diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright (c)2012, Felipe Lessa
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above
+ copyright notice, this list of conditions and the following
+ disclaimer in the documentation and/or other materials provided
+ with the distribution.
+
+ * Neither the name of Felipe Lessa nor the names of other
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/include/qq.h b/include/qq.h
new file mode 100644
--- /dev/null
+++ b/include/qq.h
@@ -0,0 +1,11 @@
+-- Stolen from yesod-auth.
+--
+-- CPP macro which choses which quasyquotes syntax to use depending
+-- on GHC version.
+--
+-- QQ stands for quasiquote.
+#if GHC7
+# define QQ(x) x
+#else
+# define QQ(x) $x
+#endif
diff --git a/src/Yesod/Auth/FB.hs b/src/Yesod/Auth/FB.hs
new file mode 100644
--- /dev/null
+++ b/src/Yesod/Auth/FB.hs
@@ -0,0 +1,142 @@
+module Yesod.Auth.FB
+ ( authFacebook
+ , facebookLogin
+ , facebookLogout
+ , getUserAccessToken
+ , setUserAccessToken
+ ) where
+
+#include "qq.h"
+import Control.Applicative ((<$>))
+import Control.Monad (when)
+import Control.Monad.IO.Class (MonadIO, liftIO)
+import Control.Monad.Trans.Class (lift)
+import Control.Monad.Trans.Maybe (MaybeT(..))
+import Data.Monoid (mappend)
+import Data.Text (Text)
+import Network.Wai (queryString)
+import Yesod.Auth
+import Yesod.Handler
+import Yesod.Widget
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
+import qualified Facebook as FB
+import qualified Network.HTTP.Conduit as H
+import qualified Yesod.Auth.Message as Msg
+
+
+-- | Route for login using this authentication plugin.
+facebookLogin :: AuthRoute
+facebookLogin = PluginR "fb" ["login"]
+
+
+-- | Route for logout using this authentication plugin. At the
+-- time of writing, Facebook's policies
+-- () specified that the
+-- user needs to be logged out from Facebook itself as well.
+facebookLogout :: AuthRoute
+facebookLogout = PluginR "fb" ["logout"]
+
+
+-- | Yesod authentication plugin using Facebook.
+authFacebook :: YesodAuth master
+ => FB.Credentials -- ^ Your application's credentials.
+ -> H.Manager -- ^ HTTP connection manager.
+ -> [FB.Permission] -- ^ Permissions to be requested.
+ -> AuthPlugin master
+authFacebook creds manager perms = AuthPlugin "fb" dispatch login
+ where
+ -- Get the URL in facebook.com where users are redirected to.
+ getRedirectUrl :: (YesodAuth master, Monad m) =>
+ (Route Auth -> Route master)
+ -> GGHandler sub master m Text
+ getRedirectUrl tm = do
+ render <- getUrlRender
+ let proceedUrl = render (tm proceedR)
+ return $ FB.getUserAccessTokenStep1 creds proceedUrl perms
+ proceedR = PluginR "fb" ["proceed"]
+
+ -- Redirect the user to Facebook.
+ dispatch "GET" ["login"] =
+ redirectText RedirectTemporary =<< getRedirectUrl =<< getRouteToMaster
+ -- Take Facebook's code and finish authentication.
+ dispatch "GET" ["proceed"] = do
+ tm <- getRouteToMaster
+ render <- getUrlRender
+ query <- queryString <$> waiRequest
+ let proceedUrl = render (tm proceedR)
+ query' = [(a,b) | (a, Just b) <- query]
+ token <- liftIO $
+ FB.runFacebookT creds manager $
+ FB.getUserAccessTokenStep2 proceedUrl query'
+ setUserAccessToken token
+ setCreds True (createCreds token)
+ -- Logout the user from our site and from Facebook.
+ dispatch "GET" ["logout"] = do
+ m <- getYesod
+ tm <- getRouteToMaster
+ mtoken <- getUserAccessToken
+ when (redirectToReferer m) setUltDestReferer
+
+ -- Facebook doesn't redirect back to our chosen address
+ -- when the user access token is invalid, so we need to
+ -- check its validity before anything else.
+ let isValid = liftIO .
+ FB.runNoAuthFacebookT manager .
