from django.db import transaction, IntegrityError
from rest_framework.exceptions import ValidationError
from .models import Client

import logging

logger = logging.getLogger(__name__)


class ClientService:
    @staticmethod
    def create_client(data: dict, user=None) -> Client:
        """
        Create a Client instance with model validation and handle IntegrityError.
        """
        # Instantiate model and run model-level validation
        client = Client(**data)
        try:
            client.full_clean()
        except Exception as e:
            logger.error(f"Client validation failed: {e}")
            raise ValidationError({"detail": str(e)})

        try:
            with transaction.atomic():
                client.save()
        except IntegrityError as exc:
            logger.error(f"Integrity error creating client: {exc}")
            # Convert DB integrity errors into DRF ValidationError for the API layer
            raise ValidationError({"detail": str(exc)})

        return client

    @staticmethod
    def update_client(instance: Client, data: dict, user=None) -> Client:
        """
        Update the given Client instance. Validate and save.
        """
        for attr, value in data.items():
            setattr(instance, attr, value)

        try:
            instance.full_clean()
        except Exception as e:
            logger.error(f"Client validation failed on update: {e}")
            raise ValidationError({"detail": str(e)})

        try:
            with transaction.atomic():
                instance.save()
        except IntegrityError as exc:
            logger.error(f"Integrity error updating client: {exc}")
            raise ValidationError({"detail": str(exc)})

        return instance

    @staticmethod
    def delete_client(instance: Client, user=None) -> Client:
        """
        Soft-delete the client (if you want soft delete).
        If hard delete is desired, call instance.delete() instead.
        """
        instance.is_active = False
        instance.save()
        return instance