// Copyright 2017 Google LLC
//
// 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.

/**
 * Demonstrates how to authenticate to Google Cloud Platform APIs using the
 * Google Cloud Client Libraries.
 */

'use strict';

const authCloudImplicit = async () => {
  // [START auth_cloud_implicit]
  // Imports the Google Cloud client library.
  const {Storage} = require('@google-cloud/storage');

  // Instantiates a client. If you don't specify credentials when constructing
  // the client, the client library will look for credentials in the
  // environment.
  const storage = new Storage();

  try {
    // Makes an authenticated API request.
    const results = await storage.getBuckets();

    const [buckets] = results;

    console.log('Buckets:');
    buckets.forEach((bucket) => {
      console.log(bucket.name);
    });
  } catch (err) {
    console.error('ERROR:', err);
  }
  // [END auth_cloud_implicit]
};

const authCloudExplicit = async ({projectId, keyFilename}) => {
  // [START auth_cloud_explicit]
  // Imports the Google Cloud client library.
  const {Storage} = require('@google-cloud/storage');

  // Instantiates a client. Explicitly use service account credentials by
  // specifying the private key file. All clients in google-cloud-node have this
  // helper, see https://github.com/GoogleCloudPlatform/google-cloud-node/blob/master/docs/authentication.md
  // const projectId = 'project-id'
  // const keyFilename = '/path/to/keyfile.json'
  const storage = new Storage({projectId, keyFilename});

  // Makes an authenticated API request.
  try {
    const [buckets] = await storage.getBuckets();

    console.log('Buckets:');
    buckets.forEach((bucket) => {
      console.log(bucket.name);
    });
  } catch (err) {
    console.error('ERROR:', err);
  }
  // [END auth_cloud_explicit]
};

const cli = require(`yargs`)
  .demand(1)
  .command(
    `auth-cloud-implicit`,
    `Loads credentials implicitly.`,
    {},
    authCloudImplicit
  )
  .command(
    `auth-cloud-explicit`,
    `Loads credentials explicitly.`,
    {
      projectId: {
        alias: 'p',
        default: process.env.GCLOUD_PROJECT,
      },
      keyFilename: {
        alias: 'k',
        default: process.env.GOOGLE_APPLICATION_CREDENTIALS,
      },
    },
    authCloudExplicit
  )
  .example(`node $0 implicit`, `Loads credentials implicitly.`)
  .example(`node $0 explicit`, `Loads credentials explicitly.`)
  .wrap(120)
  .recommendCommands()
  .epilogue(
    `For more information, see https://cloud.google.com/docs/authentication`
  )
  .help()
  .strict();

if (module === require.main) {
  cli.parse(process.argv.slice(2));
}