[InstanceD [] (AppT (ConT Queryable) (ConT Lyrics))
  [FunD toURLParams
     [Clause [VarP r_2]
        (NormalB
           (ListE [InfixE (Just (LitE (StringL "lyrics_id")))
                          (VarE =.)
                          (Just (AppE (VarE lyricsLyricsId) (VarE r_2))),
                   InfixE (Just (LitE (StringL "text")))
                          (VarE =.)
                          (Just (AppE (VarE lyricsText) (VarE r_2)))]))
 []]]]

-- | Upload audio file 'fn' to VKontakte. Register optional 'artist'
-- and 'title' for it.
uploadAudio :: T.Text -> Maybe T.Text -> Maybe T.Text
               -> API s VKError (ActionResponse SavedAudio)
uploadAudio fn artist title = do
  (AR (UploadServer uploadURL)) <- toAPI GetUploadServer

  let msrv = uriToRoute <$> (parseURI $ T.unpack uploadURL)
  (srvURL, srvArgs, srvRoute) <- hoistEither $ note (mkError "bad upload url") msrv
  -- создаем запрос, файл будет послан в потоке
  let fnPart = partFileSource "file" $ T.unpack fn
      parts = Multipart $ (fnPart:srvArgs)
  mreq <- sendMultipart (basicBuilder "audioUpload" srvURL) srvRoute parts
  req <- hoistEither $ note (mkError "can't construct request") mreq
  -- посылаем запрос
  manager <- liftManager ask
  resp <- liftIO $ try $ httpLbs req manager
  res <- hoistEither $ first HTTPError resp
  -- парсим ответ в запрос 'Save' и добавляем файл в наш аккаунт
  save <- hoistEither $ receive res
  toAPI save{saveArtist = artist, saveTitle = title}
...

data Privacy = AllowAll
             | AllowFriends
             | AllowFriendsOfFriends
             | AllowFriendsOfFriendsOnly
             | AllowNobody
             | AllowOnlyMe
             | AllowList Int
             | AllowUser Int
             | DenyList Int
             | DenyUser Int
             deriving Show

instance FromJSON Privacy where
  parseJSON =
    withText "Privacy" doParse
    where
      doParse txt =
        case parse parser "" txt of
        Left _ -> mempty
        Right v -> pure v
      parser =
        try (string "friends_of_friends_only" >> return AllowFriendsOfFriendsOnly)
        <|> try (string "friends_of_friends" >> return AllowFriendsOfFriends)
        <|> (string "friends" >> return AllowFriends)
        <|> (string "nobody" >> return AllowNobody)
        <|> (string "only_me" >> return AllowOnlyMe)
        <|> (string "list" >> many1 digit >>= return . AllowList . read)
        <|> (many1 digit >>= return . AllowUser . read)
        <|> (string "all" >> return AllowAll)
        <|> (string "-" >>
             ((many1 digit >>= return . DenyUser . read)
              <|> (string "list" >> many1 digit >>= return . DenyList . read)))

spec :: Spec
spec = do
  describe "OAuth authorization" $ do
    it "doesn't ask for any permissions" $ do
      execVKAPI () (vksettings Nothing) getAuthToken
        >>= (`shouldSatisfy` checkAuthToken)
    it "asks for some permissions" $ do
      execVKAPI () (vksettings $ Just [Audio, Video]) getAuthToken
        >>= (`shouldSatisfy` checkAuthToken)
  where
    getAuthToken =
      liftState $ gets _vkAuthToken

checkAuthToken :: Either (APIError VKError) (Maybe AuthToken) -> Bool
checkAuthToken (Right (Just (AuthToken _ _ _))) = True
checkAuthToken _ = False

vksettings :: Maybe [AuthPermissions] -> VKSettings
vksettings scope = createSettings appId userName userPass scope

