Code-Example-Jett

    @IBAction func signInTapped(_ sender: AnyObject) {

        if let email = emailField.text, let pwd = pwdField.text {
            FIRAuth.auth()?.signIn(withEmail: email, password: pwd, completion: { (user, error) in
                if error == nil {
                    print("JETT: Email user authenticated with Firebase")
                    if let user = user {
                        let userData = ["provider": user.providerID,
                                        "uid": user.uid]
                        self.completeSignIn(id: user.uid, userData: userData)
                    }
                } else {
                    FIRAuth.auth()?.createUser(withEmail: email, password: pwd, completion: { (user, error) in
                        if error != nil {
                            print("JETT: Unable to authenticate with Firebase using email")
                        } else {
                            print("JETT: Successfully Authenticated with Firebase")
                            if let user = user {
                                let userData = ["provider": user.providerID,
                                                "uid": user.uid]
                                self.completeSignIn(id: user.uid, userData: userData)
                            }
                        }
                    })
                }
            })
        }

    }