data InvitationError
  = InvitationExpired
  | InvitationAlreadyAccepted
  | InvitationNotFound
  deriving (Eq, Show)

  | InvitationExpired
  | InvitationAlreadyAccepted

  | InvitationError InvitationError

findInvitation :: (MonadDB m) => InvitationCode -> m (Maybe Invitation)
findInvitation ic = liftdb $ FindInvitation ic

findCurrentInvitation :: (MonadDB m) => C.UTCTime -> InvitationCode -> m (Either InvitationError Invitation)
findCurrentInvitation t ic =
  maybe (Left InvitationNotFound) checkInvitation <$> liftdb (FindInvitation ic)
  where
    checkInvitation i
      | t .-. (i ^. invitationTime) > fromSeconds (60 * 60 * 72 :: Int) = Left InvitationExpired
      | isJust (i ^. acceptanceTime) = Left InvitationAlreadyAccepted
      | otherwise = Right i

  inv <- findInvitation ic

  inv <- findCurrentInvitation t ic

    Nothing -> raiseSubjectNotFound act
    Just i
      | t .-. (i ^. invitationTime) > fromSeconds (60 * 60 * 72 :: Int) ->
        raiseOpForbidden uid InvitationExpired act
    Just i
      | isJust (i ^. acceptanceTime) ->
        raiseOpForbidden uid InvitationAlreadyAccepted act
    Just i -> withProjectAuth (i ^. P.projectId) (i ^. P.invitingUser) act

    Left InvitationNotFound -> raiseSubjectNotFound act
    Left InvitationExpired -> raiseOpForbidden uid (InvitationError InvitationExpired) act
    Left InvitationAlreadyAccepted -> raiseOpForbidden uid (InvitationError InvitationAlreadyAccepted) act
    Right i -> withProjectAuth (i ^. P.projectId) (i ^. P.invitingUser) act

  ALTER TABLE bids ADD COLUMN currency currency_t NOT NULL;

import Aftok.Database (acceptInvitation, createUser)

import Aftok.Database (acceptInvitation, createUser, findCurrentInvitation)

import Data.Text as T
import Data.Text.Encoding as T

import qualified Data.Text as T
import qualified Data.Text.Encoding as T

        _captchaToken :: Text,

        _captchaToken :: Maybe Text,

      <*> (v .: "captchaToken")
      <*> (parseInvitationCodes . maybeToList =<< v .:? "invitation_codes")

      <*> (v .:? "captchaToken")
      <*> (parseInvitationCodes . join . maybeToList =<< v .:? "invitation_codes")

  captchaResult <- liftIO $ checkCaptcha cfg (userData ^. captchaToken)
  case captchaResult of
    Left err ->
      let cmsg = "Captcha check failed, please try again."
       in snapErrorJS 400 cmsg (RegCaptchaError err)
    Right _ -> pure ()

  now <- liftIO C.getCurrentTime
  (_, invs) <- partitionEithers <$> snapEval (traverse (findCurrentInvitation now) (userData ^. invitationCodes))
  if null invs
    then checkCaptcha' (userData ^. captchaToken)
    else pure () -- skip the captcha check with a valid invitation code

  now <- liftIO C.getCurrentTime

  where
    checkCaptcha' = \case
      Just ct -> do
        captchaResult <- liftIO $ checkCaptcha cfg ct
        case captchaResult of
          Left err ->
            let cmsg = "Captcha check failed, please try again."
             in snapErrorJS 400 cmsg (RegCaptchaError err)
          Right _ -> pure ()
      Nothing ->
        let cmsg = "Captcha token or invitation code required."
         in snapErrorJS 400 cmsg ()

curl -k -v -H 'Content-Type: application/json' -d '{"username":"USER", "password":"PASS", "email":"$to_email$", "btcAddr":"BTC_ADDR", "invitation_codes":["$inv_code$"]}' 'https://aftok.com/register'

curl --header 'Content-Type: application/json' \\
     --data '{"username":"USER", "password":"PASS", "recoveryType": "email", "recoveryEmail":"$to_email$", "invitation_codes":["$inv_code$"]}' \\
     'https://aftok.com/api/register'