module Foundation where

import Import.NoFoundation hiding (requestHeaders)
import Database.Persist.Sql (ConnectionPool, runSqlPool)
import Text.Hamlet          (hamletFile)

import Yesod.Core.Types     (Logger)
import qualified Yesod.Core.Unsafe as Unsafe

import qualified Data.Text.Encoding                 as TE
import qualified Data.Text.Encoding.Error           as TEE

import Data.Map.Lazy (Map)
import qualified Data.Map.Lazy as Map

import Network.Wai (requestHeaders)

-- | The foundation datatype for your application. This can be a good place to
-- keep settings and values requiring initialization before your application
-- starts running, such as database connections. Every handler will have
-- access to the data present here.
data App = App
    { appSettings    :: AppSettings
    , appStatic      :: EmbeddedStatic
    , appConnPool    :: ConnectionPool -- ^ Database connection pool.
    , appHttpManager :: Manager
    , appLogger      :: Logger
    }

data MenuItem = MenuItem
    { menuItemLabel :: Text
    , menuItemRoute :: Route App
    }

-- This is where we define all of the routes in our application. For a full
-- explanation of the syntax, please see:
-- http://www.yesodweb.com/book/routing-and-handlers
--
-- Note that this is really half the story; in Application.hs, mkYesodDispatch
-- generates the rest of the code. Please see the following documentation
-- for an explanation for this split:
-- http://www.yesodweb.com/book/scaffolding-and-the-site-template#scaffolding-and-the-site-template_foundation_and_application_modules
--
-- This function also generates the following type synonyms:
-- type Handler = HandlerT App IO
-- type Widget = WidgetT App IO ()
mkYesodData "App" $(parseRoutesFile "config/routes")

-- | A convenient synonym for creating forms.
type Form x = Html -> MForm (HandlerT App IO) (FormResult x, Widget)

-- Please see the documentation for the Yesod typeclass. There are a number
-- of settings which can be configured by overriding methods here.
instance Yesod App where
    approot = ApprootRequest $ \_ req -> maybe "" (TE.decodeUtf8With TEE.lenientDecode) $ Map.lookup "AppRoot" (Map.fromList $ requestHeaders req)

    -- Store session data on the client in encrypted cookies,
    -- default session idle timeout is 120 minutes
    makeSessionBackend _ = Just <$> defaultClientSessionBackend
        120    -- timeout in minutes
        "client_session_key.aes"

    -- Yesod Middleware allows you to run code before and after each handler function.

    -- The defaultYesodMiddleware adds the response header "Vary: Accept, Accept-Language" and performs authorization checks.
    -- Some users may also want to add the defaultCsrfMiddleware, which:
    --   a) Sets a cookie with a CSRF token in it.
    --   b) Validates that incoming write requests include that token in either a header or POST parameter.
    -- To add it, chain it together with the defaultMiddleware: yesodMiddleware = defaultYesodMiddleware . defaultCsrfMiddleware
    -- For details, see the CSRF documentation in the Yesod.Core.Handler module of the yesod-core package.
    yesodMiddleware = defaultYesodMiddleware

    defaultLayout widget = do
        msgs <- getMessages

        mCurrentRoute <- getCurrentRoute

        -- Define the menu items of the header.
        let menuItems =
              [ MenuItem "Inventory" InventoryListingR
              , MenuItem "Reference" ReferenceListingR
              , MenuItem "List" ListR
              ]
            currentMenu = listToMaybe
              [ menuItemLabel
              | MenuItem{..} <- menuItems
              , Just menuItemRoute == mCurrentRoute
              ]

        -- We break up the default layout into two components:
        -- default-layout is the contents of the body tag, and
        -- default-layout-wrapper is the entire page. Since the final
        -- value passed to hamletToRepHtml cannot be a widget, this allows
        -- you to use normal widget features in default-layout.

        pc <- widgetToPageContent $ do
          setTitle . toHtml . maybe "Bar Inventory" ("Bar Inventory – " <>) $ do
            cM <- currentMenu
            guard $ cM /= "Inventory"
            return cM
          addScript $ StaticR jquery_js
          addScript $ StaticR webshim_polyfiller_js
          $(widgetFile "default-layout")
        withUrlRenderer $(hamletFile "templates/default-layout-wrapper.hamlet")


    -- This function creates static content files in the static folder
    -- and names them based on a hash of their content. This allows
    -- expiration dates to be set far in the future without worry of
    -- users receiving stale content.
    addStaticContent = embedStaticContent appStatic StaticR Right

    -- What messages should be logged. The following includes all messages when
    -- in development, and warnings and errors in production.
    shouldLog app _source level =
        appShouldLogAll (appSettings app)
            || level == LevelWarn
            || level == LevelError

    makeLogger = return . appLogger

    -- Provide proper Bootstrap styling for default displays, like
    -- error pages
    defaultMessageWidget title body = $(widgetFile "default-message-widget")

    cleanPath _ s = if corrected == s
                    then Right $ filter (not . null) s
                    else Left corrected
      where
        corrected = rds s

        rds [] = []
        rds [x] = [x]
        rds (x:y:ss)
          | null x
          , null y = rds (x:ss)
          | otherwise = x : rds (y:ss)

-- How to run database actions.
instance YesodPersist App where
    type YesodPersistBackend App = SqlBackend
    runDB action = do
        master <- getYesod
        runSqlPool action $ appConnPool master
instance YesodPersistRunner App where
    getDBRunner = defaultGetDBRunner appConnPool

-- This instance is required to use forms. You can modify renderMessage to
-- achieve customized and internationalized form validation messages.
instance RenderMessage App FormMessage where
    renderMessage _ _ = defaultFormMessage

-- Useful when writing code that is re-usable outside of the Handler context.
-- An example is background jobs that send email.
-- This can also be useful for writing code that works across multiple Yesod applications.
instance HasHttpManager App where
    getHttpManager = appHttpManager

unsafeHandler :: App -> Handler a -> IO a
unsafeHandler = Unsafe.fakeHandlerGetLogger appLogger

-- Note: Some functionality previously present in the scaffolding has been
-- moved to documentation in the Wiki. Following are some hopefully helpful
-- links:
--
-- https://github.com/yesodweb/yesod/wiki/Sending-email
-- https://github.com/yesodweb/yesod/wiki/Serve-static-files-from-a-separate-domain
-- https://github.com/yesodweb/yesod/wiki/i18n-messages-in-the-scaffolding