+ FB.isValid
+ valid <- maybe (return False) isValid mtoken
+
+ case (valid, mtoken) of
+ (True, Just token) -> do
+ render <- getUrlRender
+ redirectText RedirectTemporary $
+ FB.getUserLogoutUrl token (render $ tm LogoutR)
+ _ -> redirect RedirectTemporary (tm LogoutR)
+ -- Anything else gives 404
+ dispatch _ _ = notFound
+
+ -- Small widget for multiple login websites.
+ login :: YesodAuth master =>
+ (Route Auth -> Route master)
+ -> GWidget sub master ()
+ login tm = do
+ redirectUrl <- lift (getRedirectUrl tm)
+ [QQ(whamlet)|
+
+ _{Msg.Facebook}
+|]
+
+
+-- | Create an @yesod-auth@'s 'Creds' for a given
+-- @'FB.AccessToken' 'FB.User'@.
+createCreds :: FB.UserAccessToken -> Creds m
+createCreds (FB.UserAccessToken userId _ _) = Creds "fb" id_ []
+ where id_ = "http://graph.facebook.com/" `mappend` TE.decodeUtf8 userId
+
+
+-- | Set the Facebook's user access token on the user's session.
+-- Usually you don't need to call this function, but it may
+-- become handy together with 'FB.extendUserAccessToken'.
+setUserAccessToken :: MonadIO m =>
+ FB.UserAccessToken
+ -> GGHandler sub master m ()
+setUserAccessToken (FB.UserAccessToken userId data_ exptime) = do
+ setSession "_FBID" (TE.decodeUtf8 userId)
+ setSession "_FBAT" (TE.decodeUtf8 data_)
+ setSession "_FBET" (T.pack $ show exptime)
+
+
+-- | Get the Facebook's user access token from the session.
+-- Returns @Nothing@ if it's not found (probably because the user
+-- is not logged in via @yesod-auth-fb@). Note that the returned
+-- access token may have expired, we recommend using
+-- 'FB.hasExpired' and 'FB.isValid'.
+getUserAccessToken :: MonadIO mo =>
+ GGHandler sub master mo (Maybe FB.UserAccessToken)
+getUserAccessToken = runMaybeT $ do
+ userId <- MaybeT $ lookupSession "_FBID"
+ data_ <- MaybeT $ lookupSession "_FBAT"
+ exptime <- MaybeT $ lookupSession "_FBET"
+ return $ FB.UserAccessToken (TE.encodeUtf8 userId)
+ (TE.encodeUtf8 data_)
+ (read $ T.unpack exptime)
diff --git a/yesod-auth-fb.cabal b/yesod-auth-fb.cabal
new file mode 100644
--- /dev/null
+++ b/yesod-auth-fb.cabal
@@ -0,0 +1,48 @@
+Name: yesod-auth-fb
+Version: 0.0
+Synopsis: [PREVIEW] Authentication backend for Yesod using Facebook.
+Homepage: https://github.com/meteficha/yesod-auth-fb
+License: BSD3
+License-file: LICENSE
+Author: Felipe Lessa, Michael Snoyman
+Maintainer: Felipe Lessa
+Category: Web
+Build-type: Simple
+Cabal-version: >= 1.6
+Extra-source-files: include/qq.h, README
+
+Description:
+ /THIS IS A PREVIEW RELEASE!/
+ .
+ This package allows you to use Yesod's authentication framework
+ with Facebook as your backend. That is, your site's users will
+ log in to your site through Facebook. Your application need to
+ be registered on Facebook.
+
+Source-repository head
+ type: git
+ location: git://github.com/meteficha/yesod-auth-fb.git
+
+flag ghc7
+
+Library
+ hs-source-dirs: src
+
+ if flag(ghc7)
+ Cpp-options: -DGHC7
+ Build-depends: base >= 4.3 && < 5
+ else
+ Build-depends: base >= 4 && < 4.3
+
+ Build-depends: yesod-core >= 0.9 && < 0.10
+ , yesod-auth >= 0.7 && < 0.8
+ , wai
+ , http-conduit
+ , text >= 0.7 && < 0.12
+ , transformers >= 0.1.3 && < 0.3
+ , fb >= 0.6.0.1 && < 0.7
+
+ Exposed-modules: Yesod.Auth.FB
+ Extensions: GADTs QuasiQuotes CPP OverloadedStrings
+ GHC-options: -Wall
+ Include-dirs: include