []
        ins = zipWith inputConstraint argumentCategories argumentNames 
     
        inputConstraint PointerType name = PP.text "\"m\"(*(char*)" <> PP.text name <> PP.text ")"
        inputConstraint VoidType name = error $ "Void Parameter: " ++ name
        inputConstraint _ name = PP.text "\"g\"(" <> PP.text name <> PP.text ")"
  
  
        showConstraints constraints = PP.text ":" <+> PP.hsep (PP.punctuate PP.comma $ constraints)
        asmStatements = 
            subq ++
            pushes ++
            map (\trapnum -> PP.text "\"dc.w" <+> PP.text "0x" <> PP.text (showHex trapnum "") 
                          <> PP.text "\\n\\t\"") words
            ++ pop
  
        (subq, pop) = case returnCategory of
                VoidType -> ([], [])
                _ -> (ifpascal [PP.text "\"subq #" <> PP.int size <> PP.text ", %%sp\\n\\t\""],
                      [PP.text "\"move" <> szLetter <+> src <+> PP.text ", %0\\n\\t\""])
            where
                size = case returnCategory of
                    PointerType -> 4 ; LongType -> 4 ; WordType -> 2 ; ByteType -> 2 {- keep stack aligned -}
                   
                szLetter = PP.text $ case returnCategory of
                    PointerType -> ".l" ; LongType -> ".l" ; WordType -> ".w" ; ByteType -> ".b"
                src = case mbParamRegs of
                        Nothing -> PP.text "%%sp@+"
                        Just (ParameterRegs (Just r) _) -> PP.text r
                        Just (ParameterRegs Nothing _) -> error $ "no reg for return value: " ++ name
    
                ifpascal x = case mbParamRegs of Nothing -> x ; Just _ -> []
    
        pushes = case mbParamRegs of
                    Nothing -> zipWith (mkPush Nothing) argumentCategories
                    Just (ParameterRegs _ regs) -> zipWith3 mkPush (map Just regs) argumentCategories
            $
                map (\i -> PP.char '%' <> PP.int i) $
                (if returnsValue then [1..] else [0..])
  
        endtxt = PP.text "\\n\\t\""
        mkPush Nothing PointerType operand = PP.text "\"pea" <+> operand <> endtxt
        mkPush (Just reg) PointerType operand = PP.text "\"lea" <+> operand <> PP.comma <+> PP.text reg <> endtxt
        mkPush mbReg size operand =
            PP.text "\"move" <> PP.text sz <+> operand <> PP.comma <+> dst    <> endtxt
            where
                sz = case size of
                    LongType -> ".l" ; WordType -> ".w" ; ByteType -> ".b"
                dst = case mbReg of
                    Nothing -> PP.text "%%sp@-"
                    Just reg -> PP.text reg

outputItem _ _ = ""

collectPragmas xs = evalState (mapM doit xs) Map.empty
    where
        doit x@(PragmaParameterItem name params) = modify (Map.insert name params) >> return x
        doit (FunctionItem cconv rettype name argumentTypes argumentNames inlines _) = do
            m <- get
            return $ FunctionItem cconv rettype name argumentTypes argumentNames inlines (Map.lookup name m)
        doit x = return x

parseTypeMap tm = Map.fromList $ map handleLine $ lines tm
    where
        handleLine tml = case words tml of
            (x : xs) -> (trim $ unwords xs, case x of
                            "B" -> ByteType ; "W" -> WordType ; "L" -> LongType ; "P" -> PointerType)
processFile inputDir outputDir file
    | isLower (head file) = putStrLn $ "Skipping " ++ file ++ " (standard library or MPW runtime)"
    | ".h" `isSuffixOf` file = do
        print $ (outputDir </> takeFileName file)
        -- readFile (inputDir </> file)
        f <- openFile (inputDir </> file) ReadMode
        hSetEncoding f latin1
        txt <- hGetContents f
        let parseResult = parse (many item) file txt
        typeMap <- fmap parseTypeMap $ readFile "../Retro68/types.txt"
        case parseResult of
            Right items -> do
                outf <- openFile (outputDir </> file) WriteMode
                hSetEncoding outf latin1

                let processed = concatMap (outputItem typeMap) $ collectPragmas $ items
                if (file == "ConditionalMacros.h")
                    then do
                        hPutStrLn outf $ unlines [
                                "#define TARGET_CPU_68K 1",
                                "#define TARGET_OS_MAC 1",
                                "#define TARGET_RT_MAC_CFM 0",
                                "#define TARGET_RT_MAC_MACHO 0",

                                "#define TYPE_LONGLONG 1",
                                "#define pascal",
                                "#ifdef __cplusplus",
                                "#define TYPE_BOOL 1",
                                "#endif"
                            ]
                        
                        hPutStr outf $ unlines $
                            map (\line -> if line == "#elif defined(__GNUC__)"
                                    then "#elif 0"
                                    else line) $
                            lines $ processed
                    else
                        hPutStr outf $ processed
                hClose outf
            Left err -> putStrLn $ file ++ ": " ++ show err
    | otherwise = do
        putStrLn $ "Unknown: " ++ file

main = do
    [inputDir,outputDir] <- getArgs
    files <- getDirectoryContents inputDir
    Control.Exception.try (createDirectory outputDir) :: IO (Either Control.Exception.IOException ())
    mapM (processFile inputDir outputDir) files
    return ()