pay/internal/gateway/product.go

package gateway

import (
	"errors"

	"gorm.io/gorm"

	"github.com/wangjia/pay/internal/model"
	"github.com/wangjia/pay/internal/money"
)

// DBProductResolver 按 biz_code 解析套餐,金额取给定结算币种的权威价。
// 优先查 ProductPrice(分币种 int64 价);该币种无行且币种=CNY 时回退 Product.Price(v1 元 string)。
type DBProductResolver struct{ db *gorm.DB }

func NewDBProductResolver(db *gorm.DB) *DBProductResolver { return &DBProductResolver{db: db} }

func (r *DBProductResolver) Resolve(sku, currency string) (int64, string, string, error) {
	var p model.Product
	err := r.db.Where("biz_code = ? AND active = ?", sku, true).First(&p).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return 0, "", "", ErrProductNotFound
	}
	if err != nil {
		return 0, "", "", err
	}
	// 1) 分币种权威价
	var pp model.ProductPrice
	err = r.db.Where("product_id = ? AND currency = ?", p.ID, currency).First(&pp).Error
	if err == nil {
		return pp.AmountMinor, p.Name, p.BizCode, nil
	}
	if !errors.Is(err, gorm.ErrRecordNotFound) {
		return 0, "", "", err
	}
	// 2) 回退:仅 CNY 用 v1 Product.Price(元 string)
	if currency == "CNY" && p.Price != "" {
		minor, perr := money.Parse(p.Price, "CNY")
		if perr != nil {
			return 0, "", "", perr
		}
		return minor, p.Name, p.BizCode, nil
	}
	// 该套餐不支持此结算币种
	return 0, "", "", ErrProductNotFound
}