Add alipay provider.

pp/provider.go

@@ -0,0 +1,26 @@
+// Copyright 2022 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pp
+
+type PaymentProvider interface {
+	Pay(productName string, paymentId string, price float64, returnUrl string, notifyUrl string) (string, error)
+}
+
+func GetPaymentProvider(typ string, appId string, appPublicKey string, appPrivateKey string, authorityPublicKey string, authorityRootPublicKey string) PaymentProvider {
+	if typ == "Alipay" {
+		return NewAlipayPaymentProvider(appId, appPublicKey, appPrivateKey, authorityPublicKey, authorityRootPublicKey)
+	}
+	return nil
+}