path: root/Plugins/Monitors/Common.hs

-----------------------------------------------------------------------------
-- |
-- Module      :  Plugins.Monitors.Common
-- Copyright   :  (c) Andrea Rossato
-- License     :  BSD-style (see LICENSE)
--
-- Maintainer  :  Andrea Rossato <andrea.rossato@unibz.it>
-- Stability   :  unstable
-- Portability :  unportable
--
-- Utilities for creating monitors for Xmobar
--
-----------------------------------------------------------------------------

module Plugins.Monitors.Common (
                       -- * Monitors
                       -- $monitor
                         Monitor
                       , MConfig (..)
                       , Opts (..)
                       , setConfigValue
                       , getConfigValue
                       , mkMConfig
                       , runM
                       , io
                       -- * Parsers
                       -- $parsers
                       , runP
                       , skipRestOfLine
                       , getNumbers
                       , getNumbersAsString
                       , getAllBut
                       , getAfterString
                       , skipTillString
                       , parseTemplate
                       -- ** String Manipulation
                       -- $strings
                       , padString
                       , showWithPadding
                       , showWithColors
                       , showWithColors'
                       , showPercentWithColors
                       , showPercentsWithColors
                       , showPercentBar
                       , showLogBar
                       , showWithUnits
                       , takeDigits
                       , showDigits
                       , floatToPercent
                       , stringParser
                       -- * Threaded Actions
                       -- $thread
                       , doActionTwiceWithDelay
                       , catRead
                       ) where


import Control.Concurrent
import Control.Monad.Reader
import qualified Data.ByteString.Lazy.Char8 as B
import Data.IORef
import qualified Data.Map as Map
import Data.List
import Numeric
import Text.ParserCombinators.Parsec
import System.Console.GetOpt
import Control.Exception (SomeException,handle)
import System.Process (readProcess)

import Plugins
-- $monitor

type Monitor a = ReaderT MConfig IO a

data MConfig =
    MC { normalColor :: IORef (Maybe String)
       , low         :: IORef Int
       , lowColor    :: IORef (Maybe String)
       , high        :: IORef Int
       , highColor   :: IORef (Maybe String)
       , template    :: IORef String
       , export      :: IORef [String]
       , ppad        :: IORef Int
       , minWidth    :: IORef Int
       , maxWidth    :: IORef Int
       , padChars    :: IORef [Char]
       , padRight    :: IORef Bool
       , barBack     :: IORef String
       , barFore     :: IORef String
       , barWidth    :: IORef Int
       }

-- | from 'http:\/\/www.haskell.org\/hawiki\/MonadState'
type Selector a = MConfig -> IORef a

sel :: Selector a -> Monitor a
sel s =
    do hs <- ask
       liftIO $ readIORef (s hs)

mods :: Selector a -> (a -> a) -> Monitor ()
mods s m =
    do v <- ask
       io $ modifyIORef (s v) m

setConfigValue :: a -> Selector a -> Monitor ()
setConfigValue v s =
       mods s (\_ -> v)

getConfigValue :: Selector a -> Monitor a
getConfigValue s =
    sel s

mkMConfig :: String
          -> [String]
          -> IO MConfig
mkMConfig tmpl exprts =
    do lc <- newIORef Nothing
       l  <- newIORef 33
       nc <- newIORef Nothing
       h  <- newIORef 66
       hc <- newIORef Nothing
       t  <- newIORef tmpl
       e  <- newIORef exprts
       p  <- newIORef 0
       mn <- newIORef 0
       mx <- newIORef 0
       pc <- newIORef " "
       pr <- newIORef False
       bb <- newIORef ":"
       bf <- newIORef "#"
       bw <- newIORef 10
       return $ MC nc l lc h hc t e p mn mx pc pr bb bf bw

data Opts = HighColor String
          | NormalColor String
          | LowColor String
          | Low String
          | High String
          | Template String
          | PercentPad String
          | MinWidth String
          | MaxWidth String
          | Width String
          | PadChars String
          | PadAlign String
          | BarBack String
          | BarFore String
          | BarWidth String

options :: [OptDescr Opts]
options =
    [ Option ['H']  ["High"]     (ReqArg High "number"               )  "The high threshold"
    , Option ['L']  ["Low"]      (ReqArg Low "number"                )  "The low threshold"
    , Option ['h']  ["high"]     (ReqArg HighColor "color number"    )  "Color for the high threshold: ex \"#FF0000\""
    , Option ['n']  ["normal"]   (ReqArg NormalColor "color number"  )  "Color for the normal threshold: ex \"#00FF00\""
    , Option ['l']  ["low"]      (ReqArg LowColor "color number"     )  "Color for the low threshold: ex \"#0000FF\""
    , Option ['t']  ["template"] (ReqArg Template "output template"  )  "Output template."
    , Option ['p']  ["ppad"]     (ReqArg PercentPad "percent padding")  "Minimum percentage width."
    , Option ['m']  ["minwidth"] (ReqArg MinWidth "minimum width"    )  "Minimum field width"
    , Option ['M']  ["maxwidth"] (ReqArg MaxWidth "maximum width"    )  "Maximum field width"
    , Option ['w']  ["width"]    (ReqArg Width "fixed width"         )  "Fixed field width"
    , Option ['c']  ["padchars"] (ReqArg PadChars "padding chars"    )  "Characters to use for padding"
    , Option ['a']  ["align"]    (ReqArg PadAlign "padding alignment")  "'l' for left padding, 'r' for right"
    , Option ['b']  ["bback"]    (ReqArg BarBack "bar background"    )  "Characters used to draw bar backgrounds"
    , Option ['f']  ["bfore"]    (ReqArg BarFore "bar foreground"    )  "Characters used to draw bar foregrounds"
    , Option ['W']  ["bwidth"]   (ReqArg BarWidth "bar width"        )  "Bar width"
    ]

