{-|
Module      : Game.Werewolf.Command
Description : Command data structures.

Copyright   : (c) Henry J. Wylde, 2015
License     : BSD3
Maintainer  : public@hjwylde.com

Command data structures.
-}

{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes            #-}

module Game.Werewolf.Command (
    -- * Command
    Command(..),

    -- ** Instances
    devourVoteCommand, lynchVoteCommand, noopCommand, pingCommand, quitCommand, seeCommand,
    statusCommand,
) where

import Control.Lens         hiding (only)
import Control.Monad.Except
import Control.Monad.Extra
import Control.Monad.State  hiding (state)
import Control.Monad.Writer

import           Data.List
import qualified Data.Map  as Map
import           Data.Text (Text)

import Game.Werewolf.Engine
import Game.Werewolf.Game     hiding (isGameOver, isSeersTurn, isVillagersTurn, isWerewolvesTurn,
                               killPlayer)
import Game.Werewolf.Player   hiding (doesPlayerExist)
import Game.Werewolf.Response
import Game.Werewolf.Role     hiding (Villagers, Werewolves, findByName_, name, _name)

data Command = Command { apply :: forall m . (MonadError [Message] m, MonadState Game m, MonadWriter [Message] m) => m () }

devourVoteCommand :: Text -> Text -> Command
devourVoteCommand callerName targetName = Command $ do
    validatePlayer callerName callerName
    unlessM (isPlayerWerewolf callerName)           $ throwError [playerCannotDoThatMessage callerName]
    unlessM isWerewolvesTurn                        $ throwError [playerCannotDoThatRightNowMessage callerName]
    whenJustM (getPlayerVote callerName) . const    $ throwError [playerHasAlreadyVotedMessage callerName]
    validatePlayer callerName targetName
    whenM (isPlayerWerewolf targetName)             $ throwError [playerCannotDevourAnotherWerewolf callerName]

    votes %= Map.insert callerName targetName

    aliveWerewolfNames <- uses players $ map _name . filterAlive . filterWerewolves

    tell [playerMadeDevourVoteMessage aliveWerewolfNames callerName targetName]

lynchVoteCommand :: Text -> Text -> Command
lynchVoteCommand callerName targetName = Command $ do
    validatePlayer callerName callerName
    unlessM isVillagersTurn                         $ throwError [playerCannotDoThatRightNowMessage callerName]
    whenJustM (getPlayerVote callerName) . const    $ throwError [playerHasAlreadyVotedMessage callerName]
    validatePlayer callerName targetName

    votes %= Map.insert callerName targetName

noopCommand :: Command
noopCommand = Command $ return ()

pingCommand :: Command
pingCommand = Command $ use turn >>= \turn' -> case turn' of
    Seers       -> tell [pingSeersMessage]
    Villagers   -> do
        game <- get

        tell [waitingOnMessage Nothing $ filter (flip Map.notMember (game ^. votes) . _name) (filterAlive $ game ^. players)]
    Werewolves  -> tell [pingWerewolvesMessage]
    NoOne       -> return ()
    NightFalling -> return ()
    DayBreaking  -> return ()

quitCommand :: Text -> Command
quitCommand callerName = Command $ do
    validatePlayer callerName callerName

    caller <- uses players $ findByName_ callerName

    killPlayer caller
    tell [playerQuitMessage caller]

    sees    %= Map.delete callerName
    votes   %= Map.delete callerName

seeCommand :: Text -> Text -> Command
seeCommand callerName targetName = Command $ do
    validatePlayer callerName callerName
    unlessM (isPlayerSeer callerName)           $ throwError [playerCannotDoThatMessage callerName]
    unlessM isSeersTurn                         $ throwError [playerCannotDoThatRightNowMessage callerName]
    whenJustM (getPlayerSee callerName) . const $ throwError [playerHasAlreadySeenMessage callerName]
    validatePlayer callerName targetName

    sees %= Map.insert callerName targetName

statusCommand :: Text -> Command
statusCommand callerName = Command $ use turn >>= \turn' -> case turn' of
    Seers       -> do
        game <- get

        tell $ standardStatusMessages turn' (game ^. players)
    Villagers   -> do
        game <- get

        tell $ standardStatusMessages turn' (game ^. players)
        tell [waitingOnMessage (Just [callerName]) $ filter (flip Map.notMember (game ^. votes) . _name) (filterAlive $ game ^. players)]
    Werewolves  -> do
        unlessM (doesPlayerExist callerName) $ throwError [playerDoesNotExistMessage callerName callerName]

        game <- get

        tell $ standardStatusMessages turn' (game ^. players)
        whenM (isPlayerWerewolf callerName) $ tell [waitingOnMessage (Just [callerName]) $ filter (flip Map.notMember (game ^. votes) . _name) (filterAlive . filterWerewolves $ game ^. players)]
    NoOne       -> do
        aliveAllegiances <- uses players $ nub . map (_allegiance . _role) . filterAlive

        when (length aliveAllegiances <= 1) $ turn .= NoOne >> get >>= tell . gameOverMessages
    NightFalling -> return ()
    DayBreaking  -> return ()
    where
        standardStatusMessages turn players = [
            currentTurnMessage callerName turn,
            rolesInGameMessage (Just [callerName]) $ map _role players,
            playersInGameMessage callerName players
            ]

validatePlayer :: (MonadError [Message] m, MonadState Game m) => Text -> Text -> m ()
validatePlayer callerName name = do
    whenM isGameOver                $ throwError [gameIsOverMessage callerName]
    unlessM (doesPlayerExist name)  $ throwError [playerDoesNotExistMessage callerName name]
    whenM (isPlayerDead name)       $ throwError [if callerName == name then playerIsDeadMessage callerName else targetIsDeadMessage callerName name]