{-| 
Module      : Gargantext.API.Settings
Description : Settings of the API (Server and Client)
Copyright   : (c) CNRS, 2017-Present
License     : AGPL + CECILL v3
Maintainer  : team@gargantext.org
Stability   : experimental
Portability : POSIX
-}


{-# OPTIONS_GHC -fno-warn-name-shadowing #-}

{-# LANGUAGE NoImplicitPrelude           #-}
{-# LANGUAGE DataKinds                   #-}
{-# LANGUAGE DeriveGeneric               #-}
{-# LANGUAGE ScopedTypeVariables         #-}
{-# LANGUAGE TemplateHaskell             #-}
{-# LANGUAGE OverloadedStrings           #-}
{-# LANGUAGE FlexibleInstances           #-}

module Gargantext.API.Settings
    where

import System.Log.FastLogger
import GHC.Enum
import GHC.Generics (Generic)
import Prelude (Bounded())
import System.Environment (lookupEnv)
import System.IO (FilePath)
import Database.PostgreSQL.Simple (Connection, connect)
import Network.HTTP.Client (Manager)
import Network.HTTP.Client.TLS (newTlsManager)

import Data.Maybe (fromMaybe)
import Data.Either (either)
import Data.Text
import Data.Text.Encoding (encodeUtf8)
import Data.ByteString.Lazy.Internal

import Servant
import Servant.Client (BaseUrl, parseBaseUrl)
import Servant.Job.Async (newJobEnv, defaultSettings)
import Web.HttpApiData (parseUrlPiece)
import qualified Jose.Jwk as Jose
import qualified Jose.Jwa as Jose

import Control.Concurrent
import Control.Monad.Logger
import Control.Lens
import Gargantext.Prelude
import Gargantext.Database.Utils (databaseParameters, HasConnection(..))
import Gargantext.API.Ngrams (NgramsRepo, HasRepoVar(..), initRepo)
import Gargantext.API.Orchestrator.Types

type PortNumber = Int

data SendEmailType = SendEmailViaAws
                   | LogEmailToConsole
                   | WriteEmailToFile
    deriving (Show, Read, Enum, Bounded, Generic)


data Settings = Settings
    { _allowedOrigin   :: ByteString -- ^ allowed origin for CORS
    , _allowedHost     :: ByteString   -- ^ allowed host for CORS
    , _appPort         :: PortNumber
    , _logLevelLimit   :: LogLevel -- ^ log level from the monad-logger package
--    , _dbServer        :: Text
--    ^ this is not used yet
    , _jwtSecret       :: Jose.Jwk -- ^ key from the jose-jwt package
    , _sendLoginEmails :: SendEmailType
    , _scrapydUrl      :: BaseUrl
    }

makeLenses ''Settings


parseJwk :: Text -> Jose.Jwk
parseJwk secretStr = jwk
    where
        secretBs = encodeUtf8 secretStr
        jwk      = Jose.SymmetricJwk secretBs 
                                     Nothing 
                                     Nothing 
                                     (Just $ Jose.Signed Jose.HS256)

devSettings :: Settings
devSettings = Settings
    { _allowedOrigin = "http://localhost:8008"
    , _allowedHost = "localhost:3000"
    , _appPort = 3000
    , _logLevelLimit = LevelDebug
--    , _dbServer = "localhost"
    -- generate with dd if=/dev/urandom bs=1 count=32 | base64
    -- make sure jwtSecret differs between development and production, because you do not want
    -- your production key inside source control.
    , _jwtSecret = parseJwk "MVg0YAPVSPiYQc/qIs/rV/X32EFR0zOJWfHFgMbszMw="
    , _sendLoginEmails = LogEmailToConsole
    , _scrapydUrl = fromMaybe (panic "Invalid scrapy URL") $ parseBaseUrl "http://localhost:6800"
    }



reqSetting :: FromHttpApiData a => Text -> IO a
reqSetting name = do
    e <- fromMaybe (panic $ "Missing " <> name) <$> lookupEnv (unpack name)
    pure $ either (panic $ "Unable to parse " <> name) identity $ parseUrlPiece $ pack e

optSetting :: FromHttpApiData a => Text -> a -> IO a
optSetting name d = do
    me <- lookupEnv (unpack name)
    case me of
        Nothing -> pure d
        Just e -> pure $ either (panic $ "Unable to parse " <> name) identity $ parseUrlPiece $ pack e

--settingsFromEnvironment :: IO Settings
--settingsFromEnvironment =
--    Settings <$> (encodeUtf8 <$> reqSetting "ALLOWED_ORIGIN")
--             <*> (encodeUtf8 <$> reqSetting "ALLOWED_HOST")
--             <*> optSetting "PORT" 3000
--             <*> (parseLogLevel <$> optSetting "LOG_LEVEL" "warn")
--             <*> reqSetting "DB_SERVER"
--             <*> (parseJwk <$> reqSetting "JWT_SECRET")
--             <*> optSetting "SEND_EMAIL" SendEmailViaAws

data FireWall = FireWall { unFireWall :: Bool }

data Env = Env
  { _env_settings :: !Settings
  , _env_logger   :: !LoggerSet
  , _env_conn     :: !Connection
  , _env_repo_var :: !(MVar NgramsRepo)
  , _env_manager  :: !Manager
  , _env_self_url :: !BaseUrl
  , _env_scrapers :: !ScrapersEnv
  }
  deriving (Generic)

makeLenses ''Env

instance HasConnection Env where
  connection = env_conn

instance HasRepoVar Env where
  repoVar = env_repo_var

data MockEnv = MockEnv
  { _menv_firewall :: !FireWall
  }
  deriving (Generic)

makeLenses ''MockEnv

newEnv :: PortNumber -> FilePath -> IO Env
newEnv port file = do
  manager <- newTlsManager
  settings <- pure (devSettings & appPort .~ port) -- TODO read from 'file'
  when (port /= settings ^. appPort) $
    panic "TODO: conflicting settings of port"
  self_url <- parseBaseUrl $ "http://0.0.0.0:" <> show port
  param <- databaseParameters file
  conn <- connect param
  repo_var <- newMVar initRepo
  scrapers_env <- newJobEnv defaultSettings manager
  logger <- newStderrLoggerSet defaultBufSize
  pure $ Env
    { _env_settings = settings
    , _env_logger   = logger
    , _env_conn     = conn
    , _env_repo_var = repo_var
    , _env_manager  = manager
    , _env_scrapers = scrapers_env
    , _env_self_url = self_url
    }