优化结构

pkg/paymentkit/callback.go

@@ -6,14 +6,6 @@ import (
 	"fmt"
 )
 
-const (
-	ProviderAlipay   = "alipay"
-	ProviderAlipayV3 = "alipay-v3"
-	ProviderWechatV2 = "wechat-v2"
-	ProviderWechatV3 = "wechat-v3"
-	ProviderApple    = "apple-iap"
-)
-
 // CallbackAck is the provider-facing HTTP acknowledgement returned after a
 // payment notification is processed.
 type CallbackAck struct {

pkg/paymentkit/provider.go

@@ -0,0 +1,36 @@
+package paymentutil
+
+const (
+	ProviderAlipay     = "alipay"
+	ProviderAlipayV3   = "alipay-v3"
+	ProviderWechatV2   = "wechat-v2"
+	ProviderWechatV3   = "wechat-v3"
+	ProviderApple      = "apple-iap"
+	ProviderChinaums   = "chinaums"
+	ProviderSFT        = "sft"
+	ProviderSuperPay   = "supper-pay"
+	ProviderWechatGame = "wechat-game-pay"
+	ProviderDouyinGame = "douyin-game-pay"
+	ProviderDouyin     = "douyin"
+	ProviderQQ         = "qq"
+	ProviderAllinPay   = "allinpay"
+	ProviderLakala     = "lakala"
+	ProviderPayPal     = "paypal"
+	ProviderSaobei     = "saobei"
+	ProviderInternal   = "internal"
+
+	ModeExternal = "external"
+	ModeInternal = "internal"
+)
+
+var externalProviders = [...]string{
+	ProviderAlipay, ProviderAlipayV3, ProviderWechatV2, ProviderWechatV3, ProviderApple,
+	ProviderChinaums, ProviderSFT, ProviderSuperPay, ProviderWechatGame, ProviderDouyinGame,
+	ProviderDouyin, ProviderQQ, ProviderAllinPay, ProviderLakala, ProviderPayPal, ProviderSaobei,
+}
+
+// SupportedProviders returns a copy so callers cannot mutate the process-wide
+// provider catalog.
+func SupportedProviders() []string {
+	return append([]string(nil), externalProviders[:]...)
+}