{-# LANGUAGE LambdaCase, CPP #-}
module Puppet.Daemon (initDaemon) where

import           Control.Exception
import           Control.Lens
import qualified Data.Either.Strict as S
import           Data.FileCache
import qualified Data.HashMap.Strict as HM
import qualified Data.Text as T
import qualified Data.Text.IO as T
import           Data.Tuple.Strict
import qualified Data.Vector as V
import           Debug.Trace
import           Erb.Compute
import           Foreign.Ruby.Safe
import           Hiera.Server
import qualified System.Log.Logger as LOG

import           Puppet.Interpreter
import           Puppet.Interpreter.IO
import           Puppet.Interpreter.Types
import           Puppet.Manifests
import           Puppet.PP
import           Puppet.Parser
import           Puppet.Parser.Types
import           Puppet.Plugins
import           Puppet.Preferences
import           Puppet.Stats
import           Puppet.Utils

loggerName :: String
loggerName = "Puppet.Daemon"

logDebug :: T.Text -> IO ()
logDebug   = LOG.debugM   loggerName . T.unpack
-- logInfo :: T.Text -> IO ()
-- logInfo    = LOG.infoM    loggerName . T.unpack
-- logWarning :: T.Text -> IO ()
-- logWarning = LOG.warningM loggerName . T.unpack
-- logError :: T.Text -> IO ()
-- logError   = LOG.errorM   loggerName . T.unpack

{-| This is a high level function, that will initialize the parsing and
interpretation infrastructure from the 'Prefs' structure, and will return a
function that will take a node name, 'Facts' and return either an error or the
'FinalCatalog', along with the dependency graph and catalog of exported resources. It also return a few IO
functions that can be used in order to query the daemon for statistics,
following the format in "Puppet.Stats".

It will internaly initialize a thread for the LUA interpreter, and a thread for the Ruby one.
It should cache the AST of every .pp file, and could use a bit of memory. As a comparison, it
fits in 60 MB with the author's manifests, but really breathes when given 300 MB
of heap space. In this configuration, even if it spawns a ruby process for every
template evaluation, it is way faster than the puppet stack.

It can optionnaly talk with PuppetDB, by setting an URL in the 'Prefs' data
structure. The recommended way to set it to http://localhost:8080 and set a SSH
tunnel :

> ssh -L 8080:localhost:8080 puppet.host

Canveats :

* It might be buggy when top level statements that are not class\/define\/nodes
are altered, or when files loaded with require are changed.

* The catalog is not computed exactly the same way Puppet does. Some good practices are enforced.
As an example querying a dictionary with a non existent key returns undef in puppet, whereas it throws an error with language-puppet.

initDaemon :: Preferences IO -> IO DaemonMethods
initDaemon prefs = do
    logDebug "initDaemon"
    traceEventIO "initDaemon"
    templateStats <- newStats
    parserStats   <- newStats
    catalogStats  <- newStats
    pfilecache    <- newFileCache
    let getStatements = parseFunction prefs pfilecache parserStats
    intr          <- startRubyInterpreter
    getTemplate   <- initTemplateDaemon intr prefs templateStats
    hquery        <- case prefs ^. hieraPath of
                         Just p  -> fmap (either error id) $ startHiera p
                         Nothing -> return dummyHiera
    luacontainer <- initLuaMaster (T.pack (prefs ^. modulesPath))
    let myprefs = prefs & prefExtFuncs %~ HM.union luacontainer
    return (DaemonMethods (gCatalog myprefs getStatements getTemplate catalogStats hquery) parserStats catalogStats templateStats)

gCatalog :: Preferences IO
         -> ( TopLevelType -> T.Text -> IO (S.Either PrettyError Statement) )
         -> (Either T.Text T.Text -> T.Text -> Container ScopeInformation -> IO (S.Either PrettyError T.Text))
         -> MStats
         -> HieraQueryFunc IO
         -> T.Text
         -> Facts
         -> IO (S.Either PrettyError (FinalCatalog, EdgeMap, FinalCatalog, [Resource]))
gCatalog prefs getStatements getTemplate stats hquery ndename facts = do
    logDebug ("Received query for node " <> ndename)
    traceEventIO ("START gCatalog " <> T.unpack ndename)
    (stmts :!: warnings) <- measure stats ndename $
                getCatalog interpretMonad
                           (prefs ^. prefPDB)
                           (prefs ^. natTypes)
                           (prefs ^. prefExtFuncs)
                           (prefs ^. ignoredmodules)
    mapM_ (\(p :!: m) -> LOG.logM loggerName p (displayS (renderCompact (ttext ndename <> ":" <+> m)) "")) warnings
    traceEventIO ("STOP gCatalog " <> T.unpack ndename)
    return stmts

parseFunction :: Preferences IO -> FileCache (V.Vector Statement) -> MStats -> TopLevelType -> T.Text -> IO (S.Either PrettyError Statement)
parseFunction prefs filecache stats topleveltype toplevelname =
    case compileFileList prefs topleveltype toplevelname of
        S.Left rr -> return (S.Left rr)
        S.Right fname -> do
            let sfname = T.unpack fname
                handleFailure :: SomeException -> IO (S.Either String (V.Vector Statement))
                handleFailure e = return (S.Left (show e))
            x <- measure stats fname (query filecache sfname (parseFile sfname `catch` handleFailure))
            case x of
                S.Right stmts -> filterStatements topleveltype toplevelname stmts
                S.Left rr -> return (S.Left (PrettyError (red (text rr))))

-- TODO this is wrong, see
-- http://docs.puppetlabs.com/puppet/3/reference/lang_namespaces.html#behavior
compileFileList :: Preferences IO -> TopLevelType -> T.Text -> S.Either PrettyError T.Text
compileFileList prefs TopNode _ = S.Right (T.pack (prefs ^. manifestPath) <> "/site.pp")
compileFileList prefs _ name = moduleInfo
        moduleInfo | length nameparts == 1 = S.Right (mpath <> "/" <> name <> "/manifests/init.pp")
                   | null nameparts = S.Left "no name parts, error in compilefilelist"
                   | otherwise = S.Right (mpath <> "/" <> head nameparts <> "/manifests/" <> T.intercalate "/" (tail nameparts) <> ".pp")
        mpath = T.pack (prefs ^. modulesPath)
        nameparts = T.splitOn "::" name

parseFile :: FilePath -> IO (S.Either String (V.Vector Statement))
parseFile fname = do
    traceEventIO ("START parsing " ++ fname)
    cnt <- T.readFile fname
    o <- case runPParser puppetParser fname cnt of
        Right r -> traceEventIO ("Stopped parsing " ++ fname) >> return (S.Right r)
        Left rr -> traceEventIO ("Stopped parsing " ++ fname ++ " (failure: " ++ show rr ++ ")") >> return (S.Left (show rr))
    traceEventIO ("STOP parsing " ++ fname)
    return o