"""
Custom Authentication Backends — Email login + Phone (OTP) login.
"""
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth import get_user_model

User = get_user_model()


class EmailBackend(ModelBackend):
    """
    Authentication backend: email + password.
    """
    
    def authenticate(self, request, username=None, password=None, **kwargs):
        email = username or kwargs.get('email')
        
        if email is None or password is None:
            return None
        
        try:
            user = User.objects.get(email=email)
        except User.DoesNotExist:
            User().set_password(password)
            return None
        
        if user.check_password(password) and self.user_can_authenticate(user):
            return user
        
        return None
    
    def get_user(self, user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None


class PhoneBackend(ModelBackend):
    """
    Authentication backend: phone — used after OTP verification.
    Does NOT check password; OTP verification is handled externally.
    """

    def authenticate(self, request, phone=None, **kwargs):
        if phone is None:
            return None

        try:
            user = User.objects.get(phone=phone)
        except User.DoesNotExist:
            return None

        if self.user_can_authenticate(user):
            return user
        return None

    def get_user(self, user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None