{-# LANGUAGE ConstraintKinds           #-}
{-# LANGUAGE ExistentialQuantification #-}
module Development.IDE.Graph.Database(
    ShakeDatabase,
    ShakeValue,
    shakeNewDatabase,
    shakeRunDatabase,
    shakeRunDatabaseForKeys,
    shakeProfileDatabase,
    shakeGetBuildStep,
    shakeGetDatabaseKeys,
    shakeGetDirtySet,
    shakeGetCleanKeys
    ,shakeGetBuildEdges) where
import           Control.Concurrent.STM.Stats            (readTVarIO)
import           Data.Dynamic
import           Data.Maybe
import           Development.IDE.Graph.Classes           ()
import           Development.IDE.Graph.Internal.Action
import           Development.IDE.Graph.Internal.Database
import           Development.IDE.Graph.Internal.Options
import           Development.IDE.Graph.Internal.Profile  (writeProfile)
import           Development.IDE.Graph.Internal.Rules
import           Development.IDE.Graph.Internal.Types


-- Placeholder to be the 'extra' if the user doesn't set it
data NonExportedType = NonExportedType

shakeNewDatabase :: ShakeOptions -> Rules () -> IO ShakeDatabase
shakeNewDatabase opts rules = do
    let extra = fromMaybe (toDyn NonExportedType) $ shakeExtra opts
    (theRules, actions) <- runRules extra rules
    db <- newDatabase extra theRules
    pure $ ShakeDatabase (length actions) actions db

shakeRunDatabase :: ShakeDatabase -> [Action a] -> IO [a]
shakeRunDatabase = shakeRunDatabaseForKeys Nothing

-- | Returns the set of dirty keys annotated with their age (in # of builds)
shakeGetDirtySet :: ShakeDatabase -> IO [(Key, Int)]
shakeGetDirtySet (ShakeDatabase _ _ db) =
    Development.IDE.Graph.Internal.Database.getDirtySet db

-- | Returns the build number
shakeGetBuildStep :: ShakeDatabase -> IO Int
shakeGetBuildStep (ShakeDatabase _ _ db) = do
    Step s <- readTVarIO $ databaseStep db
    return s

-- Only valid if we never pull on the results, which we don't
unvoid :: Functor m => m () -> m a
unvoid = fmap undefined

-- | Assumes that the database is not running a build
shakeRunDatabaseForKeys
    :: Maybe [Key]
      -- ^ Set of keys changed since last run. 'Nothing' means everything has changed
    -> ShakeDatabase
    -> [Action a]
    -> IO [a]
shakeRunDatabaseForKeys keysChanged (ShakeDatabase lenAs1 as1 db) as2 = do
    incDatabase db keysChanged
    fmap (drop lenAs1) $ runActions db $ map unvoid as1 ++ as2

-- | Given a 'ShakeDatabase', write an HTML profile to the given file about the latest run.
shakeProfileDatabase :: ShakeDatabase -> FilePath -> IO ()
shakeProfileDatabase (ShakeDatabase _ _ s) file = writeProfile file s

-- | Returns the clean keys in the database
shakeGetCleanKeys :: ShakeDatabase -> IO [(Key, Result )]
shakeGetCleanKeys (ShakeDatabase _ _ db) = do
    keys <- getDatabaseValues db
    return [ (k,res) | (k, Clean res) <- keys]

-- | Returns the total count of edges in the build graph
shakeGetBuildEdges :: ShakeDatabase -> IO Int
shakeGetBuildEdges (ShakeDatabase _ _ db) = do
    keys <- getDatabaseValues db
    let ress = mapMaybe (getResult . snd) keys
    return $ sum $ map (length . getResultDepsDefault [] . resultDeps) ress

-- | Returns an approximation of the database keys,
--   annotated with how long ago (in # builds) they were visited
shakeGetDatabaseKeys :: ShakeDatabase -> IO [(Key, Int)]
shakeGetDatabaseKeys (ShakeDatabase _ _ db) = getKeysAndVisitAge db