    module Propellor.DotDir
            ( distrepo
            , dotPropellor
            , interactiveInit
            , checkRepoUpToDate
            ) where

    import Propellor.Message
    import Propellor.Bootstrap
    import Propellor.Git
    import Propellor.Gpg
    import Propellor.Types.Result
    import Utility.UserInfo
    import Utility.Monad
    import Utility.Process
    import Utility.SafeCommand
    import Utility.Exception
    import Utility.Directory
    import Utility.Path
    -- This module is autogenerated by the build system.
    import qualified Paths_propellor as Package

    import Data.Char
    import Data.List
    import Data.Version
    import Control.Monad
    import Control.Monad.IfElse
    import System.FilePath
    import System.Posix.Directory
    import System.IO
    import System.Console.Concurrent
    import Control.Applicative
    import Prelude

    distdir :: FilePath
    distdir = "/usr/src/propellor"

    -- A distribution may include a bundle of propellor's git repository here.
    -- If not, it will be pulled from the network when needed.
    distrepo :: FilePath
    distrepo = distdir </> "propellor.git"

    -- File containing the head rev of the distrepo.
    disthead :: FilePath
    disthead = distdir </> "head"

    upstreambranch :: String
    upstreambranch = "upstream/master"

    -- Using the joeyh.name mirror of the main propellor repo because
    -- it is accessible over https for better security.
    netrepo :: String
    netrepo = "https://git.joeyh.name/git/propellor.git"

    dotPropellor :: IO FilePath
    dotPropellor = do
            home <- myHomeDir
            return (home </> ".propellor")

    -- Detect if propellor was built using stack. This is somewhat of a hack.
    buildSystem :: IO String
    buildSystem = do
            d <- Package.getLibDir
            return $ if "stack-work" `isInfixOf` d then "stack" else "cabal"

    interactiveInit :: IO ()
    interactiveInit = ifM (doesDirectoryExist =<< dotPropellor)
            ( error "~/.propellor/ already exists, not doing anything"
            , do
                    welcomeBanner
                    setup
            )

    -- | Determine whether we need to create a cabal sandbox in ~/.propellor/,
    -- which we do if the user has configured cabal to require a sandbox, and the
    -- build system is cabal.
    cabalSandboxRequired :: IO Bool
    cabalSandboxRequired = ifM cabal
            ( do
                    home <- myHomeDir
                    ls <- lines <$> catchDefaultIO []
                            (readFile (home </> ".cabal" </> "config"))
                    -- For simplicity, we assume a sane ~/.cabal/config here:
                    return $ any ("True" `isInfixOf`) $
                            filter ("require-sandbox:" `isPrefixOf`) ls
            , return False
            )
      where
            cabal = buildSystem >>= \bSystem -> return (bSystem == "cabal")

    say :: String -> IO ()
    say = outputConcurrent

    sayLn :: String -> IO ()
    sayLn s = say (s ++ "\n")

    welcomeBanner :: IO ()
    welcomeBanner = say $ unlines $ map prettify
            [ ""
            , ""
            , "                                 _         ______`|                     ,-.__"
            , " .---------------------------  /   ~___-=O`/|O`/__|                    (____.'"
            , "  - Welcome to              -- ~          / | /    )        _.-'-._"
            , "  -            Propellor!   --  `/-==__ _/__|/__=-|        (       ~_"
            , " `---------------------------   *             ~ | |         '--------'"
            , "                                            (o)  `"
            , ""
            , ""
            ]
      where
            prettify = map (replace '~' '\\')
            replace x y c
                    | c == x = y
                    | otherwise = c

    prompt :: String -> [(String, IO ())] -> IO ()
    prompt p cs = do
            say (p ++ " [" ++ intercalate "|" (map fst cs) ++ "] ")
            flushConcurrentOutput
            hFlush stdout
            r <- map toLower <$> getLine
            if null r
                    then snd (head cs) -- default to first choice on return
                    else case filter (\(s, _) -> map toLower s == r) cs of
                            [(_, a)] -> a
                            _ -> do
                                    sayLn "Not a valid choice, try again.. (Or ctrl-c to quit)"
                                    prompt p cs

    section :: IO ()
    section = do
            sayLn ""
            sayLn "------------------------------------------------------------------------------"
            sayLn ""

