/**
 * This gist was inspired from https://gist.github.com/homam/8646090 which I wanted to work when uploading an image from
 * a base64 string.
 * Updated to use Promise (bluebird)
 * Web: https://mayneweb.com
 *
 * @param  {string}  base64 Data
 * @return {string}  Image url
 */
const imageUpload = async (base64) => {
  
  // You can either "yarn add aws-sdk" or "npm i aws-sdk"
  const AWS = require('aws-sdk');

  // Configure AWS with your access and secret key.
  const { ACCESS_KEY_ID, SECRET_ACCESS_KEY, AWS_REGION, S3_BUCKET } = process.env;

  // Configure AWS to use promise
  AWS.config.setPromisesDependency(require('bluebird'));
  AWS.config.update({ accessKeyId: ACCESS_KEY_ID, secretAccessKey: SECRET_ACCESS_KEY, region: AWS_REGION });

  // Create an s3 instance
  const s3 = new AWS.S3();

  // Ensure that you POST a base64 data to your server.
  // Let's assume the variable "base64" is one.
  const base64Data = new Buffer.from(base64.replace(/^data:image\/\w+;base64,/, ""), 'base64');

  // Getting the file type, ie: jpeg, png or gif
  const type = base64.split(';')[0].split('/')[1];

  // Generally we'd have an userId associated with the image
  // For this example, we'll simulate one
  const userId = 1;

  // With this setup, each time your user uploads an image, will be overwritten.
  // To prevent this, use a different Key each time.
  // This won't be needed if they're uploading their avatar, hence the filename, userAvatar.js.
  const params = {
    Bucket: S3_BUCKET,
    Key: `${userId}.${type}`, // type is not required
    Body: base64Data,
    ACL: 'public-read',
    ContentEncoding: 'base64', // required
    ContentType: `image/${type}` // required. Notice the back ticks
  }

  // The upload() is used instead of putObject() as we'd need the location url and assign that to our user profile/database
  // see: http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#upload-property
  let location = '';
  let key = '';
  try {
    const { Location, Key } = await s3.upload(params).promise();
    location = Location;
    key = Key;
  } catch (error) {
     // console.log(error)
  }
  
  // Save the Location (url) to your database and Key if needs be.
  // As good developers, we should return the url and let other function do the saving to database etc
  console.log(location, key);
  
  return location;
  
  // To delete, see: https://gist.github.com/SylarRuby/b3b1430ca633bc5ffec29bbcdac2bd52
}

module.exports = imageUpload;