Settings.hs

module Settings where

import ClassyPrelude.Yesod
import Control.Exception           (throw)
import Data.Aeson                  (Result (..), fromJSON, withObject, (.!=),
                                    (.:?))
import Data.FileEmbed              (embedFile)
import Data.Yaml                   (decodeEither')
import Database.Persist.Postgresql (PostgresConf)
import Language.Haskell.TH.Syntax  (Exp, Name, Q)
import Network.Wai.Handler.Warp    (HostPreference)
import Yesod.Default.Config2       (applyEnvValue)
import Yesod.Default.Util          (WidgetFileSettings, widgetFileNoReload,
                                    widgetFileReload)
import Settings.Config             (configPath)

data AppSettings = AppSettings
    { appStaticDir              :: String
    , appDatabaseConf           :: PostgresConf
    , appRoot                   :: Text
    , appHost                   :: HostPreference
    , appPort                   :: Int
    , appIpFromHeader           :: Bool
    , appDetailedRequestLogging :: Bool
    , appShouldLogAll           :: Bool
    , appReloadTemplates        :: Bool
    , appMutableStatic          :: Bool
    , appSkipCombining          :: Bool
    , appHeroku                 :: Bool
    , appOA2Providers           :: [OA2Provider]
    }

data OA2Provider = OA2Provider
    { oa2provider     :: String
    , oa2clientId     :: String
    , oa2clientSecret :: String
    }

instance FromJSON OA2Provider where
    parseJSON = withObject "OA2Provider" $ \o -> OA2Provider
        <$> o .: "provider"
        <*> o .: "id"
        <*> o .: "secret"

instance FromJSON AppSettings where
    parseJSON = withObject "AppSettings" $ \o -> do
        let defaultDev =
#if DEVELOPMENT
                True
#else
                False
#endif
        appStaticDir              <- o .: "static-dir"
        appDatabaseConf           <- o .: "database"
        appRoot                   <- o .: "approot"
        appHost                   <- fromString <$> o .: "host"
        appPort                   <- o .: "port"
        appIpFromHeader           <- o .: "ip-from-header"

        appHeroku                 <- o .: "heroku"

        appDetailedRequestLogging <- o .:? "detailed-logging" .!= defaultDev
        appShouldLogAll           <- o .:? "should-log-all"   .!= defaultDev
        appReloadTemplates        <- o .:? "reload-templates" .!= defaultDev
        appMutableStatic          <- o .:? "mutable-static"   .!= defaultDev
        appSkipCombining          <- o .:? "skip-combining"   .!= defaultDev

        appOA2Providers           <- o .:? "oauth2"           .!= []

        return AppSettings {..}

-- | Settings for 'widgetFile', such as which template languages to support and
-- default Hamlet settings.
--
-- For more information on modifying behavior, see:
--
-- https://github.com/yesodweb/yesod/wiki/Overriding-widgetFile
widgetFileSettings :: WidgetFileSettings
widgetFileSettings = def

-- | How static files should be combined.
combineSettings :: CombineSettings
combineSettings = def

-- The rest of this file contains settings which rarely need changing by a
-- user.

widgetFile :: String -> Q Exp
widgetFile = (if appReloadTemplates compileTimeAppSettings
                then widgetFileReload
                else widgetFileNoReload)
              widgetFileSettings

-- | Raw bytes at compile time of @config/settings.yml@
configSettingsYmlBS :: ByteString
configSettingsYmlBS = $(configPath >>= embedFile)

-- | @config/settings.yml@, parsed to a @Value@.
configSettingsYmlValue :: Value
configSettingsYmlValue = either throw id $ decodeEither' configSettingsYmlBS

-- | A version of @AppSettings@ parsed at compile time from @config/settings.yml@.
compileTimeAppSettings :: AppSettings
compileTimeAppSettings =
    case fromJSON $ applyEnvValue False mempty configSettingsYmlValue of
        Error e -> error e
        Success settings -> settings

-- The following two functions can be used to combine multiple CSS or JS files
-- at compile time to decrease the number of http requests.
-- Sample usage (inside a Widget):
--
-- > $(combineStylesheets 'StaticR [style1_css, style2_css])

combineStylesheets :: Name -> [Route Static] -> Q Exp
combineStylesheets = combineStylesheets'
    (appSkipCombining compileTimeAppSettings)
    combineSettings

combineScripts :: Name -> [Route Static] -> Q Exp
combineScripts = combineScripts'
    (appSkipCombining compileTimeAppSettings)
    combineSettings