{-# LANGUAGE CPP, ScopedTypeVariables, OverloadedStrings #-}

module OfficialServer.DBInteraction

(

    startDBConnection

) where

import Prelude hiding (catch);

import System.Process

import System.IO

import Control.Concurrent

import qualified Control.Exception as Exception

import Control.Monad

import qualified Data.Map as Map

import Data.Maybe

import System.Log.Logger

import Data.Time

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

import CoreTypes

import Utils

localAddressList = ["127.0.0.1", "0:0:0:0:0:0:0:1", "0:0:0:0:0:ffff:7f00:1"]

fakeDbConnection serverInfo = forever $ do

    q <- readChan $ dbQueries serverInfo

    case q of

        CheckAccount clUid _ clHost -> do

            writeChan (coreChan serverInfo) $ ClientAccountInfo (clUid,

                if clHost `elem` localAddressList then Admin else Guest)

        ClearCache -> return ()

        SendStats {} -> return ()

#if defined(OFFICIAL_SERVER)

pipeDbConnectionLoop queries coreChan hIn hOut accountsCache =

    Exception.handle (\(e :: Exception.IOException) -> warningM "Database" (show e) >> return accountsCache) $

    do

    q <- readChan queries

    updatedCache <- case q of

        CheckAccount clUid clNick _ -> do

            let cacheEntry = clNick `Map.lookup` accountsCache

            currentTime <- getCurrentTime

            if (isNothing cacheEntry) || (currentTime `diffUTCTime` (fst . fromJust) cacheEntry > 2 * 24 * 60 * 60) then

                do

                    hPutStrLn hIn $ show q

                    hFlush hIn

                    (clId, accountInfo) <- hGetLine hOut >>= (maybeException . maybeRead)

                    writeChan coreChan $ ClientAccountInfo (clId, accountInfo)

                    return $ Map.insert clNick (currentTime, accountInfo) accountsCache

                `Exception.onException`

                    (unGetChan queries q)

                else

                do

                    writeChan coreChan $ ClientAccountInfo (clUid, snd $ fromJust cacheEntry)

                    return accountsCache

        ClearCache -> return Map.empty

        SendStats {} -> (

                (hPutStrLn hIn $ show q) >>

                hFlush hIn >>

                return accountsCache)

                `Exception.onException`

                (unGetChan queries q)

    pipeDbConnectionLoop queries coreChan hIn hOut updatedCache

    where

        maybeException (Just a) = return a

        maybeException Nothing = ioError (userError "Can't read")

pipeDbConnection accountsCache serverInfo = do

    updatedCache <-

        Exception.handle (\(e :: Exception.IOException) -> warningM "Database" (show e) >> return accountsCache) $ do

            (Just hIn, Just hOut, _, _) <- createProcess (proc "./OfficialServer/extdbinterface" [])

                    {std_in = CreatePipe,

                    std_out = CreatePipe}

            hSetBuffering hIn LineBuffering

            hSetBuffering hOut LineBuffering

            hPutStrLn hIn $ dbHost serverInfo

            hPutStrLn hIn $ dbLogin serverInfo

            hPutStrLn hIn $ dbPassword serverInfo

            pipeDbConnectionLoop (dbQueries serverInfo) (coreChan serverInfo) hIn hOut accountsCache

    threadDelay (3 * 10^6)

    pipeDbConnection updatedCache serverInfo

dbConnectionLoop serverInfo =

        if (not . null $ dbHost serverInfo) then

            pipeDbConnection Map.empty serverInfo

        else

            fakeDbConnection serverInfo

#else

dbConnectionLoop = fakeDbConnection

#endif

startDBConnection serverInfo =

    forkIO $ dbConnectionLoop serverInfo