<div id={audioVolumeBarContainerId} ref="audioVolumeBarContainer" className="audio-volume-bar-container">
        <Button id={toggleBtnId} ref="toggleButton" bsSize="small" onClick={this.toggle}>
                <Glyphicon glyph={toggleIcon}/>
        </Button>
        <div className={audioVolumeBarClasses}>
                <div className="audio-volume-min-max" onClick={this.volumeToMax}>
                        <Glyphicon glyph="volume-up" />
                </div>
                <div ref="audioVolumePercentContainer" className="audio-volume-percent-container" onClick={this.adjustVolumeTo}>
                        <div className="audio-volume-percent" style={style}></div>
                </div>
                <div className="audio-volume-min-max" onClick={this.volumeToMin}>
                        <Glyphicon glyph="volume-off" />
                </div>
        </div>
</div>

div_ (("className" $= "audio-volume-bar-container"):mouseLeaveHlr) $ do
   bootstrap_ "Button" ["bsSize" $= "small"
                       , onClick toggleHlr
                       ] $
     bootstrap_ "Glyphicon" ["glyph" $= toggleIcon] mempty
   div_ ["className" $= classes] $ do
     div_ ["className" $= "audio-volume-min-max"
          , onClick (\_ _ ->
                      dispatch st (AdjustVolume $ fromFactor (1::Int)))] $
       bootstrap_ "Glyphicon" ["glyph" $= "volume-up"] mempty
     div_ ["className" $= "audio-volume-percent-container"
          , onClick adjustVolumeToHlr] $
       div_ ["className" $= "audio-volume-percent"
            , "style" @= style] mempty
     div_ ["className" $= "audio-volume-min-max"
          , onClick (\_ _ ->
                      dispatch st (AdjustVolume $ fromFactor (0::Int)))] $
       bootstrap_ "Glyphicon" ["glyph" $= "volume-off"] mempty

runAPI :: State -> VKAction -> VK.VKAPI ApiState a -> (a -> VKAction) -> IO ()
runAPI State{..} action apiAction hlr =
  void . forkIO $ do
    res <- runMaybeT $ do
      -- авторизованы ли мы?
      as <- hoistMaybe apiState
      _ <- hoistMaybe $ if VK.isAuthorized as then Just True else Nothing
      lift $ do
        -- AJAX в работе, покажем спиннер
        alterStore store (SetAjaxRunning True)
        -- выполняем запрос
        (res, nas) <- VK.runVKAPI as apiAction
        alterStore store (SetApiState nas)
        -- закончили, уберем спиннер
        alterStore store (SetAjaxRunning False)
        -- покажем ошибку или передадим результат обработчику
        either apiError handleAction res
    -- нужна авторизация, авторизуемся и повторим
    when (isNothing res) $
      alterStore store (Authorize action)
  where
    handleAction v = alterStore store (hlr v)

spec :: Spec
spec = session "VK application tests" $ using Chrome $ do
  it "login to Vkontakte with user credentials" $ runWD $ do
    dir <- liftIO getCurrentDirectory
    openPage $ "file://" ++ dir ++ "/example/vk.html"
    cw <- getCurrentWindow
    findElem (ByCSS "div.authorization > div.panel-body > a.btn") >>= click
    liftIO $ threadDelay 3000000
    ws <- windows
    length ws `shouldBe` 2
    let Just vkW = find (/= cw) ws
    focusWindow vkW
    findElem (ByName "email") >>= sendKeys userName
    findElem (ByName "pass") >>= sendKeys userPass
    findElem (ByCSS "form input.button") >>= click
    authUrl <- getCurrentURL
    closeWindow vkW

    focusWindow cw
    findElem (ByCSS "input.form-control") >>= sendKeys (T.pack authUrl)
    liftIO $ threadDelay 3000000
    findElem (ByCSS "button") >>= click
    liftIO $ threadDelay 3000000

  it "selects \"AnyAudio\"" $ runWD $ do
    findElem (ByCSS "a[href=\"#/audios/set-audio-selector/any-audio\"]") >>= click
    liftIO $ threadDelay 3000000
    pagerEls <- findElems (ByCSS "a[href^=\"#/audios/get-audio/\"]")
    length pagerEls `shouldBe` 11

    activeEls <- findElems (ByCSS "li.active a[href=\"#\"]")
    length activeEls `shouldBe` 1