{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell   #-}

{-

This is basically very manual test. Check following link for details.

Google web oauth: https://developers.google.com/accounts/docs/OAuth2WebServer

Google OAuth 2.0 playround: https://developers.google.com/oauthplayground/

-}

module Main where

import           Keys                          (googleKey)
import           Network.OAuth.OAuth2

import           Control.Monad                 (liftM)
import           Data.Aeson                    (FromJSON)
import           Data.Aeson.TH                 (defaultOptions, deriveJSON)
import qualified Data.ByteString.Char8         as BS
import qualified Data.ByteString.Lazy.Internal as BL
import           Data.Text                     (Text)
import           Network.HTTP.Conduit
import           Prelude                       hiding (id)
import           System.Environment            (getArgs)

--------------------------------------------------

data Token = Token { issued_to   :: Text
                   , audience    :: Text
                   , user_id     :: Maybe Text
                   , scope       :: Text
                   , expires_in  :: Integer
                   , access_type :: Text
                   } deriving (Show)


$(deriveJSON defaultOptions ''Token)

data User = User { id          :: Text
                 , name        :: Text
                 , given_name  :: Text
                 , family_name :: Text
                 , link        :: Text
                 , picture     :: Text
                 , gender      :: Text
                 , locale      :: Text
                 } deriving (Show)

$(deriveJSON defaultOptions ''User)

--------------------------------------------------

main :: IO ()
main = do
    xs <- getArgs
    mgr <- newManager tlsManagerSettings
    case xs of
        ["offline"] -> offlineCase mgr
        _ -> normalCase mgr

offlineCase :: Manager -> IO ()
offlineCase mgr = do
    BS.putStrLn $ authorizationUrl googleKey `appendQueryParam` (googleScopeEmail ++ googleAccessOffline)
    putStrLn "visit the url and paste code here: "
    code <- fmap BS.pack getLine
    (Right token) <- fetchAccessToken mgr googleKey code
    f token
    --
    -- obtain a new access token with refresh token, which turns out only in response at first time.
    -- Revoke Access https://www.google.com/settings/security
    --
    case refreshToken token of
        Nothing -> putStrLn "Failed to fetch refresh token"
        Just tk -> do
            (Right token') <- fetchRefreshToken mgr googleKey tk
            f token'
            --validateToken accessToken >>= print
            --(validateToken' accessToken :: IO (OAuth2Result Token)) >>= print
    where f token = do
            print token
            validateToken mgr token >>= print
            (validateToken' mgr token :: IO (OAuth2Result Token)) >>= print

normalCase :: Manager -> IO ()
normalCase mgr = do
    BS.putStrLn $ authorizationUrl googleKey `appendQueryParam` googleScopeUserInfo
    putStrLn "visit the url and paste code here: "
    code <- fmap BS.pack getLine
    (Right token) <- fetchAccessToken mgr googleKey code
    putStr "AccessToken: " >> print token
    -- get response in ByteString
    validateToken mgr token >>= print
    -- get response in JSON
    (validateToken' mgr token :: IO (OAuth2Result Token)) >>= print
    -- get response in ByteString
    userinfo mgr token >>= print
    -- get response in JSON
    (userinfo' mgr token :: IO (OAuth2Result User)) >>= print

--------------------------------------------------
-- Google API

-- | This is special for google Gain read-only access to the user's email address.
googleScopeEmail :: QueryParams
googleScopeEmail = [("scope", "https://www.googleapis.com/auth/userinfo.email")]

-- | Gain read-only access to basic profile information, including a
googleScopeUserInfo :: QueryParams
googleScopeUserInfo = [("scope", "https://www.googleapis.com/auth/userinfo.profile")]

-- | Access offline
googleAccessOffline :: QueryParams
googleAccessOffline = [("access_type", "offline")
                      ,("approval_prompt", "force")]

-- | Token Validation
validateToken :: Manager
                 -> AccessToken
                 -> IO (OAuth2Result BL.ByteString)
validateToken mgr token =
   authGetBS' mgr token url
   where url = "https://www.googleapis.com/oauth2/v1/tokeninfo"

validateToken' :: FromJSON a
                  => Manager
                  -> AccessToken
                  -> IO (OAuth2Result a)
validateToken' mgr token = liftM parseResponseJSON $ validateToken mgr token

-- | fetch user email.
--   for more information, please check the playround site.
--
userinfo :: Manager
            -> AccessToken
            -> IO (OAuth2Result BL.ByteString)
userinfo mgr token = authGetBS mgr token "https://www.googleapis.com/oauth2/v2/userinfo"

userinfo' :: FromJSON a
             => Manager
             -> AccessToken
             -> IO (OAuth2Result a)
userinfo' mgr token = authGetJSON mgr token "https://www.googleapis.com/oauth2/v2/userinfo"