const express = require('express');
const busboy = require('connect-busboy');
const path = require('path');
const fs = require('fs-extra');
const bodyParser = require('body-parser');
const crypto = require('crypto');
const conf = require('./config.js');
const stream = require('stream');
const fetch = require('node-fetch');

let aws_credentials = conf.aws_credentials;
let bitly_credentials = conf.bitly_credentials;
let isProduction = conf.env === 'production';

const AWS = require('aws-sdk');
const s3 = new AWS.S3();

const app = express();
const redis = require('redis');
const redis_client = redis.createClient();

redis_client.on('error', err => {
  console.log(err);
});

app.use(busboy());
app.use(bodyParser.json());
app.use(express.static(path.join(__dirname, '../public')));

app.get('/download/:id', (req, res) => {
  res.sendFile(path.join(__dirname + '/../public/download.html'));
});

app.get('/assets/download/:id', (req, res) => {
  let id = req.params.id;
  if (!validateID(id)) {
    res.sendStatus(404);
    return;
  }

  redis_client.hget(id, 'filename', (err, reply) => {
    // maybe some expiration logic too
    if (!reply) {
      res.sendStatus(404);
    } else {
      let params = {
        Bucket: aws_credentials.bucketName,
        Key: id
      };

      s3.headObject(params, function(err, data) {
        res.writeHead(200, {
          'Content-Disposition': 'attachment; filename=' + reply,
          'Content-Type': 'application/octet-stream',
          'Content-Length': data.ContentLength
        });
        let file_stream = s3.getObject(params).createReadStream();

        file_stream.on('finish', () => {
          redis_client.del(id);
          s3.deleteObject(params, function(err, data) {
            if (!err) {
              console.log('Deleted off s3.');
            }
          });
        });

        file_stream.pipe(res);
      });
    }
  });
});

app.post('/delete/:id', (req, res) => {
  let id = req.params.id;

  if (!validateID(id)) {
    res.send(404);
    return;
  }

  let delete_token = req.body.delete_token;

  if (!delete_token) {
    res.sendStatus(404);
  }

  redis_client.hget(id, 'delete', (err, reply) => {
    if (!reply || delete_token !== reply) {
      res.sendStatus(404);
    } else {
      redis_client.del(id);
      let params = {
        Bucket: aws_credentials.bucketName,
        Key: id
      };

      s3.deleteObject(params, function(err, data) {
        if (!err) {
          console.log('Deleted off s3.');
        }
      });

      res.sendStatus(200);
    }
  });
});

app.post('/upload/:id', (req, res, next) => {
  if (!validateID(req.params.id)) {
    res.send(404);
    return;
  }

  req.pipe(req.busboy);
  req.busboy.on('file', (fieldname, file, filename) => {
    console.log('Uploading: ' + filename);

    let params = {
      Bucket: aws_credentials.bucketName,
      Key: req.params.id,
      Body: file
    };

    s3.upload(params, function(err, data) {
      if (err) {
        console.log(err, err.stack); // an error occurred
      } else {
        let id = req.params.id;
        let uuid = crypto.randomBytes(10).toString('hex');

        redis_client.hmset([id, 'filename', filename, 'delete', uuid]);

        redis_client.expire(id, 86400000);
        console.log('Upload Finished of ' + filename);

        if (isProduction) {
          let url =
            req.protocol +
            `://` +
            req.get('host') +
            '/download/' +
            req.params.id +
            '/';
          fetch(
            'https://api-ssl.bitly.com/v3/shorten?access_token=' +
              bitly_credentials.api_key +
              '&longUrl=' +
              encodeURIComponent(url) +
              '&format=txt'
          )
            .then(res => {
              return res.text();
            })
            .then(body => {
              res.json({
                uuid: uuid,
                url: body
              });
            });
        } else {
          res.json({
            uuid: uuid,
            url: url
          });
        }
      }
    });
  });
});

let server = app.listen(3000, () => {
  console.log('Portal app listening on port 3000!');
});

let validateID = route_id => {
  return route_id.match(/^[0-9a-fA-F]{32}$/) !== null;
};

if (bitly_credentials.api_key === 'INSERT API KEY HERE') {
  throw new Error('Copy paste a bitly API key into server/config.js');
}