{-# LANGUAGE CPP, Rank2Types #-}
module TailTypes (
    Interval,
    fromInterval,
    TailTarget(..),
    TailRuntime(..),
    TailMatch(..), TailAction(..),
    TailMatches,
    Tail(..), 
    tailName, tailErrMsg
  ) where

import qualified System.Posix.Types
import qualified System.Posix.IO
import qualified Text.Regex
#ifdef INOTIFY
import qualified System.INotify as INotify
#endif

import Display

newtype Interval = Interval Int
instance Show Interval where
  show (Interval x) = show (fromIntegral x / 1000000.0)
instance Read Interval where
  readsPrec n s = map (\(x,s) -> (Interval $ floor (1000000.0 * x), s)) $ readsPrec n s
fromInterval (Interval x) = x

data TailTarget = TailPath !FilePath | TailFd !System.Posix.Types.Fd
instance Show TailTarget where
  show (TailFd 0) = "-"
  show (TailFd x) = '&':(show x)
  show (TailPath path) = path
instance Read TailTarget where
  readsPrec _ "-" = [(TailFd System.Posix.IO.stdInput, "")]
  readsPrec n ('&':s) = map (\(f,s) -> (TailFd f, s)) $ readsPrec n s
  readsPrec _ s = [(TailPath s, "")]

data TailMatch =
    MatchAll
  | MatchRegex !Text.Regex.Regex
  | MatchNotRegex !Text.Regex.Regex
data TailAction =
    ActionNone
  | ActionHide
  | ActionColor !TermColor
  | ActionSubst !String
  | ActionExecute !String
type TailMatches = [(TailMatch, TailAction)]

data Tail = Tail{
  tailTarg :: TailTarget,
  tailPollInterval :: !Interval,
  tailReopenInterval :: !Interval,
#ifdef INOTIFY
  tailPollINotify :: !Bool,
  tailReopenINotify :: !Bool,
#endif
  tailBegin :: !Bool,
  tailTimeFmt :: !String,
  tailMatches :: !TailMatches
}

tailName = show . tailTarg

tailErrMsg t msg =
  errMsg ("ztail " ++ tailName t ++ ": " ++ msg)

data TailRuntime = TailRuntime
  { trUnlock :: forall a. IO a -> IO a
  , trText :: Tail -> String -> IO ()
#ifdef INOTIFY
  , trINotify :: Maybe INotify.INotify
#endif
}