{- git-annex assistant webapp configurators
 -
 - Copyright 2012 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

{-# LANGUAGE TypeFamilies, QuasiQuotes, MultiParamTypeClasses, TemplateHaskell, OverloadedStrings, RankNTypes #-}

module Assistant.WebApp.Configurators where

import Assistant.Common
import Assistant.WebApp
import Assistant.WebApp.SideBar
import Utility.Yesod
import qualified Remote
import Logs.Web (webUUID)
import Logs.Trust
import Annex.UUID (getUUID)
import Init
import qualified Git.Construct
import qualified Git.Config
import qualified Annex
import Locations.UserConfig

import Yesod
import Data.Text (Text)
import qualified Data.Text as T
import Data.Char
import System.Posix.Directory

{- An intro message, list of repositories, and nudge to make more. -}
introDisplay :: Text -> Widget
introDisplay ident = do
	webapp <- lift getYesod
	l <- lift $ runAnnex [] $ do
		u <- getUUID
		rs <- map Remote.uuid <$> Remote.remoteList
		rs' <- snd <$> trustPartition DeadTrusted rs
		Remote.prettyListUUIDs $ filter (/= webUUID) $ nub $ u:rs'
	let remotelist = zip counter l
	let n = length l
	let numrepos = show n
	let notenough = n < 2
	let barelyenough = n == 2
	let morethanenough = n > 2
	$(widgetFile "configurators/intro")
	lift $ modifyWebAppState $ \s -> s { showIntro = False }
	where
		counter = map show ([1..] :: [Int])

data RepositoryPath = RepositoryPath Text
	deriving Show

{- Custom field display for a RepositoryPath, with an icon etc.
 -
 - Validates that the path entered is not empty, and is a safe value
 - to use as a repository. -}
repositoryPathField :: forall sub. Bool -> Field sub WebApp Text
repositoryPathField autofocus = Field { fieldParse = parse, fieldView = view }
	where
		view idAttr nameAttr attrs val isReq =
			[whamlet|<input type="text" *{attrs} id="#{idAttr}" name="#{nameAttr}" :isReq:required :autofocus:autofocus value="#{either id id val}">|]

		parse [path]
			| T.null path = nopath
			| otherwise = liftIO $ checkRepositoryPath path
		parse [] = return $ Right Nothing
		parse _ = nopath

		nopath = return $ Left "Enter a location for the repository"

{- As well as checking the path for a lot of silly things, tilde is
 - expanded in the returned path. -}
checkRepositoryPath :: Text -> IO (Either (SomeMessage WebApp) (Maybe Text))
checkRepositoryPath p = do
	home <- myHomeDir
	let basepath = expandTilde home $ T.unpack p
	path <- absPath basepath
	let parent = parentDir path
	problems <- catMaybes <$> mapM runcheck
		[ (return $ path == "/", "Enter the full path to use for the repository.")
		, (return $ all isSpace basepath, "A blank path? Seems unlikely.")
		, (doesFileExist path, "A file already exists with that name.")
		, (return $ path == home, "Sorry, using git-annex for your whole home directory is not currently supported.")
		, (not <$> doesDirectoryExist parent, "Parent directory does not exist.")
		, (cannotWrite path, "Cannot write a repository there.")
		]
	return $ 
		case headMaybe problems of
			Nothing -> Right $ Just $ T.pack basepath
			Just prob -> Left prob
	where
		runcheck (chk, msg) = ifM (chk)
			( return $ Just msg
			, return Nothing
			)
		cannotWrite path = do
			tocheck <- ifM (doesDirectoryExist path)
				(return path, return $ parentDir path)
			not <$> (catchBoolIO $ fileAccess tocheck False True False)
		expandTilde home ('~':path) = home </> path
		expandTilde _ path = path

{- On first run, if run in the home directory, default to putting it in
 - ~/Desktop/annex, when a Desktop directory exists, and ~/annex otherwise.
 -
 - If run in another directory, the user probably wants to put it there. -}
defaultRepositoryPath :: Bool -> IO FilePath
defaultRepositoryPath firstrun = do
	cwd <- liftIO $ getCurrentDirectory
	home <- myHomeDir
	if home == cwd && firstrun
		then ifM (doesDirectoryExist $ home </> "Desktop")
			(return "~/Desktop/annex", return "~/annex")
		else return cwd

addRepositoryForm :: Form RepositoryPath
addRepositoryForm msg = do
	path <- T.pack . addTrailingPathSeparator
		<$> (liftIO . defaultRepositoryPath =<< lift inFirstRun)
	(pathRes, pathView) <- mreq (repositoryPathField True) "" (Just path)
	let (err, errmsg) = case pathRes of
		FormMissing -> (False, "")
		FormFailure l -> (True, concat $ map T.unpack l)
		FormSuccess _ -> (False, "")
	let form = do
		webAppFormAuthToken
		$(widgetFile "configurators/addrepository/form")
	return (RepositoryPath <$> pathRes, form)

addRepository :: Bool -> Widget
addRepository firstrun = do
	setTitle $ if firstrun then "Getting started" else "Add repository"
	((res, form), enctype) <- lift $ runFormGet addRepositoryForm
	case res of
		FormSuccess (RepositoryPath p) -> go $ T.unpack p
		_ -> $(widgetFile "configurators/addrepository")
	where
		go path
			| firstrun = lift $ startFullAssistant path
			| otherwise = error "TODO"

{- Bootstraps from first run mode to a fully running assistant in a
 - repository, by running the postFirstRun callback, which returns the
 - url to the new webapp. -}
startFullAssistant :: FilePath -> Handler ()
startFullAssistant path = do
	webapp <- getYesod
	url <- liftIO $ do
		makeRepo path
		changeWorkingDirectory path
		fromJust $ postFirstRun webapp
	redirect $ T.pack url

{- Makes a new git-annex repository. -}
makeRepo :: FilePath -> IO ()
makeRepo path = do
	unlessM (boolSystem "git" [Param "init", Param "--quiet", File path]) $
		error "git init failed!"
	g <- Git.Config.read =<< Git.Construct.fromPath path
	state <- Annex.new g
	Annex.eval state $ initialize $ Just "new repo" -- TODO better description
	autostart <- autoStartFile
	createDirectoryIfMissing True (parentDir autostart)
	appendFile autostart $ path ++ "\n"

getAddRepositoryR :: Handler RepHtml
getAddRepositoryR = bootstrap (Just Config) $ do
	sideBarDisplay
	addRepository False

getConfigR :: Handler RepHtml
getConfigR = bootstrap (Just Config) $ do
	sideBarDisplay
	ifM (lift inFirstRun)
		( addRepository True
		, do
			setTitle "Configuration"
			$(widgetFile "configurators/main")
		)