{-# 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 Data.Word
import Data.Bits
-------------
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


checkNetCmd :: B.ByteString -> (Bool, Bool)
checkNetCmd msg = check decoded
    where
        decoded = fromEngineMsg msg
        check Nothing = (False, False)
        check (Just ms) | B.length ms > 0 = let m = B.head ms in (m `Set.member` legalMessages, m == '+')
                        | otherwise        = (False, False)
        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 ", mapParams Map.! "MAPGEN"]]
        , msgs
        ]
    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"
        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


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
        ]