{-# LANGUAGE OverloadedStrings #-}
module Config(Configuration(..),defaultConfiguration,HttpConfiguration (..)) where
  
import Toml (TomlCodec, (.=))
import qualified Toml
import System.IO
import qualified Data.Text as T

-- this module should handle everything connected to our TOML config
#if defined(HTTP_SUPPORT) || defined(HTTPS_SUPPORT)
import Data.String
import qualified Network.Wai.Handler.Warp as HTTP
#endif

#ifdef HTTPS_SUPPORT
import qualified Network.Wai.Handler.WarpTLS as HTTPS
#endif

data Configuration = Configuration
  { cppDummy :: () -- this is a hack to get around the , rules of haskell records and the preprocessor
#ifdef HTTP_SUPPORT
  , httpConf :: [HttpConfiguration]
#endif
#ifdef HTTPS_SUPPORT
  , httpsConf :: [(HttpConfiguration,HttpsConfiguration)]
#endif
#ifdef FASTCGI_SUPPORT
  , fastCgiConf :: [FastCgiConfiguration]
#endif
#ifdef CGI_SUPPORT
  , cgiConf :: [CgiConfiguration]
#endif
  }

#if defined(HTTP_SUPPORT) || defined(HTTPS_SUPPORT)
-- We leave it as a Text here and defer the conversion to the warp type to the last possible moment.
-- At least we can touch and print a String. Excepet that we don't use it so we don't need it in another
-- form
type BindPreference = String

_BindPreference :: Toml.TomlBiMap BindPreference Toml.AnyValue
_BindPreference = Toml._String

bindPreference :: Toml.Key -> TomlCodec BindPreference
bindPreference = Toml.match _BindPreference

data HttpConfiguration = HttpConfiguration
  { port :: Int
  , bindPref :: BindPreference
  }
httpDefaultSettings :: HttpConfiguration
httpDefaultSettings = HttpConfiguration 80 "*"
#endif

#ifdef HTTPS_SUPPORT
data HttpsConfiguration = HttpsConfiguration
  { certFile :: FilePath
  , certChain :: [FilePath]
  , keyFile :: FilePath
  }
httpsDefaultSettings :: HttpsConfiguration
httpsDefaultSettings = HttpsConfiguration "certificate.pem" [] "key.pem"
#endif

#ifdef FASTCGI_SUPPORT
data FastCgiConfiguration = FastCgiConfiguration
#endif

#ifdef CGI_SUPPORT
data CgiConfiguration = CgiConfiguration
#endif

defaultConfiguration :: Configuration
defaultConfiguration = Configuration ()
#ifdef HTTP_SUPPORT
  [httpDefaultSettings]
#endif
#ifdef HTTPS_SUPPORT
  [(httpDefaultSettings,httpsDefaultSettings)]
#endif
#ifdef FASTCGI_SUPPORT
  [FastCgiConfiguration]
#endif
#ifdef CGI_SUPPORT
  [CgiConfiguration]
#endif

#if defined(HTTP_SUPPORT) || defined(HTTPS_SUPPORT)
-- why a String? Why is the only way to generate a HostPreference by its IsString instance?
-- why does warp not expose its constructors??
httpConfigConstructor :: Int -> String -> HTTP.Settings
httpConfigConstructor port bind = HTTP.setPort port $ HTTP.setHost (fromString bind) HTTP.defaultSettings
httpConfigCodec :: TomlCodec HttpConfiguration
httpConfigCodec = HttpConfiguration
  <$> Toml.int "Port"       .= port
  <*> bindPreference "Bind" .= bindPref
#endif

#ifdef HTTPS_SUPPORT
httpsConfigCodec :: TomlCodec (HttpConfiguration,HttpsConfiguration)
httpsConfigCodec = Toml.pair httpConfigCodec httpsConfigCodec'

httpsConfigCodec' :: TomlCodec HttpsConfiguration
httpsConfigCodec' = HttpsConfiguration
-- the hardcoded strings are a bloody hack, but we can't extract the values back out of a config (they are there
-- warp just doesn't export the neccesarry types). So we hardcode default values, which is kind of realy bad, but
-- we don't need it in our usecase
  <$> Toml.string "Certificate"             .= certFile
  <*> Toml.arrayOf Toml._String "CertChain" .= certChain
  <*> Toml.string "KeyFile"                 .= keyFile
#endif

#ifdef FASTCGI_SUPPORT
fastCgiConfigCodec :: TomlCodec FastCgiConfiguration
fastCgiConfigCodec = pure FastCgiConfiguration
#endif

#ifdef CGI_SUPPORT
cgiConfigCodec :: TomlCodec CgiConfiguration
cgiConfigCodec = pure CgiConfiguration
#endif

configurationCodec :: TomlCodec Configuration
configurationCodec = pure (Configuration ())
#ifdef HTTP_SUPPORT
  <*> Toml.list httpConfigCodec "http" .= httpConf
#endif
#ifdef HTTPS_SUPPORT
  <*> Toml.list httpsConfigCodec "https" .= httpsConf
#endif
#ifdef FASTCGI_SUPPORT
  <*> Toml.list fastCgiConfigCodec "fast-cgi" .= fastCgiConf
#endif
#ifdef CGI_SUPPORT
  <*> Toml.list cgiConfigCodec "cgi" .= cgiConf
#endif