module Main where

import Text.PrettyPrint.HughesPJ

import qualified Data.MultiMap as MM

import Data.Maybe

import Data.List

import Data.Char

data HWProtocol = Command String [CmdParam]

data CmdParam = Skip

              | SS

              | LS

              | IntP

              | Many [CmdParam]

data ClientStates = NotConnected

                  | JustConnected

                  | ServerAuth

                  | Lobby

data ParseTree = PTPrefix String [ParseTree]

               | PTCommand String HWProtocol

cmd = Command

cmd1 s p = Command s [p]

cmd2 s p1 p2 = Command s [p1, p2]

breakCmd (PTCommand (c:cs) params) = (c, PTCommand cs params)

commands = [

        cmd "CONNECTED" [Skip, IntP]

        , cmd1 "NICK" SS

        , cmd1 "PROTO" IntP

        , cmd1 "ASKPASSWORD" SS

        , cmd1 "SERVER_AUTH" SS

        , cmd1 "JOINING" SS

        , cmd1 "BANLIST" $ Many [SS]

        , cmd1 "JOINED" $ Many [SS]

        , cmd1 "LOBBY:JOINED" $ Many [SS]

        , cmd2 "LOBBY:LEFT" SS LS

        , cmd2 "CLIENT_FLAGS" SS $ Many [SS]

        , cmd2 "LEFT" SS $ Many [SS]

        , cmd1 "SERVER_MESSAGE" LS

        , cmd1 "EM" $ Many [LS]

        , cmd1 "PING" $ Many [SS]

        , cmd2 "CHAT" SS LS

        , cmd2 "SERVER_VARS" SS LS

        , cmd2 "BYE" SS LS

        , cmd1 "INFO" $ Many [SS]

        , cmd "KICKED" []

    ]

groupByFirstChar :: [ParseTree] -> [(Char, [ParseTree])]

groupByFirstChar = MM.assocs . MM.fromList . map breakCmd

makePT cmd@(Command n p) = PTCommand n cmd

bpt cmds = if isJust emptyNamed then cmdLeaf $ fromJust emptyNamed else subtree

    where

        emptyNamed = find (\(_, (PTCommand n _:_)) -> null n) assocs

        assocs = groupByFirstChar cmds

        subtree = map buildsub assocs

        buildsub (c, cmds) = let st = bpt cmds in if null $ drop 1 st then maybeMerge c st else PTPrefix [c] st

        maybeMerge c cmd@[PTCommand {}] = PTPrefix [c] cmd

        maybeMerge c cmd@[PTPrefix s ss] = PTPrefix (c:s) ss

        cmdLeaf (c, (hwc:_)) = [PTPrefix [c] [hwc]]

dumpTree = vcat . map dt

    where

    dt (PTPrefix s st) = text s $$ (nest 1 $ vcat $ map dt st)

    dt _ = empty

pas2 = buildSwitch $ buildParseTree commands

    where

        buildSwitch cmds = text "case getNextChar of" $$ (nest 4 . vcat $ map buildCase cmds) $$ elsePart

        buildCase (PTCommand {}) = text "#10: <call cmd handler>;"

        buildCase (PTPrefix (s:ss) cmds) = quotes (char s) <> text ": " <> consumePrefix ss (buildSwitch cmds)

        consumePrefix "" = id

        consumePrefix str = (text "consume" <> (parens . quotes $ text str) <> semi $$)

        zeroChar = text "#0: state:= pstDisconnected;"

        elsePart = text "else <unknown cmd> end;"

    where

        maybeQuotes s = if null $ tail s then quotes $ text s else text s

        l = text "const letters: array[0.." <> (int $ length letters - 1) <> text "] of char = "

            <> parens (hsep . punctuate comma $ map maybeQuotes letters) <> semi

        s = text "const commands: array[0.." <> (int $ length commands - 1) <> text "] of integer = "

            <> parens (hsep . punctuate comma $ map text commands) <> semi

        fixName = map fixChar

        fixChar c | isLetter c = c

                  | otherwise = '_'

pas = renderArrays $ buildTables $ buildParseTree commands

    where

        buildTables cmds = let (_, _, _, t1, t2, t3) = foldr walk (0, [0], -10, [], [], [[]]) cmds in (tail t1, tail t2, concat t3)

        walk (PTCommand _ (Command n params)) (lc, s:sh, pc, tbl1, tbl2, (t3:tbl3)) =

        walk (PTPrefix prefix cmds) l = lvldown $ foldr fpf (foldr walk (lvlup l) cmds) prefix

        lvlup (lc, sh, pc, tbl1, tbl2, tbl3) = (lc, 0:sh, pc, tbl1, tbl2, []:tbl3)

        lvldown (lc, s1:s2:sh, pc, tbl1, t:tbl2, t31:t32:tbl3) = (lc, s1+s2:sh, pc, tbl1, (if null t32 then "0" else show s1):tbl2, (t31 ++ t32):tbl3)

        fpf c (lc, s:sh, pc, tbl1, tbl2, tbl3) = (lc + 1, s+1:sh, pc, [c]:tbl1, "0":tbl2, tbl3)

main = putStrLn $ renderStyle style{lineLength = 80} pas