from rest_framework import serializers
from basic_info import models as basic_models


class BaseSerializer(serializers.ModelSerializer):
    merchant = serializers.PrimaryKeyRelatedField(
        queryset=basic_models.Merchant.objects.all(),
        required=False  # 创建时由视图层设置
    )

    def to_representation(self, instance):
        try:
            merchant = self.context['request'].user.employee.merchant
            if instance.merchant != merchant:
                # 数据保护手段
                raise PermissionError("无权限访问该对象")
        except (KeyError, AttributeError):
            # TODO: log something?
            raise PermissionError("无权限访问该对象")

        result = super().to_representation(instance)
        if self.context.get('expand_merchant', False):
            result['merchant'] = {
                'id': instance.merchant.id,
                'name': instance.merchant.name
            }
        return result


class QuickInputSerializer(serializers.ModelSerializer):
    class Meta:
        model = basic_models.QuickInput
        fields = ['name', 'value', 'group']


class ProductCategorySerializer(BaseSerializer):
    class Meta:
        model = basic_models.ProductCategory
        fields = '__all__'


class ProductSerializer(BaseSerializer):
    class Meta:
        model = basic_models.Product
        fields = '__all__'

    def to_representation(self, instance):
        result = super().to_representation(instance)
        result['category'] = {
            'id': instance.category.id,
            'name': instance.category.name
        }
        return result


class WareHouseSerializer(BaseSerializer):
    class Meta:
        model = basic_models.WareHouse
        fields = '__all__'


class SupplierSerializer(BaseSerializer):
    class Meta:
        model = basic_models.Supplier
        fields = '__all__'


class EmployeeSerializer(BaseSerializer):
    class Meta:
        model = basic_models.Employee
        fields = '__all__'


class CustomerSerializer(BaseSerializer):
    created_by = serializers.PrimaryKeyRelatedField(
        queryset=basic_models.Employee.objects.all(),
        required=False,
    )

    class Meta:
        model = basic_models.Customer
        fields = '__all__'


class VehicleTypeSerializer(BaseSerializer):
    class Meta:
        model = basic_models.VehicleType
        fields = '__all__'


class BankAccountSerializer(BaseSerializer):
    class Meta:
        model = basic_models.BankAccount
        fields = '__all__'


class DeviceInfoSerializer(BaseSerializer):
    class Meta:
        model = basic_models.DeviceInfo
        fields = '__all__'


class VehicleTransportRecordSerializer(BaseSerializer):
    vehicle_type_name = serializers.CharField(source='vehicle_type.name', read_only=True)
    
    class Meta:
        model = basic_models.VehicleTransportRecord
        fields = '__all__'
        depth = 1  # 展开外键关系