    setup :: IO ()
    setup = do
            sayLn "Propellor's configuration file is ~/.propellor/config.hs"
            sayLn ""
            sayLn "Let's get you started with a simple config that you can adapt"
            sayLn "to your needs. You can start with:"
            sayLn "   A: A clone of propellor's git repository    (most flexible)"
            sayLn "   B: The bare minimum files to use propellor  (most simple)"
            prompt "Which would you prefer?"
                    [ ("A", void $ actionMessage "Cloning propellor's git repository" fullClone)
                    , ("B", void $ actionMessage "Creating minimal config" minimalConfig)
                    ]
            changeWorkingDirectory =<< dotPropellor

            section
            sayLn "Let's try building the propellor configuration, to make sure it will work..."
            sayLn ""
            b <- buildSystem
            void $ boolSystem "git"
                    [ Param "config"
                    , Param "propellor.buildsystem"
                    , Param b
                    ]
            ifM cabalSandboxRequired
                    ( void $ boolSystem "cabal"
                            [ Param "sandbox"
                            , Param "init"
                            ]
                    , return ()
                    )
            buildPropellor Nothing
            sayLn ""
            sayLn "Great! Propellor is bootstrapped."

            section
            sayLn "Propellor can use gpg to encrypt private data about the systems it manages,"
            sayLn "and to sign git commits."
            gpg <- getGpgBin
            ifM (inPath gpg)
                    ( setupGpgKey
                    , do
                            sayLn "You don't seem to have gpg installed, so skipping setting it up."
                            explainManualSetupGpgKey
                    )

            section
            sayLn "Everything is set up ..."
            sayLn "Your next step is to edit ~/.propellor/config.hs"
            sayLn "and run propellor again to try it out."
            sayLn ""
            sayLn "For docs, see https://propellor.branchable.com/"
            sayLn "Enjoy propellor!"

    explainManualSetupGpgKey :: IO ()
    explainManualSetupGpgKey = do
            sayLn "Propellor can still be used without gpg, but it won't be able to"
            sayLn "manage private data. You can set this up later:"
            sayLn " 1. gpg --gen-key"
            sayLn " 2. propellor --add-key (pass it the key ID generated in step 1)"

    setupGpgKey :: IO ()
    setupGpgKey = do
            ks <- listSecretKeys
            sayLn ""
            case ks of
                    [] -> makeGpgKey
                    [(k, d)] -> do
                            sayLn $ "You have one gpg key: " ++ desckey k d
                            prompt "Should propellor use that key?"
                                    [ ("Y", propellorAddKey k)
                                    , ("N", sayLn $ "Skipping gpg setup. If you change your mind, run: propellor --add-key " ++ k)
                                    ]
                    _ -> do
                            let nks = zip ks (map show ([1..] :: [Integer]))
                            sayLn "I see you have several gpg keys:"
                            forM_ nks $ \((k, d), n) ->
                                    sayLn $ "   " ++ n ++ "   " ++ desckey k d
                            prompt "Which of your gpg keys should propellor use?"
                                    (map (\((k, _), n) -> (n, propellorAddKey k)) nks)
      where
            desckey k d = d ++ "  (keyid " ++ k ++ ")"

    makeGpgKey :: IO ()
    makeGpgKey = do
            sayLn "You seem to not have any gpg secret keys."
            prompt "Would you like to create one now?"
                    [("Y", rungpg), ("N", nope)]
      where
            nope = do
                    sayLn "No problem."
                    explainManualSetupGpgKey
            rungpg = do
                    sayLn "Running gpg --gen-key ..."
                    gpg <- getGpgBin
                    void $ boolSystem gpg [Param "--gen-key"]
                    ks <- listSecretKeys
                    case ks of
                            [] -> do
                                    sayLn "Hmm, gpg seemed to not set up a secret key."
                                    prompt "Want to try running gpg again?"
                                            [("Y", rungpg), ("N", nope)]
                            ((k, _):_) -> propellorAddKey k

    propellorAddKey :: String -> IO ()
    propellorAddKey keyid = do
            sayLn ""
            sayLn $ "Telling propellor to use your gpg key by running: propellor --add-key " ++ keyid
            d <- dotPropellor
            unlessM (boolSystem (d </> "propellor") [Param "--add-key", Param keyid]) $ do
                    sayLn "Oops, that didn't work! You can retry the same command later."
                    sayLn "Continuing onward ..."

