{-|

Module     : Application
Copyright  : Jonathan Lamothe
License    : GPL-3
Maintainer : jonathan@jlamothe.net

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

-}

{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE RecordWildCards #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Application
    ( getApplicationDev
    , appMain
    , develMain
    , makeFoundation
    , makeLogWare
    -- * for DevelMain
    , getApplicationRepl
    , shutdownApp
    -- * for GHCI
    , handler
    ) where

import Control.Monad.Logger                 (liftLoc)
import Import
import Language.Haskell.TH.Syntax           (qLocation)
import Network.HTTP.Client.TLS              (getGlobalManager)
import Network.Wai (Middleware)
import Network.Wai.Handler.Warp             (Settings, defaultSettings,
                                             defaultShouldDisplayException,
                                             runSettings, setHost,
                                             setOnException, setPort, getPort)
import Network.Wai.Middleware.RequestLogger (Destination (Logger),
                                             IPAddrSource (..),
                                             OutputFormat (..), destination,
                                             mkRequestLogger, outputFormat)
import System.Log.FastLogger                (defaultBufSize, newStdoutLoggerSet,
                                             toLogStr)

-- Import all relevant handler modules here.
-- Don't forget to add new modules to your cabal file!
import Handler.Common
import Handler.Home

-- This line actually creates our YesodDispatch instance. It is the second half
-- of the call to mkYesodData which occurs in Foundation.hs. Please see the
-- comments there for more details.
mkYesodDispatch "App" resourcesApp

-- | This function allocates resources (such as a database connection pool),
-- performs initialization and returns a foundation datatype value. This is also
-- the place to put your migrate statements to have automatic database
-- migrations handled by Yesod.
makeFoundation :: AppSettings -> IO App
makeFoundation appSettings = do
    -- Some basic initializations: HTTP connection manager, logger, and static
    -- subsite.
    appHttpManager <- getGlobalManager
    appLogger <- newStdoutLoggerSet defaultBufSize >>= makeYesodLogger
    appStatic <-
        (if appMutableStatic appSettings then staticDevel else static)
        (appStaticDir appSettings)

    -- Return the foundation
    return App {..}

-- | Convert our foundation to a WAI Application by calling @toWaiAppPlain@ and
-- applying some additional middlewares.
makeApplication :: App -> IO Application
makeApplication foundation = do
    logWare <- makeLogWare foundation
    -- Create the WAI application and apply middlewares
    appPlain <- toWaiAppPlain foundation
    return $ logWare $ defaultMiddlewaresNoLogging appPlain

makeLogWare :: App -> IO Middleware
makeLogWare foundation =
    mkRequestLogger def
        { outputFormat =
            if appDetailedRequestLogging $ appSettings foundation
                then Detailed True
                else Apache
                        (if appIpFromHeader $ appSettings foundation
                            then FromFallback
                            else FromSocket)
        , destination = Logger $ loggerSet $ appLogger foundation
        }


-- | Warp settings for the given foundation value.
warpSettings :: App -> Settings
warpSettings foundation =
      setPort (appPort $ appSettings foundation)
    $ setHost (appHost $ appSettings foundation)
    $ setOnException (\_req e ->
        when (defaultShouldDisplayException e) $ messageLoggerSource
            foundation
            (appLogger foundation)
            $(qLocation >>= liftLoc)
            "yesod"
            LevelError
            (toLogStr $ "Exception from Warp: " ++ show e))
      defaultSettings

-- | For yesod devel, return the Warp settings and WAI Application.
getApplicationDev :: IO (Settings, Application)
getApplicationDev = do
    (_, wsettings, app) <- getSettings
    return (wsettings, app)

getAppSettings :: IO AppSettings
getAppSettings = loadYamlSettings [configSettingsYml] [] useEnv

-- | main function for use by yesod devel
develMain :: IO ()
develMain = develMainHelper getApplicationDev

-- | The @main@ function for an executable running this site.
appMain :: IO ()
appMain = do
    -- Get the settings from all relevant sources
    settings <- loadYamlSettingsArgs
        -- fall back to compile-time values, set to [] to require values at runtime
        [configSettingsYmlValue]

        -- allow environment variables to override
        useEnv

    -- Generate the foundation from the settings
    foundation <- makeFoundation settings

    -- Generate a WAI Application from the foundation
    app <- makeApplication foundation

    -- Run the application with Warp
    runSettings (warpSettings foundation) app


--------------------------------------------------------------
-- Functions for DevelMain.hs (a way to run the app from GHCi)
--------------------------------------------------------------
getApplicationRepl :: IO (Int, App, Application)
getApplicationRepl = do
    (foundation, wsettings, app1) <- getSettings
    return (getPort wsettings, foundation, app1)

shutdownApp :: App -> IO ()
shutdownApp _ = return ()


---------------------------------------------
-- Functions for use in development with GHCi
---------------------------------------------

-- | Run a handler
handler :: Handler a -> IO a
handler h = getAppSettings >>= makeFoundation >>= flip unsafeHandler h

getSettings :: IO (App, Settings, Application)
getSettings = do
    settings <- getAppSettings
    foundation <- makeFoundation settings
    wsettings <- getDevSettings $ warpSettings foundation
    app <- makeApplication foundation
    return (foundation, wsettings, app)

--jl