From cc832865dc1777afcb754e64a3a115986254f005 Mon Sep 17 00:00:00 2001
From: jiangyong27 <yong27@163.com>
Date: Tue, 5 Nov 2024 22:55:25 +0800
Subject: [PATCH] reverse pay

---
 weixin/wxpay_partner.go | 94 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 90 insertions(+), 4 deletions(-)

diff --git a/weixin/wxpay_partner.go b/weixin/wxpay_partner.go
index 0bc50f1..daa5e47 100644
--- a/weixin/wxpay_partner.go
+++ b/weixin/wxpay_partner.go
@@ -2,10 +2,12 @@ package weixin
 
 import (
 	"bytes"
+	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
 	"net/http"
+	"os"
 )
 
 var (
@@ -16,11 +18,14 @@ type WxpayPartnerConfig struct {
 	MchId    string
 	AppId    string
 	ApiKeyV2 string
+	CertFile string
+	KeyFile  string
 }
 
 type WxpayPartner struct {
 	config    *WxpayPartnerConfig
 	stdClient *http.Client
+	tlsClient *http.Client
 }
 
 type MicroPayRequest struct {
@@ -34,11 +39,30 @@ type MicroPayRequest struct {
 	Attach     string
 }
 
+type ReversePayRequest struct {
+	SubMchId   string
+	SubAppId   string
+	OutTradeNo string
+}
+
 func NewWxpayPartner(cfg *WxpayPartnerConfig) *WxpayPartner {
-	return &WxpayPartner{
+	if cfg.MchId != "" {
+
+	}
+	c := &WxpayPartner{
 		config:    cfg,
 		stdClient: &http.Client{},
 	}
+	var err error
+	if cfg.KeyFile != "" && cfg.CertFile != "" {
+		certBody, _ := os.ReadFile(cfg.CertFile)
+		keyBody, _ := os.ReadFile(cfg.KeyFile)
+		c.tlsClient, err = c.withCert(certBody, keyBody)
+		if err != nil {
+			panic(err)
+		}
+	}
+	return c
 }
 
 func (p *WxpayPartner) MicroPay(req *MicroPayRequest) error {
@@ -67,7 +91,7 @@ func (p *WxpayPartner) MicroPay(req *MicroPayRequest) error {
 
 	params.Set("sign", params.SignMd5(p.config.ApiKeyV2))
 	reqUrl := "https://api.mch.weixin.qq.com/pay/micropay"
-	body, err := p.post(reqUrl, params)
+	body, err := p.post(reqUrl, params, false)
 	if err != nil {
 		return err
 	}
@@ -88,11 +112,73 @@ func (p *WxpayPartner) MicroPay(req *MicroPayRequest) error {
 	return nil
 }
 
+func (p *WxpayPartner) Reverse(req *ReversePayRequest) error {
+	params := make(Params)
+	params.Set("appid", p.config.AppId)
+	params.Set("mch_id", p.config.MchId)
+	params.Set("sub_mch_id", req.SubMchId)
+	params.Set("nonce_str", randomStr(32))
+	params.Set("out_trade_no", req.OutTradeNo)
+
+	if req.SubAppId != "" {
+		params.Set("sub_appid", req.SubAppId)
+	}
+
+	params.Set("sign", params.SignMd5(p.config.ApiKeyV2))
+	reqUrl := "https://api.mch.weixin.qq.com/secapi/pay/reverse"
+	body, err := p.post(reqUrl, params, true)
+	if err != nil {
+		return err
+	}
+	result := make(Params)
+	result.Decode(body)
+
+	if result.GetString("return_code") != "SUCCESS" {
+		return errors.New(string(body))
+	}
+
+	if result.GetString("result_code") != "SUCCESS" {
+		if result.GetString("err_code") == "USERPAYING" {
+			return ErrUserPaying
+		}
+		return fmt.Errorf("%s:%s",
+			result.GetString("err_code"), result.GetString("err_code_des"))
+	}
+	return nil
+}
+
+// 附着商户证书
+func (c *WxpayPartner) withCert(cert, key []byte) (*http.Client, error) {
+	tlsCert, err := tls.X509KeyPair(cert, key)
+	if err != nil {
+		return nil, err
+	}
+
+	conf := &tls.Config{
+		Certificates: []tls.Certificate{tlsCert},
+	}
+	trans := &http.Transport{
+		TLSClientConfig: conf,
+	}
+
+	return &http.Client{
+		Transport: trans,
+	}, nil
+
+}
+
 // 发送请求
-func (c *WxpayPartner) post(url string, params Params) ([]byte, error) {
+func (c *WxpayPartner) post(url string, params Params, tls bool) ([]byte, error) {
 	var httpc *http.Client
 
-	httpc = c.stdClient
+	if tls {
+		if c.tlsClient == nil {
+			return nil, errors.New("tls wepay is not initialized")
+		}
+		httpc = c.tlsClient
+	} else {
+		httpc = c.stdClient
+	}
 
 	buf := bytes.NewBuffer(params.Encode())
 	resp, err := httpc.Post(url, "application/xml; charset=utf-8", buf)