doArgs :: [String]
       -> ([String] -> Monitor String)
       -> Monitor String
doArgs args action =
    do case (getOpt Permute options args) of
         (o, n, []  ) -> do doConfigOptions o
                            action n
         (_, _, errs) -> return (concat errs)

doConfigOptions :: [Opts] -> Monitor ()
doConfigOptions [] = io $ return ()
doConfigOptions (o:oo) =
    do let next = doConfigOptions oo
           nz s = let x = read s in max 0 x
       case o of
         High         h -> setConfigValue (read h) high >> next
         Low          l -> setConfigValue (read l) low >> next
         HighColor   hc -> setConfigValue (Just hc) highColor >> next
         NormalColor nc -> setConfigValue (Just nc) normalColor >> next
         LowColor    lc -> setConfigValue (Just lc) lowColor >> next
         Template     t -> setConfigValue t template >> next
         PercentPad   p -> setConfigValue (nz p) ppad >> next
         MinWidth    mn -> setConfigValue (nz mn) minWidth >> next
         MaxWidth    mx -> setConfigValue (nz mx) maxWidth >> next
         Width        w -> setConfigValue (nz w) minWidth >>
                           setConfigValue (nz w) maxWidth >> next
         PadChars    pc -> setConfigValue pc padChars >> next
         PadAlign    pa -> setConfigValue (isPrefixOf "r" pa) padRight >> next
         BarBack     bb -> setConfigValue bb barBack >> next
         BarFore     bf -> setConfigValue bf barFore >> next
         BarWidth    bw -> setConfigValue (nz bw) barWidth >> next

runM :: [String] -> IO MConfig -> ([String] -> Monitor String) -> Int -> (String -> IO ()) -> IO ()
runM args conf action r cb = do go
    where go = do
            c <- conf
            let ac = doArgs args action
                he = return . (++) "error: " . show . flip asTypeOf (undefined::SomeException)
            s <- handle he $ runReaderT ac c
            cb s
            tenthSeconds r
            go

io :: IO a -> Monitor a
io = liftIO



-- $parsers

runP :: Parser [a] -> String -> IO [a]
runP p i =
    do case (parse p "" i) of
         Left _ -> return []
         Right x  -> return x

getAllBut :: String -> Parser String
getAllBut s =
    manyTill (noneOf s) (char $ head s)

getNumbers :: Parser Float
getNumbers = skipMany space >> many1 digit >>= \n -> return $ read n

getNumbersAsString :: Parser String
getNumbersAsString = skipMany space >> many1 digit >>= \n -> return n

skipRestOfLine :: Parser Char
skipRestOfLine =
    do many $ noneOf "\n\r"
       newline

getAfterString :: String -> Parser String
getAfterString s =
    do { try $ manyTill skipRestOfLine $ string s
       ; v <- manyTill anyChar $ newline
       ; return v
       } <|> return ("<" ++ s ++ " not found!>")

skipTillString :: String -> Parser String
skipTillString s =
    manyTill skipRestOfLine $ string s

-- | Parses the output template string
templateStringParser :: Parser (String,String,String)
templateStringParser =
    do { s <- nonPlaceHolder
       ; com <- templateCommandParser
       ; ss <- nonPlaceHolder
       ; return (s, com, ss)
       }
    where
      nonPlaceHolder = liftM concat . many $
                       (many1 $ noneOf "<") <|> colorSpec

-- | Recognizes color specification and returns it unchanged
colorSpec :: Parser String
colorSpec = (try $ string "</fc>") <|> try (
            do string "<fc="
               s <- many1 (alphaNum <|> char ',' <|> char '#')
               char '>'
               return $ "<fc=" ++ s ++ ">")

-- | Parses the command part of the template string
templateCommandParser :: Parser String
templateCommandParser =
    do { char '<'
       ; com <- many $ noneOf ">"
       ; char '>'
       ; return com
       }

-- | Combines the template parsers
templateParser :: Parser [(String,String,String)]
templateParser = many templateStringParser --"%")

-- | Takes a list of strings that represent the values of the exported
-- keys. The strings are joined with the exported keys to form a map
-- to be combined with 'combine' to the parsed template. Returns the
-- final output of the monitor.
parseTemplate :: [String] -> Monitor String
parseTemplate l =
    do t <- getConfigValue template
       s <- io $ runP templateParser t
       e <- getConfigValue export
       let m = Map.fromList . zip e $ l
       return $ combine m s

