feat: add otp and hashing modules

src/modules/otp/otp.entity.ts

@@ -33,13 +33,13 @@ export class OTP {
 
   @Index()
   @Column({ type: 'timestamptz' })
-  expiredAt: Date;
+  expiresAt: Date;
 
   @Column({ type: 'boolean', default: false })
   used: boolean;
 
   @BeforeInsert()
   setExpiry() {
-    this.expiredAt = new Date(Date.now() + 2 * 60 * 1000);
+    this.expiresAt = new Date(Date.now() + 2 * 60 * 1000);
   }
 }

src/modules/otp/otp.module.ts

@@ -6,5 +6,6 @@ import { OTP } from './otp.entity';
 @Module({
   imports: [TypeOrmModule.forFeature([OTP])],
   providers: [OtpService],
+  exports: [OtpService],
 })
 export class OtpModule {}

src/modules/otp/providers/otp.service.ts

@@ -1,7 +1,13 @@
-import { Injectable } from '@nestjs/common';
-import { Repository } from 'typeorm';
+import {
+  HttpException,
+  HttpStatus,
+  Injectable,
+  UnauthorizedException,
+} from '@nestjs/common';
+import { LessThan, Repository } from 'typeorm';
 import { OTP } from '../otp.entity';
 import { InjectRepository } from '@nestjs/typeorm';
+import { Cron } from '@nestjs/schedule';
 
 @Injectable()
 export class OtpService {
@@ -31,9 +37,52 @@ export class OtpService {
     });
 
     if (lastOTP && Date.now() - lastOTP.createdAt.getTime() < 60_000) {
-      //   throw new TooMany();
+      throw new HttpException(
+        'Too many requests! Try again after 1 min.',
+        HttpStatus.TOO_MANY_REQUESTS,
+      );
     }
 
-    return '';
+    const code = this.generateOTPCode();
+    // TODO: Hash the code
+
+    const otp = this.otpRepository.create({ phone, code });
+
+    await this.otpRepository.save(otp);
+
+    return code;
+  }
+
+  /**
+   * Verify OTP
+   */
+  public async verifyOTP(phone: string, code: string): Promise<OTP> {
+    const otp = await this.otpRepository.findOne({
+      where: { phone, used: false },
+      order: { createdAt: 'DESC' },
+    });
+
+    if (!otp) throw new UnauthorizedException('Invalid OTP');
+
+    if (otp.expiresAt < new Date()) {
+      throw new UnauthorizedException('OTP expired');
+    }
+
+    // TODO: Compared hashed otp
+    if (otp.code !== code) {
+      throw new UnauthorizedException('Invalid OTP');
+    }
+
+    otp.used = true;
+    await this.otpRepository.save(otp);
+
+    return otp;
+  }
+
+  @Cron('0 */10 * * * *')
+  public async cleanupExpired(): Promise<void> {
+    await this.otpRepository.delete({
+      expiresAt: LessThan(new Date()),
+    });
   }
 }