{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE LambdaCase            #-}
{-# LANGUAGE RankNTypes            #-}

-- | The module should not depend on the Interpreter module
module Puppet.Interpreter.Utils where

import           Control.Lens               hiding (Strict)
import           Control.Monad.Operational
import           Control.Monad.Writer.Class
import qualified Data.ByteString            as BS
import qualified Data.HashMap.Strict        as HM
import           Data.Maybe                 (fromMaybe)
import qualified Data.Maybe.Strict          as S
import           Data.Text (Text)
import qualified Data.Text                  as T
import qualified Data.Text.Encoding         as T
import           Data.Tuple.Strict
import qualified System.Log.Logger          as LOG

import           Puppet.Interpreter.Types
import           Puppet.Parser.Types
import           Puppet.Parser.Utils
import           Puppet.Paths
import           Puppet.PP

initialState :: Facts
             -> Container Text -- ^ Server settings
             -> InterpreterState
initialState facts settings = InterpreterState baseVars initialclass mempty [ContRoot] dummyppos mempty [] []
    where
        callervars = HM.fromList [("caller_module_name", PString "::" :!: dummyppos :!: ContRoot), ("module_name", PString "::" :!: dummyppos :!: ContRoot)]
        factvars = fmap (\x -> x :!: initialPPos "facts" :!: ContRoot) facts
        settingvars = fmap (\x -> PString x :!: initialPPos "settings" :!: ContClass "settings") settings
        baseVars = HM.fromList [ ("::", ScopeInformation (factvars `mappend` callervars) mempty mempty (CurContainer ContRoot mempty) mempty S.Nothing)
                               , ("settings", ScopeInformation settingvars mempty mempty (CurContainer (ContClass "settings") mempty) mempty S.Nothing)
                               ]
        initialclass = mempty & at "::" ?~ (ClassIncludeLike :!: dummyppos)


getModulename :: RIdentifier -> Text
getModulename (RIdentifier t n) =
    let gm x = case T.splitOn "::" x of
                   [] -> x
                   (y:_) -> y
    in case t of
        "class" -> gm n
        _       -> gm t


extractPrism :: Doc -> Prism' a b -> a -> InterpreterMonad b
extractPrism msg p a = case preview p a of
    Just b  -> return b
    Nothing -> throwPosError ("Could not extract prism in" <+> msg)

-- Scope
popScope :: InterpreterMonad ()
popScope = curScope %= tail

pushScope :: CurContainerDesc -> InterpreterMonad ()
pushScope s = curScope %= (s :)

getScopeName :: InterpreterMonad Text
getScopeName = scopeName <$> getScope

scopeName :: CurContainerDesc -> Text
scopeName (ContRoot        ) = "::"
scopeName (ContImported x  ) = "::imported::" `T.append` scopeName x
scopeName (ContClass x     ) = x
scopeName (ContDefine dt dn _) = "#define/" `T.append` dt `T.append` "/" `T.append` dn
scopeName (ContImport _ x  ) = "::import::" `T.append` scopeName x

getScope :: InterpreterMonad CurContainerDesc
{-# INLINABLE getScope #-}
getScope = use curScope >>= \s -> if null s
                                      then throwPosError "Internal error: empty scope!"
                                      else return (head s)


getCurContainer :: InterpreterMonad CurContainer
{-# INLINABLE getCurContainer #-}
getCurContainer = do
    scp <- getScopeName
    preuse (scopes . ix scp . scopeContainer) >>= \case
        Just x -> return x
        Nothing -> throwPosError ("Internal error: can't find the current container for" <+> green (string (T.unpack scp)))

rcurcontainer :: Resource -> CurContainerDesc
rcurcontainer r = fromMaybe ContRoot (r ^? rscope . _head)

-- Singleton getters available in the InterpreterMonad --
getPuppetPaths :: InterpreterMonad PuppetDirPaths
getPuppetPaths = singleton PuppetPaths

getNodeName:: InterpreterMonad NodeName
getNodeName = singleton GetNodeName

isIgnoredModule :: Text -> InterpreterMonad Bool
isIgnoredModule m = singleton (IsIgnoredModule m)

-- | Throws an error if we are in strict mode
-- A warning in permissive mode
checkStrict :: Doc -- ^ The warning message.
            -> Doc -- ^ The error message.
            -> InterpreterMonad ()
checkStrict wrn err = do
    extMod <- isExternalModule
    let priority = if extMod then LOG.NOTICE else LOG.WARNING
    str <- singleton IsStrict
    if str && not extMod
        then throwPosError err
        else do
          srcname <- use (curPos._1.lSourceName)
          logWriter priority (wrn <+> "at" <+> string srcname)

isExternalModule :: InterpreterMonad Bool
isExternalModule =
    getScope >>= \case
      ContClass n      -> isExternal n
      ContDefine n _ _ -> isExternal n
      _                -> return False
    where
      isExternal = singleton . IsExternalModule . head . T.splitOn "::"


-- Logging --
warn :: (Monad m, MonadWriter InterpreterWriter m) => Doc -> m ()
warn d = tell [LOG.WARNING :!: d]

debug :: (Monad m, MonadWriter InterpreterWriter m) => Doc -> m ()
debug d = tell [LOG.DEBUG :!: d]

logWriter :: (Monad m, MonadWriter InterpreterWriter m) => LOG.Priority -> Doc -> m ()
logWriter prio d = tell [prio :!: d]

-- General --
isEmpty :: (Eq x, Monoid x) => x -> Bool
isEmpty = (== mempty)

safeDecodeUtf8 :: BS.ByteString -> InterpreterMonad Text
{-# INLINABLE safeDecodeUtf8 #-}
safeDecodeUtf8 i = return (T.decodeUtf8 i)

dropInitialColons :: Text -> T.Text
dropInitialColons t = fromMaybe t (T.stripPrefix "::" t)

normalizeRIdentifier :: Text -> T.Text -> RIdentifier
normalizeRIdentifier = RIdentifier . dropInitialColons