feat: 初始提交云印享付费打印服务后端

cloudprint-backend/pkg/pay/wechat.go

@@ -0,0 +1,200 @@
+package pay
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/xml"
+	"fmt"
+	"math/rand"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/cloudprint/cloudprint-backend/config"
+	"github.com/iGoogle-ink/gopay"
+)
+
+// RandomString generates a random string with given length
+func RandomString(length int) string {
+	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	b := make([]byte, length)
+	for i := range b {
+		b[i] = charset[rand.Intn(len(charset))]
+	}
+	return string(b)
+}
+
+type WeChatPay struct {
+	client *gopay.WxPayClient
+	config *config.WeChatConfig
+}
+
+type UnifiedOrderResponse struct {
+	ReturnCode    string `xml:"return_code"`
+	ReturnMsg     string `xml:"return_msg"`
+	ResultCode    string `xml:"result_code"`
+	PrepayID      string `xml:"prepay_id,omitempty"`
+	CodeURL       string `xml:"code_url,omitempty"`
+	MWebURL       string `xml:"mweb_url,omitempty"`
+	ErrCode       string `xml:"err_code,omitempty"`
+	ErrMsg        string `xml:"err_msg,omitempty"`
+	TransactionID string `xml:"transaction_id,omitempty"`
+	TradeState    string `xml:"trade_state,omitempty"`
+	TotalFee      int    `xml:"total_fee,omitempty"`
+}
+
+type PayCallback struct {
+	ReturnCode    string `xml:"return_code"`
+	ReturnMsg     string `xml:"return_msg"`
+	AppID         string `xml:"appid"`
+	MchID         string `xml:"mch_id"`
+	NonceStr      string `xml:"nonce_str"`
+	Sign          string `xml:"sign"`
+	ResultCode    string `xml:"result_code"`
+	TransactionID string `xml:"transaction_id"`
+	OutTradeNo    string `xml:"out_trade_no"`
+	TotalFee      int    `xml:"total_fee"`
+	TimeEnd       string `xml:"time_end"`
+}
+
+func NewWeChatPay(cfg *config.WeChatConfig) *WeChatPay {
+	client := gopay.NewWxPayClient(cfg.AppID, cfg.MchID, cfg.ApiKey, cfg.NotifyURL)
+	if cfg.CertPath != "" {
+		client.SetCertFilePath(cfg.CertPath)
+	}
+	return &WeChatPay{
+		client: client,
+		config: cfg,
+	}
+}
+
+func (p *WeChatPay) createSign(params map[string]string) string {
+	keys := make([]string, 0, len(params))
+	for k := range params {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	var signParts []string
+	for _, k := range keys {
+		if params[k] != "" && k != "sign" {
+			signParts = append(signParts, fmt.Sprintf("%s=%s", k, params[k]))
+		}
+	}
+	signStr := strings.Join(signParts, "&")
+	signStr += "&key=" + p.config.ApiKey
+
+	md5Hash := md5.New()
+	md5Hash.Write([]byte(signStr))
+	return strings.ToUpper(hex.EncodeToString(md5Hash.Sum(nil)))
+}
+
+func (p *WeChatPay) UnifiedOrder(ctx context.Context, orderNo string, amount float64, description, openID, clientIP string) (*UnifiedOrderResponse, error) {
+	nonceStr := RandomString(32)
+	totalFee := int(amount * 100) // Convert to fen
+
+	// Build request body
+	body := gopay.UnifiedOrder{
+		AppID:          p.config.AppID,
+		MchID:          p.config.MchID,
+		NonceStr:       nonceStr,
+		Body:           description,
+		OutTradeNo:     orderNo,
+		TotalFee:       totalFee,
+		SpbillCreateIP: clientIP,
+		NotifyURL:      p.config.NotifyURL,
+		TradeType:      "JSAPI",
+		OpenID:         openID,
+	}
+
+	// Use go-pay client to call unified order
+	resp, err := p.client.UnifiedOrder(ctx, body)
+	if err != nil {
+		return nil, fmt.Errorf("unified order failed: %w", err)
+	}
+
+	result := &UnifiedOrderResponse{
+		ReturnCode: resp.GetString("return_code"),
+		ReturnMsg:  resp.GetString("return_msg"),
+		ResultCode: resp.GetString("result_code"),
+		PrepayID:   resp.GetString("prepay_id"),
+		CodeURL:    resp.GetString("code_url"),
+		MWebURL:    resp.GetString("mweb_url"),
+		ErrCode:    resp.GetString("err_code"),
+		ErrMsg:     resp.GetString("err_msg"),
+	}
+
+	return result, nil
+}
+
+func (p *WeChatPay) QueryOrder(ctx context.Context, orderNo string) (string, int, error) {
+	nonceStr := RandomString(32)
+
+	body := gopay.QueryOrder{
+		AppID:      p.config.AppID,
+		MchID:      p.config.MchID,
+		NonceStr:   nonceStr,
+		OutTradeNo: orderNo,
+	}
+
+	resp, err := p.client.QueryOrder(ctx, body)
+	if err != nil {
+		return "", 0, err
+	}
+
+	tradeState := resp.GetString("trade_state")
+	totalFee := resp.GetInt("total_fee")
+
+	return tradeState, totalFee, nil
+}
+
+func (p *WeChatPay) ParseCallback(body []byte) (*PayCallback, error) {
+	var callback PayCallback
+	if err := xml.Unmarshal(body, &callback); err != nil {
+		return nil, fmt.Errorf("failed to parse callback: %w", err)
+	}
+	return &callback, nil
+}
+
+func (p *WeChatPay) ValidateCallback(callback *PayCallback) bool {
+	params := map[string]string{
+		"return_code":    callback.ReturnCode,
+		"return_msg":     callback.ReturnMsg,
+		"appid":          callback.AppID,
+		"mch_id":         callback.MchID,
+		"nonce_str":      callback.NonceStr,
+		"result_code":    callback.ResultCode,
+		"transaction_id": callback.TransactionID,
+		"out_trade_no":   callback.OutTradeNo,
+		"total_fee":      fmt.Sprintf("%d", callback.TotalFee),
+		"time_end":       callback.TimeEnd,
+	}
+
+	expectedSign := p.createSign(params)
+	return callback.Sign == expectedSign
+}
+
+func (p *WeChatPay) GenerateJSAPIPayParams(prepayID string) (map[string]string, error) {
+	nonceStr := RandomString(32)
+	timestamp := fmt.Sprintf("%d", time.Now().Unix())
+
+	params := map[string]string{
+		"appId":     p.config.AppID,
+		"timeStamp": timestamp,
+		"nonceStr":  nonceStr,
+		"package":   "prepay_id=" + prepayID,
+		"signType":  "MD5",
+	}
+
+	paySign := p.createSign(map[string]string{
+		"appId":     p.config.AppID,
+		"timeStamp": timestamp,
+		"nonceStr":  nonceStr,
+		"package":   "prepay_id=" + prepayID,
+		"signType":  "MD5",
+	})
+
+	params["paySign"] = paySign
+	return params, nil
+}