    minimalConfig :: IO Result
    minimalConfig = do
            d <- dotPropellor
            createDirectoryIfMissing True d
            changeWorkingDirectory d
            void $ boolSystem "git" [Param "init"]
            addfile "config.cabal" cabalcontent
            addfile "config.hs" configcontent
            addfile "stack.yaml" stackcontent
            return MadeChange
      where
            addfile f content = do
                    writeFile f (unlines content)
                    void $ boolSystem "git" [Param "add" , File f]
            cabalcontent =
                    [ "-- This is a cabal file to use to build your propellor configuration."
                    , ""
                    , "Name: config"
                    , "Cabal-Version: >= 1.6"
                    , "Build-Type: Simple"
                    , "Version: 0"
                    , ""
                    , "Executable propellor-config"
                    , "  Main-Is: config.hs"
                    , "  GHC-Options: -threaded -Wall -fno-warn-tabs -O0"
                    , "  Extensions: TypeOperators"
                    , "  Build-Depends: propellor >= 3.0, base >= 4.9"
                    ]
            configcontent =
                    [ "-- This is the main configuration file for Propellor, and is used to build"
                    , "-- the propellor program.    https://propellor.branchable.com/"
                    , ""
                    , "import Propellor"
                    , "import qualified Propellor.Property.File as File"
                    , "import qualified Propellor.Property.Apt as Apt"
                    , "import qualified Propellor.Property.Cron as Cron"
                    , "import qualified Propellor.Property.User as User"
                    , ""
                    , "main :: IO ()"
                    , "main = defaultMain hosts"
                    , ""
                    , "-- The hosts propellor knows about."
                    , "hosts :: [Host]"
                    , "hosts ="
                    , "        [ mybox"
                    , "        ]"
                    , ""
                    , "-- An example host."
                    , "mybox :: Host"
                    , "mybox = host \"mybox.example.com\" $ props"
                    , "        & osDebian Unstable X86_64"
                    , "        & Apt.stdSourcesList"
                    , "        & Apt.unattendedUpgrades"
                    , "        & Apt.installed [\"etckeeper\"]"
                    , "        & Apt.installed [\"ssh\"]"
                    , "        & User.hasSomePassword (User \"root\")"
                    , "        & File.dirExists \"/var/www\""
                    , "        & Cron.runPropellor (Cron.Times \"30 * * * *\")"
                    , ""
                    ]
            stackcontent =
                    -- This should be the same resolver version in propellor's
                    -- own stack.yaml
                    [ "resolver: " ++ stackResolver
                    , "packages:"
                    , "- '.'"
                    , "extra-deps:"
                    , "- propellor-" ++ showVersion Package.version
                    ]

    stackResolver :: String
    stackResolver = "lts-9.21"

    fullClone :: IO Result
    fullClone = do
            d <- dotPropellor
            let enterdotpropellor = changeWorkingDirectory d >> return True
            ok <- ifM (doesFileExist distrepo <||> doesDirectoryExist distrepo)
                    ( allM id
                            [ boolSystem "git" [Param "clone", File distrepo, File d]
                            , fetchUpstreamBranch distrepo
                            , enterdotpropellor
                            , boolSystem "git" [Param "remote", Param "rm", Param "origin"]
                            ]
                    , allM id
                            [ boolSystem "git" [Param "clone", Param netrepo, File d]
                            , enterdotpropellor
                            -- Rename origin to upstream and avoid
                            -- git push to that read-only repo.
                            , boolSystem "git" [Param "remote", Param "rename", Param "origin", Param "upstream"]
                            , boolSystem "git" [Param "config", Param "--unset", Param "branch.master.remote", Param "upstream"]
                            ]
                    )
            return (toResult ok)

    fetchUpstreamBranch :: FilePath -> IO Bool
    fetchUpstreamBranch repo = do
            changeWorkingDirectory =<< dotPropellor
            boolSystem "git"
                    [ Param "fetch"
                    , File repo
                    , Param ("+refs/heads/master:refs/remotes/" ++ upstreambranch)
                    , Param "--quiet"
                    ]

