text: // Copyright 2017, Google, Inc.
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //    http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  const Spanner = require('@google-cloud/spanner');
  
  const spanner = Spanner();
  
  const instance = spanner.instance('quiz-instance');
  const database = instance.database('quiz-database');
  const table = database.table('feedback');
  
  
  function saveFeedback(
      { email, quiz, timestamp, rating, feedback, score }) {
      const rev_email = email
          .replace(/[@\.]/g, '_')
          .split('_')
          .reverse()
          .join('_');
      const record = {
          feedbackId: `${rev_email}_${quiz}_${timestamp}`,
          email,
          quiz,
          timestamp,
          rating,
          score,
          feedback,
      };
      console.log('Feedback saved');
      return table.insert(record);
  }
  
  
  module.exports = {
      saveFeedback
  };