{-# LANGUAGE CPP #-}
module Main where

import Control.Monad
import Control.Concurrent
import System.Directory
import System.FilePath
import System.IO
import System.IO.Error
#ifdef WIN32
import System.Win32.Mutex
#else
import System.Posix.IO
#endif
import System.Exit
import System.Console.GetOpt
import System.Environment
import Data.Maybe
import Data.Version (showVersion)

import Capture
import TimeLog
import UpgradeLog1
import CommonStartup

import Paths_arbtt (version)


data Conf = Conf {
	cSampleRate :: Integer
	}
defaultConf = Conf 60

data Opts = Help | Version | SetRate Integer
	deriving Eq

versionStr = "arbtt-capture " ++ showVersion version
header = "Usage: arbtt-capture [OPTIONS...]"

options :: [OptDescr Opts]
options = 
     [ Option "h?"     ["help"]
              (NoArg Help)
	      "show this help"
     , Option "V"      ["version"]
              (NoArg Version)
	      "show the version number"
     , Option "r"      ["sample-rate"]
     	      (ReqArg (SetRate . read) "RATE")
	      "set the sample rate in seconds (default: 60)"
     ]	     

-- | This is very raw, someone ought to improve this
lockFile filename = do
#ifdef WIN32
    success <- claimMutex filename
    unless success $ do
    	hPutStrLn stderr ("arbtt [Error]: Could not aquire lock for " ++ filename ++"!")
	exitFailure
#else
    flip catch (\e -> hPutStrLn stderr ("arbtt [Error]: Could not aquire lock for " ++ filename ++"!") >> exitFailure) $ do
        fd <- openFd (filename  ++ ".lck") WriteOnly (Just 0o644) defaultFileFlags
        setLock fd (WriteLock, AbsoluteSeek, 0, 0)
#endif       

main = do
    commonStartup
    
    args <- getArgs
    flags <- case getOpt Permute options args of
    	(o, [], []) | Help `notElem` o && Version `notElem` o -> return o
	(o, _, _)   | Version `elem` o -> do
		hPutStrLn stderr versionStr
		exitSuccess
	(o, _, _)   | Help `elem` o -> do
                hPutStr stderr (usageInfo header options)
		exitSuccess
	(_,_,errs) -> do
                hPutStr stderr (concat errs ++ usageInfo header options)
                exitFailure

    let sampleRate = foldr (.) id
                     (map (\f -> case f of {SetRate r -> const r; _ -> id}) flags)
		     60

    dir <- getAppUserDataDirectory "arbtt"
    createDirectoryIfMissing False dir
    let captureFile = dir </> "capture.log"
    lockFile captureFile
    upgradeLogFile1 captureFile
    setupCapture
    runLogger captureFile (sampleRate * 1000) captureData