ft(Email-microservice): separate our mail service from the rest of th…

…e system

  - Send email from serverless using aws-lambda.
  - Failed email store and send after certain minutes.

[Delivery #187658871]

package.json

@@ -41,6 +41,7 @@
   "devDependencies": {
     "@babel/helper-compilation-targets": "^7.23.6",
     "@eslint/js": "^9.1.1",
+    "@types/aws-sdk": "^2.7.0",
     "@types/bcryptjs": "^2.4.6",
     "@types/cors": "^2.8.17",
     "@types/dotenv": "^8.2.0",

src/sequelize/migrations/20240527133340-create-failed-email.js

@@ -0,0 +1,44 @@
+'use strict';
+/** @type {import('sequelize-cli').Migration} */
+module.exports = {
+  async up(queryInterface, Sequelize) {
+    await queryInterface.createTable('failedEmails', {
+      id: {
+        allowNull: false,
+        autoIncrement: true,
+        primaryKey: true,
+        type: Sequelize.INTEGER
+      },
+      userId: {
+        type: Sequelize.INTEGER
+      },
+      email: {
+        type: Sequelize.STRING
+      },
+      subject: {
+        type: Sequelize.STRING
+      },
+      body: {
+        type: Sequelize.TEXT
+      },
+      attempts: {
+        type: Sequelize.INTEGER
+      },
+      lastAttempted: {
+        type: Sequelize.DATE,
+        defaultValue: Sequelize.NOW,
+      },
+      createdAt: {
+        allowNull: false,
+        type: Sequelize.DATE
+      },
+      updatedAt: {
+        allowNull: false,
+        type: Sequelize.DATE
+      }
+    });
+  },
+  async down(queryInterface, Sequelize) {
+    await queryInterface.dropTable('failedEmails');
+  }
+};

src/sequelize/models/failedemail.ts

@@ -0,0 +1,59 @@
+import { DataTypes, Model } from 'sequelize';
+import sequelize from '../../config/dbConnection';
+
+interface FailedEmailAttributes {
+  id: number;
+  userId: number;
+  email: string;
+  subject: string;
+  body: string;
+  attempts: number;
+  lastAttempted: Date;
+}
+
+class FailedEmail extends Model<FailedEmailAttributes> implements FailedEmailAttributes {
+   id!: number;
+   userId!: number;
+   email!: string;
+   subject!: string;
+   body!: string;
+   attempts!: number;
+   lastAttempted!: Date;
+}
+
+FailedEmail.init({
+  id: {
+    type: DataTypes.INTEGER,
+    autoIncrement: true,
+    primaryKey: true,
+  },
+  userId: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+  },
+  email: {
+    type: DataTypes.STRING,
+    allowNull: false,
+  },
+  subject: {
+    type: DataTypes.STRING,
+    allowNull: false,
+  },
+  body: {
+    type: DataTypes.TEXT,
+    allowNull: false,
+  },
+  attempts: {
+    type: DataTypes.INTEGER,
+    defaultValue: 0,
+  },
+  lastAttempted: {
+    type: DataTypes.DATE,
+    defaultValue: DataTypes.NOW,
+  },
+}, {
+  sequelize,
+  modelName: 'failedEmails',
+});
+
+export default FailedEmail;

src/services/mail.service.ts

@@ -1,23 +1,38 @@
+import FailedEmail from "../sequelize/models/failedemail";
 import { IUser } from "../types";
 import { env } from "../utils/env";
 import transporter from "../utils/transporter";
+import axios from "axios";
+import cron from "node-cron";
 
 export const sendEmailService = async (user: IUser, subject: string, template: any, token?: number) => {
   try {
-    const mailOptions = {
-      from: env.smtp_user,
+    const apiEndpoint: any = process.env.URL_SEND_EMAIL;
+    const emailData = {
       to: user.email,
       subject: subject,
-      html: template,
+      body: template,
     };
-
-
-    const info = await transporter.sendMail(mailOptions);
-    //@ts-ignore
+
+    const response = await axios.post(apiEndpoint, emailData);
   } catch (error: any) {
-    throw new Error(error.message);
+    try {
+      const rs = await FailedEmail.create({
+        // @ts-ignore
+        userId: user.id,
+        email: user.email,
+        subject: subject,
+        body: template,
+        attempts: 1,
+        lastAttempted: new Date(),
+      });
+    } catch (error: any) {
+      throw new Error(error.message);
+    }
+    throw error;
   }
 };
+
 export const sendNotification = async (email: string | undefined, subject: string, template: any) => {
   try {
     const mailOptions = {
@@ -33,3 +48,31 @@ export const sendNotification = async (email: string | undefined, subject: strin
     throw new Error(error.message);
   }
 };
+
+const retryFailedEmail = async () => {
+  const allFailedEmail = await FailedEmail.findAll();
+
+  for (const email of allFailedEmail) {
+    try {
+      const apiEndpoint: any = process.env.URL_SEND_EMAIL;
+
+      const failedEmailData = {
+        to: email.dataValues.email,
+        subject: email.dataValues.subject,
+        body: email.dataValues.body,
+      };
+
+      const response = await axios.post(apiEndpoint, failedEmailData);
+      await email.destroy();
+    } catch (error: any) {
+      email.attempts = email.dataValues.attempts + 1;
+      email.dataValues.lastAttempted = new Date();
+      await email.save();
+      throw new Error(error.message);
+    }
+  }
+};
+
+cron.schedule("0 * * * *", () => {
+  retryFailedEmail();
+});