Refactor email purge time configuration and usage to be more precise.

- New purgeTIme now allows to configure a purge to be every X minutes, hours or days.
- Also remove a bit more trust by pulling footer deletion time from config.
- TODO: implement 'convertUp' function, converting numbers up to the biggest possible value where `i > 2 (so 48hrs still works as per slogan and domain)`. I.e. 72hrs = 3 days, 360minutes = 6hrs, 1440minutes to 24hrs

Co-authored-by: Johannes Bülow <kontakt@jmbit.de>

application/config.sample.js

@@ -1,7 +1,11 @@
 const config = {
 	email: {
 		domains: process.env.EMAIL_DOMAINS,
-		deleteMailsOlderThanDays: process.env.EMAIL_DELETE_MAILS_OLDER_THAN_DAYS || 2
+		purgeTime: process.env.PURGE_TIME || {
+			time: 48,
+			unit: 'hours', // minutes, hours, days
+			convert: true, // Convert to highest sensible unit
+		}
 	},
 	imap: {
 		user: process.env.IMAP_USER,

application/helper.js

@@ -0,0 +1,41 @@
+const config = require('./config')
+const moment = require('moment')
+
+class Helper {
+
+    /**
+     * Normalize our config into a proper timestamp, so we know what emails to purge
+     * @returns {Date}
+     */
+    purgeTimeStamp() {
+        return moment()
+        .subtract(config.email.purgeTime.time, config.email.purgeTime.unit)
+        .toDate()
+    }
+
+    /**
+     * Check if time difference between now and purgeTimeStamp is more than one day 
+     * @param {Date} now
+     * @param {Date} past
+     * @returns {Boolean}
+     */
+    moreThanOneDay(now, past) {
+        const DAY_IN_MS = 24 * 60 * 60 * 1000;
+        if((now - past) / DAY_IN_MS >= 1){
+            return  true
+        } else {
+            return false
+        }
+    }
+
+    /**
+     * Convert time to highest possible unit where i > 2
+     * @returns {Date}
+     */
+    convertUp(time, unit) {
+        // TODO: Implement
+        return time +` ${unit}`
+    }
+};
+
+module.exports = Helper

application/imap-service.js

@@ -8,7 +8,8 @@ const debug = require('debug')('48hr-email:imap')
 const _ = require('lodash')
 const moment = require('moment')
 const Mail = require('../domain/mail')
-
+const Helper = require('./helper')
+const helper = new(Helper)
 
 // Just adding some missing functions to imap-simple... :-)
 
@@ -199,22 +200,30 @@ class ImapService extends EventEmitter {
 	 * @param {Date} deleteMailsBefore delete mails before this date instance
 	 */
 	async deleteOldMails(deleteMailsBefore) {
-		let uids = await this._searchWithoutFetch([
-			['!DELETED'],
-			['BEFORE', deleteMailsBefore]
-		])
+		let uids = []
+		if (helper.moreThanOneDay(moment(), deleteMailsBefore)) {
+			//fetch mails from date -1day (calculated in MS) to avoid wasting resources
+			deleteMailsBefore = deleteMailsBefore - 24 * 60 * 60 * 1000
+			uids = await this._searchWithoutFetch([
+				['!DELETED'],
+				['BEFORE', deleteMailsBefore]
+			])
+		} else {
+			uids = await this._searchWithoutFetch([
+				['!DELETED']
+			])
+		}
+
 		if (uids.length === 0) {
 			return
 		}
 
-		const DeleteOlderThan = moment()
-		.subtract(this.config.email.deleteMailsOlderThanDays, 'days')
-		.toDate()
+		const DeleteOlderThan = helper.purgeTimeStamp()
 
 		const uidsWithHeaders = await this._getMailHeaders(uids)
 		uidsWithHeaders.forEach(mail => {
 			if (mail['attributes'].date > DeleteOlderThan || this.config.http.examples.uids.includes(parseInt(mail['attributes'].id))) {
-				uids.filter(uid => uid !== mail['attributes'].uid)
+				uids = uids.filter(uid => uid !== mail['attributes'].uid)
 			}
 		})
 

application/mail-processing-service.js

@@ -3,6 +3,9 @@ const debug = require('debug')('48hr-email:imap-manager')
 const mem = require('mem')
 const moment = require('moment')
 const ImapService = require('./imap-service')
+const Helper = require('./helper')
+const helper = new(Helper)
+
 
 class MailProcessingService extends EventEmitter {
 	constructor(mailRepository, imapService, clientNotification, config) {
@@ -71,15 +74,7 @@ class MailProcessingService extends EventEmitter {
 
