module Propellor.Property.Sudo where

import Data.List

import Propellor.Base
import Propellor.Property.File
import qualified Propellor.Property.Apt as Apt
import Propellor.Property.User

-- | Allows a user to run any command with sudo.
-- If the user has a password, sudo is configured to require it.
-- If not, NOPASSWORD is enabled for the user.
--
-- Writes to the file /etc/sudoers.d/000users rather than the main sudoers
-- file. This file should come before other include files that may eg,
-- allow running more specific commands without a password, since sudo
-- uses the last matching configuration line.
--
-- If the main sudoers file contains a conflicting line for
-- the user for ALL commands, the line will be removed.
--
-- Also ensures that the main sudoers file includes /etc/sudoers.d/
enabledFor :: User -> RevertableProperty DebianLike DebianLike
enabledFor user@(User u) = setup `requires` Apt.installed ["sudo"] <!> cleanup
  where
        setup :: Property UnixLike
        setup = property' desc $ \w -> do
                locked <- liftIO $ isLockedPassword user
                ensureProperty w $ combineProperties desc $ props
                        & containsLine sudoers "#includedir /etc/sudoers.d"
                        & fileProperty desc
                                (modify locked . filter (wanted locked))
                                dfile
                        & removeconflicting sudoers
          where
                desc = u ++ " is sudoer"

        cleanup :: Property DebianLike
        cleanup = tightenTargets $ combineProperties desc $ props
                & removeconflicting sudoers
                & removeconflicting dfile
          where
                desc = u ++ " is not sudoer"

        removeconflicting = fileProperty "remove conflicting" (filter notuserline)

        sudoers = "/etc/sudoers"
        dfile = "/etc/sudoers.d/000users"
        sudobaseline = u ++ " ALL=(ALL:ALL)"
        notuserline l = not (sudobaseline `isPrefixOf` l)
        sudoline True = sudobaseline ++ " NOPASSWD:ALL"
        sudoline False = sudobaseline ++ " ALL"
        wanted locked l
                | notuserline l = True
                | "NOPASSWD" `isInfixOf` l = locked
                | otherwise = True
        modify locked ls
                | sudoline locked `elem` ls = ls
                | otherwise = ls ++ [sudoline locked]

-- | Sets up a file in /etc/sudoers.d/, which /etc/sudoers includes,
-- with the specified content.
--
-- The FilePath can be relative to that directory.
sudoersDFile :: FilePath -> [Line] -> RevertableProperty DebianLike Linux
sudoersDFile dfile content = setup `requires` Apt.installed ["sudo"] <!> cleanup
  where
        f = "/etc/sudoers.d" </> dfile
        -- sudoers.d files should not be world readable
        setup = hasContentProtected f content
        cleanup = tightenTargets $ notPresent f