mailing: added queue

src/lib/mail.ts

@@ -4,47 +4,85 @@ import {ConfMail} from './types/conf'
 import * as nodemailer from 'nodemailer'
 import * as os from 'os'
 
-export async function sendMail(conf: ConfMail, subject: string, html: string, cc?: string) {
+// TODO: in confMail
+
+const QUEUE_PERIOD = 5000
+const queue: EmailContent[] = []
+let conf: ConfMail|undefined
+
+export function initConfMail(confMail: ConfMail) {
+  conf = confMail
+
+  ;(async () => {
+    while (true) {
+      await consumeQueue()
+      await new Promise((res) => setTimeout(res, QUEUE_PERIOD))
+    }
+  })()
+}
+
+export async function queueEmail(subject: string, html: string, cc?: string) {
+  queue.push({ subject, body: html, cc })
+}
+
+async function consumeQueue() {
+  while (queue.length) {
+    const mail = queue.shift()
+    if (mail) {
+      await sendEmail(mail.subject, mail.body, mail.cc)
+    }
+  }
+}
+
+async function sendEmail(subject: string, html: string, cc?: string) {
+
+  if (!conf) {
+    console.error(`Mail is not properly configured.`)
+    return
+  }
 
   console.log(`[mail] Subject: ${subject}`)
   console.log(`[mail] Body: ${html}`)
-  if (conf.enabled) {
-    let transporter = nodemailer.createTransport({
-      host: conf.host,
-      port: conf.port,
-      secure: false, // true for 465, false for other ports
-      auth: {
-        user: conf.username, // generated ethereal user
-        pass: conf.apikey // generated ethereal password
-      },
-      authMethod: conf.auth,
-      requireTLS: true,
-    });
-
-// send mail with defined transport object
-    let info = await transporter.sendMail({
-      from: conf.from,
-      to: conf.to,
-      cc: (conf.cc ? [conf.cc] : []).concat(cc ? [cc] : []).join(','),
-      subject,
-      html
-    })
+  if (!conf.enabled) {
+    console.warn(`Mail is disabled.`)
+    return
   }
+
+  let transporter = nodemailer.createTransport({
+    host: conf.host,
+    port: conf.port,
+    secure: false, // true for 465, false for other ports
+    auth: {
+      user: conf.username, // generated ethereal user
+      pass: conf.apikey // generated ethereal password
+    },
+    authMethod: conf.auth,
+    requireTLS: true,
+  });
+
+  // send mail with defined transport object
+  let info = await transporter.sendMail({
+    from: conf.from,
+    to: conf.to,
+    cc: (conf.cc ? [conf.cc] : []).concat(cc ? [cc] : []).join(','),
+    subject,
+    html
+  })
 }
 
 export const mail = {
 
-  onEstablished: (conf: Conf, target: string, message = `Connection established for ${target}`, getHtml: () => string = () => `
+  onEstablished: (target: string, message = `Connection established for ${target}`, getHtml: () => string = () => `
       <p>
         Connection from [${os.hostname}] to ${target} established on ${moment().format('DD-MM-YYYY HH:mm:ss')}.
       </p>
     `) => {
     return async (cc?: string) => {
-      await sendMail(conf.mail, `[dw] [${os.hostname}] ${message}`, getHtml(), cc)
+      await queueEmail(`[dw] [${os.hostname}] ${message}`, getHtml(), cc)
     }
   },
 
-  onDisconnect: (conf: Conf, target: string, message = `Connection closed for ${target}`, getErrorMessage: () => string = () => '', getHtml: (waitingDelay: number, recallDelay: number) => string = (waitingDelay: number, recallDelay: number) => `
+  onDisconnect: (target: string, message = `Connection closed for ${target}`, getErrorMessage: () => string = () => '', getHtml: (waitingDelay: number, recallDelay: number) => string = (waitingDelay: number, recallDelay: number) => `
       <p>
         Connection from [${os.hostname}] to ${target} was lost on ${moment().format('dd-MM-YYYY HH:mm:ss')}.
       </p>
@@ -55,18 +93,24 @@ export const mail = {
   `) => {
     return async (waitingDelay: number, recallDelay: number, cc?: string) => {
       console.log('Waiting %s seconds...', (waitingDelay / 1000).toFixed(0))
-      await sendMail(conf.mail, `[dw] [${os.hostname}] ${message}`, getHtml(waitingDelay, recallDelay), cc)
+      await queueEmail(`[dw] [${os.hostname}] ${message}`, getHtml(waitingDelay, recallDelay), cc)
     }
   },
 
-  onRestartSuccess: (conf: Conf, target: string, message = `Connection recovered for ${target}`, getHtml: () => string = () => `
+  onRestartSuccess: (target: string, message = `Connection recovered for ${target}`, getHtml: () => string = () => `
       <p>
         Connection from [${os.hostname}] to ${target} was recovered on ${moment().format('dd-MM-YYYY HH:mm:ss')}.
       </p>
     `) => {
     return async (cc?: string) => {
       console.log(`${message}`)
-      await sendMail(conf.mail, `[dw] [${os.hostname}] ${message}`, getHtml(), cc)
+      await queueEmail(`[dw] [${os.hostname}] ${message}`, getHtml(), cc)
     }
   },
 }
+
+interface EmailContent {
+  subject: string
+  body: string
+  cc?: string
+}