{-# LANGUAGE TupleSections #-}
module Data.Dependency
(
resolveDependencies
, Dependency (..)
, PackageSet (..)
, Version (..)
, DepM
, ResolveError (..)
, Constraint (..)
) where
import Control.Arrow
import Control.Monad
import Data.Dependency.Error
import Data.Dependency.Sort
import Data.Dependency.Type
import Data.Foldable (toList)
import Data.List (groupBy)
import qualified Data.Map as M
import qualified Data.Set as S
lookupMap :: String -> M.Map String a -> DepM a
lookupMap k ps = case M.lookup k ps of
Just x -> Right x
Nothing -> Left (NotPresent k)
checkWith :: Dependency
-> [Dependency]
-> S.Set Dependency
-> DepM Dependency
checkWith x ds s
| check x ds = Right x
| otherwise = lookupSet (Just x) ds (S.deleteMax s)
lookupSet :: Maybe Dependency
-> [Dependency]
-> S.Set Dependency
-> DepM Dependency
lookupSet x ds s = case S.lookupMax s of
Just x' -> checkWith x' ds s
Nothing -> g x
where g Nothing = Left InternalError
g (Just x') = Left (Conflicts (_libName <$> ds') (_libName x'))
where ds' = filter (\d -> not (check x' [d])) ds
latest :: PackageSet Dependency -> [Dependency] -> Dependency -> DepM (String, Dependency)
latest (PackageSet ps) ds d@(Dependency ln _ _) =
(ln,) <$> (lookupSet (Just d) ds =<< lookupMap ln ps)
buildSequence :: [Dependency] -> [[Dependency]]
buildSequence = reverse . groupBy independent . sortDeps
where independent (Dependency ln ls _) (Dependency ln' ls' _) =
ln' `notElem` (fst <$> ls) && ln `notElem` (fst <$> ls')
iterateM :: (Monad m) => Int -> (a -> m a) -> a -> m [a]
iterateM 0 _ _ = pure []
iterateM n f x = (x:) <$> (iterateM (n-1) f =<< f x)
saturateDeps :: PackageSet Dependency -> Dependency -> DepM (S.Set Dependency)
saturateDeps ps = resolve <=< saturateDeps' ps
where resolve set = last <$> iterateM n next set
next depSet = S.unions <$> sequence (saturateDeps' ps <$> toList depSet)
n = length (toList ps)
saturateDeps' :: PackageSet Dependency -> Dependency -> DepM (S.Set Dependency)
saturateDeps' (PackageSet ps) dep = S.fromList <$> list
where list = (:) dep <$> (traverse (lookupSet Nothing (crunch ps)) =<< deps)
deps = sequence [ lookupMap lib ps | lib <- fst <$> _libDependencies dep ]
crunch = mconcat . fmap toList . toList
resolveDependencies :: PackageSet Dependency
-> [Dependency]
-> DepM [[Dependency]]
resolveDependencies ps = select . getLatest <=< fmap prepare . saturate
where select = fmap (fmap (fmap snd))
saturate = fmap S.unions . traverse (saturateDeps ps)
prepare = (buildSequence &&& id) . toList
getLatest (stepped, allDeps) = traverse (traverse (latest ps allDeps)) stepped