{-# LANGUAGE FlexibleInstances      #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE LambdaCase             #-}
{-# LANGUAGE MultiParamTypeClasses  #-}
{-# LANGUAGE OverloadedStrings      #-}
{-# LANGUAGE TemplateHaskell        #-}
module Puppet.Preferences (
    dfPreferences
  , HasPreferences(..)
  , Preferences(Preferences)
  , PuppetDirPaths
  , HasPuppetDirPaths(..)
) where

import           Control.Lens
import           Control.Monad              (mzero)
import           Data.Aeson
import qualified Data.HashMap.Strict        as HM
import qualified Data.HashSet               as HS
import           Data.Maybe                 (fromMaybe)
import           Data.Text                  (Text)
import qualified Data.Text                  as T
import           System.Posix               (fileExist)
import qualified System.Log.Logger         as LOG

import           Puppet.Interpreter.Types
import           Puppet.NativeTypes
import           Puppet.NativeTypes.Helpers
import           Puppet.Stdlib
import           Puppet.Paths
import qualified Puppet.Puppetlabs          as Puppetlabs
import           Puppet.Utils
import           PuppetDB.Dummy

data Preferences m = Preferences
    { _prefPuppetPaths     :: PuppetDirPaths
    , _prefPDB             :: PuppetDBAPI m
    , _prefNatTypes        :: Container NativeTypeMethods -- ^ The list of native types.
    , _prefExtFuncs        :: Container ( [PValue] -> InterpreterMonad PValue )
    , _prefHieraPath       :: Maybe FilePath
    , _prefIgnoredmodules  :: HS.HashSet Text
    , _prefStrictness      :: Strictness
    , _prefExtraTests      :: Bool
    , _prefKnownusers      :: [Text]
    , _prefKnowngroups     :: [Text]
    , _prefExternalmodules :: HS.HashSet Text
    , _prefPuppetSettings  :: Container Text
    , _prefFactsOverride   :: Container PValue
    , _prefFactsDefault    :: Container PValue
    , _prefLogLevel        :: LOG.Priority
    }

data Defaults = Defaults
    { _dfKnownusers      :: Maybe [Text]
    , _dfKnowngroups     :: Maybe [Text]
    , _dfIgnoredmodules  :: Maybe [Text]
    , _dfStrictness      :: Maybe Strictness
    , _dfExtratests      :: Maybe Bool
    , _dfExternalmodules :: Maybe [Text]
    , _dfPuppetSettings  :: Maybe (Container Text)
    , _dfFactsDefault    :: Maybe (Container PValue)
    , _dfFactsOverride   :: Maybe (Container PValue)
    } deriving Show


makeClassy ''Preferences

instance FromJSON Defaults where
    parseJSON (Object v) = Defaults
                           <$> v .:? "knownusers"
                           <*> v .:? "knowngroups"
                           <*> v .:? "ignoredmodules"
                           <*> v .:? "strict"
                           <*> v .:? "extratests"
                           <*> v .:? "externalmodules"
                           <*> v .:? "settings"
                           <*> v .:? "factsdefault"
                           <*> v .:? "factsoverride"
    parseJSON _ = mzero

-- | generate default preferences
dfPreferences :: FilePath
               -> IO (Preferences IO)
dfPreferences basedir = do
    let dirpaths = puppetPaths basedir
        modulesdir = dirpaths ^. modulesPath
        testdir = dirpaths ^. testPath
    typenames <- fmap (map takeBaseName) (getFiles (T.pack modulesdir) "lib/puppet/type" ".rb")
    defaults <- loadDefaults (testdir ++ "/defaults.yaml")
    labsFunctions <- Puppetlabs.extFunctions modulesdir
    let loadedTypes = HM.fromList (map defaulttype typenames)
    return $ Preferences dirpaths
                         dummyPuppetDB (baseNativeTypes `HM.union` loadedTypes)
                         (HM.union stdlibFunctions labsFunctions)
                         (Just (basedir <> "/hiera.yaml"))
                         (getIgnoredmodules defaults)
                         (getStrictness defaults)
                         (getExtraTests defaults)
                         (getKnownusers defaults)
                         (getKnowngroups defaults)
                         (getExternalmodules defaults)
                         (getPuppetSettings dirpaths defaults)
                         (getFactsOverride defaults)
                         (getFactsDefault defaults)
                         LOG.NOTICE -- good default as INFO is quite noisy

loadDefaults :: FilePath -> IO (Maybe Defaults)
loadDefaults fp = do
  p <- fileExist fp
  if p then loadYamlFile fp else return Nothing

-- Utilities for getting default values from the yaml file
-- It provides (the same) static defaults (see the 'Nothing' case) when
--     no default yaml file or
--     not key/value for the option has been provided
getKnownusers :: Maybe Defaults -> [Text]
getKnownusers = fromMaybe ["mysql", "vagrant","nginx", "nagios", "postgres", "puppet", "root", "syslog", "www-data"] . (>>= _dfKnownusers)

getKnowngroups :: Maybe Defaults -> [Text]
getKnowngroups = fromMaybe ["adm", "syslog", "mysql", "nagios","postgres", "puppet", "root", "www-data", "postfix"] . (>>= _dfKnowngroups)

getStrictness :: Maybe Defaults -> Strictness
getStrictness = fromMaybe Permissive . (>>= _dfStrictness)

getIgnoredmodules :: Maybe Defaults -> HS.HashSet Text
getIgnoredmodules = maybe mempty HS.fromList . (>>= _dfIgnoredmodules)

getExtraTests :: Maybe Defaults -> Bool
getExtraTests = fromMaybe True . (>>= _dfExtratests)

getExternalmodules :: Maybe Defaults -> HS.HashSet Text
getExternalmodules = maybe mempty HS.fromList . (>>= _dfExternalmodules)

getPuppetSettings :: PuppetDirPaths -> Maybe Defaults -> Container Text
getPuppetSettings dirpaths = fromMaybe df . (>>= _dfPuppetSettings)
    where
      df :: Container Text
      df = HM.fromList [ ("confdir", T.pack $ dirpaths^.baseDir)
                       , ("strict_variables", "true")
                       ]

getFactsOverride :: Maybe Defaults -> Container PValue
getFactsOverride = fromMaybe mempty . (>>= _dfFactsOverride)

getFactsDefault :: Maybe Defaults -> Container PValue
getFactsDefault = fromMaybe mempty . (>>= _dfFactsDefault)