 	async _deleteOldMails() {
 		try {
-			await this.imapService.deleteOldMails(
-				moment()
-					// Because of how we have to handle the times (IMAP isnt time-aware), we need to subtract one day
-					// to get all mails in their last few hours before technical purge
-					// 
-					// This is a bit of a hack, but it works. See imap-service.js#deleteOldMails (L211-227) for more info
-					.subtract(this.config.email.deleteMailsOlderThanDays - 1, 'days')
-					.toDate()
-			)
+			await this.imapService.deleteOldMails(helper.purgeTimeStamp())
 		} catch (error) {
 			console.log('can not delete old messages', error)
 		}

infrastructure/web/routes/inbox.js

@@ -3,6 +3,12 @@ const express = require('express')
 const router = new express.Router()
 const {param} = require('express-validator')
 const config = require('../../../application/config')
+const Helper = require('../../../application/helper')
+const helper = new(Helper)
+
+const purgeTime = config.email.purgeTime.convert ? helper.convertUp(config.email.purgeTime.time, config.email.purgeTime.unit) 
+	: config.email.purgeTime.time +` ${config.email.purgeTime.unit}`;
+
 const sanitizeAddress = param('address').customSanitizer(
 	(value, {req}) => {
 		return req.params.address
@@ -15,6 +21,7 @@ router.get('^/:address([^@/]+@[^@/]+)', sanitizeAddress, (req, res, _next) => {
 	const mailProcessingService = req.app.get('mailProcessingService')
 	res.render('inbox', {
 		title: `${config.http.branding[0]} | ` + req.params.address,
+		purgeTime: purgeTime,
 		address: req.params.address,
 		mailSummaries: mailProcessingService.getMailSummaries(req.params.address),
 		branding: config.http.branding,
@@ -41,6 +48,7 @@ router.get(
 				res.set('Cache-Control', 'private, max-age=600')
 				res.render('mail', {
 					title: mail.subject + " | " + req.params.address,
+					purgeTime: purgeTime,
 					address: req.params.address,
 					mail,
 					uid: req.params.uid,
@@ -50,6 +58,7 @@ router.get(
 				res.render(
 					'error',
 					{
+						purgeTime: purgeTime,
 						address: req.params.address,
 						message: 'This mail could not be found. It either does not exist or has been deleted from our servers!',
 						branding: config.http.branding
@@ -124,6 +133,7 @@ router.get(
 				res.render(
 					'error',
 					{
+						purgeTime: purgeTime,
 						address: req.params.address,
 						message: 'This attachment could not be found. It either does not exist or has been deleted from our servers!',
 						branding: config.http.branding,
@@ -163,6 +173,7 @@ router.get(
 				res.render(
 					'error',
 					{
+						purgeTime: purgeTime,
 						address: req.params.address,
 						message: 'This mail could not be found. It either does not exist or has been deleted from our servers!',
 						branding: config.http.branding,

infrastructure/web/routes/login.js

@@ -4,11 +4,17 @@ const router = new express.Router()
 const randomWord = require('random-word')
 const {check, validationResult} = require('express-validator')
 const config = require('../../../application/config')
+const Helper = require('../../../application/helper')
+const helper = new(Helper)
+
+const purgeTime = config.email.purgeTime.convert ? helper.convertUp(config.email.purgeTime.time, config.email.purgeTime.unit) 
+	: config.email.purgeTime.time +` ${config.email.purgeTime.unit}`;
 
 router.get('/', (req, res, _next) => {
 	res.render('login', {
 		title: `${config.http.branding[0]} | Your temporary Inbox`,
 		username: randomWord(),
+		purgeTime: purgeTime,
 		domains: config.email.domains,
 		branding: config.http.branding,
 	})
@@ -39,6 +45,7 @@ router.post(
 			return res.render('login', {
 				userInputError: true,
 				title: `${config.http.branding[0]} | Your temporary Inbox`,
+				purgeTime: purgeTime,
 				username: randomWord(),
 				branding: config.http.branding,
 			})

infrastructure/web/views/layout.twig

@@ -28,7 +28,7 @@
     {% block footer %}
     <section class="container footer">
       <hr>
-      <h4>{{ branding[0] }} offered by <a href="{{ branding[2] }}" style="text-decoration:underline" target="_blank">{{ branding[1] }}</a> | All Emails will be deleted after 48hrs |  This project is <a href="https://github.com/crazyco-xyz/48hr.email" style="text-decoration:underline" target="_blank">open-source ♥</a></h4>
+      <h4>{{ branding[0] }} offered by <a href="{{ branding[2] }}" style="text-decoration:underline" target="_blank">{{ branding[1] }}</a> | All Emails will be deleted after {{ purgeTime }} |  This project is <a href="https://github.com/crazyco-xyz/48hr.email" style="text-decoration:underline" target="_blank">open-source ♥</a></h4>
     </section>
     {% endblock %}