from django.contrib.auth import get_user_model
from drf_spectacular.utils import extend_schema_field
from rest_framework import serializers

from core.serializers.mini import UserMiniSerializer

User = get_user_model()


class BaseModelSerializer(serializers.ModelSerializer):
    """
    Base serializer for all models inheriting from BaseModel.
    Returns audit fields with a nested user mini representation.
    """

    id = serializers.UUIDField(read_only=True)
    created_by = UserMiniSerializer(read_only=True)
    updated_by = UserMiniSerializer(read_only=True)
    created_at = serializers.SerializerMethodField()
    updated_at = serializers.SerializerMethodField()
    can_delete = serializers.SerializerMethodField()

    class Meta:
        model = None
        fields = (
            "id",
            "created_by",
            "updated_by",
            "created_at",
            "updated_at",
            "can_delete",
        )
        read_only_fields = fields

    def to_internal_value(self, data):
        if isinstance(data, dict):
            data = data.copy()
            for name, field in self.fields.items():
                if (
                    name in data
                    and data[name] is None
                    and isinstance(field, (serializers.CharField, serializers.URLField))
                ):
                    data[name] = ""
        return super().to_internal_value(data)

    @extend_schema_field(serializers.CharField)
    def get_created_at(self, obj) -> str:
        return obj.created_at_display

    @extend_schema_field(serializers.CharField)
    def get_updated_at(self, obj) -> str:
        return obj.updated_at_display

    @extend_schema_field(serializers.BooleanField)
    def get_can_delete(self, obj) -> bool:
        return bool(getattr(obj, "can_delete", False))