    checkRepoUpToDate :: IO ()
    checkRepoUpToDate = whenM (gitbundleavail <&&> dotpropellorpopulated) $ do
            headrev <- takeWhile (/= '\n') <$> readFile disthead
            changeWorkingDirectory =<< dotPropellor
            headknown <- catchMaybeIO $
                    withQuietOutput createProcessSuccess $
                            proc "git" ["log", headrev]
            if (headknown == Nothing)
                    then updateUpstreamMaster headrev
                    else do
                            theirhead <- getCurrentGitSha1 =<< getCurrentBranchRef
                            when (theirhead /= headrev) $ do
                                    merged <- not . null <$>
                                            readProcess "git" ["log", headrev ++ "..HEAD", "--ancestry-path"]
                                    unless merged $
                                            warnoutofdate True
      where
            gitbundleavail = doesFileExist disthead
            dotpropellorpopulated = do
                    d <- dotPropellor
                    doesFileExist (d </> "propellor.cabal")

    -- Updates upstream/master in dotPropellor so merging from it will update
    -- to the latest distrepo.
    --
    -- We cannot just fetch the distrepo because the distrepo contains only
    -- 1 commit. So, trying to merge with it will result in lots of merge
    -- conflicts, since git cannot find a common parent commit.
    --
    -- Instead, the new upstream/master branch is updated by taking the
    -- current upstream/master branch (which must be an old version of propellor,
    -- as distributed), and diffing from it to the current origin/master,
    -- and committing the result. This is done in a temporary clone of the
    -- repository, giving it a new master branch. That new branch is fetched
    -- into the user's repository, as if fetching from a upstream remote,
    -- yielding a new upstream/master branch.
    --
    -- If there's no upstream/master, or the repo is not using the distrepo,
    -- do nothing.
    updateUpstreamMaster :: String -> IO ()
    updateUpstreamMaster newref = do
            changeWorkingDirectory =<< dotPropellor
            go =<< getoldref
      where
            go Nothing = return ()
            go (Just oldref) = do
                    let tmprepo = ".git/propellordisttmp"
                    let cleantmprepo = void $ catchMaybeIO $ removeDirectoryRecursive tmprepo
                    cleantmprepo
                    git ["clone", "--quiet", ".", tmprepo]

                    changeWorkingDirectory tmprepo
                    git ["fetch", distrepo, "--quiet"]
                    git ["reset", "--hard", oldref, "--quiet"]
                    v <- gitVersion
                    let mergeparams =
                            [ "merge", newref
                            , "-s", "recursive"
                            , "-Xtheirs"
                            , "--quiet"
                            , "-m", "merging upstream version"
                            ] ++ if v >= [2,9]
                                    then [ "--allow-unrelated-histories" ]
                                    else []
                    git mergeparams

                    void $ fetchUpstreamBranch tmprepo
                    cleantmprepo
                    warnoutofdate True

            git = run "git"
            run cmd ps = unlessM (boolSystem cmd (map Param ps)) $
                    error $ "Failed to run " ++ cmd ++ " " ++ show ps

            -- Get ref that the upstreambranch points to, only when
            -- the distrepo is being used.
            getoldref = do
                    mref <- catchMaybeIO $ takeWhile (/= '\n')
                            <$> readProcess "git" ["show-ref", upstreambranch, "--hash"]
                    case mref of
                            Just _ -> do
                                    -- Normally there will be no upstream
                                    -- remote when the distrepo is used.
                                    -- Older versions of propellor set up
                                    -- an upstream remote pointing at the
                                    -- distrepo.
                                    ifM (hasRemote "upstream")
                                            ( do
                                                    v <- remoteUrl "upstream"
                                                    return $ case v of
                                                            Just rurl | rurl == distrepo -> mref
                                                            _ -> Nothing
                                            , return mref
                                            )
                            Nothing -> return mref

    warnoutofdate :: Bool -> IO ()
    warnoutofdate havebranch = warningMessage $ unlines
            [ "** Your ~/.propellor/ is out of date.."
            , indent "A newer upstream version is available in " ++ distrepo
            , indent $ if havebranch
                    then "To merge it, run: git merge " ++ upstreambranch
                    else "To merge it, find the most recent commit in your repository's history that corresponds to an upstream release of propellor, and set refs/remotes/" ++ upstreambranch ++ " to it. Then run propellor again."
            ]
      where
            indent s = "   " ++ s