otp cooldown

libs/common/src/helper/differenceInSeconds.ts

@@ -0,0 +1,4 @@
+export function differenceInSeconds(date1: Date, date2: Date): number {
+  const diffInMilliseconds = date1.getTime() - date2.getTime(); // Difference in milliseconds
+  return Math.floor(diffInMilliseconds / 1000); // Convert to seconds and round down
+}

src/auth/services/user-auth.service.ts

@@ -18,6 +18,8 @@ import { EmailService } from '../../../libs/common/src/util/email.service';
 import { OtpType } from '../../../libs/common/src/constants/otp-type.enum';
 import { UserEntity } from '../../../libs/common/src/modules/user/entities/user.entity';
 import * as argon2 from 'argon2';
+import { differenceInSeconds } from '@app/common/helper/differenceInSeconds';
+import { LessThan, MoreThan } from 'typeorm';
 
 @Injectable()
 export class UserAuthService {
@@ -124,7 +126,38 @@ export class UserAuthService {
   }
 
   async generateOTP(data: UserOtpDto): Promise<string> {
-    await this.otpRepository.delete({ email: data.email, type: data.type });
+    const threeDaysAgo = new Date();
+    threeDaysAgo.setDate(threeDaysAgo.getDate() - 3);
+    await this.otpRepository.softDelete({ email: data.email, type: data.type });
+    await this.otpRepository.delete({
+      email: data.email,
+      type: data.type,
+      createdAt: LessThan(threeDaysAgo),
+    });
+    const countOfOtp = await this.otpRepository.count({
+      withDeleted: true,
+      where: {
+        email: data.email,
+        type: data.type,
+        createdAt: MoreThan(threeDaysAgo),
+      },
+    });
+    const lastOtp = await this.otpRepository.findOne({
+      where: { email: data.email, type: data.type },
+      order: { createdAt: 'DESC' },
+      withDeleted: true,
+    });
+    const cooldown = 30 * Math.pow(2, countOfOtp - 1);
+    if (lastOtp) {
+      const now = new Date();
+      const timeSinceLastOtp = differenceInSeconds(now, lastOtp.createdAt);
+
+      if (timeSinceLastOtp < cooldown) {
+        throw new Error(
+          `Please wait ${cooldown - timeSinceLastOtp} more seconds before requesting a new OTP.`,
+        );
+      }
+    }
     const otpCode = Math.floor(100000 + Math.random() * 900000).toString();
     const expiryTime = new Date();
     expiryTime.setMinutes(expiryTime.getMinutes() + 1);