Implemented email notifications

config.example.js

@@ -22,5 +22,26 @@ module.exports = {
     // If a collision occurs, a new code will be generated and tested again for up to 100 times.
     alphabet: '1234567890abcdef',
     length: 8
+  },
+
+  notifications: {
+    interval: 10,
+    maxAttempt: 12,
+    adminUrl: 'http://localhost:3001/admin/',
+
+    mail: {
+      from: '"Recv" <recv@localhost>',
+
+      transport: {
+        // passed directly to NodeMailer's createTransport. See nodemailer.com for more information.
+        host: 'smtp.ethereal.email',
+        port: 587,
+        secure: false,
+        auth: {
+          user: 'recv',
+          pass: 'test'
+        }
+      }
+    }
   }
 };

emails/uploadnotification/html.ejs

@@ -0,0 +1,33 @@
+<%
+function humanFileSize(bytes, si)
+{
+  var thresh = si ? 1000 : 1024;
+  if(Math.abs(bytes) < thresh)
+  {
+    return bytes + ' B';
+  }
+
+  var units = si
+    ? ['kB','MB','GB','TB','PB','EB','ZB','YB']
+    : ['KiB','MiB','GiB','TiB','PiB','EiB','ZiB','YiB'];
+  var u = -1;
+
+  do
+  {
+    bytes /= thresh;
+    ++u;
+  }
+  while(Math.abs(bytes) >= thresh && u < units.length - 1);
+
+  return bytes.toFixed(1) + ' ' + units[u];
+}
+%>
+<p>Hello <%= user.name %>,</p>
+<p>The following files have just been uploaded:</p>
+<ul>
+  <% upload.files.forEach((file) => { %>
+    <li><%= file.name %> (<%= humanFileSize(file.size, true) %>)</li>
+  <% }) %>
+</ul>
+<p>You can download these files by logging in to <a href="<%= adminUrl %>"><%= adminUrl %></a></p>
+<p>Cheers,<br />Recv</p>

emails/uploadnotification/subject.ejs

@@ -0,0 +1 @@
+📄 File upload notification

index.js

@@ -2,6 +2,7 @@
 
 const config = require('./config');
 const Repository = require('./lib/repository');
+const NotificationWorker = require('./lib/workers/notification');
 
 const _ = require('lodash');
 const fs = require('fs');
@@ -96,6 +97,10 @@ const webpackConfig = require('./webpack.config.js');
     app.get('/admin', (req, res) => { res.redirect(301, '/#/admin/') });
 
 
+    // Background workers
+    var notificationWorker = new NotificationWorker(repository);
+    notificationWorker.start(config.notifications.interval * 1000);
+
 
     var server = app.listen(config.port, () => console.log('Recv running on port ' + server.address().port));
   }

lib/api/upload.js

@@ -106,6 +106,11 @@ module.exports = (repository, tusServer) =>
         }
 
         var uploadId = await repository.uploads.insert(decoded.codeUserId, decoded.code, req.body.files, expiration);
+        await repository.notifications.insert({
+          userId: decoded.codeUserId,
+          uploadId: uploadId
+        });
+
         res.send({ id: uploadId });
       });
     });

lib/repository/index.js

@@ -7,6 +7,7 @@ const Datastore = require('nedb');
 const UserRepository = require('./user').UserRepository;
 const CodeRepository = require('./code').CodeRepository;
 const UploadRepository = require('./upload').UploadRepository;
+const NotificationRepository = require('./notification').NotificationRepository;
 
 
 class Repository
@@ -46,6 +47,7 @@ class Repository
         self.users = new UserRepository(initStore('user.db'));
         self.codes = new CodeRepository(initStore('code.db'));
         self.uploads = new UploadRepository(initStore('upload.db'));
+        self.notifications = new NotificationRepository(initStore('notification.db'));
 
         self.users.init()
           .then(() => { resolve() })

