digest_app/module_auth/api/utils.py

from typing import Optional
from module_project import constants
from module_project.utils import ApiResponse
from module_iam.models import IAmPrincipal, IAmPrincipalOtp
from rest_framework_simplejwt.tokens import RefreshToken
from django.core.exceptions import ValidationError
import logging

logger = logging.getLogger(__name__)


def generate_token_and_user_data(principal):
    """
    Generate a token and user data based on an 'IAmPrincipal' object.

    Args:
        principal (IAmPrincipal): The user object.

    Returns:
        dict: A dictionary containing token data and user information.
    """
    refresh = RefreshToken.for_user(principal)
    data = {
        "access": str(refresh.access_token),
        "refresh": str(refresh),
        "first_name": principal.first_name,
        "phone_no": str(principal.phone_no),
        "complete": principal.register_complete,
    }
    return data

class AuthService:
    """
    Provides authentication services for IAmPrincipal users.
    """

    def __init__(self, principal_model, otp_model=None):
        self.principal_model = principal_model
        self.otp_model = otp_model

    def authenticate(self, principal_id: str, otp: Optional[str] = None, password: Optional[str] = None) -> None:
        """
        Authenticates a principal using OTP and/or password.

        Raises:
            AuthenticationError: If authentication fails.
        """
        try:
            principal = self.get_principal(principal_id)
            self.validate_principal_status(principal)
            self.validate_credentials_provided(otp, password)

            if otp:
                self.authenticate_with_otp(principal, otp)
            else:
                self.authenticate_with_password(principal, password)
        except ValidationError as e:
            raise e
        except Exception as e:
            logger.error(f"Authentication failed for principal {principal_id}: {str(e)}")
            raise ValidationError("Authentication failed") from e

    def get_principal(self, principal_id: str) -> IAmPrincipal:
        """Retrieves a principal instance by ID."""
        try:
            return self.principal_model.objects.get(pk=principal_id)
        except self.principal_model.DoesNotExist:
            raise ValidationError("Invalid principal ID")
        
    def get_principal_by_email(self, email: str):
        """Retrieves a principal instance by email."""
        try:
            return self.principal_model.objects.get(email=email)
        except self.principal_model.DoesNotExist:
            raise ValidationError(constants.EMAIL_NOT_REGISTERED)

    def validate_principal_status(self, principal: IAmPrincipal) -> None:
        """Validates that the principal is active."""
        if not principal.is_active:
            raise ValidationError(constants.ACCOUNT_DEACTIVATED)

    def validate_credentials_provided(self, otp: Optional[str], password: Optional[str]) -> None:
        """Ensures that at least one of OTP or password is provided."""
        if otp is None and password is None:
            raise ValidationError(constants.OTP_OR_PASSWORD_REQUIRED)

    def authenticate_with_otp(self, principal: IAmPrincipal, otp: str) -> None:
        """Authenticates using OTP."""
        if self.otp_model is None:
            raise ValidationError("OTP authentication is not supported")

        otp_instance = self.otp_model.objects.filter(principal=principal, otp_code=otp).last()
        if not otp_instance:
            raise ValidationError(constants.OTP_INVALID)

        if otp_instance.is_expired():
            raise ValidationError(constants.OTP_EXPIRED)

        otp_instance.is_used = True
        otp_instance.save()

    def authenticate_with_password(self, principal: IAmPrincipal, password: str) -> None:
        """Authenticates using password."""
        if not principal.check_password(password):
            raise ValidationError(constants.INVALID_PASSWORD)


def authticate_with_otp_and_passsword(principal: IAmPrincipal, otp=None, password=None):
    """
    Authenticate a principal using OTP and/or Password.

    Parameters:
    - principal (User): The principal object to authenticate.
    - otp (str, optional): One-Time Password (OTP). Default is None.
    - password (str, optional): User's password. Default is None.

    Returns:
    None: Successful authentication.
    Response: Error response if authentication fails.

    Example:
    ```
    principal = User.objects.get(phone_no='8987546598')
    otp = request.data.get("otp")
    password = request.data.get("password")

    result = authenticate_with_otp_and_password(principal, otp, password)
    if isinstance(result, Response):
        return result  # Authentication failed, return error response
    else:
        # Authentication successful, proceed with authorized actions.
    ```
    """

    if not principal.is_active:
        return ApiResponse.error(
            message=constants.ACCOUNT_DEACTIVATED, errors=constants.ACCOUNT_DEACTIVATED
        )

    # Ensure that either OTP or password is provided
    if otp is None and password is None:
        return ApiResponse.error(
            message=constants.OTP_OR_PASSWORD_REQUIRED, errors=constants.OTP_OR_PASSWORD_REQUIRED
        )

    if otp:
        otp_instance = IAmPrincipalOtp.objects.filter(
            principal=principal, otp_code=otp
        ).last()

        if not otp_instance:
            return ApiResponse.error(
                message=constants.OTP_INVALID, errors=constants.OTP_INVALID
            )

        if otp_instance.is_expired():
            return ApiResponse.error(
                message=constants.OTP_EXPIRED, errors=constants.OTP_EXPIRED
            )

        otp_instance.is_used = True
        otp_instance.save()

    elif password:
        print(password)
        if not principal.check_password(password):
            return ApiResponse.error(
                message=constants.INVALID_PASSWORD, errors=constants.INVALID_PASSWORD
            )
        print("after passsowrd", password)

    return None

def get_principal_by_email(email: str):
    try:
        principal = IAmPrincipal.objects.get(email=email)
        return principal
    except IAmPrincipal.DoesNotExist:
        error_response = {
            "message": constants.EMAIL_NOT_REGISTERED,
            "errors": constants.EMAIL_NOT_REGISTERED,
        }
    return ApiResponse.error(**error_response)