78 lines
2.4 KiB
Haskell
78 lines
2.4 KiB
Haskell
{-# LANGUAGE FlexibleContexts #-}
|
|
{-# LANGUAGE DeriveDataTypeable #-}
|
|
module Web.Authenticate.Facebook where
|
|
|
|
import Network.HTTP.Enumerator
|
|
import Data.List (intercalate)
|
|
import Data.Aeson
|
|
import qualified Data.ByteString.Lazy.Char8 as L8
|
|
import Web.Authenticate.Internal (qsEncode)
|
|
import Data.Data (Data)
|
|
import Data.Typeable (Typeable)
|
|
import Control.Exception (Exception, throwIO)
|
|
import Data.Attoparsec.Lazy (parse, eitherResult)
|
|
import qualified Data.ByteString.Char8 as S8
|
|
|
|
data Facebook = Facebook
|
|
{ facebookClientId :: String
|
|
, facebookClientSecret :: String
|
|
, facebookRedirectUri :: String
|
|
}
|
|
deriving (Show, Eq, Read, Ord, Data, Typeable)
|
|
|
|
newtype AccessToken = AccessToken { unAccessToken :: String }
|
|
deriving (Show, Eq, Read, Ord, Data, Typeable)
|
|
|
|
getForwardUrl :: Facebook -> [String] -> String
|
|
getForwardUrl fb perms = concat
|
|
[ "https://graph.facebook.com/oauth/authorize?client_id="
|
|
, qsEncode $ facebookClientId fb
|
|
, "&redirect_uri="
|
|
, qsEncode $ facebookRedirectUri fb
|
|
, if null perms
|
|
then ""
|
|
else "&scope=" ++ qsEncode (intercalate "," perms)
|
|
]
|
|
|
|
accessTokenUrl :: Facebook -> String -> String
|
|
accessTokenUrl fb code = concat
|
|
[ "https://graph.facebook.com/oauth/access_token?client_id="
|
|
, qsEncode $ facebookClientId fb
|
|
, "&redirect_uri="
|
|
, qsEncode $ facebookRedirectUri fb
|
|
, "&client_secret="
|
|
, qsEncode $ facebookClientSecret fb
|
|
, "&code="
|
|
, qsEncode code
|
|
]
|
|
|
|
getAccessToken :: Facebook -> String -> IO AccessToken
|
|
getAccessToken fb code = do
|
|
let url = accessTokenUrl fb code
|
|
b <- simpleHttp $ S8.pack url
|
|
let (front, back) = splitAt 13 $ L8.unpack b
|
|
case front of
|
|
"access_token=" -> return $ AccessToken back
|
|
_ -> error $ "Invalid facebook response: " ++ back
|
|
|
|
graphUrl :: AccessToken -> String -> String
|
|
graphUrl (AccessToken s) func = concat
|
|
[ "https://graph.facebook.com/"
|
|
, func
|
|
, "?access_token="
|
|
, s
|
|
]
|
|
|
|
getGraphData :: AccessToken -> String -> IO (Either String Value)
|
|
getGraphData at func = do
|
|
let url = graphUrl at func
|
|
b <- simpleHttp $ S8.pack url
|
|
return $ eitherResult $ parse json b
|
|
|
|
getGraphData' :: AccessToken -> String -> IO Value
|
|
getGraphData' a b = getGraphData a b >>= either (throwIO . InvalidJsonException) return
|
|
|
|
data InvalidJsonException = InvalidJsonException String
|
|
deriving (Show, Typeable)
|
|
instance Exception InvalidJsonException
|