from rest_framework import serializers
from rest_framework.exceptions import ValidationError as DRFValidationError
from .models import Client
from .services import ClientService


class ClientSerializer(serializers.ModelSerializer):
    class Meta:
        model = Client
        fields = [
            'id', 'name', 'client_type', 'tax_id',
            'email', 'phone', 'address', 'city', 'postal_code',
            'created_at', 'is_active'
        ]
        read_only_fields = ['id', 'created_at', 'is_active']

    def _get_request_user(self):
        """
        Sigurno dohvaćanje korisnika iz contexta serializer-a.
        Request iz RequestFactory može biti WSGIRequest bez atributa 'user',
        zato koristimo getattr.
        """
        request = self.context.get('request') if self.context else None
        return getattr(request, 'user', None)

    def create(self, validated_data):
        """
        Delegate creation to service layer.
        """
        try:
            user = self._get_request_user()
            return ClientService.create_client(validated_data, user=user)
        except DRFValidationError:
            # re-raise as-is
            raise
        except Exception as exc:
            # wrap non-DRF exceptions
            raise DRFValidationError({"detail": str(exc)})

    def update(self, instance, validated_data):
        """
        Delegate update to service layer.
        """
        try:
            user = self._get_request_user()
            return ClientService.update_client(instance, validated_data, user=user)
        except DRFValidationError:
            raise
        except Exception as exc:
            raise DRFValidationError({"detail": str(exc)})