'use strict';

const Promise = require('bluebird');
const filesize = require('filesize');

const AWS = require('aws-sdk');
// AWS.config.update({
//   accessKeyId: '',
//   secretAccessKey: '',
//   region: ''
// });
const s3 = new AWS.S3();
const cloudwatch = new AWS.CloudWatch();

const reducer = (acc, currVal) => acc + currVal;

async function go() {
  try {
    const data = await s3.listBuckets().promise();
    const names = data.Buckets.map(bucket => bucket.Name);
    const sizes = await Promise.mapSeries(names, async name => {
      try {
        const opts = {
          StartTime: new Date('2019-06-03T00:00:00'),
          EndTime: new Date('2019-06-13T00:00:00'),
          MetricName: 'BucketSizeBytes',
          Namespace: 'AWS/S3',
          Period: 86400 / 2,
          Dimensions: [{ Name: 'BucketName', Value: name }, { Name: 'StorageType', Value: 'StandardStorage' }],
          Statistics: ['Maximum']
        };
        const stats = await cloudwatch.getMetricStatistics(opts).promise();
        const points = stats.Datapoints;
        if (typeof points.pop() === 'undefined') {
          console.log(`${name} - ${filesize(0)}`);
          return 0;
        } else {
          console.log(`${name} - ${filesize(points.pop().Maximum)}`);
          return points.pop().Maximum;
        }
      } catch (e) {
        console.log(e);
      }
    });
    console.log(filesize(sizes.reduce(reducer)));
  } catch (e) {
    console.log(e);
  }
}

go(); // run