{- git-annex assistant thread to detect when upgrade is available
 -
 - Copyright 2013 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

{-# LANGUAGE CPP #-}

module Assistant.Threads.Upgrader (
	upgraderThread
) where

import Assistant.Common
import Assistant.Upgrade

import Assistant.Types.UrlRenderer
import Assistant.DaemonStatus
import Assistant.Alert
import Utility.NotificationBroadcaster
import Utility.Tmp
import qualified Annex
import qualified Build.SysConfig
import qualified Utility.Url as Url
import qualified Annex.Url as Url
import qualified Git.Version
import Types.Distribution
#ifdef WITH_WEBAPP
import Assistant.WebApp.Types
#endif

import Data.Time.Clock
import qualified Data.Text as T

upgraderThread :: UrlRenderer -> NamedThread
upgraderThread urlrenderer = namedThread "Upgrader" $
	when (isJust Build.SysConfig.upgradelocation) $ do
		{- Check for upgrade on startup, unless it was just
		 - upgraded. -}
		unlessM (liftIO checkSuccessfulUpgrade) $
			checkUpgrade urlrenderer
		h <- liftIO . newNotificationHandle False . networkConnectedNotifier =<< getDaemonStatus
		go h =<< liftIO getCurrentTime
  where
  	{- Wait for a network connection event. Then see if it's been
	 - half a day since the last upgrade check. If so, proceed with
	 - check. -}
	go h lastchecked = do
		liftIO $ waitNotification h
		autoupgrade <- liftAnnex $ annexAutoUpgrade <$> Annex.getGitConfig
		if autoupgrade == NoAutoUpgrade
			then go h lastchecked
			else do
				now <- liftIO getCurrentTime
				if diffUTCTime now lastchecked > halfday
					then do
						checkUpgrade urlrenderer
						go h =<< liftIO getCurrentTime
					else go h lastchecked
	halfday = 12 * 60 * 60

checkUpgrade :: UrlRenderer -> Assistant ()
checkUpgrade urlrenderer = do
	debug [ "Checking if an upgrade is available." ]
	go =<< getDistributionInfo
  where
	go Nothing = debug [ "Failed to check if upgrade is available." ]
	go (Just d) = do
		let installed = Git.Version.normalize Build.SysConfig.packageversion
		let avail = Git.Version.normalize $ distributionVersion d
		let old = Git.Version.normalize <$> distributionUrgentUpgrade d
		if Just installed <= old
			then canUpgrade High urlrenderer d
			else if installed < avail
				then canUpgrade Low urlrenderer d
				else debug [ "No new version found." ]

canUpgrade :: AlertPriority -> UrlRenderer -> GitAnnexDistribution -> Assistant ()
canUpgrade urgency urlrenderer d = ifM autoUpgradeEnabled
	( startDistributionDownload d
	, do
#ifdef WITH_WEBAPP
		button <- mkAlertButton True (T.pack "Upgrade") urlrenderer (ConfigStartUpgradeR d)
		void $ addAlert (canUpgradeAlert urgency (distributionVersion d) button)
#else
		noop
#endif
	)

getDistributionInfo :: Assistant (Maybe GitAnnexDistribution)
getDistributionInfo = do
	ua <- liftAnnex Url.getUserAgent
	liftIO $ withTmpFile "git-annex.tmp" $ \tmpfile h -> do
		hClose h
		ifM (Url.downloadQuiet distributionInfoUrl [] [] tmpfile ua)
			( readish <$> readFileStrict tmpfile
			, return Nothing
			)

distributionInfoUrl :: String
distributionInfoUrl = fromJust Build.SysConfig.upgradelocation ++ ".info"