module Propellor.Property where
import System.Directory
import Control.Monad
import Data.Monoid
import Control.Monad.IfElse
import "mtl" Control.Monad.Reader
import Propellor.Types
import Propellor.Types.Attr
import Propellor.Engine
import Utility.Monad
makeChange :: IO () -> Propellor Result
makeChange a = liftIO a >> return MadeChange
noChange :: Propellor Result
noChange = return NoChange
propertyList :: Desc -> [Property] -> Property
propertyList desc ps = Property desc $ ensureProperties ps
combineProperties :: Desc -> [Property] -> Property
combineProperties desc ps = Property desc $ go ps NoChange
where
go [] rs = return rs
go (l:ls) rs = do
r <- ensureProperty l
case r of
FailedChange -> return FailedChange
_ -> go ls (r <> rs)
before :: Property -> Property -> Property
p1 `before` p2 = Property (propertyDesc p1) $ do
r <- ensureProperty p1
case r of
FailedChange -> return FailedChange
_ -> ensureProperty p2
flagFile :: Property -> FilePath -> Property
flagFile property flagfile = Property (propertyDesc property) $
go =<< liftIO (doesFileExist flagfile)
where
go True = return NoChange
go False = do
r <- ensureProperty property
when (r == MadeChange) $ liftIO $
unlessM (doesFileExist flagfile) $
writeFile flagfile ""
return r
onChange :: Property -> Property -> Property
property `onChange` hook = Property (propertyDesc property) $ do
r <- ensureProperty property
case r of
MadeChange -> do
r' <- ensureProperty hook
return $ r <> r'
_ -> return r
(==>) :: Desc -> Property -> Property
(==>) = flip describe
infixl 1 ==>
check :: IO Bool -> Property -> Property
check c property = Property (propertyDesc property) $ ifM (liftIO c)
( ensureProperty property
, return NoChange
)
boolProperty :: Desc -> IO Bool -> Property
boolProperty desc a = Property desc $ ifM (liftIO a)
( return MadeChange
, return FailedChange
)
revert :: RevertableProperty -> RevertableProperty
revert (RevertableProperty p1 p2) = RevertableProperty p2 p1
host :: HostName -> Host
host hn = Host [] (\_ -> newAttr hn)
(&) :: IsProp p => Host -> p -> Host
(Host ps as) & p = Host (ps ++ [toProp p]) (getAttr p . as)
infixl 1 &
(!) :: Host -> RevertableProperty -> Host
(Host ps as) ! p = Host (ps ++ [toProp q]) (getAttr q . as)
where
q = revert p
infixl 1 !