{- git-annex command
 -
 - Copyright 2014 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Command.VPop where

import Common.Annex
import Command
import qualified Git
import qualified Git.Command
import qualified Git.Ref
import Types.View
import Logs.View
import Command.View (checkoutViewBranch)

cmd :: [Command]
cmd = [notBareRepo $ notDirect $
	command "vpop" (paramOptional paramNumber) seek SectionMetaData
	"switch back to previous view"]

seek :: CommandSeek
seek = withWords start

start :: [String] -> CommandStart
start ps = go =<< currentView
  where
	go Nothing = error "Not in a view."
	go (Just v) = do
		showStart "vpop" (show num)
		removeView v
		(oldvs, vs) <- splitAt (num - 1) . filter (sameparentbranch v)
			<$> recentViews
		mapM_ removeView oldvs
		case vs of
			(oldv:_) -> next $ next $ do
				showOutput
				checkoutViewBranch oldv (return . branchView)
			_ -> next $ next $ do
				showOutput
				inRepo $ Git.Command.runBool
					[ Param "checkout"
					, Param $ Git.fromRef $ Git.Ref.base $
						viewParentBranch v
					]
	sameparentbranch a b = viewParentBranch a == viewParentBranch b

	num = fromMaybe 1 $ readish =<< headMaybe ps 
