module Main where

   import System.IO
   import System.Random

   data Move = Scissors | Paper | Rock | Unknown deriving (Eq,Show)
   data Outcome = Winner | Draw | Loser | ND deriving (Show)

   str2Move :: String -> Move
   str2Move s = do
      case s of
         "s" -> Scissors
         "p" -> Paper
         "r" -> Rock
         _   -> Unknown

   getWinner :: Move -> Move
   getWinner m = do
      case m of
         Scissors -> Rock
         Rock     -> Paper
         Paper    -> Scissors
         Unknown  -> Unknown

   getOutcome :: Move -> Move -> Outcome
   getOutcome player cpu
      | player == Unknown || cpu == Unknown = ND
      | player == cpu = Draw
      | cpu == winner = Loser
      | otherwise = Winner
      where winner = getWinner player

   getCpuMove :: StdGen -> Move
   getCpuMove gen = do
      let (randNumber, newGen) = randomR(1, 3) gen :: (Int, StdGen)
      case randNumber of
         1 -> Rock
         2 -> Scissors
         3 -> Paper

   main = do
      gen <- getStdGen
      putStr "Enter your choice (s, p or r): "
      hFlush stdout
      line <- getLine

      let player = str2Move line
      let cpu = getCpuMove gen
      let outcome = getOutcome player cpu

      putStrLn $ "Player Chose: " ++ (show player)
      putStrLn $ "Cpu Chose   : " ++ (show cpu)
      putStrLn $ "Outcome     : " ++ (show outcome)

/** Responds to signals of interest */                                                                    
void daemon_signalhandler(int sig) {                                      
                                                                            
   switch (sig) {                                                         
                                                                            
      case SIGHUP:                                                        
         /* this should just refresh configs and restart */                                      
         break;                                                           
                                                                            
      case SIGTERM:                                                       
         /* mark the server as no longer running */                                               
         break;                                                           
   }                                                                      
                                                                            
}                                                                         

/* attach the signal handlers now */                                  
signal(SIGCHLD, SIG_IGN);                                             
signal(SIGTSTP, SIG_IGN);                                             
signal(SIGTTOU, SIG_IGN);                                             
signal(SIGTTIN, SIG_IGN);                                             
signal(SIGHUP, daemon_signalhandler);                                 
signal(SIGTERM, daemon_signalhandler);