-- This file is part of Intricacy
-- Copyright (C) 2013 Martin Bays <mbays@sdf.org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of version 3 of the GNU General Public License as
-- published by the Free Software Foundation, or any later version.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see http://www.gnu.org/licenses/.

module InteractUtil where

import Control.Monad.State
import Control.Applicative
import qualified Data.Map as Map
import Data.Map (Map)
import Control.Monad.Writer
import Control.Monad.Trans.Error
import Control.Monad.Trans.Maybe
import Data.Maybe
import Data.Char
import Data.List
import System.Directory
import Data.Array
import Data.Function (on)

import Hex
import Command
import Physics
import Mundanities
import GameStateTypes
import EditGameState
import Frame
import Lock
import Protocol
import Metagame
import MainState
import InputMode
import Util

checkWon :: UIMonad uiM => MainStateT uiM ()
checkWon = do
    st <- gets psCurrentState
    frame <- gets psFrame
    wasSolved <- gets psSolved
    let solved = checkSolved (frame,st)
    when (solved /= wasSolved) $ do
	modify $ \ps -> ps {psSolved = solved}
	obdg <- lift $ getUIBinding IMPlay CmdOpen
	lift $ if solved then do
		drawMessage $ "Unlocked! '"++obdg++"' to open."
		reportAlerts st [AlertUnlocked]
	    else drawMessage ""

doForce force = do
    st:_ <- gets esGameStateStack
    let (st',alerts) = runWriter $ resolveSinglePlForce force st
    lift (reportAlerts st' alerts) >> pushEState st'
drawTile pos tile painting = do
    modify $ \es -> es {selectedPiece = Nothing}
    lastMP <- gets lastModPos
    modifyEState $ modTile tile pos lastMP painting
    modify $ \es -> es {lastModPos = pos}
paintTilePath tile from to = if from == to
    then modify $ \es -> es {lastModPos = to}
    else let from' = (hexVec2HexDirOrZero $ to<->from) <+> from
	in drawTile from' tile True >> paintTilePath tile from' to

pushEState :: UIMonad uiM => GameState -> MainStateT uiM ()
pushEState st = do
    st':sts <- gets esGameStateStack
    when (st' /= st) $ modify $ \es -> es {esGameStateStack = st:st':sts, esUndoneStack = []}
pushPState :: UIMonad uiM => (GameState,PlayerMove) -> MainStateT uiM ()
pushPState (st,pm) = do
    st' <- gets psCurrentState
    stms <- gets psGameStateMoveStack
    when (st' /= st) $ modify $ \ps -> ps {psCurrentState = st,
	    psGameStateMoveStack = (st',pm):stms, psUndoneStack = []}
modifyEState :: UIMonad uiM => (GameState -> GameState) -> MainStateT uiM ()
modifyEState f = do
    st:_ <- gets esGameStateStack
    pushEState $ f st

doPhysicsTick :: UIMonad uiM => PlayerMove -> GameState -> uiM (GameState, [Alert])
doPhysicsTick pm st =
    let r@(st',alerts) = runWriter $ physicsTick pm st in
    reportAlerts st' alerts >> return r

nextLock :: Bool -> FilePath -> IO FilePath
nextLock newer path = do
    lockdir <- confFilePath "locks"
    time <- (Just <$> (fullLockPath path >>= getModificationTime))
	`catchIO` const (return Nothing)
    paths <- getDirContentsRec lockdir
    maybe path (drop (length lockdir + 1) . fst) . listToMaybe .
	(if newer then id else reverse) . sortBy (compare `on` snd) .
	filter (maybe (const True)
	    (\x y -> (if newer then (<) else (>)) x (snd y)) time) <$>
	(\p -> (,) p <$> getModificationTime p) `mapM` paths

setLockPath path = do
    lock <- liftIO $ fullLockPath path >>= readLock
    modify $ \ms -> ms {curLockPath = path, curLock = lock}

declare undecl@(Undeclared soln ls al) = do
    ourName <- mgetOurName
    ourUInfo <- mgetUInfo ourName
    pbdg <- lift.lift $ getUIBinding IMMeta $ CmdPlaceLock Nothing
    idx <- askLockIndex "Secure behind which lock?"
	("You first need to place ('"++pbdg++"') a lock to secure your solution behind.")
	(\i -> isJust $ userLocks ourUInfo ! i)
    guard $ isJust $ userLocks ourUInfo ! idx
    lift $ curServerActionAsyncThenInvalidate
	(DeclareSolution soln ls al idx)
	-- rather than recurse through the tree to find what scores may have
	-- changed as a result of this declaration, or leave it to timeouts
	-- and explicit refreshes to reveal it, we just invalidate all UInfos.
	(Just AllCodenames)

startMark = '^'

