Implement Application Completion Workflow with Certificate Generation and Email Notification

package.json

@@ -37,6 +37,7 @@
     "passport-google-oauth20": "^2.0.0",
     "passport-jwt": "^4.0.1",
     "passport-linkedin-oauth2": "github:auth0/passport-linkedin-oauth2#v3.0.0",
+    "pdf-lib": "^1.17.1",
     "pg": "^8.10.0",
     "reflect-metadata": "^0.1.13",
     "ts-node": "^10.9.1",
@@ -61,7 +62,6 @@
     "@types/pg": "^8.10.1",
     "@types/prettier": "^2.7.2",
     "@types/supertest": "^2.0.12",
-    "@types/uuid": "^9.0.2",
     "@typescript-eslint/eslint-plugin": "^5.62.0",
     "@typescript-eslint/parser": "^5.59.5",
     "eslint": "^8.46.0",

src/entities/baseEntity.ts

@@ -1,10 +1,10 @@
+import { randomUUID } from 'crypto'
 import {
   BeforeInsert,
   BeforeUpdate,
   Column,
   PrimaryGeneratedColumn
 } from 'typeorm'
-import { v4 as uuidv4 } from 'uuid'
 
 class BaseEntity {
   @PrimaryGeneratedColumn('uuid')
@@ -28,7 +28,7 @@ class BaseEntity {
   @BeforeInsert()
   async generateUuid(): Promise<void> {
     if (!this.uuid) {
-      this.uuid = uuidv4()
+      this.uuid = randomUUID()
     }
   }
 }

src/entities/mentee.entity.ts

@@ -3,6 +3,7 @@ import Mentor from './mentor.entity'
 import profileEntity from './profile.entity'
 import { ApplicationStatus, StatusUpdatedBy } from '../enums'
 import BaseEntity from './baseEntity'
+import { UUID } from 'typeorm/driver/mongodb/bson.typings'
 
 @Entity('mentee')
 class Mentee extends BaseEntity {
@@ -22,8 +23,8 @@ class Mentee extends BaseEntity {
   @Column({ type: 'json' })
   application: Record<string, unknown>
 
-  @Column({ type: 'bigint', nullable: true, default: null })
-  certificate_id!: bigint
+  @Column({ type: 'uuid', nullable: true, default: null })
+  certificate_id!: UUID
 
   @Column({ default: null, nullable: true })
   journal!: string

src/enums/index.ts

@@ -12,7 +12,8 @@ export enum EmailStatusTypes {
 export enum ApplicationStatus {
   PENDING = 'pending',
   REJECTED = 'rejected',
-  APPROVED = 'approved'
+  APPROVED = 'approved',
+  COMPLETED = 'completed'
 }
 
 export enum StatusUpdatedBy {

src/services/admin/email.service.ts

@@ -18,7 +18,8 @@ const transporter = nodemailer.createTransport({
 export const sendEmail = async (
   to: string,
   subject: string,
-  message: string
+  message: string,
+  attachments?: Array<{ filename: string; path: string }>
 ): Promise<{
   statusCode: number
   message: string
@@ -35,7 +36,8 @@ export const sendEmail = async (
       from: `"Sustainable Education Foundation" <${SMTP_MAIL}>`,
       to,
       subject,
-      html
+      html,
+      attachments
     })
 
     const email = new Email(to, subject, message, EmailStatusTypes.SENT)

src/services/admin/generateCertificate.ts

@@ -0,0 +1,40 @@
+import { PDFDocument, rgb } from 'pdf-lib'
+import fs from 'fs'
+
+export async function generateCertificate(
+  menteeName: string,
+  sourcePdfPath: string,
+  outputPath: string
+): Promise<string> {
+  try {
+    const existingPdfBytes = fs.readFileSync(sourcePdfPath)
+    const pdfDoc = await PDFDocument.load(existingPdfBytes)
+    const page = pdfDoc.getPage(0)
+    const fontSize = 24
+    const datezFontSize = 18
+
+    page.drawText(menteeName, {
+      x: 66,
+      y: page.getHeight() - 220,
+      size: fontSize,
+      color: rgb(0, 0, 0)
+    })
+
+    const issueDate = new Date().toLocaleDateString()
+
+    page.drawText(issueDate, {
+      x: 160,
+      y: page.getHeight() - 476,
+      size: datezFontSize,
+      color: rgb(0, 0, 0)
+    })
+
+    const pdfBytes = await pdfDoc.save()
+
+    fs.writeFileSync(outputPath, pdfBytes)
+    return outputPath
+  } catch (error) {
+    console.error('Failed to modify the PDF:', error)
+    throw error
+  }
+}

src/services/admin/mentee.service.ts

@@ -111,9 +111,23 @@ export const updateStatus = async (
         profile: {
           uuid: profileUuid
         }
-      }
+      },
+      relations: ['mentor']
     })
 
