feat(v2): 一次性收款管线 CreateOrder/GetOrder/Retry/Cancel + DBProductResolver

internal/gateway/product.go

@@ -0,0 +1,41 @@
+package gateway
+
+import (
+	"errors"
+
+	"gorm.io/gorm"
+
+	"github.com/wangjia/pay/internal/model"
+	"github.com/wangjia/pay/internal/money"
+)
+
+// DBProductResolver resolves a SKU (product biz_code) against the products table.
+// v1 Product.Price is a "元" string; we parse it into int64 minor units for the
+// given settlement currency. 加币种维度到 product 是 P3+ 的事;P2 用单一默认币种。
+type DBProductResolver struct {
+	db       *gorm.DB
+	currency string
+}
+
+func NewDBProductResolver(db *gorm.DB, currency string) *DBProductResolver {
+	if currency == "" {
+		currency = "CNY"
+	}
+	return &DBProductResolver{db: db, currency: currency}
+}
+
+func (r *DBProductResolver) Resolve(sku string) (int64, string, 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
+	}
+	minor, err := money.Parse(p.Price, r.currency)
+	if err != nil {
+		return 0, "", "", "", err
+	}
+	return minor, r.currency, p.Name, p.BizCode, nil
+}