jumpMark :: UIMonad uiM => Char -> MainStateT uiM ()
jumpMark ch = do
    mst <- get
    void.runMaybeT $ case ms2im mst of
	IMEdit -> do
	    st <- liftMaybe $ ch `Map.lookup` esMarks mst
	    lift $ setMark '\'' >> pushEState st
	IMPlay -> do
	    mst' <- liftMaybe $ ch `Map.lookup` psMarks mst
	    put mst' { psMarks = Map.insert '\'' mst $ psMarks mst }
	IMReplay -> do
	    mst' <- liftMaybe $ ch `Map.lookup` rsMarks mst
	    put mst' { rsMarks = Map.insert '\'' mst $ rsMarks mst }
	_ -> return ()

setMark :: (Monad m) => Char -> MainStateT m ()
setMark ch = get >>= \mst -> case mst of
    -- ugh... remind me why I'm not using lens?
    EditState { esMarks = marks, esGameStateStack = (st:_) } ->
	put $ mst { esMarks = Map.insert ch st marks }
    PlayState {} -> put $ mst { psMarks = Map.insert ch mst $ psMarks mst }
    ReplayState {} -> put $ mst { rsMarks = Map.insert ch mst $ rsMarks mst }
    _ -> return ()

askLockIndex prompt failMessage pred = do
    let ok = filter pred [0,1,2]
    case length ok of
	0 -> (lift.lift) (drawError failMessage) >> mzero
	1 -> return $ head ok
	_ -> ask ok
    where
	ask ok = do
	    let prompt' = prompt ++ " [" ++ intersperse ',' (map lockIndexChar ok) ++ "]"
	    idx <- MaybeT $ lift $ join . (((charLockIndex<$>).listToMaybe)<$>) <$>
		textInput prompt' 1 False True Nothing Nothing
	    if idx `elem` ok then return idx else ask ok
confirmOrBail prompt = (guard =<<) $ lift.lift $ confirm prompt
confirm :: UIMonad uiM => String -> uiM Bool
confirm prompt = do
    drawPrompt False $ prompt ++ " [y/N] "
    setYNButtons
    waitConfirm <* endPrompt
    where
	waitConfirm = do
	    cmds <- getInput IMTextInput
	    case msum $ map ansOfCmd cmds of
		Just answer -> return answer
		Nothing -> waitConfirm
	ansOfCmd (CmdInputChar 'y') = Just True
	ansOfCmd (CmdInputChar 'Y') = Just True
	ansOfCmd CmdRedraw = Nothing
	ansOfCmd CmdRefresh = Nothing
	ansOfCmd CmdUnselect = Nothing
	ansOfCmd _ = Just False

-- | TODO: draw cursor
textInput :: UIMonad uiM => String -> Int -> Bool -> Bool -> Maybe [String] -> Maybe String -> uiM (Maybe String)
textInput prompt maxlen hidden endOnMax mposss init = getText (fromMaybe "" init, Nothing) <* endPrompt
    where
	getText :: UIMonad uiM => (String, Maybe String) -> uiM (Maybe String)
	getText (s,mstem) = do
	    drawPrompt (length s == maxlen) $ prompt ++ " " ++ if hidden then replicate (length s) '*' else s
	    if endOnMax && isNothing mstem && maxlen <= length s
	    then return $ Just $ take maxlen s
	    else do
		cmds <- getInput IMTextInput
		case foldM applyCmd (s,mstem) cmds of
		    Left False -> return Nothing
		    Left True -> return $ Just s
		    Right (s',mstem') -> getText (s',mstem')
	    where
		applyCmd (s,mstem) (CmdInputChar c) = case c of
		    '\ESC' -> Left False
		    '\a' -> Left False -- ^G
		    '\ETX' -> Left False -- ^C
		    '\n' -> Left True
		    '\r' -> Left True
		    '\NAK' -> Right ("",Nothing)  -- ^U
		    '\b' -> Right $ (take (length s - 1) s, Nothing)
		    '\DEL' -> Right $ (take (length s - 1) s, Nothing)
		    '\t' -> case mposss of
			Nothing -> Right (s,mstem)
			Just possibilities -> case mstem of
			    Nothing -> let
				completions = filter (completes s) possibilities
				pref = if null completions then s else
				    let c = head completions
				    in head [ c' | n <- reverse [0..length c],
					let c'=take n c, all (completes c') completions ]
				in Right (pref,Just pref)
			    Just stem -> let
				completions = filter (completes stem) possibilities
				later = filter (>s) completions
				s' | null completions = s
				   | null later = head completions
				   | otherwise = minimum later
				in Right (s',mstem)
		    _ -> Right $ if isPrint c
			    then ((if length s >= maxlen then id else (++[c])) s, Nothing)
			    else (s,mstem)
		applyCmd x (CmdInputSelLock idx) =
		    Right $ ([lockIndexChar idx], Nothing)
		applyCmd x (CmdInputSelUndecl (Undeclared _ _ (ActiveLock name idx))) =
		    Right $ (name++[':',lockIndexChar idx], Nothing)
		applyCmd x (CmdInputCodename name) =
		    Right $ (name, Nothing)
		applyCmd x CmdRedraw = Right x
		applyCmd x CmdRefresh = Right x
		applyCmd x CmdUnselect = Right x
		applyCmd _ _ = Left False
	completes s s' = take (length s) s' == s