send/app.js

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

client.on('error', function(err) {
  console.log(err);
});

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

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

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

  client.hget(id, 'filename', function(err, reply) {
    // maybe some expiration logic too
    if (!reply) {
      res.sendStatus(404);
    } else {
      res.setHeader('Content-Disposition', 'attachment; filename=' + reply);
      res.setHeader('Content-Type', 'application/octet-stream');

      res.download(__dirname + '/static/' + id, reply, function(err) {
        if (!err) {
          client.del(id);
          fs.unlinkSync(__dirname + '/static/' + id);
        }
      });
    }
  });
});

app.post('/delete/:id', function(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);
  }

  client.hget(id, 'delete', function(err, reply) {
    if (!reply) {
      res.sendStatus(404);
    } else {
      client.del(id);
      fs.unlinkSync(__dirname + '/static/' + id);
      res.sendStatus(200);
    }
  });
});

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

  var fstream;
  req.pipe(req.busboy);
  req.busboy.on('file', function(fieldname, file, filename) {
    console.log('Uploading: ' + filename);

    //Path where image will be uploaded
    fstream = fs.createWriteStream(__dirname + '/static/' + req.params.id);
    file.pipe(fstream);
    fstream.on('close', function() {
      let id = req.params.id;
      let uuid = crypto.randomBytes(10).toString('hex');

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

      // delete the file off the server in 24 hours
      // setTimeout(function() {
      //   fs.unlinkSync(__dirname + "/static/" + id);
      // }, 86400000);

      client.expire(id, 86400000);
      console.log('Upload Finished of ' + filename);
      res.send(uuid);
    });
  });
});

app.listen(3000, function() {
  console.log('Portal app listening on port 3000!');
});

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