{-# LANGUAGE OverloadedStrings #-}

module EngineInteraction where

import qualified Data.Set as Set

import Control.Monad

import qualified Codec.Binary.Base64 as Base64

import qualified Data.ByteString.Char8 as B

import qualified Data.ByteString as BW

import qualified Data.Map as Map

import qualified Data.List as L

import Data.Word

import Data.Bits

import Control.Arrow

-------------

import CoreTypes

import Utils

toEngineMsg :: B.ByteString -> B.ByteString

toEngineMsg msg = B.pack $ Base64.encode (fromIntegral (BW.length msg) : BW.unpack msg)

fromEngineMsg :: B.ByteString -> Maybe B.ByteString

fromEngineMsg msg = liftM BW.pack (Base64.decode (B.unpack msg) >>= removeLength)

    where

        removeLength (x:xs) = if length xs == fromIntegral x then Just xs else Nothing

        removeLength _ = Nothing

splitMessages :: B.ByteString -> [B.ByteString]

splitMessages = L.unfoldr (\b -> if B.null b then Nothing else Just $ B.splitAt (1 + fromIntegral (BW.head b)) b)

checkNetCmd :: B.ByteString -> (B.ByteString, B.ByteString)

checkNetCmd msg = check decoded

    where

        decoded = liftM (splitMessages . BW.pack) $ Base64.decode $ B.unpack msg

        check Nothing = (B.empty, B.empty)

        check (Just msgs) = let (a, b) = (filter isLegal msgs, filter isNonEmpty a) in (encode a, encode b)

        encode = B.pack . Base64.encode . BW.unpack . B.concat

        isLegal m = (B.length m > 1) && (flip Set.member legalMessages . B.head . B.tail $ m)

        isNonEmpty = (/=) '+' . B.head

        legalMessages = Set.fromList $ "M#+LlRrUuDdZzAaSjJ,sNpPwtghbc12345" ++ slotMessages

        slotMessages = "\128\129\130\131\132\133\134\135\136\137\138"

replayToDemo :: [TeamInfo]

        -> Map.Map B.ByteString B.ByteString

        -> Map.Map B.ByteString [B.ByteString]

        -> [B.ByteString]

        -> [B.ByteString]

replayToDemo teams mapParams params msgs = concat [

        [em "TD"]

        , maybeScript

        , maybeMap

        , [eml ["etheme ", head $ params Map.! "THEME"]]

        , [eml ["eseed ", mapParams Map.! "SEED"]]

        , [eml ["e$gmflags ", showB gameFlags]]

        , schemeFlags

        , [eml ["e$template_filter ", mapParams Map.! "TEMPLATE"]]

        , [eml ["e$mapgen ", mapgen]]

        , mapgenSpecific

        , concatMap teamSetup teams

        , msgs

        , [em "!"]

        ]

    where

        em = toEngineMsg

        eml = em . B.concat

        mapGenTypes = ["+rnd+", "+maze+", "+drawn+"]

        maybeScript = let s = head $ params Map.! "SCRIPT" in if s == "Normal" then [] else [eml ["escript Scripts/Multiplayer/", s, ".lua"]]

        maybeMap = let m = mapParams Map.! "MAP" in if m `elem` mapGenTypes then [] else [eml ["emap ", m]]

        scheme = tail $ params Map.! "SCHEME"

        mapgen = mapParams Map.! "MAPGEN"

        mapgenSpecific = case mapgen of

            "+maze+" -> [eml ["e$maze_size ", head $ params Map.! "MAZE_SIZE"]]

            "+drawn" -> drawnMapData . head $ params Map.! "DRAWNMAP"

            _ -> []

        gameFlags :: Word32

        gameFlags = foldl (\r (b, f) -> if b == "false" then r else r .|. f) 0 $ zip scheme gameFlagConsts

        schemeFlags = map (\(v, (n, m)) -> eml [n, " ", showB $ (readInt_ v) * m])

            $ filter (\(_, (n, _)) -> not $ B.null n)

            $ zip (drop (length gameFlagConsts) scheme) schemeParams

        ammoStr :: B.ByteString

        ammoStr = head . tail $ params Map.! "AMMO"

        ammo = let l = B.length ammoStr `div` 4; ((a, b), (c, d)) = (B.splitAt l . fst &&& B.splitAt l . snd) . B.splitAt (l * 2) $ ammoStr in

                   (map (\(x, y) -> eml [x, " ", y]) $ zip ["eammloadt", "eammprob", "eammdelay", "eammreinf"] [a, b, c, d])

                   ++ [em "eammstore" | scheme !! 14 == "true" || scheme !! 20 == "false"]

        initHealth = scheme !! 27

        teamSetup :: TeamInfo -> [B.ByteString]

        teamSetup t = (++) ammo $

                eml ["eaddteam <hash> ", showB $ (1 + (readInt_ $ teamcolor t) :: Int) * 1234, " ", teamname t]

                : em "erdriven"

                : eml ["efort ", teamfort t]

drawnMapData :: B.ByteString -> [B.ByteString]

drawnMapData = error "drawnMapData"

schemeParams :: [(B.ByteString, Int)]

schemeParams = [

      ("e$damagepct", 1)

    , ("e$turntime", 1000)

    , ("", 0)

    , ("e$sd_turns", 1)

    , ("e$casefreq", 1)

    , ("e$minestime", 1000)

    , ("e$minesnum", 1)

    , ("e$minedudpct", 1)

    , ("e$explosives", 1)

    , ("e$healthprob", 1)

    , ("e$hcaseamount", 1)

    , ("e$waterrise", 1)

    , ("e$healthdec", 1)

    , ("e$ropepct", 1)

    , ("e$getawaytime", 1)

    ]

gameFlagConsts :: [Word32]

gameFlagConsts = [

          0x00001000

        , 0x00000010

        , 0x00000004

        , 0x00000008

        , 0x00000020

        , 0x00000040

        , 0x00000080

        , 0x00000100

        , 0x00000200

        , 0x00000400

        , 0x00000800

        , 0x00002000

        , 0x00004000

        , 0x00008000

        , 0x00010000

        , 0x00020000

        , 0x00040000

        , 0x00080000

        , 0x00100000

        , 0x00200000

        , 0x00400000

        , 0x00800000

        , 0x01000000

        , 0x02000000

        , 0x04000000

        ]