{-# 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.Plugins
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)