App.hs

-- | Look up user locally, then in brig, then return the 'UserId'.  If either lookup fails, return
-- 'Nothing'.  See also: 'Spar.App.createUser'.
--
-- ASSUMPTIONS: User creation on brig/galley is idempotent.  Any incomplete creation (because of
-- brig or galley crashing) will cause the lookup here to yield invalid user.
getUser :: SAML.UserRef -> Spar (Maybe UserId)
getUser uref = do
  muid <- wrapMonadClient $ Data.getUser uref
  case muid of
    Nothing -> pure Nothing
    Just uid -> Intra.confirmUserId uid

-- | Create a fresh 'Data.Id.UserId', store it on C* locally together with 'SAML.UserRef', then
-- create user on brig with that 'UserId'.  See also: 'Spar.App.getUser'.
--
-- The manual for the team admin should say this: when deleting a user, delete it on the IdP first,
-- then delete it on the team admin page in wire.  If a user is deleted in wire but not in the IdP,
-- it will be recreated on the next successful login attempt.
--
-- When an sso login succeeds for a user that is marked as deleted in brig, it is recreated by spar.
-- This is necessary because brig does not talk to spar when deleting users, and we may have
-- 'UserId' records on spar that are deleted on brig.  Without this lenient behavior, there would be
-- no way for admins to reuse a 'SAML.UserRef' if it has ever been associated with a deleted user in
-- the past.
--
-- FUTUREWORK: once we support <https://github.com/wireapp/hscim scim>, brig will refuse to delete
-- users that have an sso id, unless the request comes from spar.  then we can make users
-- undeletable in the team admin page, and ask admins to go talk to their IdP system.
createUser :: SAML.UserRef -> Spar UserId
createUser suid = do
  buid <- Id <$> liftIO UUID.nextRandom
  teamid <- (^. idpExtraInfo) <$> getIdPConfigByIssuer (suid ^. uidTenant)
  insertUser suid buid
  buid' <- Intra.createUser suid buid teamid
  assert (buid == buid') $ pure buid