node.js lab10

var fs = require('fs');
var formidable = require('formidable');
var MongoClient = require('mongodb').MongoClient;
var assert = require('assert');
var ObjectID = require('mongodb').ObjectID;
const express = require('express')
const app = express()

const mongourl = process.env.MONGOURL || "mongodb://developer:developer123@ds143593.mlab.com:43593/herbert1228";

MongoClient.connect(mongourl, function (err, db) {
  try {
    assert.equal(err, null);
    console.log('Connected to MongoDB')
  } catch (err) {
    res.status(500).end("MongoClient connect() failed!");
    return (-1);
  }

  app.set('view engine', 'ejs')

  app.post('/fileupload', (req, res) => {
    const form = new formidable.IncomingForm();

    form.parse(req, function (err, fields, files) {
      console.log(JSON.stringify(files));

      const filename = files.filetoupload.path;
      if (files.filetoupload.size == 0) {
        res.status(500).end('No file uploaded!')
      }
      const title = (fields.title.length > 0) ? fields.title : "untitled";
      const desc = (fields.desc.length > 0) ? fields.desc : "untitled";
      const mimetype = files.filetoupload.type

      console.log("title = " + title);
      console.log("filename = " + filename);

      fs.readFile(filename, function (err, data) {
        const new_photo = {
          title,
          desc,
          mimetype,
          image: new Buffer(data).toString('base64')
        }
        insertPhoto(db, new_photo, function (result) {
          res.status(200).end('Photo was inserted into MongoDB!');
        })
      })
    })
  })

  app.get('/photos', (req, res) => {
    findPhoto(db, {}, function (photos) {
      res.render('list', {photos: photos})
    })
  })

  app.get('/display', (req, res) => {
    const criteria = {_id: ObjectID(req.query._id)}

    findPhoto(db, criteria, function (photo) {
      console.log('Photo returned = ' + photo.length);
      const p = {image, title, desc, mimetype} = photo[0]
      const contentType = {};
      if (mimetype == "image/jpeg" || mimetype == "image/png") {
        console.log(`Preparing to send ${mimetype}`);
        res.render('photo', p)
      } else {
        res.status(500).end("Not JPEG format!!!");
      }
    });
  })

  app.get('/upload', (req, res) => {
    res.render('upload', null)
  })

  app.get('*', (req, res) => {
    res.redirect('/photos')
  })

  app.listen(4000, () => console.log('server listening port 4000'))

})

function insertPhoto(db, r, callback) {
  db.collection('photo').insertOne(r, function (err, result) {
    assert.equal(err, null);
    console.log("insert was successful!");
    console.log(JSON.stringify(result));
    callback(result);
  });
}

function findPhoto(db, criteria, callback) {
  var cursor = db.collection("photo").find(criteria);
  var photos = [];
  cursor.each(function (err, doc) {
    assert.equal(err, null);
    if (doc != null) {
      photos.push(doc);
    } else {
      callback(photos);
    }
  });
}