module Main where
import Data.Char (isSpace)
import qualified Data.Map as M
import Distribution.Hackage.DB
import Distribution.Text (simpleParse)
import Prelude
import qualified Prelude as P (map)
import System.Console.ANSI
main = do
db <- readHackage
input <- getContents
let ls = lines input
mapM_ (highlightOutdated db) ls
-- | Take an individual line of output and see if the first word on
-- the line looks like a package identifier (/i.e./ @foo-0.3.2@). If
-- so, compare it to the latest version on Hackage, and highlight it
-- if the version differs (in red if the version is older than the
-- latest on Hackage, or cyan if newer), also printing the version of
-- the latest Hackage release in blue.
highlightOutdated :: Hackage -> String -> IO ()
highlightOutdated db s = do
let (p,rest) = break isSpace s
-- try to parse the beginning of the line as a package identifier (like foo-1.3.2)
case simpleParse p of
Nothing -> putStrLn s
Just pkgId ->
-- look up this package name in the Hackage DB
case (M.lookup (getPkgName pkgId) db) of
Nothing -> putStrLn s
Just versions -> do
-- get the latest version and compare it to the stated version
let latest = maximum . P.map fst . M.assocs $ versions
case compare (pkgVersion pkgId) latest of
EQ -> putStrLn s
LT -> doHighlight p latest Red rest -- show outdated versions in red
GT -> doHighlight p latest Cyan rest -- show newer versions in cyan
-- | Output a package name highlighted in a given color, along with
-- another version in blue.
doHighlight :: String -> Version -> Color -> String -> IO ()
doHighlight s latest color rest = do
setSGR [SetColor Foreground Vivid color]
putStr s
setSGR []
putStr " ("
setSGR [SetColor Foreground Vivid Blue]
putStr (showVersion latest)
setSGR []
putStr ")"
putStrLn rest
getPkgName :: PackageIdentifier -> String
getPkgName pkgId = case pkgName pkgId of PackageName name -> name