from django.shortcuts import render, redirect
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status, authentication
from rest_framework.authtoken.models import Token
from django.contrib.auth import authenticate
from join.settings import TOKEN_EXPIRATION_TIME
from .serializer import LoginSerializer
from rest_framework.permissions import IsAuthenticated
from django.db import models
from django.utils import timezone


class LoginView(APIView):
    serializer_class = LoginSerializer

    def _create_token_response(self, user):
        token, created = ExpiringToken.objects.get_or_create(user=user)

        if not created and token.is_expired():
            token.delete()
            token = ExpiringToken.objects.create(user=user)

        if created or not token.expires_at:
            token.expires_at = timezone.now() + TOKEN_EXPIRATION_TIME
            token.save()

        return Response({'token': token.key, 'user_id': user.id}, status=status.HTTP_200_OK)
    
    def post(self, request):
        serializer = self.serializer_class(data=request.data)
        
        if serializer.is_valid():
            email = serializer.validated_data['email']
            password = serializer.validated_data['password']
            user = authenticate(request, email=email, password=password)
            
            if user:
                if not user.is_active:
                    return Response({'error': 'Account is inactive, please check your mails'}, status=status.HTTP_403_FORBIDDEN)
                return self._create_token_response(user)
            return Response({'error': 'Unable to login with provided credentials.'}, status=status.HTTP_401_UNAUTHORIZED)
          
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

class LogoutView(APIView):
    authentication_classes = [authentication.TokenAuthentication]
    permission_classes = [IsAuthenticated]

    def post(self, request):
        token = getattr(request.user, 'auth_token', None)

        if token is None:
            return Response({"error": "No active session or token already expired"}, status=status.HTTP_400_BAD_REQUEST)

        token.delete()
        return Response({"message": "Successfully logged out"}, status=status.HTTP_200_OK)

class AuthView(APIView):
    authentication_classes = [authentication.TokenAuthentication]

    def get(self, request):
        if not request.user.is_authenticated:
            return Response({"error": "User is not logged in"}, status=status.HTTP_401_UNAUTHORIZED)

        try:
            token = ExpiringToken.objects.get(user=request.user)
        except ExpiringToken.DoesNotExist:
            return Response({"error": "Token does not exist, please log in again"}, status=status.HTTP_401_UNAUTHORIZED)

        if token.is_expired():
            token.delete()
            return Response({"error": "Token expired, please log in again"}, status=status.HTTP_401_UNAUTHORIZED)

        return Response({"user_id": request.user.id}, status=status.HTTP_200_OK)

class ExpiringToken(Token):
    expires_at = models.DateTimeField(null=True, blank=True)

    def is_expired(self):
        return self.expires_at and self.expires_at < timezone.now()

    def save(self, *args, **kwargs):
        if not self.expires_at:
            self.expires_at = timezone.now() + TOKEN_EXPIRATION_TIME
        super().save(*args, **kwargs)