+    const menteeName =
+      mentee.application.firstName + ' ' + mentee.application.lastName
+
+    const content = await getEmailContent('mentee', state, menteeName)
+
+    if (content) {
+      await sendEmail(
+        mentee.application.email as string,
+        content.subject,
+        content.message,
+        content.attachment
+      )
+    }
     // Handle Approve status
     if (approvedApplications && state === 'approved') {
       return {
@@ -126,22 +140,10 @@ export const updateStatus = async (
         {
           state,
           status_updated_by: statusUpdatedBy,
-          status_updated_date: new Date()
+          status_updated_date: new Date(),
+          certificate_id: content?.uniqueId
         }
       )
-      const content = getEmailContent(
-        'mentee',
-        state,
-        mentee.application.firstName as string
-      )
-
-      if (content) {
-        await sendEmail(
-          mentee.application.email as string,
-          content.subject,
-          content.message
-        )
-      }
       return {
         statusCode: 200,
         message: 'Mentee application state successfully updated'

src/services/admin/mentor.service.ts

@@ -28,7 +28,7 @@ export const updateMentorStatus = async (
 
     await mentorRepository.update({ uuid: mentorId }, { state: status })
 
-    const content = getEmailContent(
+    const content = await getEmailContent(
       'mentor',
       status,
       mentor.application.firstName as string

src/services/mentee.service.ts

@@ -76,7 +76,7 @@ export const addMentee = async (
 
     await menteeRepository.save(newMentee)
 
-    const content = getEmailContent(
+    const content = await getEmailContent(
       'mentee',
       ApplicationStatus.PENDING,
       application.firstName as string

src/services/mentor.service.ts

@@ -81,7 +81,7 @@ export const createMentor = async (
 
     const savedMentor = await mentorRepository.save(newMentor)
 
-    const content = getEmailContent(
+    const content = await getEmailContent(
       'mentor',
       ApplicationStatus.PENDING,
       application.firstName as string

src/utils.ts

@@ -6,7 +6,8 @@
 import multer from 'multer'
 import ejs from 'ejs'
 import { ApplicationStatus } from './enums'
-
+import { generateCertificate } from './services/admin/generateCertificate'
+import { randomUUID } from 'crypto'
 export const signAndSetCookie = (res: Response, uuid: string): void => {
   const token = jwt.sign({ userId: uuid }, JWT_SECRET ?? '')
 
@@ -65,7 +66,7 @@
     subject: string
     message: string
   }
 ): any => {
   const templatePath = path.join(__dirname, 'templates', `${templateName}.ejs`)
 
   return new Promise<string>((resolve, reject) => {
@@ -79,11 +80,19 @@
   })
 }
 
-export const getEmailContent = (
+export const getEmailContent = async (
   type: 'mentor' | 'mentee',
   status: ApplicationStatus,
   name: string
-): { subject: string; message: string } | undefined => {
+): Promise<
+  | {
+      subject: string
+      message: string
+      attachment?: Array<{ filename: string; path: string }>
+      uniqueId?: string
+    }
+  | undefined
+> => {
   if (type === 'mentor') {
     switch (status) {
       case ApplicationStatus.PENDING:
@@ -166,6 +175,30 @@
           We do offer the possibility for you to apply again next time if you meet the eligibility criteria. We invite you to stay engaged with us by attending our events, reaching out to our admissions team, and taking advantage of any opportunities to connect with our current students and alumni.<br /><br />
           Thank you again for considering our program and for the time you invested in your application. We wish you all the best in your future endeavours.`
         }
+      case ApplicationStatus.COMPLETED: {
+        const uniqueId = randomUUID()
+        const pdfFileName = await generateCertificate(
+          name,
+          './src/certificates/certificate_template.pdf',
+          `./src/certificates/mentee/${uniqueId}_certificate.pdf`
+        )
+        return {
+          subject: 'Congratulations! You have completed ScholarX',
+          message: `Dear ${name},<br /><br />
+            We are delighted to inform you that you have successfully completed the ScholarX program. We extend our heartfelt congratulations to you!<br /><br />
+            We are proud of your dedication, hard work, and commitment to the program. You have demonstrated exceptional talent, and we are confident that you will go on to achieve great success in your academic and professional pursuits.<br /><br />
+            To commemorate your achievement, we have attached your certificate of completion. Please download and save the certificate for your records.<br /><br />
+            We look forward to seeing the unique perspective and insights you will bring to the program. We believe that you will flourish in this year's edition of ScholarX, and we are thrilled to be a part of your academic or professional journey.<br /><br />
+            Once again, congratulations on your completion! We cannot wait to see the great things you will achieve in the future.`,
+          attachment: [
+            {
+              filename: `${name}_certificate.pdf`,
+              path: pdfFileName
+            }
+          ],
+          uniqueId
+        }
+      }
       default:
         return undefined
     }