{-
 - psl backdropper_consol | grep -v hs | grep -v RUSER | gawk '{print $2}' | xargs kill -9
 -}
-- |
-- * backdropper_consol
--
-- [@Author@] Yann Golanski.
--
-- [@Maintainer@] Yann Golanski <yann@kierun.org>
--
-- [@Description@] Wallpaper/Backdrop changer. 
--
-- This works as follow.  A configuration file must be created (see example 
-- "sample_wallpaper_list" file) containing one image per line with the full 
-- path.  Once the backdropper_consol is started (and pointed to said file), 
-- it will read all the images and pick a random one to display with qiv.  You
-- can get qiv from http://www.klografx.net/qiv/ or change the source to use
-- whatever viewing program you prefer.  It will display all the images in the 
-- configuration file before re-reading it.  
--
-- A time (delay) between changes can be set.   Upcoming is a feature to only
-- display images while you are at work -- based on time of day and idleness 
-- of the user running backdropper_consol.
--
-- A GUI will be upcoming. 
--
-- The backdropper_consol takes the following options:
--  -h, -?         --help                 Show usage info
--  -V, -v         --version              Print version
--  -l[Log Level]  --logging[=Log Level]  Logging level: debug, info (DEFAULT), notice, warning, error, critical, alert or emergency.
--  -c[FILE]       --config[=FILE]        configure FILE containing list of images.
--  -d[INT]        --delay[=INT]          Time between changes in seconds.
--  -g             --gui                  Have a nice (?!) GUI (default is no).
--
-- A typical usage would be of the form:
--  backdropper_consol --config'='/home/yann/.rotate_wallpaper_list --delay'='900
--
-- Things still to do are 
--
--  * Only rotate during work hours.
--  * Making sure that all images are shown within a day.
--  * Make a nice GUI.
--
-- (c)2008 Yann Golanski, GPLv3 or above.
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation, either version 3 of the License, or
--  (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
--
{------------------------------------------------------------------------------}
import Rotating_backdrop_logic
import System.Console.GetOpt
import Data.Maybe
import System.Environment
import System
import IO
import Control.Monad
import System.Directory
import System.Log.Logger
import System.Log.Handler.Syslog
import Logger_logic

{------------------------------------------------------------------------------}
-- | New data type to hold the command line options.
data Options = Options
 { optInput  :: Maybe FilePath
  ,optLogLvl :: Maybe String
  ,optDelay  :: Int
  ,optGUI    :: Bool
 } deriving Show


{------------------------------------------------------------------------------}
-- | Default values for the command line options.
defaultOptions = Options
 { optInput = Nothing
  ,optLogLvl = Nothing
  ,optDelay = 0
  ,optGUI = False
 }


{------------------------------------------------------------------------------}
-- | Constructor for the command line options.
options :: [OptDescr (Options -> IO Options)]
options = [ 

  -- Prints help and exit.
  Option ['h','?'] ["help"] 
    (NoArg (\ opts -> exitHelp))
    "Show usage info"

  -- Print version and exit.
  ,Option ['V','v'] ["version"]
	  (NoArg (\_ -> do hPutStrLn stderr "Version 1.1"; exitWith ExitSuccess))
	  "Print version"

  -- Sets the configuration file containing list of images.
  ,Option "l" ["logging"]
    (OptArg (\arg opts -> return opts {optLogLvl = arg} ) "Log Level")
    "Logging level: debug, info (DEFAULT), notice, warning, error, critical, alert or emergency."

  -- Sets the configuration file containing list of images.
  ,Option "c" ["config"]
    (OptArg (\arg opts -> return opts {optInput = arg} ) "FILE")
    "configure FILE containing list of images."

  -- Set the time between calls.
  ,Option "d" ["delay"]
    (OptArg (\arg opts -> return opts {optDelay = 
    case arg of
      Nothing -> 0
      (Just d) -> read d
    --(read arg)
    } ) "INT")
    "Time between changes in seconds."

  -- To use a GUI or not...
  ,Option "g" ["gui"]
	  (NoArg (\opt -> return opt { optGUI = True }))
	  "Have a nice (?!) GUI (default is no)."

  -- Options done.
 ]


{------------------------------------------------------------------------------}
-- | Parse the command line options.
parseCmdOpts :: IO (Options, [String])
parseCmdOpts = do
  (optsActions, rest, errors) <- getArgs >>= return . getOpt RequireOrder options
  when (not (null errors)) $ do
    mapM_ (hPutStrLn stderr) errors
    showHelp
    exitFailure
  opts <- foldl (>>=) (return defaultOptions) optsActions
  return (opts, rest)


{------------------------------------------------------------------------------}
-- | Shows the getOpts generated help.
showHelp :: IO ()
showHelp = do
  prg <- getProgName
  hPutStrLn stderr (usageInfo prg options)
  hFlush stderr


{------------------------------------------------------------------------------}
-- | Shows the getOpts generated help then quits.
exitHelp :: IO a
exitHelp = do
  showHelp
  exitWith ExitSuccess


{------------------------------------------------------------------------------}
-- | Main entry point.
main = do (opts, args) <- parseCmdOpts
          --putStrLn $ show opts
          --putStrLn $ "config = " ++ show (optInput opts)
          --let d = (60 * 15) -- 15 minutes.
          --
          case (optLogLvl opts) of
            Nothing -> updateGlobalLogger "backdropper" (setLevel INFO)
            (Just p) -> case p of 
                          "debug" -> updateGlobalLogger "backdropper" (setLevel DEBUG)
                          "info" -> updateGlobalLogger "backdropper" (setLevel INFO)
                          "notice" -> updateGlobalLogger "backdropper" (setLevel NOTICE)
                          "warning" -> updateGlobalLogger "backdropper" (setLevel WARNING)
                          "error" -> updateGlobalLogger "backdropper" (setLevel ERROR)
                          "critical" -> updateGlobalLogger "backdropper" (setLevel CRITICAL)
                          "alert" -> updateGlobalLogger "backdropper" (setLevel ALERT)
                          "emergency" -> updateGlobalLogger "backdropper" (setLevel EMERGENCY)
                          _ -> updateGlobalLogger "backdropper" (setLevel DEBUG)
          {-
          logger DEBUG "This is a debug."
          logger INFO "This is an info."
          logger NOTICE "This is a notice."
          logger WARNING "This is a warning."
          logger ERROR "This is an error!"
          logger CRITICAL "This is a critical error!"
          logger ALERT "This is an alert!"
          logger EMERGENCY "This is an emergency!"
          exitWith ExitSuccess
          -}
          logger INFO "Backdropper started..."
          let d = (optDelay opts)
          case (optInput opts) of
            Nothing  -> do
                    home <- getHomeDirectory
                    mainLoop (home ++ "/.rotate_wallpaper_list") d
            (Just p) -> mainLoop p d
          exitWith ExitSuccess