Battery monitor: watts and time left (Petr Rockai)

1 files changed, 72 insertions, 43 deletions

diff --git a/Plugins/Monitors/Batt.hs b/Plugins/Monitors/Batt.hs
index 547dd02..bb2027c 100644
--- a/Plugins/Monitors/Batt.hs
+++ b/Plugins/Monitors/Batt.hs
@@ -12,67 +12,96 @@
 --
 -----------------------------------------------------------------------------
 
-module Plugins.Monitors.Batt where
+module Plugins.Monitors.Batt ( battConfig, runBatt, runBatt' ) where
 
 import qualified Data.ByteString.Lazy.Char8 as B
 import Plugins.Monitors.Common
 import System.Posix.Files (fileExist)
 
-data Batt = Batt Float String
-          | NA
+data Result = Result { percent :: Float, watts :: Float, time :: Float, ac :: String }
+            | NA
+
+base = "/sys/class/power_supply"
 
 battConfig :: IO MConfig
 battConfig = mkMConfig
-       "Batt: <left>%" -- template
-       ["leftbar", "left", "status"] -- available replacements
+       "Batt: <watts>, <left> / <timeleft>" -- template
+       ["leftbar", "left", "status", "timeleft", "watts"] -- available replacements
 
-type File = (String, String)
+data Files = Files { f_full :: String, f_now :: String
+                   , f_voltage :: String, f_current :: String } | NoFiles
+data Battery = Battery { full :: Float, now :: Float, voltage :: Float, current :: Float }
 
-file2batfile :: String -> (File, File)
-file2batfile s = ( (s' ++ "/charge_full", s' ++ "/energy_full")
-                 , (s' ++ "/charge_now" , s' ++ "/energy_now" )
-                 )
-    where s' = "/sys/class/power_supply/" ++ s
+batteryFiles :: String -> IO Files
+batteryFiles bat =
+  do is_charge <- fileExist $ prefix ++ "/charge_now"
+     is_energy <- fileExist $ prefix ++ "/energy_now"
+     return $ case (is_charge, is_energy) of
+       (True, _) -> files "/charge"
+       (_, True) -> files "/energy"
+       _ -> NoFiles
+  where prefix = base ++ "/" ++ bat
+        files ch = Files { f_full = prefix ++ ch ++ "_full"
+                         , f_now = prefix ++ ch ++ "_now"
+                         , f_current = prefix ++ "/current_now"
+                         , f_voltage = prefix ++ "/voltage_now" }
 
-readFileBatt :: (File, File) -> IO (String, String, String)
-readFileBatt (f,n) =
-    do a  <- rf f
-       b  <- rf n
-       ac <- fileExist "/sys/class/power_supply/AC0/online"
-       c  <- if not ac
-             then return []
-             else do s <- B.unpack `fmap` catRead "/sys/class/power_supply/AC0/online"
-                     return $ if s == "1\n" then "<fc=green>On</fc>" else"<fc=red>Off</fc>"
-       return (a,b,c)
-    where rf file = do
-            fe <- fileExist (fst file)
-            if fe
-               then B.unpack `fmap` catRead (fst file)
-               else do fe' <- fileExist (snd file)
-                       if fe'
-                          then B.unpack `fmap` catRead (snd file)
-                          else return []
+haveAc :: IO (Maybe Bool)
+haveAc = do know <- fileExist $ base ++ "/AC/online"
+            if know
+               then do s <- B.unpack `fmap` catRead (base ++ "/AC/online")
+                       return $ Just $ s == "1\n"
+               else return Nothing
 
-parseBATT :: [(File,File)] -> IO Batt
-parseBATT bfs =
-    do [(a0,b0,c0),(a1,b1,_),(a2,b2,_)] <- mapM readFileBatt (take 3 $ bfs ++ repeat (("",""),("","")))
-       let read' s = if s == [] then 0 else read s
-           left    = (read' b0 + read' b1 + read' b2) / (read' a0 + read' a1 + read' a2) --present / full
-       return $ if isNaN left then NA else Batt left c0
+readBattery :: Files -> IO Battery
+readBattery NoFiles = return $ Battery 0 0 0 0
+readBattery files =
+    do a <- grab $ f_full files -- microwatthours
+       b <- grab $ f_now files
+       c <- grab $ f_voltage files -- microvolts
+       d <- grab $ f_current files -- microwatts (huh!)
+       return $ Battery (3600 * a / 1000000) -- wattseconds
+                        (3600 * b / 1000000) -- wattseconds
+                        (c / 1000000) -- volts
+                        (d / c) -- amperes
+    where grab = fmap (read . B.unpack) . catRead
 
-formatBatt :: Float -> Monitor [String]
-formatBatt x = do
-  p <- showPercentsWithColors [x]
-  b <- showPercentBar (100 * x) x
-  return (b:p)
+readBatteries :: [Files] -> IO Result
+readBatteries bfs =
+    do bats <- mapM readBattery (take 3 bfs)
+       ac' <- haveAc
+       let ac = if ac' == Just True then True else False
+           sign = if ac then 1 else -1
+           left = (sum $ map now bats) / (sum $ map full bats)
+           watts = sign * (sum $ map voltage bats) * (sum $ map current bats)
+           time = if watts == 0 then 0 else sum $ map time' bats -- negate sign
+           time' b = (if ac then full b - now b else now b) / (sign * watts)
+           acstr = case ac' of
+             Nothing -> "?"
+             Just True -> "<fc=green>On</fc>"
+             Just False -> "<fc=red>Off</fc>"
+       return $ if isNaN left then NA else Result left watts time acstr
 
 runBatt :: [String] -> Monitor String
 runBatt = runBatt' ["BAT0","BAT1","BAT2"]
 
 runBatt' :: [String] -> [String] -> Monitor String
 runBatt' bfs _ = do
-  c <- io $ parseBATT (map file2batfile bfs)
+  c <- io $ readBatteries =<< mapM batteryFiles bfs
   case c of
-    Batt x s -> do l <- formatBatt x
-                   parseTemplate (l ++ [s])
+    Result x w t s -> do l <- fmtPercent x
+                         parseTemplate (l ++ [s] ++ [fmtTime $ floor t, fmtWatts w])
     NA -> return "N/A"
+ where fmtPercent :: Float -> Monitor [String]
+       fmtPercent x = do
+         p <- showPercentsWithColors [x]
+         b <- showPercentBar (100 * x) x
+         return (b:p)
+       fmtWatts x = color x $ showDigits 1 x ++ "W"
+       fmtTime x = hours ++ ":" ++ if length minutes == 2 then minutes else "0" ++ minutes
+         where hours = show (x `div` 3600)
+               minutes = show ((x `mod` 3600) `div` 60)
+       color x str | x >= 0 = "<fc=orange>" ++ str ++ "</fc>"
+                   | x >= -10 = "<fc=green>" ++ str ++ "</fc>"
+                   | x >= -12 = str
+                   | otherwise = "<fc=red>" ++ str ++ "</fc>"