package model

import (
	"lone-services/pkg/modelbase"
	"lone-services/services/product/internal/dao"

	"gorm.io/gorm"
)

type ProductModel struct {
	modelbase.Base
}

func (m ProductModel) TableName() string {
	return modelbase.Prefix() + "product"
}

func (m ProductModel) Init() ProductModel {
	m.Table = m.TableName()
	return m
}

func (m ProductModel) Create(data *dao.ProductCreate) error {
	return m.Base.Create(data)
}

// IncrNumber 原子增加库存
func (m ProductModel) IncrNumber(id int64, n uint32) (int64, error) {
	ret := modelbase.DB().Table(m.TableName()).
		Where("id = ?", id).
		Update("number", gorm.Expr("number + ?", n))
	return ret.RowsAffected, ret.Error
}

// DecrNumber 原子减少库存（库存不足时 RowsAffected=0）
func (m ProductModel) DecrNumber(id int64, n uint32) (int64, error) {
	ret := modelbase.DB().Table(m.TableName()).
		Where("id = ? AND number >= ?", id, n).
		Update("number", gorm.Expr("number - ?", n))
	return ret.RowsAffected, ret.Error
}