text: /**
   * Copyright 2016, 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.
   */
  
  'use strict';
  
  const process = require('process'); // Required to mock environment variables
  
  // [START gae_flex_storage_app]
  const format = require('util').format;
  const express = require('express');
  const Multer = require('multer');
  const bodyParser = require('body-parser');
  
  // By default, the client will authenticate using the service account file
  // specified by the GOOGLE_APPLICATION_CREDENTIALS environment variable and use
  // the project specified by the GOOGLE_CLOUD_PROJECT environment variable. See
  // https://github.com/GoogleCloudPlatform/google-cloud-node/blob/master/docs/authentication.md
  // These environment variables are set automatically on Google App Engine
  const Storage = require('@google-cloud/storage');
  
  // Instantiate a storage client
  const storage = Storage();
  
  const app = express();
  app.set('view engine', 'pug');
  app.use(bodyParser.json());
  
  // Multer is required to process file uploads and make them available via
  // req.files.
  const multer = Multer({
    storage: Multer.memoryStorage(),
    limits: {
      fileSize: 5 * 1024 * 1024, // no larger than 5mb, you can change as needed.
    },
  });
  
  // A bucket is a container for objects (files).
  const bucket = storage.bucket(process.env.GCLOUD_STORAGE_BUCKET);
  
  // Display a form for uploading files.
  app.get('/', (req, res) => {
    res.render('form.pug');
  });
  
  // Process the file upload and upload to Google Cloud Storage.
  app.post('/upload', multer.single('file'), (req, res, next) => {
    if (!req.file) {
      res.status(400).send('No file uploaded.');
      return;
    }
  
    // Create a new blob in the bucket and upload the file data.
    const blob = bucket.file(req.file.originalname);
    const blobStream = blob.createWriteStream();
  
    blobStream.on('error', err => {
      next(err);
    });
  
    blobStream.on('finish', () => {
      // The public URL can be used to directly access the file via HTTP.
      const publicUrl = format(
        `https://storage.googleapis.com/${bucket.name}/${blob.name}`
      );
      res.status(200).send(publicUrl);
    });
  
    blobStream.end(req.file.buffer);
  });
  
  const PORT = process.env.PORT || 8080;
  app.listen(PORT, () => {
    console.log(`App listening on port ${PORT}`);
    console.log('Press Ctrl+C to quit.');
  });
  // [END gae_flex_storage_app]
  
  module.exports = app;
  