'use strict';

const Stream = require('stream');
const request = require('request');
const AWS = require('aws-sdk');

const s3 = new AWS.S3({apiVersion: '2006-03-01', region: 'ap-northeast-2'});

// fetch binary from `url` and upload to s3 using `key` as object key
const store = (url, key) => {
  return new Promise((resolve, reject) => {
    const patchedStream = new Stream.PassThrough();

    request({
      method: 'GET',
      url: url,
      encoding: null // returns body as Buffer
    }).on('error', (e) => {
      // something went wrong during fetch avatar.
      return reject(e);
    }).on('response', (res) => {
      if (res.statusCode.toString().slice(0, 1) !== '2') { // server respond with unexpected status code
        return reject(new Error(`Unexpected status code ${res.statusCode}`));
      }

      s3.upload({
        Bucket: process.env.S3_BUCKET,
        Key: key,
        ContentType: res.headers['content-type'] || 'application/octet-stream',
        Body: patchedStream // note that `res` is Readable Stream, not Buffer.
      }, (e, data) => {
        if (e) { return reject(e); }

        resolve(data);
      });
    }).pipe(patchedStream);
  });
};


module.exports = exports = store;