app/utils/otp_utils.py

import random
from app.database import redis_client
from fastapi import HTTPException

async def generate_and_save_otp(mobile: str):
    otp = random.randint(100000, 999999)

    # Rate limiting (1 OTP per minute)
    if await redis_client.get(f"rate_limit:{mobile}"):
        raise HTTPException(status_code=429, detail="Too many requests. Try again later.")

    # Save OTP in Redis for 5 minutes
    await redis_client.setex(f"otp:{mobile}", 300, otp)
    await redis_client.setex(f"rate_limit:{mobile}", 60, 1)

    # Simulate sending OTP
    print(f"OTP for {mobile}: {otp}")
    return otp

async def validate_otp(mobile: str, otp: str):
    stored_otp = await redis_client.get(f"otp:{mobile}")
    if not stored_otp or stored_otp != otp:
        raise HTTPException(status_code=400, detail="Invalid or expired OTP")
    await redis_client.delete(f"otp:{mobile}")