hetch/app/Main.hs

module Main where

import Data.List (isPrefixOf)
import Data.Maybe (fromMaybe)
import System.Environment (lookupEnv)
import System.IO (readFile')
import Control.Monad.IO.Class (MonadIO)

fromIOMaybe :: (MonadIO m) => a -> m (Maybe a) -> m a
fromIOMaybe failsafe maybeVal = do
  res <- maybeVal
  case res of
    Nothing -> return failsafe
    (Just val) -> return val

readUptime :: String -> Int
readUptime "" = 0
readUptime uptime
        | length (words uptime) > 1 = floor (read . head $ words uptime :: Float)
        | otherwise = floor (read uptime :: Float)

getUptime :: Int -> String
getUptime uptime
        | uptime < 60 = remS
        | uptime < 3600 = unwords [remM, remS]
        | otherwise = unwords [remH, remM, remS]
    where
        totalM = uptime `div` 60
        remS = show (uptime `mod` 60) <> "s"
        remM = show (totalM `mod` 60) <> "m"
        remH = show (totalM `div` 60) <> "h"

getKVer :: String -> String
getKVer "" = ""
getKVer info
        | length (words info) < 3 = head (words info)
        | otherwise = (\(k : ks) -> unwords [k, (!! 1) ks]) (words info)

findPrettyName :: [String] -> String
findPrettyName [] = "Unknown"
findPrettyName (o : os)
        | "PRETTY_NAME" `isPrefixOf` o = tail . init $ dropWhile (/='"') o
        | otherwise = findPrettyName os

parseKB :: String -> Int
parseKB "" = 0
parseKB line = read (head . tail $ words line) :: Int

getMemory :: String -> String
getMemory memInfo
        | length (lines memInfo) < 2 = "N/A"
        | otherwise = memAvail <> "/" <> memTotal
    where
      memAvail = show ((parseKB . (!! 2) $ lines memInfo) `div` 1000) <> "MB"
      memTotal = show ((parseKB . head $ lines memInfo) `div` 1000) <> "MB"

getWM :: String -> String -> String
getWM desktop session = unwords [desktop, "(" <> session <> ")"]

main :: IO ()
main = do
        uptime <- readFile' "/proc/uptime"
        version <- readFile' "/proc/version"
        osRelease <- readFile' "/etc/os-release"
        hostname <- readFile' "/proc/sys/kernel/hostname"
        meminfo <- readFile' "/proc/meminfo"
        username <- fromIOMaybe "username" (lookupEnv "USER")
        currentDesktop <- fromIOMaybe "Unknown" (lookupEnv "XDG_CURRENT_DESKTOP")
        sessionType <- fromIOMaybe "Unkown" (lookupEnv "XDG_SESSION_TYPE")
        locale <- fromIOMaybe "un_KN.own" (lookupEnv "LANG")
        let userandhost = username <> "@" <> init hostname
        putStr
                ( unlines
                        [ "\x1b[1;35m  █         \x1b[1;34m" <> userandhost
                        , "\x1b[1;35m   █        \x1b[1;34m" <> take (length userandhost) (repeat '-')
                        , "\x1b[1;35m    █       \x1b[1;34m" <> "up\t" <> getUptime (readUptime uptime)
                        , "\x1b[1;35m     █      \x1b[1;34m" <> "wm\t" <> getWM currentDesktop sessionType
                        , "\x1b[1;35m    ███     \x1b[1;34m" <> "krl\t" <> getKVer version
                        , "\x1b[1;35m   █  ██    \x1b[1;34m" <> "os\t" <> findPrettyName (lines osRelease)
                        , "\x1b[1;35m  █    ██   \x1b[1;34m" <> "lcl\t" <> locale
                        , "\x1b[1;35m █      ██  \x1b[1;34m" <> "mem\t" <> getMemory meminfo
                        ]
                )