feat: add cron email

package.json

@@ -36,8 +36,10 @@
     "@nestjs/jwt": "^8.0.0",
     "@nestjs/passport": "^8.0.1",
     "@nestjs/platform-express": "^8.2.4",
+    "@nestjs/schedule": "^1.0.2",
     "@nestjs/swagger": "^5.1.5",
     "@prisma/client": "^3.8.1",
+    "@types/cron": "^1.7.3",
     "@types/faker": "^5.5.9",
     "@types/nodemailer": "^6.4.4",
     "class-transformer": "^0.5.1",

src/app.module.ts

@@ -1,17 +1,21 @@
 import { CityModule } from './user/city/city.module';
 import { Module } from '@nestjs/common';
+import { ScheduleModule } from '@nestjs/schedule';
 import { ConfigModule } from 'config/config.module';
 import { AnimalModule } from './animal/animal.module';
 import { BreedModule } from './animal/breed.module';
 import { AuthModule } from './auth/auth.module';
 import { PrismaService } from './prisma.service';
 import { UserModule } from './user/user.module';
+import { EmailModule } from './email/email.module';
 
 @Module({
   imports: [
     PrismaService,
     AuthModule,
     ConfigModule,
+    ScheduleModule.forRoot(),
+    EmailModule,
     CityModule,
     UserModule,
     AnimalModule,

src/dtos/email/emailSchedule.ts

@@ -0,0 +1,19 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsDateString, IsEmail, IsNotEmpty, IsString } from 'class-validator';
+
+export class EmailScheduleDto {
+  @ApiProperty()
+  @IsEmail()
+  public recipient!: string;
+
+  @IsString()
+  @IsNotEmpty()
+  public subject!: string;
+
+  @IsString()
+  @IsNotEmpty()
+  public content!: string;
+
+  @IsDateString()
+  public date!: string;
+}

src/dtos/email/index.ts

@@ -0,0 +1 @@
+export * from './emailSchedule';

src/dtos/index.ts

@@ -2,3 +2,4 @@ export * from './utils';
 export * from './auth';
 export * from './animals';
 export * from './users';
+export * from './email';

src/email/email.module.ts

@@ -1,9 +1,11 @@
 import { Module } from '@nestjs/common';
 import EmailService from './email.service';
+import EmailSchedulingController from './emailSchedule.controller';
+import EmailSchedulingService from './emailSchedule.service';
 
 @Module({
-  controllers: [],
-  providers: [EmailService],
+  controllers: [EmailSchedulingController],
+  providers: [EmailService, EmailSchedulingService],
   exports: [EmailService],
 })
 export class EmailModule {}

src/email/emailSchedule.controller.ts

@@ -0,0 +1,16 @@
+import { Body, Controller, Post } from '@nestjs/common';
+import EmailSchedulingService from './emailSchedule.service';
+import { EmailScheduleDto } from '../dtos';
+
+@Controller('email-scheduling')
+export default class EmailSchedulingController {
+  constructor(
+    private readonly emailSchedulingService: EmailSchedulingService,
+  ) {}
+
+  @Post('schedule')
+  // @UseGuards(JwtAuthenticationGuard)
+  async scheduleEmail(@Body() emailSchedule: EmailScheduleDto) {
+    this.emailSchedulingService.scheduleEmail(emailSchedule);
+  }
+}

src/email/emailSchedule.service.ts

@@ -0,0 +1,38 @@
+import { Injectable } from '@nestjs/common';
+import EmailService from '../email/email.service';
+import { EmailScheduleDto } from '../dtos';
+import { SchedulerRegistry } from '@nestjs/schedule';
+import { CronJob } from 'cron';
+import { PrismaService } from 'src/prisma.service';
+
+@Injectable()
+export default class EmailSchedulingService {
+  constructor(
+    private readonly emailService: EmailService,
+    private readonly schedulerRegistry: SchedulerRegistry,
+    private readonly prisma: PrismaService,
+  ) {}
+
+  scheduleEmail(emailSchedule: EmailScheduleDto) {
+    const date = new Date(emailSchedule.date);
+    const job = new CronJob(date, () => {
+      this.emailService.sendMail({
+        to: emailSchedule.recipient,
+        subject: emailSchedule.subject,
+        text: emailSchedule.content,
+      });
+    });
+
+    this.schedulerRegistry.addCronJob(
+      `${Date.now()}-${emailSchedule.subject}`,
+      job,
+    );
+    job.start();
+  }
+
+  cancelAllScheduledEmails() {
+    this.schedulerRegistry.getCronJobs().forEach((job) => {
+      job.stop();
+    });
+  }
+}