youngee_mc_api/app/system/wxpay/wxpay_service.go

package wxpay

import (
	"context"
	"crypto/rsa"
	"github.com/gogf/gf/frame/g"
	"github.com/gogf/gf/net/ghttp"
	"github.com/wechatpay-apiv3/wechatpay-go/core"
	"github.com/wechatpay-apiv3/wechatpay-go/core/option"
	"github.com/wechatpay-apiv3/wechatpay-go/services/payments/jsapi"
	wxpayUtils "github.com/wechatpay-apiv3/wechatpay-go/utils"
	"log"
	"youngmini_server/app/utils"
)

var service = new(wxPayService)

type wxPayService struct {
}

// 给结构体绑定一个方法，相当于类方法，
func (s *wxPayService) WxPayRequest(r *ghttp.Request, req WxPayRequestData) (WxPayResponseData, error) {

	openId, err := utils.SessionTalentInfo.GetOpenIdFromSession(r)
	if err != nil {
		log.Fatalf("get WxOpenId error:%s", err)
	}
	appID := g.Config().GetString("miniapp.appid")
	mchID := g.Config().GetString("miniapp.mchid")
	mchCertificateSerialNumber := g.Config().GetString("miniapp.mchCertificateSerialNumber")
	mchAPIv3Key := g.Config().GetString("miniapp.mchAPIv3Key")

	// 使用 utils 提供的函数从本地文件中加载商户私钥，商户私钥会用来生成请求的签名
	mchPrivateKey, err := wxpayUtils.LoadPrivateKeyWithPath("./apiclient_key.pem")
	if err != nil {
		log.Fatalf("load merchant private key error:%s", err)
	}

	ctx := context.Background()
	// 使用商户私钥等初始化 client，并使它具有自动定时获取微信支付平台证书的能力
	opts := []core.ClientOption{
		option.WithWechatPayAutoAuthCipher(mchID, mchCertificateSerialNumber, mchPrivateKey, mchAPIv3Key),
	}
	client, err := core.NewClient(ctx, opts...)
	if err != nil {
		log.Fatalf("new wechat pay client err:%s", err)
	}

	svc := jsapi.JsapiApiService{Client: client}
	// 得到prepay_id，以及调起支付所需的参数和签名
	var tradeId = utils.GetUuid.GetRandomString(32)
	resp, result, err := svc.PrepayWithRequestPayment(ctx,
		jsapi.PrepayRequest{
			Appid:       core.String(appID),
			Mchid:       core.String(mchID),
			Description: core.String(req.Description),
			OutTradeNo:  core.String(tradeId),
			NotifyUrl:   core.String("https://www.weixin.qq.com/wxpay/pay.php"),
			Amount: &jsapi.Amount{
				Total: core.Int64(req.Amount),
			},
			Payer: &jsapi.Payer{
				Openid: core.String(openId),
			},
		},
	)

	if err == nil {
		log.Println(resp)
		log.Println(result)
		var packageStr = "prepay_id=" + *resp.PrepayId
		var parts []string
		parts = append(parts, appID)
		parts = append(parts, *resp.TimeStamp)
		parts = append(parts, tradeId)
		parts = append(parts, packageStr)
		sign, err := getSign(parts, mchPrivateKey)
		if err == nil {
			var res = WxPayResponseData{
				Package:   packageStr,
				TimeStamp: *resp.TimeStamp,
				NonceStr:  tradeId,
				PaySign:   sign,
			}
			return res, nil
		} else {
			log.Println(err)
		}
	} else {
		log.Println(err)
	}
	return WxPayResponseData{}, err
}

func getSign(parts []string, privateKey *rsa.PrivateKey) (string, error) {
	var str string
	for i := range parts {
		str += parts[i] + "\n"
	}
	sign, err := wxpayUtils.SignSHA256WithRSA(str, privateKey)
	if err != nil {
		log.Println(err)
		return "", err
	} else {
		log.Println(sign)
		return sign, nil
	}
}