"""商品中心序列化器（async 兼容）。"""

from rest_framework import serializers
from apps.core.serializers import AsyncModelSerializer
from .models import Category, Brand, Unit, Product


class CategorySerializer(AsyncModelSerializer):
    parent_code = serializers.CharField(source="parent.code", read_only=True, default=None)

    class Meta:
        model = Category
        fields = [
            "id", "code", "name", "parent_code", "sort_order",
            "is_deleted", "created_at", "updated_at",
        ]
        read_only_fields = ["id", "created_at", "updated_at"]


class BrandSerializer(AsyncModelSerializer):
    class Meta:
        model = Brand
        fields = ["id", "code", "name", "logo_url", "is_deleted", "created_at", "updated_at"]
        read_only_fields = ["id", "created_at", "updated_at"]


class UnitSerializer(AsyncModelSerializer):
    class Meta:
        model = Unit
        fields = ["id", "code", "name", "is_base", "is_deleted", "created_at", "updated_at"]
        read_only_fields = ["id", "created_at", "updated_at"]


class ProductSerializer(AsyncModelSerializer):
    category_code = serializers.CharField(source="category.code", read_only=True, default=None)
    brand_code = serializers.CharField(source="brand.code", read_only=True, default=None)
    base_unit_code = serializers.CharField(source="base_unit.code", read_only=True, default=None)
    base_unit_name = serializers.CharField(source="base_unit.name", read_only=True, default=None)

    class Meta:
        model = Product
        fields = [
            "id", "code", "name", "spec", "barcode",
            "category_code", "brand_code", "base_unit", "base_unit_code", "base_unit_name",
            "cost_price", "sale_price", "min_sale_price", "tax_rate",
            "is_batch_managed", "shelf_life_days",
            "status", "ext_data", "source_channel",
            "is_deleted", "created_at", "updated_at",
        ]
        read_only_fields = ["id", "created_at", "updated_at"]