-- | Given a finite "Map" and a parsed templatet produces the
-- | resulting output string.
combine :: Map.Map String String -> [(String, String, String)] -> String
combine _ [] = []
combine m ((s,ts,ss):xs) =
    s ++ str ++ ss ++ combine m xs
        where str = Map.findWithDefault err ts m
              err = "<" ++ ts ++ " not found!>"

-- $strings

type Pos = (Int, Int)

takeDigits :: Int -> Float -> Float
takeDigits d n =
    fromIntegral ((round (n * fact)) :: Int) / fact
  where fact = 10 ^ d

showDigits :: Int -> Float -> String
showDigits d n =
    showFFloat (Just d) n ""

showWithUnits :: Int -> Int -> Float -> String
showWithUnits d n x
  | x < 0 = "-" ++ showWithUnits d n (-x)
  | n > 3 || x < 10^(d + 1) = show (round x :: Int) ++ units n
  | x <= 1024 = showDigits d (x/1024) ++ units (n+1)
  | otherwise = showWithUnits d (n+1) (x/1024)
  where units = (!!) ["B", "K", "M", "G", "T"]

padString :: Int -> Int -> String -> Bool -> String -> String
padString mnw mxw pad pr s =
  let len = length s
      rmin = if mnw == 0 then 1 else mnw
      rmax = if mxw == 0 then max len rmin else mxw
      (rmn, rmx) = if rmin <= rmax then (rmin, rmax) else (rmax, rmin)
      rlen = min (max rmn len) rmx
  in if rlen < len then
       take rlen s
     else let ps = take (rlen - len) (cycle pad)
          in if pr then s ++ ps else ps ++ s

floatToPercent :: Float -> Monitor String
floatToPercent n =
  do pad <- getConfigValue ppad
     pc <- getConfigValue padChars
     pr <- getConfigValue padRight
     let p = showDigits 0 (n * 100)
     return $ padString pad pad pc pr p ++ "%"

stringParser :: Pos -> B.ByteString -> String
stringParser (x,y) =
     B.unpack . li x . B.words . li y . B.lines
    where li i l | length l > i = l !! i
                 | otherwise    = B.empty

setColor :: String -> Selector (Maybe String) -> Monitor String
setColor str s =
    do a <- getConfigValue s
       case a of
            Nothing -> return str
            Just c -> return $
                "<fc=" ++ c ++ ">" ++ str ++ "</fc>"

showWithPadding :: String -> Monitor String
showWithPadding s =
    do mn <- getConfigValue minWidth
       mx <- getConfigValue maxWidth
       p <- getConfigValue padChars
       pr <- getConfigValue padRight
       return $ padString mn mx p pr s

colorizeString :: (Num a, Ord a) => a -> String -> Monitor String
colorizeString x s = do
    h <- getConfigValue high
    l <- getConfigValue low
    let col = setColor s
        [ll,hh] = map fromIntegral $ sort [l, h] -- consider high < low
    head $ [col highColor   | x > hh ] ++
           [col normalColor | x > ll ] ++
           [col lowColor    | True]

showWithColors :: (Num a, Ord a) => (a -> String) -> a -> Monitor String
showWithColors f x = showWithPadding (f x) >>= colorizeString x

showWithColors' :: (Num a, Ord a) => String -> a -> Monitor String
showWithColors' str v = showWithColors (const str) v

showPercentsWithColors :: [Float] -> Monitor [String]
showPercentsWithColors fs =
  do fstrs <- mapM floatToPercent fs
     zipWithM (showWithColors . const) fstrs (map (*100) fs)

showPercentWithColors :: Float -> Monitor String
showPercentWithColors f = liftM head $ showPercentsWithColors [f]

showPercentBar :: Float -> Float -> Monitor String
showPercentBar v x = do
  bb <- getConfigValue barBack
  bf <- getConfigValue barFore
  bw <- getConfigValue barWidth
  let len = min bw $ round (fromIntegral bw * x)
  s <- colorizeString v (take len $ cycle bf)
  return $ s ++ (take (bw - len) $ cycle bb)

showLogBar :: Float -> Float -> Monitor String
showLogBar f v = do
  h <- fromIntegral `fmap` getConfigValue high
  bw <- fromIntegral `fmap` getConfigValue barWidth
  showPercentBar v $ f + (logBase 10 (v / h)) / bw

-- $threads

doActionTwiceWithDelay :: Int -> IO [a] -> IO ([a], [a])
doActionTwiceWithDelay delay action =
    do v1 <- newMVar []
       forkIO $! getData action v1 0
       v2 <- newMVar []
       forkIO $! getData action v2 delay
       threadDelay (delay `div` 3 * 4)
       a <- readMVar v1
       b <- readMVar v2
       return (a,b)

getData :: IO a -> MVar a -> Int -> IO ()
getData action var d =
    do threadDelay d
       s <- action
       modifyMVar_ var (\_ -> return $! s)

catRead :: FilePath -> IO B.ByteString
catRead file = B.pack `fmap` readProcess "/bin/cat" [file] ""