OTP

from django.shortcuts import render, HttpResponseRedirect,HttpResponse, redirect
from django.contrib.auth import authenticate, login, logout
from django.contrib import messages
from  django.urls import reverse
from django.contrib.auth.decorators import login_required
from django.core.mail import send_mail, BadHeaderError
from django.template.loader import render_to_string
from django.conf import settings
import random
from django.contrib.auth.models import User

@login_required()
def home(request):
    context = {}
    if request.session['otp_session_is_valid']:
	return render(request, 'login/index.html', context)
    # when otp is not valid redirect to otp_page
    return redirect('otp_page')

@login_required()
def generate_and_send_otp(request):
    rand_no = random.randint(100000, 999999)
    otp = str(rand_no)
    subject = 'Activate Your Account'
    context = {'otp': otp}
    message = render_to_string('login/otp_email.html', context)
    sender = settings.EMAIL_HOST_USER
    recipients = [request.user.email]
    send_mail(subject, message,sender, recipients, fail_silently=True)
    messages.warning(request, ('you have received otp in your mail!'))

    request.session['otp'] = otp
    return render(request, 'login/otp_page.html', context)

@login_required()
def validate_otp(request):
    user_otp = request.POST.get("otp")

    if user_otp == request.session['otp']:
        set_otp_session(request)
        return render(request, 'login/index.html')

    messages.success(request, "wrong otp")
    return redirect('otp_page')


def set_otp_session(request):
    request.session['otp_session_is_valid'] = True

def invalidate_otp_session(request):
    request.session['otp_session_is_valid'] = False

def login_user(request):

    context = {}
    return render(request, 'login/login.html', context)

def login_validate(request):
    if request.method == "POST":
        username = request.POST['username']
        password = request.POST['password']
        user = authenticate(request, username = username, password = password)
        if user is not None:
            login(request, user)
            return HttpResponseRedirect(reverse('otp_page'))
        else:
            messages.error(request, "bad username")

    context = {}
    return render(request, 'login/login.html', context)

def logout_user(request):
    logout(request)
    invalidate_otp_session(request)
    request.session['otp'] = None
    return redirect('login')