{-# LANGUAGE CPP #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

-- | The monad used for the command-line executable @stack@.

module Stack.Types.StackT
  (StackT
  ,StackLoggingT
  ,runStackT
  ,runStackLoggingT
  ,newTLSManager)
  where

import           Control.Applicative
import           Control.Monad.Base
import           Control.Monad.Catch
import           Control.Monad.IO.Class
import           Control.Monad.Logger
import           Control.Monad.Reader
import           Control.Monad.Trans.Control
import qualified Data.ByteString.Char8 as S8
import           Data.Char
import           Data.Text (Text)
import           Data.Time
import           Language.Haskell.TH.Syntax (Loc(..))
import           Network.HTTP.Client.Conduit (HasHttpManager(..))
import           Network.HTTP.Conduit
import           Prelude -- Fix AMP warning
import           Stack.Types.Internal
import           System.Log.FastLogger

#ifndef MIN_VERSION_time
#define MIN_VERSION_time(x, y, z) 0
#endif
#if !MIN_VERSION_time(1, 5, 0)
import           System.Locale
#endif

--------------------------------------------------------------------------------
-- Main StackT monad transformer

-- | The monad used for the executable @stack@.
newtype StackT config m a =
  StackT {unStackT :: ReaderT (Env config) m a}
  deriving (Functor,Applicative,Monad,MonadIO,MonadReader (Env config),MonadThrow,MonadCatch,MonadMask,MonadTrans)

deriving instance (MonadBase b m) => MonadBase b (StackT config m)

instance MonadBaseControl b m => MonadBaseControl b (StackT config m) where
    type StM (StackT config m) a = ComposeSt (StackT config) m a
    liftBaseWith     = defaultLiftBaseWith
    restoreM         = defaultRestoreM

instance MonadTransControl (StackT config) where
    type StT (StackT config) a = StT (ReaderT (Env config)) a
    liftWith = defaultLiftWith StackT unStackT
    restoreT = defaultRestoreT StackT

-- | Takes the configured log level into account.
instance (MonadIO m) => MonadLogger (StackT config m) where
  monadLoggerLog = loggerFunc

-- | Run a Stack action.
runStackT :: (MonadIO m,MonadBaseControl IO m)
          => Manager -> LogLevel -> config -> StackT config m a -> m a
runStackT manager logLevel config m =
     runReaderT (unStackT m)
                (Env config logLevel manager)

--------------------------------------------------------------------------------
-- Logging only StackLoggingT monad transformer

-- | The monad used for logging in the executable @stack@ before
-- anything has been initialized.
newtype StackLoggingT m a =
  StackLoggingT {unStackLoggingT :: ReaderT (LogLevel,Manager) m a}
  deriving (Functor,Applicative,Monad,MonadIO,MonadThrow,MonadReader (LogLevel,Manager),MonadCatch,MonadMask,MonadTrans)

deriving instance (MonadBase b m) => MonadBase b (StackLoggingT m)

instance MonadBaseControl b m => MonadBaseControl b (StackLoggingT m) where
    type StM (StackLoggingT m) a = ComposeSt StackLoggingT m a
    liftBaseWith     = defaultLiftBaseWith
    restoreM         = defaultRestoreM

instance MonadTransControl StackLoggingT where
    type StT StackLoggingT a = StT (ReaderT (LogLevel,Manager)) a
    liftWith = defaultLiftWith StackLoggingT unStackLoggingT
    restoreT = defaultRestoreT StackLoggingT

-- | Takes the configured log level into account.
instance (MonadIO m) => MonadLogger (StackLoggingT m) where
  monadLoggerLog = loggerFunc

instance HasLogLevel (LogLevel,Manager) where
  getLogLevel = fst

instance HasHttpManager (LogLevel,Manager) where
  getHttpManager = snd

-- | Run the logging monad.
runStackLoggingT :: MonadIO m
                 => Manager -> LogLevel -> StackLoggingT m a -> m a
runStackLoggingT manager logLevel m =
     runReaderT (unStackLoggingT m)
                (logLevel,manager)

-- | Convenience for getting a 'Manager'
newTLSManager :: MonadIO m => m Manager
newTLSManager = liftIO $ newManager conduitManagerSettings

--------------------------------------------------------------------------------
-- Logging functionality

-- | Logging function takes the log level into account.
loggerFunc :: (MonadIO m,ToLogStr msg,MonadReader r m,HasLogLevel r)
           => Loc -> Text -> LogLevel -> msg -> m ()
loggerFunc loc _src level msg =
  do maxLogLevel <- asks getLogLevel
     when (level >= maxLogLevel)
          (liftIO (do out <- getOutput maxLogLevel
                      S8.putStrLn (S8.pack out)))
  where getOutput maxLogLevel =
          do date <- getDate
             l <- getLevel
             lc <- getLoc
             return (date ++ l ++ S8.unpack (fromLogStr (toLogStr msg)) ++ lc)
          where getDate
                  | maxLogLevel <= LevelDebug =
                    do now <- getCurrentTime
                       return (formatTime defaultTimeLocale "%Y-%m-%d %T%Q" now ++
                               ": ")
                  | otherwise = return ""
                getLevel
                  | maxLogLevel <= LevelDebug =
                    return ("[" ++
                            map toLower (drop 5 (show level)) ++
                            "] ")
                  | otherwise = return ""
                getLoc
                  | maxLogLevel <= LevelDebug =
                    return (" @(" ++ fileLocStr ++ ")")
                  | otherwise = return ""
                fileLocStr =
                  (loc_package loc) ++
                  ':' :
                  (loc_module loc) ++
                  ' ' :
                  (loc_filename loc) ++
                  ':' :
                  (line loc) ++
                  ':' :
                  (char loc)
                  where line = show . fst . loc_start
                        char = show . snd . loc_start