eidolon/Application.hs

--  eidolon -- A simple gallery in Haskell and Yesod
--  Copyright (C) 2015  Amedeo Molnár
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU Affero 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 Affero General Public License for more details.
--
--  You should have received a copy of the GNU Affero General Public License
--  along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# OPTIONS_GHC -fno-warn-orphans #-}
module Application
    ( getApplicationDev
    , makeFoundation
    , develMain
    , appMain
    ) where

import Import
import Yesod.Default.Config2
import Yesod.Default.Handlers
import Database.Persist.Sql (runMigration)
import Network.HTTP.Client.Conduit (newManager)
import Control.Monad
import System.Log.FastLogger (newStdoutLoggerSet, defaultBufSize, toLogStr)
import Data.Default (def)
import Yesod.Core.Types (loggerSet)

import Control.Monad.Logger                 (liftLoc, runLoggingT)
import Database.Persist.Postgresql          (createPostgresqlPool, runSqlPool,
                                             pgConnStr, pgPoolSize)
import Language.Haskell.TH.Syntax           (qLocation)
import Network.Wai.Handler.Warp             (Settings, defaultSettings,
                                             defaultShouldDisplayException,
                                             runSettings, setHost,
                                             setOnException, setPort)
import Network.Wai.Middleware.RequestLogger (Destination (Logger),
                                             IPAddrSource (..),
                                             OutputFormat (..), destination,
                                             mkRequestLogger, outputFormat)

-- Import all relevant handler modules here.
-- Don't forget to add new modules to your cabal file!
import Handler.Home
import Handler.Login
import Handler.Profile
import Handler.Upload
import Handler.NewAlbum
import Handler.Album
import Handler.Medium
import Handler.AlbumSettings
import Handler.MediumSettings
import Handler.ProfileSettings
import Handler.ProfileDelete
import Handler.Admin
import Handler.AdminProfileSettings
import Handler.AdminAlbumSettings
import Handler.AdminMediumSettings
import Handler.AdminComments
import Handler.Tag
import Handler.RootFeed
import Handler.Search
import Handler.About

-- 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 return 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 <- newManager
    appLogger <- newStdoutLoggerSet defaultBufSize >>= makeYesodLogger
    appStatic <-
        (if appMutableStatic appSettings then staticDevel else static)
        (appStaticDir appSettings)

    -- We need a log function to create a connection pool. We need a connection
    -- pool to create our foundation. And we need our foundation to get a
    -- logging function. To get out of this loop, we initially create a
    -- temporary foundation without a real connection pool, get a log function
    -- from there, and then create the real foundation.
    let mkFoundation appConnPool = App {..}
        tempFoundation = mkFoundation $ error "connPool forced in tempFoundation"
        logFunc = messageLoggerSource tempFoundation appLogger

    -- Create the database connection pool
    pool <- flip runLoggingT logFunc $ createPostgresqlPool
        (pgConnStr $ appDatabaseConf appSettings)
        (pgPoolSize $ appDatabaseConf appSettings)

    -- Perform database migration using our application's logging settings.
    runLoggingT (runSqlPool (runMigration migrateAll) pool) logFunc

    -- Return the foundation
    return $ mkFoundation pool

-- | Convert our foundation to a WAI Application by calling @toWaiAppPlain@ and
-- applyng some additional middlewares.
makeApplication :: App -> IO Application
makeApplication foundation = do
    logWare <- 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
        }

    -- Create the WAI application and apply middlewares
    appPlain <- toWaiAppPlain foundation
    return $ logWare $ defaultMiddlewaresNoLogging appPlain

-- | 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
    settings <- loadYamlSettings [configSettingsYml] [] useEnv
    foundation <- makeFoundation settings
    app <- makeApplication foundation
    wsettings <- getDevSettings $ warpSettings foundation
    return (wsettings, app)

-- | 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