lib/repository/notification.js

@@ -0,0 +1,123 @@
+const _ = require('lodash');
+
+
+class Notification
+{
+  constructor(values)
+  {
+    var self = this;
+
+    self.id = values.id || values._id || null;
+    self.userId = values.userId || null;
+    self.uploadId = values.uploadId || null;
+    self.attempt = values.attempt || 0;
+  }
+}
+
+
+class NotificationRepository
+{
+  constructor(store)
+  {
+    var self = this;
+    self.store = store;
+  }
+
+
+  list()
+  {
+    var self = this;
+
+    return new Promise((resolve, reject) =>
+    {
+      self.store.find({}, (err, docs) =>
+      {
+        if (err)
+        {
+          reject(err);
+          return;
+        }
+
+        resolve(_.map(docs, (doc) => new Notification(doc)));
+      });
+    });
+  }
+
+
+  insert(notification)
+  {
+    var self = this;
+
+    return new Promise((resolve, reject) =>
+    {
+      self.store.insert({
+        userId: notification.userId,
+        uploadId: notification.uploadId,
+        attempt: notification.attempt
+      }, (err, dbNotification) =>
+      {
+        if (err)
+        {
+          reject(err);
+          return;
+        }
+
+        resolve(dbNotification._id);
+      });
+    });
+  }
+
+
+  update(notification)
+  {
+    var self = this;
+
+    return new Promise((resolve, reject) =>
+    {
+      self.store.update({ _id: notification.id }, { $set: {
+        attempt: notification.attempt
+      }},
+        (err, numAffected) =>
+        {
+          if (err)
+          {
+            reject(err);
+            return;
+          }
+
+          if (numAffected == 0)
+          {
+            reject();
+          }
+
+          resolve();
+        });
+    });
+  }
+
+
+  delete(notificationId)
+  {
+    var self = this;
+
+    return new Promise((resolve, reject) =>
+    {
+      self.store.remove({ _id: notificationId }, (err, numRemoved) =>
+      {
+        if (err)
+        {
+          reject(err);
+          return;
+        }
+
+        resolve();
+      });
+    });
+  }
+}
+
+
+module.exports = {
+  Notification,
+  NotificationRepository
+}

lib/workers/notification.js

@@ -0,0 +1,123 @@
+const config = require('../../config');
+const async = require('async');
+const nodemailer = require('nodemailer');
+const Email = require('email-templates');
+
+
+class NotificationWorker
+{
+  constructor(repository)
+  {
+    this.repository = repository;
+  }
+
+
+  start(interval)
+  {
+    var self = this;
+
+    self.stop();
+    self.timer = setInterval(async () =>
+    {
+      if (self.ticking)
+        return;
+
+      self.ticking = true;
+      await self.tick();
+      self.ticking = false;
+    }, interval);
+  }
+
+
+  stop()
+  {
+    var self = this;
+    if (self.timer)
+    {
+      clearInterval(self.timer);
+      self.timer = null;
+    }
+  }
+
+
+  async tick()
+  {
+    var self = this;
+
+    var notifications = await self.repository.notifications.list();
+    return new Promise((resolve, reject) =>
+    {
+      async.eachOfSeries(notifications,
+        async (item) => { await self.sendNotification(item) },
+        (err) =>
+        {
+          if (err)
+            reject(err);
+          else
+            resolve();
+        });
+    })
+  }
+
+
+  async sendNotification(notification)
+  {
+    let self = this;
+    let user = await self.repository.users.get(notification.userId);
+    if (user === null || !user.email)
+      return;
+
+    let upload = await self.repository.uploads.get(notification.uploadId);
+    if (upload === null)
+      return;
+
+    return new Promise((resolve, reject) =>
+    {
+      const email = new Email({
+        message: {
+          from: config.notifications.mail.from
+        },
+
+        send: true,
+        preview: false,
+        transport: nodemailer.createTransport(config.notifications.mail.transport),
+        views: {
+          options: {
+            extension: 'ejs'
+          }
+        }
+      });
+
+      email
+        .send({
+          template: 'uploadnotification',
+          message: {
+            to: user.email
+          },
+          locals: {
+            user: user,
+            upload: upload,
+            adminUrl: config.notifications.adminUrl
+          }
+        })
+        .then(async () =>
+        {
+          await self.repository.notifications.delete(notification.id);
+          console.log('Notification sent to: ' + user.email + ' for upload ID: ' + upload.id);
+          resolve();
+        })
+        .catch(async (error) =>
+        {
+          notification.attempt++;
+          if (notification.attempt > config.notifications.maxAttempts)
+            await self.repository.notifications.delete(notification.id);
+          else
+            await self.repository.notifications.update(notification);
+
+          resolve();
+        });
+    });
+  }
+}
+
+module.exports = NotificationWorker;

package.json

@@ -25,6 +25,8 @@
     "cookie-parser": "^1.4.3",
     "debug": "^3.1.0",
     "diskusage": "^0.2.4",
+    "ejs": "^2.5.9",
+    "email-templates": "^3.6.0",
     "express": "^4.16.3",
     "express-async-handler": "^1.1.2",
     "js-cookie": "^2.2.0",
@@ -36,7 +38,9 @@
     "mz": "^2.7.0",
     "nanoid": "^1.0.2",
     "nedb": "^1.8.0",
+    "nodemailer": "^4.6.4",
     "npm": "^5.8.0",
+    "pug": "^2.0.3",
     "resolve-path": "^1.4.0",
     "tus-node-server": "^0.2.10"
   },