hackport-0.2.1: Diff.hs

module Diff
    ( diffAction
    ) where

import qualified Data.Map as Map

import Control.Monad.Trans
import Data.Char

import Action
import Cache
import Config (DiffMode(..))
import P2
import Version
import Overlays

data DiffState a
	= OnlyLeft a
	| OnlyRight a
	| Both a a

tabs :: String -> String
tabs str = let len = length str in str++(if len < 3*8
	then replicate (3*8-len) ' '
	else "")

showDiffState :: Package -> DiffState Version -> String
showDiffState pkg st = (tabs (show pkg)) ++ " [" ++ (case st of
	Both x y -> showVersion x ++ (case compare x y of
		EQ -> "="
		GT -> ">"
		LT -> "<") ++ showVersion y
	OnlyLeft x -> showVersion x ++ ">none"
	OnlyRight y ->  "none<"++showVersion y)++"]"


diffAction :: DiffMode -> HPAction ()
diffAction dm = do
    overlayPath <- getOverlayPath
    cache <- readCache overlayPath
    overlayTree <- liftIO $ readPortageTree overlayPath
    let (hackageTree, clashes) = indexToPortage cache overlayTree
    liftIO $ mapM_ putStrLn clashes
    diff hackageTree overlayTree dm

diff :: Portage -> Portage -> DiffMode -> HPAction ()
diff pt1 pt2 mode = do
        let pkgs1 = Map.map (OnlyLeft  . eVersion . maximum) pt1
        let pkgs2 = Map.map (OnlyRight . eVersion . maximum) pt2
        let union = Map.unionWith (\(OnlyLeft x) (OnlyRight y) -> Both x y) pkgs1 pkgs2
	let showFilter st = case mode of
		ShowAll -> True
		ShowMissing -> case st of
			OnlyLeft _ -> True
			Both x y -> x > y
			OnlyRight _ -> False
		ShowAdditions -> case st of
			OnlyLeft _ -> False
			Both x y -> x < y
			OnlyRight _ -> True
		ShowNewer -> case st of
			OnlyLeft _ -> False
			Both x y -> x > y
			OnlyRight _ -> False
		ShowCommon -> case st of
			OnlyLeft _ -> False
			Both x y -> x == y
			OnlyRight _ -> False
        let packages = filter (showFilter . snd) (Map.assocs union)
        mapM_ (info . uncurry showDiffState) packages