public function mask_as_user() {
    $this->load->model('User_model', '', true);

    $email = $this->input->post('email');

    //there should be some front-end validation here too, but if not permitter, dont allow this to proceed.
    if (strpos($this->session->userdata('user_type'), 'permitter') === false) {
        $return['status'] = 'error';
        $return['message']= 'You are not an admin.';
        header('Content-type: application/json');
        echo json_encode($return);
        return false;
    }

    //save the current admin account, so we know where to switch back to
    $admin_account_email = $this->session->userdata('user_email');

    //logout current user to not have overlapping session data
    //$this->logout(false, true);

    $user_data = $this->User_model->get_user_data($email);

    if ($user_data[0]){
        $user_data = $this->clean_user_data($user_data[0]);
    }
    else{
        $return['status'] = 'error';
        $return['message']= 'This is not an active client account.';
        header('Content-type: application/json');
        echo json_encode($return);
        return false;
    }
    //get userdata for user-mask account and remove unneccessary data (such as login credentials) from session array

    //prevent switching into admin accounts. Not really any sensitive data that the rest of the company can't access elsewhere, but maybe someday there will be.
    if (strpos($user_data['user_type'], 'permitter') !== false) {
        $return['status'] = 'error';
        $return['message']= 'You cannot switch into an admin account.';
        header('Content-type: application/json');
        echo json_encode($return);
        return false;
    }

    //foreach column loaded from database, create a session value.
    $this->session->set_userdata($user_data);

    //set user to loggedin.
    $this->session->set_userdata('loggedin', TRUE);

    //set the current admin account which the mask is being applied to. We will need this for returning back to the admin account without having to logout.
    $this->session->set_userdata('admin_account_email', $admin_account_email);

    $return['status'] = 'success';
    $return['redir_url'] = '/site_client/dashboard';

    header('Content-type: application/json');
    echo json_encode($return);

}